# 389 Rebuild



## grnrch (Aug 3, 2014)

New motor rebuild bored 30 over crank 10, new 4 core radiator, water pump timing chain and timing chain cover.


new pistons valves springs and, lifters. The old cover had the pointer and new one a scale, no instructions I know what 6 degrees bftdc on balancer is but where do I put that mark on the scale? We have moved the timing all over and it runs hot big time and does not take long to get to 230 and up. Also has a new cam a 744. I hope you guys might have some thoughts, as far as the water pump it was new last year we got the plates as close as we could and it was fine before the rebuild.
Richard


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## oldskool (Apr 26, 2015)

It may help to consider exactly what HAS been changed. For one thing, new pistons, rings, etc, will make more compression, which will generate more heat.

You said you have a new 4-core rad. It takes more suction from the fan, to pull air thru a 4-row rad. The best fans I know of are the 7-blade models. They come in solid hub and clutch models.

If you prefer a solid hub, there is an 18" Flex-a-Lite 7-blade #1818.

http://www.summitracing.com/parts/f...YOBcw_24lA0zICuO_0ZVp7tcg-fC4NwRUTxoCp3nw_wcB

If you prefer a clutch type, Ebay has several 7-blades listed. And you can buy a Hayden Severe Duty clutch, that will turn the fan more than a stock type clutch.

7-blade clutch fans in Fans & Kits | eBay

Hayden 2797 Thermal Fan Clutch | eBay

Then you must have a GOOD shroud. And the fan must be located just barely inside it, so the fan will pull air thru the rad, not around it.

Most guys say that if you have a pump with the cast impeller, not stamped, the stock type pumps are OK. But there are some guys who swear by the high volume pumps, like the Flowkooler.

Here's an 8-bolt, if you are using that kind.

http://www.ebay.com/itm/FlowKooler-...ron-/331376311486?hash=item4d27913cbe&vxp=mtr

But if you have switched over to the 11 bolt cover and pump, Flowkooler has an alum version.

http://www.ebay.com/itm/FlowKooler-...num-/390898397589?hash=item5b035c3195&vxp=mtr


Of course, with either pump, you need to minimize the distance between the pump and divider plate. But you said you've already done that. Other than that, as long as the thermostat is working properly, it should stay reasonably cool.


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## oldskool (Apr 26, 2015)

"...The old cover had the pointer and new one a scale, no instructions I know what 6 degrees bftdc on balancer is but where do I put that mark on the scale?..."

The only way I know to do it is to remove the cover and line up the dots on the cam and crank gears, with the crank gear dot at 12 o'clock and the cam gear dot at 6 o'clock.

Then put the cover back on and slip the balancer on. The mark on the balancer should line up with the zero mark on the cover. If not, then you'll have to etch or file a mark on your balancer, in line with the zero mark on the cover.

That may not be the best way to do it. But that's what I'd do, in order to know exactly where zero is. Otherwise, it's strictly a guess.


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## grnrch (Aug 3, 2014)

*rebuild*

Oldschool thanks for your reply I do have the 11 bolt flow cooler, 7 blade flex fan but just standard clutch, do you really think the extreme duty will move that much more air?
Thanks Richard


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## BearGFR (Aug 25, 2008)

Sounds like you may have two problems working... one is that you're not positive where TDC is (don't trust the markings on either the balancer or the timing cover until you've verified them) and you may also have a cooling problem. Cooling - did you make sure the clearance on the divider plate behind the pump is right? Too much space between that plate and the impeller vanes and you won't be able to keep it cool no matter how much time effort and money your throw at other parts of the system.

Verifying TDC is more involved. It can be done with a piston stop threaded into #1 spark plug hole without having to remove the heads if you are very careful and know how to do it. Do it wrong or leave out a step, and you're likely going to wind up with some bent valves or other damage.

Bear


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## rickm (Feb 8, 2012)

I saw that timing cover in the ames catalog and was wondering how you time the engine. they describe the timing marks as '69-later style. isn't there only 3 marks on that cover? what can you read from that scale? keep in mind, a fresh engine will be tight and will run alittle hotter than after its broken in. if im not mistaken, that cover is made by Kauffman racing equipment. give them a call and ask them your questions on timing an engine with that cover. im sure they will help you out.


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## PontiacJim (Dec 29, 2012)

1. Pontiac had 2 sizes of balancers. 1967 and earlier used a 5.25" balancer. 1968 and up used a 6.75" balancer. If you are using the 389 balancer with the newer (11 bolt water pump) timing cover, your timing marks will be incorrect. You need to get a 1968/later balancer. (you did install the divider and 2 rubber inserts behind the water pump, right?)

2. You did not mention what type of balancer you are using, stock or aftermarket? If you are using a 1968 or later 6.75" stock balancer with the rubber ring in it, it is very possible your outer ring has slipped around a bit and that mark on the balancer can't be trusted.

3. If you are not sure about your timing, an engine will heat up very fast and climb to 220-230 in just a few minutes of running if your timing is retarded too much -had that experience myself due to wrong balancer and timing cover mark. I can't tell you how much to advance it as *you can also over advance your timing and do damage* to the engine.

4. a.) Verify your balancer, you need the later '68 and up balancer to match your timing cover timing marks. If you don't have this, get one and see if that solves your timing issues. b.) If you have one, and it is stock, I suggest you ditch it and get a new aftermarket replacement so you know the outer ring has not slipped and you don't have a future experience with the outer ring coming off the old rubber ring and damaging your engine. You should have one of these anyway. Butler has them here Butler Performance - Pontiac Harmonic Balancers 

Let me know on the above, and we can go from there on the next step to look into.


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## grnrch (Aug 3, 2014)

*389*

Jim thanks for reply, the balancer is the original. The water pump was put on last year it is the flow kooler and yes the plates were replaced and everything was ok until we rebuilt the engine and put it back in.
Thanks Richard


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## oldskool (Apr 26, 2015)

Most guys seem to recommend a Powerbond or Pioneer Brand balancer, if you want a cheaper model. Or, if price is not a concern, there are several high dollar balancers. Most of the cheapest balancers do not have a lot of etched marks on 'em. Then as the price goes up, most of those models do have etched timing marks. 

http://www.summitracing.com/parts/pbb-pb1056n

Precision Parts Powerbond OEM PB1056N - Harmonic Balancer | O'Reilly Auto Parts

Precision Parts Powerbond Street Series PB1056ST - Harmonic Balancer | O'Reilly Auto Parts

http://www.autozone.com/1/products/229076-harmonic-balancer-pioneer-da-4551.html

http://www.summitracing.com/parts/pio-da-4551-hd

http://www.jbp-pontiac.com/products/harmonic_balancers/jbp_balancers.html


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## PontiacJim (Dec 29, 2012)

grnrch said:


> Jim thanks for reply, the balancer is the original. The water pump was put on last year it is the flow kooler and yes the plates were replaced and everything was ok until we rebuilt the engine and put it back in.
> Thanks Richard


OK, so last year you could time the engine with the original 389 balancer and the 11-bolt timing cover. So why can't you do this now?

If it ran fine with this combo last year and all you did was a rebuild with the listed parts, then I am suspicious as to whether or not the cam may be off. Did you use a degree wheel to set-up your cam? Did you use a crank gear with a single position sprocket or multi-position sprocket? 

Here is a quick diagram from Edelbrock and a little basic info if you don't alredy have some. Edelbrock 389-455 Brochure (Page 3 of 4)

Your situation could be a number of things. Distributor timing off, the distributor itself may be bad, cam timing off, carb may be too lean for the new cam, collapsed radiator hose, bad thermostat, etc.. You might want to consider one of the infrared temperature sensors and check the assorted problem areas - radiator, hoses, heads, water pump, etc. to see if the temps are even of if a hot spot shows up. This may narrow it down if it is a cooling system problem or something else, ie timing. Shop General Tools & Instruments The Heat Seeker 8:1 Professional Infrared Thermometer at Lowes.com

Also, did you drop your compression when building the engine? What heads? What pistons? What compression do you now have? More technical info on your build might be of help as it could be something with the parts used in the build.:thumbsup:


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## BearGFR (Aug 25, 2008)

Sorry for not reading your initial post closer - I completely missed where you said you'd already clearanced the divider plate.

Things have causes, they're just not always obvious. I'd say it's time to start at square one and double check what you think you already know. Me, I'd begin by verifying the timing marks on the balancer to ensure that it's not lying when they indicate TDC. I've personally seen brand new SFI-rated balancers and brand new timing covers "lie" by as much as 6 degrees. It's possible to verify the marks without pulling the heads if you have the proper tools and you're very careful.

Bear


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