[Milepost]

Originally Posted by GTOGEORGE

Now to get back to the origanal thread.......there is nothing wrong with a larger bore spacing, the problem is when you do that the engine quits being a Pontiac. I for one love racing my Pontiac, the engine has been together for 4 years now (over 200 passes) with the heads only coming off once. Not bad for a low 8 sec. (now high 7's) car. We (Pontiac) have a N/A car that will be in the 6's and there is a good chance we will have a Blower/Alcohol car in the 5's this year pretty darn good for old school junk! Like I said earlier we have so much more to learn about the Pontiac engine without making a white elephant out of it.

GTO George

X2
The really big bore stuff makes sense but I agree you couldn't really call it a Pontiac engine anymore. IMO The 5.3" bore monster engines can't really be called a Chevy or Ford engine either. The only reason they are is because the "Look" or Brand style of the composite body that's wrapped around a tubular chassis. If the Pontiac racer has a factory steel tub and firewall then it should have a "real" Indian style block in it...I say let's take what we have and make it better...

[Tom Vaught]

Originally Posted by GTOGEORGE

Now to get back to the origanal thread.......there is nothing wrong with a larger bore spacing, the problem is when you do that the engine quits being a Pontiac. I for one love racing my Pontiac, the engine has been together for 4 years now (over 200 passes) with the heads only coming off once. Not bad for a low 8 sec. (now high 7's) car. We (Pontiac) have a N/A car that will be in the 6's and there is a good chance we will have a Blower/Alcohol car in the 5's this year pretty darn good for old school junk! Like I said earlier we have so much more to learn about the Pontiac engine without making a white elephant out of it.

GTO George

Valid Points, George but the fact remains that we have a lot of band-aids on the current "Pontiac design" 4.62 Bore Spacing Block

The way the math works is: if you run 200 passes and the heads came off for a repair, gasket, or otherwise, at 100 passes you get to claim that you made 100 passes without any maint except for oil changes, spark plugs, etc.

The clock starts over. The Chebby Guys, like Jim Brady, who used to post here WILL get 300+ passes on their chebby engines without any repairs.

That being said, Jimmy Keen used to change the Head Gaskets, every other race, and he ran a lot of races in a year (with a lot of passes as Super Street was the largest class) and
did not want to do the change at the track after a failure so he did it before the failure.
The 347 Ford Engine making 1400+ hp at 9500 rpm was a High maint engine combination but was also a World Champion in a very tough class.

So what was your 7 second pass number and where did you make the pass?

Tom Vaught

[GTOGEORGE]

Tom,
This thread is not about my race car..........thank you very much. By the way my engine after 200 or so passes is 100% A OK. The main and rod bearings look new all 8 cylinders where also sealing very well, 6 of them at 1% or less leakage and two at 2%. I will be replacing the GRP rods shortly.........the old ones will be for sale at Norwalk. I'm very, very pleased with my KRE built engine who knows how long it could have run before it needed to be rebuilt but I don't want to take a chance on the GRP Aluminum rods. So please lets get back to the thread.
Lets say a Pontiac performance shop decides to cast a spread bore block and call it a Pontiac (Chevy Does) and I assume that if they have their own brand of heads they will be made to fit this block and then another shop decides to do the same thing and they make their heads fit there block........neither block will have any parts that will fit the other or fit a stock bore spaced block, talk about one big mess and if a racer that decides to buys one of this blocks and then tries to sell it, who in the hell is going to buy it................. talk about a white elephant! Yea, real good idea.............I'll take 2! LOL

George

[Badbird69]

Sooooooo George.........would you change your mind if KRE made one?

[GTOGEORGE]

Nope!


George

[PONTIAC DUDE]

(1) So if you are gonna design a new engine not based on any of the Pontiac parameters already set for over a half century.

(2) Pontiac is No longer an entity of GM and no longer in production.

(3) Why would it even be in the Pontiac family?

(4) How could it even be called a Pontiac.
The timing cover and valley pan set up?

(5) Most would delete the cover in this monetary build up anyway.

(6) Not to say someone won't do it but the cost per return seems "Not practical".

[Tom Vaught]

Originally Posted by PONTIAC DUDE

(1) So if you are gonna design a new engine not based on any of the Pontiac parameters already set for over a half century.

(2) Pontiac is No longer an entity of GM and no longer in production.

(3) Why would it even be in the Pontiac family?

(4) How could it even be called a Pontiac.
The timing cover and valley pan set up?

(5) Most would delete the cover in this monetary build up anyway.

(6) Not to say someone won't do it but the cost per return seems "Not practical".

You are chitting me right? (You guys are calling it a Pontiac Engine based on a Bore Spacing number, nothing else)

1) Pontiac never had "Canted Valves" in production but a CV-1 Head is allowed.

2) Pontiac never offered a 4.5" stroke from the factory and yet 4.5" and a 4.25" cranks are "allowed" as being "factory".

3) Pontiac Engines did not have "Shaft Rockers" on their V-8 Engines but shaft rocker systems are allowed.

4) Pontiac did not have 6.8" long, 2.20" bearing diameter Rods. They are allowed.

5) Pontiac did have a belt drive camshaft system for the 6 cylinder engine so I guess we could allow the BOP belt drive stuff.

6) Pontiac never had a 4.375" Bore Block but that is allowed.

So the only thing that makes the "Pontiac Engine" a "Pontiac Engine" is a engine with a 4.62" Bore Spacing.

So I can go to my Ford SOHC Engine buddies and buy a raw block designed for a 4.630" bore spacing vs a 4.620" bore spacing, have it machined to a 4.62" bore spacing and take it to all of the Pontiac Events and call it a true "Pontiac" engine (as you guys are saying THAT is what makes a True "Pontiac" engine. A engine with a 4.62" bore spacing.

You guys are so out in left field with your "has to be a 4.62" bore spacing" bs it is actually humorous.

It has nothing to do with engineering, It has to do with a single number in a book that you guys are now calling the "Holy Bore Spacing Number". You guys should join the "Flat Earth Society"

Tom Vaught

ps George, just to bring you up to speed as you have been bashing me a few times in MY topic. IT IS MY TOPIC. I STARTED IT, I CAN ADD INFO OR MOVE THE TOPIC AROUND AS I SEE FIT AS THE TOPIC STARTER.

[slowbird]

This is all fun to talk about but really if someone did spend the money to develop a block with everything to go along with it and people agreed that it is a Pontiac. Just how many people would actually fork over the $$$ to buy one? Maybe 5 people in the whole Pontiac community? There are parts and pieces out there now that have proven to make real good power with what we currently have and not many people have spend the $$$ to buy those. Just my opinion

[Elarson]

I can see both sides of the conversation....being both a purist and an engineer.
In my humble opinion, to call it a Pontiac, it has to fit one of the following:

1) designed and built by Pontiac factory

******or*******
2) retains a predominant number of critical factory dimensions and architecture; so that most major factory parts could be bolted on. Bore spacing is the biggie, head bolt pattern (at least the factory 10 in their normal places), timing cover bolt pattern, cam lobe spacing, etc. Note that I didn't give a black & white list....the use of the word predominant is intentionally gray.

As an engineer, I see the limitations of the factory architecture and if a person chooses to deviate substantially from those, it makes good engineering sense, but why call it a Pontiac?

JMHO,
Eric

[PONTIAC DUDE]

Originally Posted by Tom Vaught

You are chitting me right? (You guys are calling it a Pontiac Engine based on a Bore Spacing number, nothing else)

1) Pontiac never had "Canted Valves" in production but a CV-1 Head is allowed.

2) Pontiac never offered a 4.5" stroke from the factory and yet 4.5" and a 4.25" cranks are "allowed" as being "factory".

3) Pontiac Engines did not have "Shaft Rockers" on their V-8 Engines but shaft rocker systems are allowed.

4) Pontiac did not have 6.8" long, 2.20" bearing diameter Rods. They are allowed.

5) Pontiac did have a belt drive camshaft system for the 6 cylinder engine so I guess we could allow the BOP belt drive stuff.

6) Pontiac never had a 4.375" Bore Block but that is allowed.

So the only thing that makes the "Pontiac Engine" a "Pontiac Engine" is a engine with a 4.62" Bore Spacing. THIS IS THE POINT along with bolt on items like pan, timing covers, heads. !!!!!

So I can go to my Ford SOHC Engine buddies and buy a raw block designed for a 4.630" bore spacing vs a 4.620" bore spacing, have it machined to a 4.62" bore spacing and take it to all of the Pontiac Events and call it a true "Pontiac" engine (as you guys are saying THAT is what makes a True "Pontiac" engine. A engine with a 4.62" bore spacing.

You guys are so out in left field with your "has to be a 4.62" bore spacing" bs it is actually humorous.

It has nothing to do with engineering, It has to do with a single number in a book that you guys are now calling the "Holy Bore Spacing Number". You guys should join the "Flat Earth Society"

Tom Vaught

ps George, just to bring you up to speed as you have been bashing me a few times in MY topic. IT IS MY TOPIC. I STARTED IT, I CAN ADD INFO OR MOVE THE TOPIC AROUND AS I SEE FIT AS THE TOPIC STARTER.

Tom. We have the M/T Hemi heads that BOLTS to a Pontiac block. We have the RA V stuff with different valve configuration that BOLTS to a Pontiac block. We have the canted valve CV-1 head that BOLTS to a Pontiac block.
If ya change the parameters away from the std Pontiac block design from the original concept it is no longer a Pontiac because they are no longer in existence as a Make of Automobile.

Increasing the bore spacing and using nothing else related to a Pontiac is already available in the aftermarket. Been done.

Where would the Pontiac aspect come into play?

So according to your ideals, if I run a Small Block Chevy with the Factory designed Pontiac aluminum heads Casting #987, it is a Pontiac and can be run at Pontiac events?

[PONTIAC DUDE]

Originally Posted by Elarson

I can see both sides of the conversation....being both a purist and an engineer.
In my humble opinion, to call it a Pontiac, it has to fit one of the following:

1) designed and built by Pontiac factory

******or*******
2) retains a predominant number of critical factory dimensions and architecture; so that most major factory parts could be bolted on. Bore spacing is the biggie, head bolt pattern (at least the factory 10 in their normal places), timing cover bolt pattern, cam lobe spacing, etc. Note that I didn't give a black & white list....the use of the word predominant is intentionally gray.

As an engineer, I see the limitations of the factory architecture and if a person chooses to deviate substantially from those, it makes good engineering sense, but why call it a Pontiac?

JMHO,
Eric

X 2

[Tom Vaught]

Originally Posted by PONTIAC DUDE

So according to your ideals, if I run a Small Block Chevy with the Factory designed Pontiac aluminum heads Casting #987, it is a Pontiac and can be run at Pontiac events?

Eric made an excellent post. The question remains 'What constitutes a Pontiac Engine?'

"1) designed and built by Pontiac Factory"

a) Pontiac Trans-Ams were offered with the SB Chevy Engine and sold as a Pontiac Vehicle and what they considered to be a Pontiac Engineered Engine. Same Deal with the Buick Turbo Engine design in the TA. Pontiac Engineers changed the Buick castings to Pontiac castings to fit into the TA.

b) Pontiac Engineering contracted with companies like Brodex to offer the Aluminum SB Chevy Performance Heads with a Pontiac LOGO on them and a Pontiac Part Number.

C) Pontiac Big Chief Heads had a Pontiac Part Number and LOGO.

All of the Parts were designed by PONTIAC Engineers employed by General Motors.

So you see that for every reason why the other parts ARE NOT a Pontiac, there are examples where they considered to be a Pontiac Engine.

Again, this is a excellent description of assumed parts and assumed relationships:

2) retains a predominant number of critical factory dimensions and architecture; so that most major factory parts could be bolted on. Bore spacing is the biggie, head bolt pattern (at least the factory 10 in their normal places), timing cover bolt pattern, cam lobe spacing, etc. Note that I didn't give a black & white list....the use of the word predominant is intentionally gray.

Personally I think that when we want to call it a Pontiac Engine we conveniently forget some differences. When we want to disqualify the engine we think of things that will disqualify the engine. Purely a subjective deal.

Slowbird summed it up well:

"This is all fun to talk about but really if someone did spend the money to develop a block with everything to go along with it and people agreed that it is a Pontiac. Just how many people would actually fork over the $$$ to buy one? Maybe 5 people in the whole Pontiac community? There are parts and pieces out there now that have proven to make real good power with what we currently have and not many people have spend the $$$ to buy those. Just my opinion "

It seems that most people will not get into a engineering discussion because the engineering means nothing to them. The show guys bought the cars for that deal and are happy. The street guys are happy as they CAN make more power vs the stock stuff. Most every part for the engine is re-poped today. 5 Guys will be pushing the limit of the current design. Everyone seems happy to stay right where they are in the program.
PMD is dead so there is and never will be any Pontiac Excitement from PMD or Government Motors.

Yep, George, I saw a very nice TA/Camaro at the Texas Mile. Nice "what-if" car for a guy who wants to be different. Expensive but different. Maybe that is the actual DNA of a Pontiac guy: Willing to spend more money to be "Different".

Tom Vaught

[Half-Inch Stud]

Aftermarket TH400 case seemed NON "Turbo-Hydramatic DiV of GM" to me. Not sure what the performance gain was with thaaaaat.

I'd so like to see a 4L80 Case (bolt on Bell hsg be fine) with the TH400 valve body /governed/mech speedo. all kinds of performance improvements there.

ahem, the PMD engine redo;"I got pom poms on and say keep going, hope there is a market that is buying, and really hope for more than incremental moves in block/heads/manifolds. I hope for a 3" intake valve or bigger for the most as-cast flow.
that would be (wait for it) .. Disruptive. take the lead with that.



OMG ; and Call it a Big Block Pontiac. end of THAAAAT issue huh.

[Elarson]

Maybe that is the actual DNA of a Pontiac guy: Willing to spend more money to be "Different".

Tom Vaught



Bingo!
Eric

[BruceWilkie]

Originally Posted by Elarson

Maybe that is the actual DNA of a Pontiac guy: Willing to spend more money to be "Different".

Tom Vaught



Bingo!
Eric

X2 ...even 35 years ago when I built a SBC, I had to be different and built a 307 in a plain ol Nova and used a powerglide and quadrajet!

I like different! Its certainly more fun to win when you're the underdog.

I dont know about willing to spend more money...its more a matter of having to.

[Travis Q]

Originally Posted by BruceWilkie

Its certainly more fun to win when you're the underdog.

I used to think that, too. But it seems that, these days, it's hard to win even if you have the best of the best and are on a level playing field with the rest of the pack.

I do agree that it's a lot of fun to be sucessful with something that everyone else tells you won't be sucessful. However, I find that getting your butt kicked weekend in and weekend out gets pretty danged old pretty danged quick.

We got to have all our beans in one bag for sure.

[David Holmberg]

To me this thread (and those like it) are like the old "Great Grandfathers shovel" story.

Yup, it was my Great Grandfathers, it's had 4 new heads and 7 new handles, but...

It all depends on whats in your heart. To me, change the bore spacing, but keep the outward appearance of a Pontiac and I'm good with it.

But to each their own.

[jdw_poncho]

Originally Posted by Elarson

Maybe that is the actual DNA of a Pontiac guy: Willing to spend more money to be "Different".

Tom Vaught



Bingo!
Eric

I seem to fall into that catagory, I dont mind spending extra money to know I have a pontiac. My feeling is, not everyone races agaisnt pro cars and needs to make 3500HP to compete against the boosted 632ci engines. I believe the bore spacing at the level Im gonna race at wont be that big of a issue. I need a set of solid heads that wont lift and has proven to take the abuse.

So make me sign a confidentiality agreement and sell me a set of drawings and I'll have someone make them!!

[7T2]

jeff,
i can have a set of divorced exh port, raised runner 500cfm billet heads cut for you in 6 months for somewhere between 7 and 9 grand a pair. t-ram and valve covers are existing. conventional rocker shaft system already in cad. the beauty of cad is that models transfer directly into cutter paths with mastercam for quick manufacture.
theres enough room on the end margins of the stock 19.75" head surface to house a 4.8 space and 4.6 bores- laid it out years ago just to see if it would fit...
billet crank, rubbed water cores. moved deck features on a billet head. not hard to design- but hard to justify. not sure of the existance of a committed market ...
maybe youll be the first, jeff. gimme a call cometime-
jim

[Torment]

Maybe that is the actual DNA of a Pontiac guy: Willing to spend more money to be "Different".

Tom Vaught


Absolutely! And for someone like me that grew up racing on the streets far more than on a track - back before we knew it was a bad thing to do of course - beating the belly button brands was always that much sweeter