[Rocky 389]

In trying to settle on a good engine for my 34 ford coupe project, I've been able to buy an old 347 Pontiac engine that had been left at the local machinists shop many years ago. It was bought by a buddy and was stored for many years until he decided he was never gonna get to it and I got it for a song.
The block has been bored .125 thousanths and had new [at the time] Jahns cast pistons with a pretty good lump on the domes....was assembled with stock cam and a standard crank in great condition.
I measured the deck and found the pistons were 0.040 down the bore at TDC.
I'd love to assemble this engine with late [post 64] heads because they offer screw-in studs, big valves and if I use large open chamber heads I was hoping to get the compression down to a manageable level for street use. I've been scouring this forum and doing searches to find info on this kind of build plan with limited results...some guys hate the Jahns pistons because it's said [by some] the combination of early lumpy pistons and open chamber heads will get the compression down ok but leaves a terrible quench area not condusive to good flame travel...HMmmmmmmmm I'd hate to build this 347 [now a 364] to find it runs even slower than a stock 347 with flat-tops.
I've already bought a shiny new dual quad [P_65 Edelbrock with new 600 edelbrock carbs] setup for late heads and would really like to use later heads, timing cover/11 bolt water pump
etc etc....
I'll be using a T-5 with a Winters Champ-style quick change so gear ratio problems will be non-existant.
What do ya think? Am I on the wrong track here? Man, I'd really love to use this Pontiac motor...oh, and I already have a 58-60 [actually a 57 GMC pickup] stick bellhousing/flywheel and 11 inch clutch for it.

[Bill Hanlon]

Putting later than 59 heads on a 59 or earlier block involves a bunch of changes to coolant distribution. Can be done, but ....

Look here for more info: http://www.pontiacsafari.com/
then click
Pontiac Info
then click
Pontiac Engine Cooling

[Rocky 389]

Thanks, Bill. Guess I'll go with the earlier heads after all. That's ok because I really like the look of the earlier engine witht he external cooling hoses and early water pump....plus it sounds like it was really a better design anyway. The cooling article was great!
This also frees me up to use all original parts that fit each other like timing cover, water pump, pulleys etc etc...all stuff I have access to.
I'd suppose a pair of 58 or 59 heads will probably be my best bet...thanks again.
Rocky

[poison heart]

So what all needs to be done to fit 62 heads on a 59 block?

[PRC]

Rocky,

If you have not already done so you should check out the thread on "porting results '62 heads" in the race forum. It shows that you can still get good performance with the early heads. I agree with you that the early "reverse cooling" heads look better.

[poison heart]

Couldn't you pop the freeze plug out of the front of the 62 heads and run an early timing cover? Or are the heads differently internally? I know the coolant passages are moved forward on the 61-64 heads.

[Bill Hanlon]

I've been told that the tube that distributes coolant in the reverse flow (early) heads will not fit into the later heads. Never tried it myself.

[poison heart]

I've heard that some people don't even run those tubes in their heads

[Rocky 389]

Originally Posted by poison heart

I've heard that some people don't even run those tubes in their heads

UPDATE: Took my block, flywheel, crank and pistons/rods in to my machinist for balancing this afternoon and we were BSing about putting the late heads on the early block. He showed me a great pair of #48's all finished with new valves, springs, 3 angle valve job and the works. Said I could have 'em for 300 bucks. That's quite a motivator to make this swap work. I forgot to look at the front of the late heads to see if there is a provision to bolt the 55-59 water necks on. If they'll bolt up [leaving me with the prefered reverse coolant circulation] I'd use them even if the early distribution tubes won't fit. The tubes weren't needed after 1960 so why should I sweat them on a pair of #48 heads?
Oh, and I scored a pair of 1959 genuine GM head gaskets off ebay. I want to lay those babys against the #48 heads to see if I can drill coolant holes in the heads without causing catastrophic failure of some kind...so I can take advantage of the early reverse cooling.
Am I doing what somebody here has already tried? If so, I'd like to hear about it.
........and yes, we're gonna tap and plug-off the early rocker stud oiler holes in the block if we go this route...I already know about that.
Discuss

[Bill Hanlon]

Only person I know who had an early block & heads without the distribution tubes complained about his '58 370 overheating. He finally found a set of tubes, put them in and his overheating problems were solved.

[Rocky 389]

Bill...I'd be willing to bet the 58 heads are thin adjacent to the spark plugs and exhaust valves and therefore needed the dist.tubes. Later heads didn't suffer from lack of tubes and just to compound the issue, the later heads received heated water from the lower block......early heads received cool water from the radiator.
The plot thickens...
to be continued................

[poison heart]

I'd also be interested in this. The "porting results '62 heads" thread is about the heads I want to put on my 59 sometime. If I think about it next time I'm in the garage I'll compare a 59 head and my 62 heads and see if I can figure out why it couldnt work

[Bill Hanlon]

Originally Posted by Rocky 389

Bill...I'd be willing to bet the 58 heads are thin adjacent to the spark plugs and exhaust valves and therefore needed the dist.tubes. Later heads didn't suffer from lack of tubes and just to compound the issue, the later heads received heated water from the lower block......early heads received cool water from the radiator.
The plot thickens...
to be continued................

Rocky:
The water distribution tubes had four holes evenly spaced (one per cylinder) and four more that exactly aligned with exhaust valve spacing of each cylinder.

PH:
The 62 heads will bolt on to the 59 block as will the 59 front cover, and I'm pretty sure early inlet pieces will attach to the 62 heads. But the coolant flow from the later block will not line up with the early front cover. Larry Gorden has good pictures in an article at http://www.pontiacsafari.com/ then click Pontiac Info and then click Pontiac Engine Cooling.

[poison heart]

I see, So what what if you pull out the freeze plugs in the front and use the early front cover with the waternecks in the heads?

[badlefthand]

Good luck on your build.Not many of us throwing an old Pontiac engine in a street rod.Plenty of fix it problems compaired to other engines.Good to see there is someone else out there (no offence) as goofy as I am.

[1960 shark]

This may sound like a stupid question since you already have the Pontiac engine, But why did you opt to not use a Ford motor in a Ford Hot Rod?You have a ton of available options for a 302 and theyre a cheaper and easier too.

I have over $6000 in my Pontiac engine and its nothing extravagant.But I HAD to put a Pontiac in my Pontiac.

[Rocky 389]

Originally Posted by 1960 shark

This may sound like a stupid question since you already have the Pontiac engine, But why did you opt to not use a Ford motor in a Ford Hot Rod?You have a ton of available options for a 302 and theyre a cheaper and easier too.

I have over $6000 in my Pontiac engine and its nothing extravagant.But I HAD to put a Pontiac in my Pontiac.

Easy....I'm a pontiac guy, not a ford guy. I just love the 33-34 ford coupe's styling...purely a personal choice but I trust my Pontiac mechanicals a lot further than I trust ford's.
Now, the real issue is whether the late heads [#48s] can be drilled for water passages that correspond with the reverse-cooling early block. I'm not too worried about the head cooling issues [having no water tubes in the late heads] because Pontiac engineers appeared to have no issues with it either................and that was after the coolant had already passed through the cylinder block.
If there's no meat to drill the early coolant holes in the later heads, I'm finished......no way to get coolant from the heads back down to the block and out of the engine.
My new 59, 389 head gaskets should tell me if it's possible...can't wait to get my hands on those later heads to see!

[1960 shark]

Originally Posted by Rocky 389

Easy....I'm a pontiac guy, not a ford guy. I just love the 33-34 ford coupe's styling...purely a personal choice but I trust my Pontiac mechanicals a lot further than I trust ford's.
Now, the real issue is whether the late heads [#48s] can be drilled for water passages that correspond with the reverse-cooling early block. I'm not too worried about the head cooling issues [having no water tubes in the late heads] because Pontiac engineers appeared to have no issues with it either................and that was after the coolant had already passed through the cylinder block.
If there's no meat to drill the early coolant holes in the later heads, I'm finished......no way to get coolant from the heads back down to the block and out of the engine.
My new 59, 389 head gaskets should tell me if it's possible...can't wait to get my hands on those later heads to see!

Roger that Rocky.
Make sure and post some pictures of that Rod, Ive only seen 1 Pontiac powered hot rod Ford.My next car is going to be a Model A.

Good luck with the head situation.

[poison heart]

Screw a Ford motor, if we're going cheap why not put a small block chevy in it

[1960 shark]

Originally Posted by poison heart

Screw a Ford motor, if we're going cheap why not put a small block chevy in it

Because a Ford motor belongs in a Ford vehicle.

Ford motors are very inexpensive compared to a Pontiac.

Have a nice day.