# Need camshaft advice for 428!



## BeerHunter (Jul 13, 2018)

Hey!

First of all: My English is quite bad... Sorry for that!
I've found this forum and i think you guys seems to be like pro's!

I have a Pontiac Firebird -71 with a Pontiac 428 YH -68 with a TH400.
-----
Engine specs:
.030 overbored 428 YH -68 (433Ci?) 375hp (stock)

Pontiac #13 heads

Forged piston 2282P

Holley Street Dominator intakemanifold

Holley 750cfm, 0-4779C carb.

COMP Cams XE268H camshaft

Ohio Crankshaft

Hedman Hedders 28150, ceramic coated

2,5" exhaust

Mallory Point Dist. 2558001 (original maybe?)

Stock converter

Gear ratio: 3.42
-----

I'm going to swap:
From - To
Holley Street Dominator - 9799068 Q-jet

Holley 750cfm - Rochester Q-jet 800cfm carb.

CompCams XE268H - Melling SPC-3 (744) AND Crower 68404-16. Or: Melling SPC-7 (068)?

And that's my question... 744 or 068 camshaft?
What do YOU think?

Regards
BeerHunter (Sweden)


----------



## PontiacJim (Dec 29, 2012)

If you want a nice driver with a good power curve, then go "068" cam. If you want a little more of a race car, then go "744", but I would also go with a 2500 stall converter.

I would not use a Comp Cam ground on a 110 LSA as these tend to build additional cylinder pressure and are a little better suited for low compression engines. I assume you have 10.5 to 1 compression and run high octane gas.


----------



## bigD (Jul 21, 2016)

In a 428, the 744 would not be a race cam at all. I had a 744 in my '69 GTO 400 RA3. It was very streetable. I put over 60k miles on it as my daily driver. 

In the 428, the 744 would be milder than in a 400. 

https://www.ebay.com/itm/Melling-SP...ling+spc-3&_from=R40&rt=nc&_trksid=m570.l1313

The Summit 2802 is similar to a 744, but with more lift, and is cheaper. 

https://www.summitracing.com/parts/...-RzGGxietZQw_KF_FlLQq1jbmLPSeP7RoCJdgQAvD_BwE

But, if all you want is a smooth idle, the 068 or Summit 2801 is the way to go. IMO

https://www.ebay.com/itm/Engine-Cam...ling+spc-7&_from=R40&rt=nc&_trksid=m570.l1313

https://www.summitracing.com/parts/sum-2801 

Obviously, cam opinions differ widely, on most all car forums. And sometimes the discussions can get heated & even ugly.


----------



## BeerHunter (Jul 13, 2018)

Thanks for answering me!

PontiacJim:
I think I'm going with the "744"!
Will try it with STD-converter and see how it's goes.
CompCams = Yeah, that's why I'm going to swap! 

bigD:
I think I'm going with the "744"!
I want to have quite rough idle, but with a "correct" camshaft to suit a Pontiac 428.
My CompCams doing a lovely sound on idle. BUT it's not a good cam choice to a 428. Like PontiacJim says:
"I would not use a Comp Cam ground on a 110 LSA as these tend to build additional cylinder pressure and are a little better suited for low compression engines. I assume you have 10.5 to 1 compression and run high octane gas. "

95 Octane = "standard"
98 Octane = "Luxary" (about 1SEK/0,17USD more expensive than 95 :crying: ) = My Firebird loves to drink that delicious fuel. 0
Here in Sweden.


----------



## PontiacJim (Dec 29, 2012)

OK, sounds like a winner. 

The "744" should make a good cam in the 428 and I have never run it, but trust bigD's experience with it. You will probably notice that the cam does not quite have that "explosive" power the Comp Cam does with the 110 LSA, but don't let that fool you. You will have a broader and flatter power curve throughout the entire RPM range and most likely pull better power at higher RPM's. You might want to adjust your timing with the new cam as well.

Ouch! on the price of gas in Sweden. Nice you can get 95 octane as the best we can get in pump gas is ethanol blended 93 octane. About $3.05 USD in my area. We have octane ratings of 87 @ $2.55 USD & 89 @ $2.80 USD. Many cars will run on the 87 octane, but as the HP & luxury of the vehicle goes up, so does the requirement for higher octane gas.


----------



## bigD (Jul 21, 2016)

"...a "correct" camshaft to suit a Pontiac 428..."


Don't know that a 744 is "correct" for a 428, since they were never used in a 428. Looks like the 428's used an 066, 067, or 068. 

http://www.wallaceracing.com/enginesearch4.htm

But, the SD455 cam used the 744 specs. 

Don't know how much the low lift of the 744 will hurt power. I personally would go with the Summit 2802, to get the extra lift. But, that's just me.

The guys on the PY forum really badmouth the 744 cam.

Different strokes.


----------



## BearGFR (Aug 25, 2008)

bigD said:


> ...
> The guys on the PY forum really badmouth the 744 cam...


They tend to badmouth anything that strays from what they deem to be "the path of righteousness", which is why I spend my time here and don't go there much. 

The 744 is a good cam. The proof of that is in the might of the RA IV and SD455 engines. It may not be the 'best' cam today just because the design is from 1969 and with all the advancement in air flow/fluid dynamics knowledge coupled with computer simulation capability that has taken place since 1969, I'd certainly hope that there have been improvements since then. I'd recommend talking to the people at Bullet Cams to get their thoughts. Talk to Tim. I was very impressed with what he had to say and his reasoning, which is why I'm using them for my current build. 


?


----------



## BeerHunter (Jul 13, 2018)

PontiacJim said:


> OK, sounds like a winner.
> 
> The "744" should make a good cam in the 428 and I have never run it, but trust bigD's experience with it. You will probably notice that the cam does not quite have that "explosive" power the Comp Cam does with the 110 LSA, but don't let that fool you. You will have a broader and flatter power curve throughout the entire RPM range and most likely pull better power at higher RPM's. You might want to adjust your timing with the new cam as well.
> 
> Ouch! on the price of gas in Sweden. Nice you can get 95 octane as the best we can get in pump gas is ethanol blended 93 octane. About $3.05 USD in my area. We have octane ratings of 87 @ $2.55 USD & 89 @ $2.80 USD. Many cars will run on the 87 octane, but as the HP & luxury of the vehicle goes up, so does the requirement for higher octane gas.


95 Octane = 15,96 SEK per litre
98 Octane = 16,56 SEK per litre

1 litre = 0,264 gallons
1 gallon = 3,78 liter
1 US-dollar = 8,8 SEK

So:
1 gallon of 95 octane, will cost 60,32 SEK (6,85 dollar)
1 gallon of 98 octane, will cost 62,60 SEK (7,11 dollar)

If my calculation is correct... 



bigD:
That's the reason why I put the quotes (") in the beginning and at the end of the word, "correct"...
It's a Melling, and Pontiac have used the 068, 744, 041 in Pontiac-engines with different purposes and circumstances.
Not for an example Summit 2802. That's why I chose "correct" 
Yup, 067 in my case, was the "correct" camshaft!


----------



## BeerHunter (Jul 13, 2018)

After some advice from PY Forum (and bigD) :
I think I'll go for
Summit 2802 camshaft
Crower 68404-16 valve springs
Crower CamSavers lifters (maybe).

Soo many types and manufacturers of lifters... Hard to choose!


----------



## PontiacJim (Dec 29, 2012)

BeerHunter said:


> After some advice from PY Forum (and bigD) :
> I think I'll go for
> Summit 2802 camshaft
> Crower 68404-16 valve springs
> ...


OK, the cam should be a good choice. Kinda high on the exhaust lift, but I can't comment on it as I have never used it - only read what others have said. Just make sure you check your clearances at full rocker lift: spring retainer not hitting the top of valve guide, rocker arm not hitting the retainer, no coils bind/touching. Check that the rocker arm contact is in the middle of the valve stem at 1/2 lift. Too far forward or too much back and you may be putting additional strain on the valve stem and will speed up valve guide wear. 

I like the Crower CamSavers with the grooved oil slot. Rhodes lifters also have this. I think this a better idea than those lifters with the small hole lasered into the base. I can only picture a small particle plugging up that hole at some point.

Make sure you use a quality oil with ZDDP in it like Brad Penn or Joe Gibb along with the cam break-in lube. 

Let us all know what you think of this cam in your 428 as it would be a good follow up for others who may want to use the cam. :thumbsup:


----------



## BeerHunter (Jul 13, 2018)

Still hard to choose between:
Summit 2802
Crower 60243
Melling SPC-3

Advantages/disadvantages?


----------



## bigD (Jul 21, 2016)

SPC-3 has low lift. Barely over .400.

2802 is cheapest.

60243 will make the most power above 5000 rpm, but costs a lot more.


----------



## PontiacJim (Dec 29, 2012)

BeerHunter said:


> Still hard to choose between:
> Summit 2802
> Crower 60243
> Melling SPC-3
> ...


Flip a coin and select whatever is chosen for "heads up." Compare duration of the cams @.050" lift to get an accurate comparison. Each manufacturer has their own way of grinding the cam. One may have a "fast" ramp or one may have a more gentle ramp on the lobe - so you can get different variances of the same cam.

Notice the stock Mellings *has .406" lift *on each valve, but a larger difference between the intake/exhaust duration. The other cams have a smaller difference between the intake/exhaust duration BUT higher valve lift numbers. So they probably are pretty much equal because rather than use a longer duration to keep the valve open longer, the other cams lift the valve higher to open it longer. Higher lift means higher spring pressures which can translate into quicker wear of the parts. 

Many of us "motorheads" want to hear about how high the cam lift is - it speaks of how radical your cam is. You don't really relate to duration numbers as much, but when you say you have a cam with .550" lift, people will react. Tell them its only .406" lift and you won't get much attention or that "cool" factor. But, .406" lift with 301/313 degrees of duration is a pretty wild cam - and Pontiac knew this and did it. The general iron head did not flow much above .475" lift so why go beyond this? Being Pontiac engines are built for torque, the lower lift contributes to higher velocity speeds of the air/fuel mixture for better throttle response. So you will see the lift appears all the same, but durations were stretched. The higher lift cams were used in the better flowing Ram Air heads.

What is missing, and also a very important part of the cam spec is the Cam Overlap. The more overlap, the more "rumpity-rump" the exhaust sound, the lower the intake vacuum, and the higher the RPM range.

Crower shows to have an overlap of 63 degrees - the same as the factory "068"
Mellings shows to have an overlap of 69 degrees - the factory "744" shows as having 76 degrees
Summit shows to have an overlap of 72 degrees -
(Just for example, the Ram Air II/IV cam had 87 degrees of overlap)

Keep in mind that the bigger cubes in a 428 will be milder than the same cam in a 400CI.


That said, I think I would rule out the Crower due to the 112 LSA with stock compression. 112 LSA in my opinion is a good cam for 8.5-9.5 compression. Lift is OK on the intake, but a bit high on the exhaust. Would require matching valve springs.

The Summit cam looks good. The 114 LSA may keep cylinder pressures higher at your lower RPM's than the Mellings, but having more overlap, it should be about equal overall. Cam lift on the exhaust would appear to be a little high without changing valve springs as is the intake side. So the use of this cam would need matching springs to go with it and then you want to check coil bind and clearances under the valve spring retainer-to-valve guide.

The Mellings cam also looks good. *The 117 LSA* is a tad bit wider than the factory "744" (factory LSA was 115.5 on the "744") and will give a flatter power/torque curve and good engine vacuum. Should sound good (but not real lopey) with 69 degrees of overlap. It should also help "bleed off" cylinder pressure at lower RPM's which you will pick up at higher RPM's. This should help with the detonation factor if you have experienced this at all. The down side is the lift - .410". However, if you installed 1.65 rocker arms, your lift would increase to .450" which would be a pretty good lift for the stock heads. The 1.65 rockers will also open the valves quicker so full lift is achieved faster. Several of my source books state that you can use the 1.65 rockers on the head if under .460" lift and you use the stock 5/16" pushrods.


My opinion - 

The Summit cam looks good and would require changing springs. Lift may be a little high for stock heads, but not of big concern. I would also want to confirm that there are no valve-to-piston clearance issues. I think you are OK with a cam under .500" lift, but I would confirm that. The Summit cam seems to be a favorite on the 455CI, but not so much on a 400CI. The 428 is right in the middle, but I would lump it in with the 455 group.

The Mellings cam looks good and would be best with the 1.65 ratio rockers. You should be able to use your stock valve springs as the lift is under .460". I might try the cam with the stock 1.5 rockers and then switch to the 1.65's to see if any notable difference. The 117 LSA may help with any detonation problems.

So, both cams have their plus and negative sides. They are about equal all said and done. So a hard call. However, I might select the Mellings cam and install the 1.65 rocker arms.

Its a coin toss for me. :thumbsup:


----------



## bigD (Jul 21, 2016)

Here are 2 cams that appear on paper to be just below & just above the cams in question. Would be interesting to see dyno comparisons of all these, on the same 428. 

Street Master Hydraulic Flat Tappet Cam - Pontiac V8 276/286 - Lunati Power

https://www.summitracing.com/parts/hrs-410051-14/overview/make/pontiac

If your going to spend much time above 5000 rpm, I really like the looks of that Howards cam. Lots of guys like an 041 cam in a 428. if I used it, I'd only do so with Rhoads lifters. But, this Howards cam has less advertised dur and a 114 LSA. So, I think it would be a good 428 cam, without Rhoads lifters.

Speaking of 114° LSA, this Crane is right in the middle of these we're talkin about, & has a 114 LSA. Looks to me like it would be a great 428 street cam.

https://www.summitracing.com/parts/...EixRF9nyONKDNg0eySh9VIuf6FmIYCaIaAusEEALw_wcB 

Speaking of lifters. Many on the PY forum say that the Hylift Johnson "R" lifters are the best available for a performance Pontiac. Although the company says that these are the "bleed down" or "variable duration" type, most of the Pontiac guys say that they do not bleed down as fast as the Rhoads lifters do, therefore don't make the "ticking" sound the Rhoads make, at low rpm. 

I've used nothing but Rhoads, since the late '70's. The ticking don't bother me. But some can't stand it. If I had to use a regular type lifter, I think I'd go with the Crower CamSaver lifters, which splash a little extra oil on the cam lobes. Couldn't hurt. 

https://www.jegs.com/i/Crower/258/6...nEIU60GrpdpquFMo8818Z1loYAqwL6Q8aAqEjEALw_wcB

Rhoads also offers this feature as an option. 

https://www.summitracing.com/parts/rhl-9518l/overview/make/pontiac

I'd also swap out the flimsy wire "paperclip" retainers which most lifters have, in favor of real snap ring retainers, like the Rhoads original lifters have. I had 2 lifters come apart, because the flimsy retainer popped out. One of these was at a race. Lunati sells some lifters with snap ring retainers. Not sure what other brands offer the snap rings. 

https://www.summitracing.com/parts/...E0mixAakTTpH9GZL_vdjnVNjbo99clb0aAsmaEALw_wcB


----------



## BeerHunter (Jul 13, 2018)

PontiacJim and bigD:
Thanks for all suggestions/advice/info!

BigD:
I think 3 camshafts is enough! ?

PontiacJim:
The thing is, that I want/prefer a "swap N' run"-camshaft without change any rocker arms, check for "space" and so on.
I know I must change my valve springs to Crower 68404-16...
I don't want to spend alot of money cuz i'm already way out of my budget. ?

My first plan was to change/swap camshaft, intake manifold, carburetor.

Now:
Camshaft
Lifters
Crower 68404-16
Intake manifold
Carburetor

Like I said, i want to swap valvesprings, lifters and camshaft, startup and run.
Something like that. ?
Thanks for sorting out Crower!
Melling SPC-3 and Summit 2802, then a coinflip, then buy it!


----------



## PontiacJim (Dec 29, 2012)

Building an engine/car *never* falls within your budget! :lol: I gave up on my budget and just hold my breath and pay with the credit card. :yesnod:

Isn't camshaft selection fun? One of the most important purchases and one of the most frustrating. Just remember this, no one camshaft will do it all. This is why you have to pick an RPM range where you want your best performance to be and then make sure your trans/rear gears match it. You could have a great cam only to be a disappointment because your drivetrain did not match the cam's power & torque range.

And of course the minute you choose a cam and install it, you will take your car for a drive and then think, "I should have gotten the other camshaft."


----------



## BeerHunter (Jul 13, 2018)

PontiacJim:
Yeah, that's right! ?

No! It's not fun anywhere! ?
"one of the most frustrating." True that!

Yeah, but I think Summit 2802 and/or Melling SPC-3 will due, to 3:42 gear with TH400 and stock-converter?

"And of course the minute you choose a cam and install it, you will take your car for a drive and then think, "I should have gotten the other camshaft."
That's why I want to buy "the right one" at once! ?


----------



## BeerHunter (Jul 13, 2018)

Made a comparison between
Melling SPC-3 vs. Summit 2802
and
Melling SPC-3 vs. CompCams XE268H-10 (my current camshaft)
...just for fun!


----------



## PontiacJim (Dec 29, 2012)

Your trans & gears are fine with those cams. The 428 has the torque to pull that combination without having to use a higher stall converter.

Looking at the comparison between the Comp Cam & the other 2 cams, I would now favor the Summit cam. If you are not having any issues with the lift on the Comp cam, then you would be about the same with the Summit cam.

The Comp cam has a 110 LSA which in my opinion is better suited for lower compression engines. The Summit 114 LSA should work better. With more overlap than the other cams, it should give you a rougher idle sound.

Again, it's a coin toss. :thumbsup:


----------

