# 400 Clean up and check



## nrc17gto (Apr 23, 2018)

Hey all,

My engine has been built for at least 20 years now as that is when I got the car. We put a cam, lifters, springs, and timing chain in it shortly after that but that is as deep as I have been into it. I have a LOT of clean up I want to do to the engine as she is not as pretty as she once was so I am going to pull it out. There are also some oil leaks that I want to get all straightened out and do some inspection.

The engine is:
1969 YS block
62 Heads
292 comp cam
HEI ignition
Recently rebuilt quadrajet (using Cliff's book)
Performer RPM intake
Hooker headers
Saginaw 4 speed

Runs pretty strong.

I know some will probably say this is dumb but I want to tear it down most of the way (short of removing the crank and cam) to inspect everything while I have the engine pulled out. I am also going to put on some roller rockers that I have had for a while (stock ratio) and am considering installing a DUI distributor.

So after all of that, here is why I am posting. I really want to make sure I go with the best gasket set for everything from oil pan to valve covers. Any recommendations? Also, other than just inspecting the engine, are there other suggestions of what I should do while I have it torn down? Any tips or tricks I should put in place or commonly wore parts that would be good to replace now?

Thanks for reading!
Nick


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## BearGFR (Aug 25, 2008)

Hi Nick,

You didn't say where it's leaking from? If the rear main is leaking, you're probably going to have to pull the crank...

On my most recent build I used the BOP 1-piece oil pan gasket. I like it a lot. It's a steel core gasket that's encased in rubber with ribs on both sealing surfaces. The steel core keeps it from 'squishing out' when you tighten all the bolts. 
For valve covers, I used the Edelbrock 7590's. For intake manifold, I used the Felpro's that have the raised silicone sealing bead around the ports. For headers, I really like Remflex. For the rear main, I used one of the new BOP 1-piece seals. I had trouble this time getting mine to seal, mostly because of the (mis)shape of the aftermarket oil pan I'm running. To make sure, I put the engine together, filled it with 2 gallons of oil, and hung it from my hoist "butt down" to make sure the entire rear of the crank was submerged in oil for two days to see if it was going to drip. It took me a few tries because of the pan, but I did finally get it sealed up.

I used the good GM silicone gasket sealer - the kind that comes in a tube and needs a small 'caulking gun' to apply - on just one surface of the few gaskets where I used any sealer at all. One of the tricks is to apply a small bead of the stuff (don't go crazy, you don't want globs of it squishing out where it can circulated around in your oiling system), install the parts with the bolts LOOSE (just tight enough so that the sealant is touching both surfaces), let it cure for about an hour to start firming up, then tighten the bolts. If you don't have an inch-pound torque wrench, get one. It's not hard to overtighten the pan bolts and valve cover bolts enough to dimple them and cause leaks. I also put small dabs of it in the "corners", like where the timing cover, block, and oil pan meet and also where the heads, block, and lifter cover meet. 

Bear


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## nrc17gto (Apr 23, 2018)

Hi Bear,

Thanks for all the gasket info. I am not EXACTLY sure where all it is leaking from yet. After looking last night (was labeling the different wiring in prep of the pull) I noticed it is leaking from the front of the oil pan and also the bottom of the front of the trans is wet with oil. Would that be the rear main?

Of course the valve covers and headers are leaking as well. How about replaceable parts while I am that deep in the engine? I guess I might have to determine that after a tear down. If I pull the crank and connecting rods are there any issue reusing those bolts or are they a one time deal?

I am in no real hurry to get this back together and am hoping to really learn a lot more about all of it during the process.

Thanks!
Nick


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## PontiacJim (Dec 29, 2012)

nrc17gto said:


> Hi Bear,
> 
> Thanks for all the gasket info. I am not EXACTLY sure where all it is leaking from yet. After looking last night (was labeling the different wiring in prep of the pull) I noticed it is leaking from the front of the oil pan and also the bottom of the front of the trans is wet with oil. Would that be the rear main?
> 
> ...


You do not want to reuse rod bolts. Once you break them loose, they are done with in my book. This will require a machine shop to remove and replace them with the better ARP rod bolts which most use. While they are apart, they should be checked for roundness & size. Often it is just a little more to go with new forged I-beam rods versus rebuilding the older cast rods if you have to have them resized and new rod bolts. Forged rods are of course stronger, so a little more insurance against a rod failure. The down side may be that you will have to balance the engine with the new rods, but a machine shop might be able to match the rod balance and then you would not have to balance the engine.

I would install threaded pipe plugs in place of the press fit cups in the oil passages. The pressed in plugs will work, just make sure they are "staked" so they don't come loose. Pipe plugs screw in and won't come loose, but a machine shop may be needed unless you have the taps to do so. 

New oil pump and aftermarket hardened oil pump shaft.

I would install the 3/4 groove main bearings https://www.summitracing.com/parts/slp-113m/overview/make/pontiac


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## RMTZ67 (Mar 12, 2011)

Been there done that. Just be prepared financially. Once you crack it open that far. It wants to take the long road home. Lol


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## nrc17gto (Apr 23, 2018)

Oh man. I was really hoping to not have to take it all to a machine shop. Was thinking maybe just the heads. I guess this is only necessary if I find some kind of failure or the rear main is leaking right? I was under the car tonight and I cant tell for sure yet if it is the rear main seal or just the oil pan leaking. The oil pan seems to be leaking in multiple points all the way around.

Thanks,
Nick


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## RMTZ67 (Mar 12, 2011)

nrc17gto said:


> Oh man. I was really hoping to not have to take it all to a machine shop. Was thinking maybe just the heads. I guess this is only necessary if I find some kind of failure or the rear main is leaking right? I was under the car tonight and I can't tell for sure yet if it is the rear main seal or just the oil pan leaking. The oil pan seems to be leaking in multiple points all the way around.
> 
> Thanks,
> Nick


 I believe mine was leaking thru the rear of the valley pan or distributor. when I pulled the motor it looked like it was running down the back side of the block.behind the flywheel. rear main could have been leaking also tho it was hard to tell. Had a worn cam and a lifter ticking which caused some slight scratching of the crank from cam/lifter shavings. So I decided to rebuild it and get the compression down slightly to run on pump gas. By the way. My car also ran good when I first got it so I put a new gasket set,oil and water pump. Detailed the motor and got ten years out of it.


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## dd68gto (Nov 14, 2012)

RMTZ67 said:


> Been there done that. Just be prepared financially. Once you crack it open that far. It wants to take the long road home. Lol


X2 on above. If it's been twenty plus years I will bet you are leaking at main seal. But so do most Pontiacs. I would be ready to do a full rebuild if you start tearing it down . Then it's up to you how far and how many parts need or you want to replace . I will also add that I m willing to bet your into that motor for $2500/3000 if your able to do most work yourself,or double if you have a shop do it. I'm not trying to scare you from doing this but you really need to know up front what your heading for. Please read all you can on the threads on this forum and PY so you understand what you will need to do. Best luck Doug


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## nrc17gto (Apr 23, 2018)

I have been reading a good deal on here about intakes as well. My current setup is a performer RPM and I have no complaints on it. I do still have the factory intake that I replaced ~20 years ago. Should I clean and put the factory one back on it or stick with the performer RPM?

It is hard for me to say if the intake helped or hurt since I originally replaced it while doing the cam.

Thanks,
Nick


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## BearGFR (Aug 25, 2008)

It's up to you, really. It's doubtful that the Performer intake makes any more power than the factory intake, in fact some tests have shown that it doesn't make quite as much. However it does save you some weight on the front of the car.

Bear


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## nrc17gto (Apr 23, 2018)

Hi all,

Just wanted to update you guys. We got the engine pulled this last long weekend. We had to pull the passenger side header in order to get it to clear the A-Arm mount so I guess the headers will have to be reinstalled when the engine is back in the car (we know what a pain that is). We got it tore down to the short block and everything is looking great. The pistons and rods appear to be stock and a couple of pistons have some small dings in them (maybe from some prior build?) but overall everything looks great. I am going to get the heads checked out and start making a parts list of what is needed. I have a LOT of cleanup to do now. 

Nick


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## nrc17gto (Apr 23, 2018)

*Help!*

So another update. I have been doing a LOT of reading. My initial plan was to just clean this all up and throw it back in after getting the heads milled with a valve job and replacing "replaceable" parts like the water pump for example.

There is a noticeable ring line at the top of the stock bored cylinders that is enough to catch a fingernail on. From my understanding this is likely enough that it should be bored.

So here is my line of thinking that might be getting me down the rabbit hole. If I am going to bore it, I need to replace pistons and rods at the same time and all related components. Shouldn't I really go ahead and just get a 461 stroker kit instead of getting 30 over pistons with forged rods? My 2 biggest concerns are 1). what all outside of the stroker kit I am going to have to do that would be different than just going stock and 2). I'm afraid CR is going to kill me with my #62 iron heads.

I have been looking a bit at aluminum heads but man they are pricey. How much of my current head parts would be transferable, if any? 

I am listing everything I know about this engine down below and I am likely going to have several follow up questions so THANK YOU very much in advance for all the expertise. I am not looking to make a race engine necessarily but I do love the power. It already felt pretty good in the power department and is not really a daily cruiser whatsoever. So if I can make a good deal more power for nearly the same money, that is my goal.


1970 GTO
- 1969 400 D149, #by distributor = 9790071, #on front just below pass. head = 0693249 YS
- #62 heads
- Comp 994-16 dual valve springs
- Screw in 7/16" studs
- Factory 1.5 rockers (I do have brand new Crane 28755-16 roller rockers that I intend to use)
- COMP Cams Magnum 292H Hyd Flat Tappet Camshaft Lift: .501" /.501" Duration: 292°/292°
- Comp 852-16 lifters
- Edelbrock Performer RPM intake
- Hooker Headers Competition 4901
- HEI distributor (have bought a D.U.I. distributor to install in this process)
- Taylor plug wires
- Quadrajet that I had just rebuilt following Clif's guidance
- It appears that the crank, rods, and pistons are factory.
- Probably forgetting something....

Nick


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## GTO44 (Apr 11, 2016)

Have customer going the 461 stoker route. He's not happy with the power of his 400 and it needs to be refreshed anyways. We went with a full Butler Package. It was a little over 2k for the 461 stroker package with flat tops. With his 87cc performer rpm heads he will end up with around 10:1. You can get custom dished pistons they can spec out for you to keep the compression at what ever you desire. For example I have another customer with a pontiac 350 were doing a butler 413 stoker kit on and we had to get custom domed pistons to bring him up to 10:1. Anyways beside the storker kit... obviously the block will need to go to the machine shop. An align hone (or align bore if it needs) deck the block a few thou to clean it up and .030 over on the cylinders. The machine shop will then need to check the clearance of the rods to skirt for the longer stroke. Also, new oil pump, pickup tube, and valley pan is a good idea. I would say a new timing set but you have a decent cam in it already so yours is probably new. Besides that, jet the carb up and let er rip.


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## PontiacJim (Dec 29, 2012)

The bottom line is.......How Deep Is Your Wallet?

The Butler rotating assembly is the best bang for your buck - all new lower end parts and beefier.

Changes I would want is the 3/4 grooved main bearings if these can be substituted.

Add ARP main cap studs, but this may mean the block will have to be align honed in using them. Much stronger however.

You can use the iron #62 heads if you want, but keep compression around 9.0 ish for pump gas. Aluminum heads can go a point higher or so.

A.) You will have to order custom dished Ross pistons to drop compression with the #62 heads. But, you don't want to order anything until you have rebuilt the iron heads (if you use them) so you can get an actual cc number for the combustion chamber. This is needed to get the correct dish cc's to get you where you want on compression.
B.) If you use the 1.6 rockers, several things may need changing. First, stock Pontiac heads flow good to about .470" lift and then fall off. Aluminum heads will flow more right out of the box.
C.) Using 1.6 rockers will give you a valve lift of about .534". May not do a thing for you unless you do some porting/bowl work - but you can always try them. 
* The springs you currently have may not work - not enough open pressure at maximum lift or not enough pressure could cause a valve to bounce on the seat.
* Next, you could experience valve spring bind. So everything needs to be carefully checked for clearances.
* You may need to use the RAIV valves which are longer than the stock valves so you can use a taller spring that will not bind at higher lifts.
* With 1.6 rockers you will want to slot the pushrod holes so the pushrod does not bind/bend against the intake side of the hole.
* Install bronze valve guides - no cheap knurling of the guides.
* Get a 3-angle valve job.
* Install a new heater hose nipple at this time.
* Some like to install a hardened seat in the head for the exhaust valves. I don't, but my opinion & choice on this one. Aluminum heads will have seat inserts.
* You could save money keeping your lift where it is and using those parts already known to work.
D.) An important and overlooked item is "squish" or "quench." Included a diagram. Squish is the area between the top of the piston and bottom of the head. It is that flat area adjacent to the combustion chamber and is positioned over the piston. You want to get this area to "squish" the air/fuel mixture into the combustion chamber to aid in preventing detonation and providing a better burn. Too large a space here allows the air/fuel mixture to have enough area to ignite as the flame travels across the combustion chamber and that's where you can get detonation.
* Best distance for that space between the top of the piston & head is generally .045" - which is also about the same thickness of a compressed Felpro head gasket. BUT, Pontiac pistons can be .010" to .020" below the deck down in the cylinder. So a .045" head gasket plus the distance the piston is down in the cylinder, let's use .020" like my engine, makes the total squish distance .065". Will it work? Sure, its what the factory used. HOWEVER, this was the day of leaded gasoline where the GTO's used premium and the higher octane had a lot of detonation qualities so it was not so much a concern. Ethanol blends and lower octanes can be problematic and you want to eliminate all the variables you can so you don't get engine destroying detonation or have to retard your timing and give up power.
* So why am I telling you this? If you order custom pistons, you can order them with the piston pin hole moved to give you a "zero" deck height. This puts the top of the piston even with the top of the block (deck) and then using the Felpro .045" compressed gasket, you have a perfect squish area. If using a stock pin location, the procedure would be to mill the deck .020" which will then have the tops of the pistons even with the deck and then you use the .045" head gasket. I am not a fan of milling the block UNLESS you need to - it needs to be cleaned up due to warpage or pitting, or squaring up the block for race purposes. Milling the block can change geometry on other parts like the intake side of the head, or intake, or pushrod lengths. Mill the heads and this is amplified to include fit problems with the valley pan.
* The option I have posted many times here is what I did. My pistons are .020" down in the bore. I used a Cometic .027" head gasket ($100 each) for a total squish area of .047" which should be good and will tighten up slightly when the engine heats up. So it is right were I want it.
* This is my suggestion/opinion and option, and should be discussed with your machinist. Once he knows where down in the cylinder the piston will be (piston height), he could change the piston pin location on the custom Ross pistons you are going to need to have dished.
*So before you order a custom dished piston, you want to know what the head chamber cc's are and the piston height IF you want to move the piston pin at all.
E.) As already mentioned, you will want to check clearances between the larger throw crank and the pan rail.
F.) Other stuff: 
* aftermarket hardened oil pump rod if you haven't alread got one - that factory pump rod should not be trusted.
* 1972 and later baffled oil pan. Butler sells them inexpensively. He notes some holes may need to be slotted. Worse comes to worse, I would remove the baffle from the aftermarket pan and install it in your pan as long as your pan is good. You can buy a baffled pan on Ebay, but they seem to be pricey.
* get the rear pan oil reinforcements if you don't have these. Butler sells them. They require a little longer bolt and you may have to go to the local hardware store and get some grade 8 bolts and trim to fit.
* I like a double roller timing chain and gears.
* I am using the Butler blueprinted 60 psi pump. A little pricey. If you don't want to spend the money, get the Mellings 60 psi pump and add Tin Indian's Super Duty Oil Pump Plates Tin Indian Performance - New High Performance Pontiac Products I got this initially before Butler offered their pro oil pump in 60psi.
* see if you need the new stainless steel water pump plates and rubber inserts. Clearance the water pump impeller to plates as outlined here on the forum.

I think that should be good for starters. :thumbsup:


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## nrc17gto (Apr 23, 2018)

Wow. A lot of great info. I am going to have to read back through that a few times to let it sink in. A couple of things initially. 

I am looking at getting the edelbrock 61579-2 heads from butler along with the 4.155 461 butler rotating assembly. Also, the crane roller rockers I listed are 1.5 ratio.

Thanks again and I will be back with more. 

Nick


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## nrc17gto (Apr 23, 2018)

We tore the motor the rest of the way down tonight. I can at least say now that the rear main seal was not leaking. It was the two piece rope. Taking the block to the machine shop tomorrow. 

As mentioned before, I plan to reuse my comp 292h cam and lifters. It appears to still be in great shape. It performed and sounded great in my 400. 

Any opinions on reusing a hydraulic cam and also how will it perform in a 461 with those edelbrock heads?

Roller would be nice but wow are they pricey!

Nick

After doing a good bit of reading I believe it is fine to reuse the cam if it checks out OK. We kept track of the lifters when removing them but now I am terrified one got shifted at some point and I am going to get new ones...

Still interested in thoughts of how it is going to perform. Thanks!


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## nrc17gto (Apr 23, 2018)

Ok, so just an update for anyone following along. 

Decided to go with 
- Butler 461 Stroker kit
- Edelbrock 87cc heads - 61575
- CompCam Xtreme XR288HR cam (recommended by Butler)
- The crane 1.5 roller rockers I have had for a while but never used
- Shooting for 10:1 compression (around .44 quench)

Just waiting for rotating assembly to come in so I can get rest of block work done.

Nick


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## nrc17gto (Apr 23, 2018)

*Cam bearing help, please!*

Hi all,

I just got my block back from the machine shop and one thing has me concerned. It is the rear most cam bearing. All 4 of the other bearings I can shine a light and see the full circle. The rear most bearing LOOKS to be pushed in too far. I have tried to find a good pic of this rear bearing installed in a pontiac online but no luck so far. I am attaching a few pics (best I could get) in hopes one of the experts here can give me some advice. One of the pics is shining a light from the bottom of the engine and taking a picture through the crank side. From this angle it seems to have a small slither of light coming through from the hole in the bearing and also a bit of light coming through from in front of the bearing.

Thank you in advance....


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## PontiacJim (Dec 29, 2012)

nrc17gto said:


> Hi all,
> 
> I just got my block back from the machine shop and one thing has me concerned. It is the rear most cam bearing. All 4 of the other bearings I can shine a light and see the full circle. The rear most bearing LOOKS to be pushed in too far. I have tried to find a good pic of this rear bearing installed in a pontiac online but no luck so far. I am attaching a few pics (best I could get) in hopes one of the experts here can give me some advice. One of the pics is shining a light from the bottom of the engine and taking a picture through the crank side. From this angle it seems to have a small slither of light coming through from the hole in the bearing and also a bit of light coming through from in front of the bearing.
> 
> Thank you in advance....


In the Pontiac rebuild book by Rocky Rotella, he has a photo of the cam bearing installed. With the engine block upside down, you should be able to look down the main cap saddle and see that the cam bearing oil hole is fully exposed/open to the cam journal. It should not be 1/2 closed or even partially closed. If you cannot see the entirety of the cam bearing hole, then it is not right, period. A little off set, in my opinion, would not be a big problem per say and may have been done to get the oil hole in its correct placement, but if any portion of the hole is closed off that would be my concern.

Machinist may have not gotten it 100% and he can easily take car of the alignment before any assembly. 

Also make sure all the oiling holes for the lifters are free and clear. My 455 block was very crudded up and even though the block was hot tanked and pressure washed, I found a hardened chunk of sludge blocking one lifter oil supply hole - and you know this would have a caused a real problem to say the least once I fired it up.

Inspect all work after it comes back from the machinist. Clean the block real well. Use a lint free rag and WD-40 to wipe down all the inside of the cylinders until the rag comes up clean. The walls look shiny and clean, but you will be surprised at all the honing dust/material that is left behind in the metal's pores. :thumbsup:


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## nrc17gto (Apr 23, 2018)

Thank you PontiacJim for responding. I am going to get them to fix the bearing and I will be sure to check/clean every hole I can find in the block before putting anything together.

Nick


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## nrc17gto (Apr 23, 2018)

Hi all,

I got it all back together and we got it started a couple of weekends ago for the break in. It seems to be running rough like it is having some misfires. I am having some difficulty distinguishing between this and the large cam but it seems to still be doing it eve around 2k rpms.

We tried different plug wires and plugs with no difference. Swapped the new D.U.I. distributor out with my old HEI distributor and it seems to run a LITTLE better but still missing some. I have the timing set at 36 full mechanical advance with no vacuum hooked up.

Something super odd to me is the number 5 plug is as clean as I just put it in. This is happening with the ngk plugs and the same with the new champions I put in. I am attaching a picture of the ngk's and the champion's. You hopefully can see the one that looks clean compared to the rest.

Any thoughts on this? I have not had it on the road yet as I am hoping to get this worked out before hand. I am also linking to a short video of it running, but I don't think that helps much.


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## PontiacJim (Dec 29, 2012)

nrc17gto said:


> Hi all,
> 
> I got it all back together and we got it started a couple of weekends ago for the break in. It seems to be running rough like it is having some misfires. I am having some difficulty distinguishing between this and the large cam but it seems to still be doing it eve around 2k rpms.
> 
> ...



Well, if you have run the engine and that is how th plug came back out, as clean as new, it is either not firing or you have a dead cylinder.

If it was not firing, you would still have air/fuel entering into the cylinder and you should smell gas and the plug might also be wet.

Now if the cylinder is not getting air/fuel, the only thing that would be is a closed valve not allowing the mixture in. Pull the valve cover on that cylinder and take a look. Make sure a rocker arm has not gone sideways on you and is off the valve, pushrod has bent and is not moving the rocker, hydraulic lifter has collapsed, cam lobe has been wiped out, or the valve itself is bent or stuck.

It would seem odd that it would be an ignition problem not firing just the one plug, however, make sure your wires are not crossed and it is simply grounding out somewhere else and not firing the plug. Could be a bad wire - broken internally. You can test for a spark at the end of the boot - stick a screw driver in the end and hold the steel shaft close enough, but not touching, the exhaust manifold. You should see the spark jump from the screw driver to the manifold.


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## nrc17gto (Apr 23, 2018)

Thank you Jim for the quick response. Here is more info.

Luckily I am able to see the #5 intake rocker from my oil fill hole. I watched it as I cranked the engine and it is moving up and down. I think this eliminates a good number of valve/pushrod/rocker problems. I have no problem pulling the valve cover and will likely do so in the next night or two as I have time to go further.

I did take and stick a spare plug in the boot of #5 and it seemed to be sparking very well.

What is somewhat scaring me is that I have read a few places that a clean plug like that can come from a small coolant leak in that cylinder that is basically "washing" the plug clean during combustion. Next time I get out there I am going to do a compression test on each cylinder as well.

Nick


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## PontiacJim (Dec 29, 2012)

nrc17gto said:


> Thank you Jim for the quick response. Here is more info.
> 
> Luckily I am able to see the #5 intake rocker from my oil fill hole. I watched it as I cranked the engine and it is moving up and down. I think this eliminates a good number of valve/pushrod/rocker problems. I have no problem pulling the valve cover and will likely do so in the next night or two as I have time to go further.
> 
> ...



Hmmm. Interesting thought that it could be a water leak. One of the "old" tricks to dec-carbon a combustion chamber is to pour a little water down the carb while it is running. I have done this in the past a few times. Now I never pulled a plug to check anything, but it could make sense seeing the plug/engine is so fresh. Water injection is said to do this as well.

Also used to pour, and still do, a little Marvel Mystery Oil down the carb which is supposed to help in lubricating the top end/rings. Raise the idle up and slowly add the oil, never dump or make a big pour - you don't want to stall the engine nor hydrolock it up. 

You could have a head bolt that is not completely seating. Don't know if you ran a cleaning tap down all head bolt holes to ensure none were messed up or something had fallen into it. 

You also don't want to use any heavy amount of oil/lubricant on the head bolt threads if you used anything at all. You only want to put a couple drops on the threads and then wipe dry with a lint free cloth/rag. If oil pools into the bolt hole, the heat of the engine can cause the oil to expand and that means pressure just like a coffee pot and that pressure want to go somewhere can can crack the bolt boss and create a water leak.

Ensure your head bolts are installed in the correct holes - some of course are short while others are longer. RA IV used a couple longer than the standard 400CI and I learned this the hard way as I ordered the wrong ARP head bolts, but caught it during assembly and did not do any damage.

Without going back to read your discussion, did you have the block/heads checked for warpage? Magnafluxed for cracks?

Finally, if you know th head bolts are not bottoming out, maybe try re-torquing all your bolts. Had a seeping water leak on my brother's flathead 6-cyl engine and re-torquing the head bolts (several needed it) cured the water leak.

So a few more things to consider. Just go step at a time and try to narrow it down. :thumbsup:


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## nrc17gto (Apr 23, 2018)

PontiacJim said:


> Hmmm. Interesting thought that it could be a water leak. One of the "old" tricks to dec-carbon a combustion chamber is to pour a little water down the carb while it is running. I have done this in the past a few times. Now I never pulled a plug to check anything, but it could make sense seeing the plug/engine is so fresh. Water injection is said to do this as well.
> 
> Also used to pour, and still do, a little Marvel Mystery Oil down the carb which is supposed to help in lubricating the top end/rings. Raise the idle up and slowly add the oil, never dump or make a big pour - you don't want to stall the engine nor hydrolock it up.
> 
> ...



Good thoughts Jim. I am going to work through them.

The heads are new edelbrock heads. The block was decked and inspected. The bolts I purchased were ARP for the edelbrock heads. All holes seemed to be clean. I only used a small amount of the ARP lube on the threads.

So some bad news I would say. I just did a compression check and 7 of the cylinders were between 225 and 240. #5 cylinder is reading zero. The valves seem to be moving just fine. I stuck a scope down the hole and I see now obvious physical problems (cylinder looks fine and so does the piston). Does this lead me to the head gasket?

Thanks:frown3:


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## nrc17gto (Apr 23, 2018)

Another update after troubleshooting for a while tonight. I checked the head bolts and they are still tight. I fixed an airline to blow pressure into the cylinder. I first did it with all of the spark plugs out and #5 at TDC where both rocker arms were all the way up (valves should be closed). It was blowing air out of various spark plug holes and both banks. I then did the same test on #1 at TDC to see how it behaved. It just held compression as it should. So I then brought #5 back to TDC where both valves should be closed and put all the other spark plugs in. It then blew air up through the intake and out of the carb. 

Then, after thinking for a bit and talking with my brother (we are both decent at this kind of stuff but not pro mechanics), I decided to back the nut off of that intake rocker arm. After I did this, relieving all pressure on the spring/valve, it held pressure the same as #1 did. 

So, what does this tell me? Could it be as simple as I tightened the rocker arm too much? One thing that makes me think no is that when I first started the motor then pulled the plugs they all had carbon on them. It wasn't until the 2nd or 3rd time that the #5 plug came out completely clean, unless I simply did not notice the first time.

So my next course of action unless you pros tell me I am dumb is to pull the carb off and see if I can get my camera down the intake runner and inspect the valve. Hoping I didn't burn a valve or it is not noticeably bent.

I definitely appreciate any expert advice here. 

Thanks,
Nick


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## geeteeohguy (Feb 2, 2008)

It tells me that you had an intake valve too tight. Causing it to remain partially open, causing a dead cylinder. Set the valves properly and you should be good to go.


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## PontiacJim (Dec 29, 2012)

nrc17gto said:


> Another update after troubleshooting for a while tonight. I checked the head bolts and they are still tight. I fixed an airline to blow pressure into the cylinder. I first did it with all of the spark plugs out and [URL=https://www.gtoforum.com/usertag.php?do=list&action=hash&hash=5]#5 [/URL] at TDC where both rocker arms were all the way up (valves should be closed). It was blowing air out of various spark plug holes and both banks. I then did the same test on #1 at TDC to see how it behaved. It just held compression as it should. So I then brought [URL=https://www.gtoforum.com/usertag.php?do=list&action=hash&hash=5]#5 [/URL] back to TDC where both valves should be closed and put all the other spark plugs in. It then blew air up through the intake and out of the carb.
> 
> Then, after thinking for a bit and talking with my brother (we are both decent at this kind of stuff but not pro mechanics), I decided to back the nut off of that intake rocker arm. After I did this, relieving all pressure on the spring/valve, it held pressure the same as #1 did.
> 
> ...



OK, good news, nothing major. :thumbsup: No need to do any more investigation or pulling of parts. Simple fix.

As *geeteeohguy* said, the valve is too tight and not sealing. And if one is out of adjustment, you want to check them all now that the engine has been run up and cycled. I assume you are using poly-locks and not the factory type rocker arm nuts. If you do not have these, get them as this is what is needed to correct the problem. Any factory type nut, even if a locknut, will eventually back off.

So get the poly-locks and you will then want to "zero lash" the valves to get them correctly adjusted. This is done with engine warm and running. It will get a bit messy, so be prepared with rags and have either a fire extinguisher handy (which you should have or the water hose - do this outside, not in your garage). UNLESS you purchase the oil splash clips below.

This has been covered several times in the past. Do one side at a time. First install all your poly-locks after you put each cylinder at TDC where the valves are closed and then tighten down the poly-locks while spinning the pushrod with your thumb & finger. Tighten until you feel resistance, but can still turn the pushrod. Tighten the allen screw on the poly-lock to secure it. You will be loosening these later to adjust. Get all cylinders done this way. You can also do a valve adjustment sequence where you adjust certain cylinders based on crank position. I just find it easier on the "old" memory to simply do a cylinder at a time

Put a valve cover on one side so oil doesn't fly all over as you are only going to do one side at a time.

Fire up the engine and keep it at idle, no need to rev and spray extra oil needlessly. Then start with the first cylinder and now back the poly-lock off until the rocker arm starts clicking. Then tighten it back up slowly until the rocker stops clicking and then wait about 15 seconds to allow the lifter to pump down/normalize. If it begins to click at all, give another slight turn until it stops. That should do it and then holding the poly-lock with your wrench, tighten down on the allen screw - but don't torque the heck out of it, just nice and tight so it will not back out. You kinda get a feel for it. You essentially should not be able to turn the wrench without a good amount of force. Sometimes I will give a final twist with the wrench, but only a slight turn like a 1/16" just to cinch everything in place.

Repeat on every valve and then do the other side. If you need to stop the engine to wipe up any excess oil, do so. You can re-fire it after you mop up and continue. Now if you can wait a bit before adjusting, I highly recommend these oil splash clips which clip right onto the rocker arms and block the oil spurt holes keeping the oil spray/splash down to a minimum. You might be able to order these locally from your parts store or online if not. I use these myself and have had my set for 35 years and still use them. https://www.summitracing.com/parts/...MItPzslY7E4QIVhlcNCh2n6wadEAQYAiABEgL1NfD_BwE

So this is my advice on how to adjust the rocker arms. Others have their way of doing this, but I have always done it this way and feel it is the best and most accurate to set the valves. :yesnod:

Try one valve, maybe #5 and see if this works for you. If any problems or questions, stop and just ask before moving on. If you feel you got it right, then keep on going and do them all.


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## nrc17gto (Apr 23, 2018)

Thank you very much. I am going to get these valves adjusted and give it a go. I'm really hoping this is the end of it.

I have heard the method of adjusting them with it running and if I am brave enough I will give it a shot.

I do have roller rockers with poly locks so I am good to go there. I will report back with hopefully a new video of it firing like it is supposed to.

Thanks again for the awesome help!

Nick


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## nrc17gto (Apr 23, 2018)

I got my valves adjusted properly tonight and checked the compression. It all looked great! I am so grateful it was something simple and I am very appreciative of your advice.

I got it all running and it was running great. I decided to put my new DUI distributor back in that I was suspect of. I swapped it back in and got it wired up and timed. It SEEMS to be running as well with the DUI distributor but something that makes me suspicious is that the timing light is "flashing" very inconsistently with this distributor. Wires and plugs and all are the same. It is inconsistent enough that it makes it hard to set the timing. It has done this since I first fired the vehicle back up after building it. Original HEI lights the timing light as it should.

What do you guys think? We have run a separate ground wire for the DUI and also have a large power wire. Makes me think it is missing with it.

Attached video is with my original HEI distributor after doing all the valves and getting it back going.

Thanks,
Nick


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## PontiacJim (Dec 29, 2012)

Success and bad-ass to boot! :thumbsup: 

I would be calling/emailing DUI with your observations. They may have the answer right away or know what the problem is. Sometimes you get a batch of bad parts that could have been used during assembly of the distributor and they know it, but cannot service it unless someone contacts them to let them know. :yesnod:


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## nrc17gto (Apr 23, 2018)

Update on everything for those following along.

I ended up swapping out my distributor for a new one. Took a while because it was on backorder but I got it put back in. Timing light is now consistent as far as I can tell on on the different cylinders.

Hard to tell while idling with a big cam but when I rev it to 2500 or even 3000 and keep it steady the engine still has a shudder of sorts. I decided to take it for a drive to see how it behaved. It ran like crap. It would not rev past 3500 rpm or so under load and was pinging pretty bad. I played with the timing but it kept pinging and falling flat so I took it home for some adjustments. 

All in all I ran a ground wire from the distributor, tried different plugs, tried vacuum advance connected and disconnected, swapped to my older quadrajet, probably some other things I am forgetting as well. 

The ONLY thing that has seemed to make any difference is reducing my spark plug gap from 45 to 35. After this it would rev close to 5k but very pathetically under load. (revving up with no load does just fine) Got most of the pinging to go away by keeping the vacuum advance connected and running about 32 degrees full mechanical. 

The carb ran fine on the old 400, could it be I am not getting enough fuel with the bigger motor? I can not determine at the moment if it is a fuel delivery issue or an ignition issue causing the miss and lack of power at this point.

Sorry for the rambling but I am about to pull my hair out and am getting pretty frustrated at this point. I just want to be able to get in and drive!

Nick


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## RMTZ67 (Mar 12, 2011)

nrc17gto said:


> Update on everything for those following along.
> 
> I ended up swapping out my distributor for a new one. Took a while because it was on backorder but I got it put back in. Timing light is now consistent as far as I can tell on on the different cylinders.
> 
> ...


So I take it that the break in went well? And when you adjusted your valves they all had about the same lift? The reason I ask is when I broke in the engine in my camaro I tried everything to get it to run better and could not for the life of me figure it out. So I took it to mechanic who builds and races engines and he went thru everything and ended up at the valves. Ended up having a few rounded cam lobes. Never popped out the carb to give me a clue as to what was wrong.


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## nrc17gto (Apr 23, 2018)

RMTZ67 said:


> So I take it that the break in went well? And when you adjusted your valves they all had about the same lift? The reason I ask is when I broke in the engine in my camaro I tried everything to get it to run better and could not for the life of me figure it out. So I took it to mechanic who builds and races engines and he went thru everything and ended up at the valves. Ended up having a few rounded cam lobes. Never popped out the carb to give me a clue as to what was wrong.


Hi RMTZ67, yeah the break in seemed to go fairly well. I did put a hydraulic roller cam in it and when I did the first oil change nothing looked out of the ordinary. One of my valves ended up being off after it pumped up keeping cylinder 5 from building pressure but I remedied that one. I did a compression check a couple of nights ago and they were all from 235-245.

Thanks,
Nick


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## cij911 (Oct 25, 2017)

nrc17gto said:


> Hi RMTZ67, yeah the break in seemed to go fairly well. I did put a hydraulic roller cam in it and when I did the first oil change nothing looked out of the ordinary. One of my valves ended up being off after it pumped up keeping cylinder 5 from building pressure but I remedied that one. I did a compression check a couple of nights ago and they were all from 235-245.
> 
> Thanks,
> Nick


Sorry for the troubles...What compression ratio is the motor? (I ask because 235-245 seems high.)


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## nrc17gto (Apr 23, 2018)

cij911 said:


> Sorry for the troubles...What compression ratio is the motor? (I ask because 235-245 seems high.)


Thanks for your condolences.  Starting to regret doing the rebuild. 

It was calculated to be right around 10:1.

Nick


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## RMTZ67 (Mar 12, 2011)

Nick just hang in there. It will take a little more time and maybe money, but once you get past it will all be forgotten. Ask me how I know. (Camaro). I have just installed my engine in my Gto and will be doing my break in soon. I came to this conclusion along the way. One way. In order to help ourselves in future rebuilds if it was running decent but smoking etc, is to use the same carb,distributor fuel pump etc until after the break in. That way you can eliminate those items as our source of problems, then once it is running decent, start adding your desired new components. So take a deep breath. Keep asking questions, and if all else fails find a engine builder mechanic and let them give it a go. Good luck.


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## geeteeohguy (Feb 2, 2008)

235-245 PSI cranking compression is indicative of a compression ratio of about 12:1 or higher. Stock cranking compression on stock '67 GTO 400's I've tested in the past was always about 200-210 psi, with a true CR of about 10.5:1. There is no way a 12:1 engine (might even be higher due to some loss with your bigger cam) will run on any fuel less than about 110 octane. My bet is if you put some racing fuel in it and dial it in, it will run just fine. If it were mine, I'd be looking to install some heads with bigger chambers.....175 PSI cranking compression is about the max you want to run in a Pontiac on 93 octane fuel these days....and even that can be a balancing act.


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## nrc17gto (Apr 23, 2018)

Thanks for the replies. I think I know the problem and even though this was my first complete motor build I feel like an absolute idiot.

Looking at the pictures of my timing gear install I apparently did not line them up correctly. I mistakenly lined up the 0 on the keyway portion at 12 o'clock instead of the 0 on the tooth. I didnt even notice the tooth when I put it on...

So, I will have to tear the front of the motor back off to fix it. 

Think I did any damage?

(feeling stupid) Nick


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## PontiacJim (Dec 29, 2012)

nrc17gto said:


> Thanks for the replies. I think I know the problem and even though this was my first complete motor build I feel like an absolute idiot.
> 
> Looking at the pictures of my timing gear install I apparently did not line them up correctly. I mistakenly lined up the 0 on the keyway portion at 12 o'clock instead of the 0 on the tooth. I didnt even notice the tooth when I put it on...
> 
> ...



That would do it. Had to really look hard, but I see the "0" on the crank gear tooth. The "0" on the collar is a lot more prominent, so I am sure you are not the first person to do this. Easy enough to correct.

You should be OK. Unless you had a real radical lift cam, the valves could hit the pistons. If you wanted to be sure all is OK, get one of those inexpensive camera/scopes and snake the camera in through a spark plug hole and take a look.

Here is where degreeing the cam with a degree wheel would have caught the mistake. Being honest, I have a degree wheel and have never used it. I just line up the dots like most of us do. I will however use it when I get around to assembling my 455. :thumbsup:


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## geeteeohguy (Feb 2, 2008)

Excellent news! Running the cam that far advanced would definitely give you those whacky compression figures. Decades ago I made the same mistake, but the cam was waaay retarded. Car wouldn't get out of it's own way. Tore the timing cover off and fixed it, and all was well. Good luck, and post a follow up, please.


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## nrc17gto (Apr 23, 2018)

Got it tore down tonight, cleaned and realigned. Making progress.


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## nrc17gto (Apr 23, 2018)

I got it all back together yesterday. Went together pretty smooth. Compression is now between 180 and 190 for all cylinders. Started it up, timed it, and took it for a drive today. Much better. I have some quadrajet kinks to work out (lean at WOT?) but it is SO much better. Motor runs really smooth now and I believe I am finally on the right track. Thanks to everyone for the advice over this adventure. Many more to come!

Nick


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## PontiacJim (Dec 29, 2012)

Excellent! :thumbsup: Had to watch the whole video, so cool. Car sounds great and moves right along. In my book, nothing beats looking over an open engine bay from the drivers seat going down the road - `but I gotta have dual quads sitting there.

You might consider adding a limiter to keep the engine from torquing over as it does. This has been discussed before. You want a little movement, but with all the torque of the 461 and a good burnout (not that you would ever do one, right?) with wide tires, you are putting a lot of strain on the engine mount. Mopar had a set-up they used as a factory piece on their high-performance engines to limit engine roll.

Once you get the Q-jet dialed in, it'll be a screamer. :yesnod:


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## nrc17gto (Apr 23, 2018)

:thumbsup:A limiter sounds like a great idea. When uploading the video I noticed how much the engine was torquing, and this is with new motor mounts. I will look into that.

Nick


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