[Sirrotica]

Largest CID LS engine:

RHS 502ci Competition
Short Block
This short block is the largest cubic inch engine we build and will make big horse power when matched up with the proper heads and cam.

Okay then if you want a mountain engine, it's already been done too, any reason to make another redundant example without tying it to a Stratostreak engine for Stratostreak racers??????

If you want an engine that's already taken the best points of all designs and incorporated them together in a Pro Mountain engine it's been done already too. Sonny's builds mountain motors all the way to 932 CID, not any brand specific, so they're already available. Makes it pretty hard to think of any good reason other than to have it resemble a Stratostreak engine, to do it again.

[bobzdar]

Right, that's an aftermarket block as well and maxes out at 4.165 bore (or what a factory Pontiac block can do). I can see going to a certain point so it can be dropped in an existing car, but the stage we're getting to now with Billet blocks and new head castings etc., they aren't going to be dropped in anything resembling a factory engine bay where the size, motor mounts etc. will make any kind of difference. You're talking front and rear motor plates, tall decks etc. that don't use any factory mounting points, so what point is there in having a passing (at best) external resemblance to a pontiac?

I guess I understand with the new heads that are out, people want a block that can maximize them. But your only link to it being a Pontiac is that the heads were designed so they could bolt onto a Pontiac block. At a certain point, as an engineer, I'd rather just clean sheet it and build what's best, but I guess it's more difficult to market than if you have a link to a brand with a following.

[Sirrotica]

Chevy ford and chrysler have engines in pro cars that have nothing in common with a production engines or cars other than a name and a carbon fiber shell that resembles a front wheel drive car. Every part is racing specific and same as NASCAR nothing comes from production cars, this is what racing has evolved to.

John Force's funny says mustang on it but other than the name nothing comes from a ford production car. The engines are based off of a chrysler hemi design.

If Pontiac racers wanna run with the big dogs they have to do what the big dogs do. Basing a pro series engine from a 1955 design ain't gonna cut it, the laws of physics are not going to be broken no matter how attached Pontiac racers are to the Stratosteak design. It was ahead of it's time in 1955 and stayed with the competition for a lot longer than it should have. It does fine in the lower classes where the playing field is leveled, but in an unlimited application it was surpassed in the 60s and 70s by other designs. Pontiac knew it was going to have to go another route in the late 60s and designed the 427 Hemi and just as the Stratostreak was ahead of it's time in 1955, so was the hemi design that they gave us a peek at in 1970. I strongly believe that design would have put all other detroit car makers to shame, alas because of policies and politics it was never made, too bad for us dyed in the wool PONTIADDICTS.

The Butlers and Travis Quillen have band aided the design by turbo aspiration and have done far better than I would have expected, 6.23 is nothing to be sneezed at. To keep the engine moving forward it has to go to the level that the competition has been at for years, stretching the block but keeping the front and rear of it to resemble the Stratostreak design is the only way I see to level the playing field if you want to be a serious competitor in a pro series. This isn't going to sit well with 99.9% on this board, but if you want to claim to be a Pontiac pro racer I see no other way to move forward if your a serious racer. There is no magic bullet that can get too much more out of the Stratostreak design, no matter how much we want it.

[Brian Baker]

JMHO...create a block that doesn't have Pontiac bore spacing and doesn't allow for production spec parts to be bolted to it, and it's no longer a Pontiac. I think the modifications that were done to the Dirty Bird block are about as far as you can go and still call it a Pontiac. Start stretching the bore spacing and it's no longer a Pontiac.

[Sirrotica]

Then is a stretched pro stock chevy no longer a chevy or a stretched ford a ford????

And if it's no longer either what do you call it?

A pro series chevy or ford engine?

What's the correct answer?

[Brian Baker]

Originally Posted by Sirrotica

Then is a stretched pro stock chevy no longer a chevy or a stretched ford a ford????

And if it's no longer either what do you call it?

A pro series chevy or ford engine?

What's the correct answer?

I don't care because I'm not interested in either platform for personal use...leave it to whatever the Chevy and Ford camps want to call it. My point is, once you start stretching the bore spacing on a Pontiac, why not just jump camp and go with a platform that has already been stretched from the original design and one which is already proven?

[Probird]

Originally Posted by Sirrotica

Then is a stretched pro stock chevy no longer a chevy or a stretched ford a ford????

And if it's no longer either what do you call it?

A pro series chevy or ford engine?

What's the correct answer?

In my opinion, NO, they are no longer Chevies or Fords.

They are just an aftermarket engine. I guess you would call it a Donovan, Dart, or whoever makes the thing.

I guess you could call Lynn's stretched engine a McCarty block.

[Tom Vaught]

Originally Posted by Brian Baker

I don't care because I'm not interested in either platform for personal use...leave it to whatever the Chevy and Ford camps want to call it. My point is, once you start stretching the bore spacing on a Pontiac, why not just jump camp and go with a platform that has already been stretched from the original design and one which is already proven?

"Stratostreak Guys" is a proper term for the basic philosophy of "don't change anything"
Pontiac Guys. The part that you are missing is that Pontiac Engineering changed the block or crank assembly practically every year the engine was produced. In reality, the head bolt pattern and the bore spacing are about the ONLY things that did not change, and Pontiac was shooting from the hip when they picked the 4.625" Bore Spacing when a lot of the other engines had smaller bore spacings.

If the Purists will not let you change the Bore Spacing, 5" Cranks and Tall Decks are the only choices you have. (unless you go Boost).

As talented as Langer is, he would never be able to run 6.27 at 228 with a Naturally Aspirated Traditional Pontiac Engine locked into a 4.625" bore spacing.

Tom Vaught

[Brian Baker]

Call me a "Pontiac bore spacing purist" then.

[65nss4spdGTO]

I consider myself a Pontiac purist, but when it comes to racing, you have to move away from the factory stuff to raise the bar. Even Lynn's head won't pass as stock unless you mill off the additional intake surface and bolt an adapter plate in place or add deck to the intake and it's still a stretch. Don't get me wrong, I commend Lynn and everyone involved in the new design, but it's not a true duplication. That being said, changes need to be made to increase HP levels, you can only put so much valve in a 4.350" bore. Our larger bore engines, 4.310" are smaller then the factory Chevy 409 engine at 4.312". 2.300" valves are "big" valves for the bore sizes we currently have, you can only put so much air through a 2.300" valve. A Dart BBC Big Chief head flows around 450CFM with a 2.400" valve as delivered, airflow increases with porting.

Calvin Hill
Hill Performance
708-250-7420

[greggutknecht]

Sorry guys but i have to go along with Brian,once you stretch it its no longer an indian.Pontiac changed the engine through the years but thats the point PONTIAC changed it.

[tom s]

im with Brian on this one,If a pontiac head wont bolt to it,we might as well just run the "pro stock" pontiac.Tom

[Dragncar]

If the BBC boys can call their engines BBCs with the bores and ports moved all over the place Pontiacs can too.
Its that kind of thinking, thats its not a Pontiac if you move something that has held us back.
Sometimes you have to move something.

[BruceWilkie]

I try to look at it as what would Pontiac have done had they been allowed. BTW iirc the Big Cheif head for BBC was a Pontiac spec'd head for the "corporate" big block wasnt it? Olds had a BBC head too. Got to remember GM did not really want the chevy boys getting beat by a division within their control. Making it a "corporate" motor was as far as they would compromise.

So... where would we have gone. My guess probably take what they learned from RA5 and Hemi projects and go canted valve or created a whole new platform. Perhaps evolve to a DOHC 4 valve design. We could speculate forever. (btw a canted valve or "twisted wedge" RA5 head style COULD be an improvement.)
Since GM officially killed us off we are pretty much free to interpret Pontiacs intentions anyway we want. We are in good shape with current block size if we remain content to compete in the modest size category. Our lowly short deck 301 opens the door to compete in the small motor categories if we want to lower the deck of an IA2 type block. Got to remember the "real" SBC has been left behind just like us.(plus 409 and original BBC)

[Sirrotica]

I think Bruce has the most level headed approach to the subject. Pontiac wouldn't have stayed with the 1955 Stratostreak design had they been given free reign to change. That is born out with the engineering of the hemi 427. The reason they did not change is because of politics and policies within GM, not because they felt that had loyalty to the original 1955 design and couldn't / wouldn't change it.

It is obvious that the engineers within Pontiac felt they needed another platform for performance had the horsepower wars continued. The engineering of the OHC 6 was allowed within GM because it didn't threaten the other divisions. The OHC 6 in Sprint form belts out 207 HP with only 230 cubic inches. Pontiac then attempts to put the OHC technology on a V8 and it never sees the light of day. We can only speculate why this never happened.

I think anyone that has any common sense knows that Pontiac if left on their own would have developed some outstanding powerplants and they had already shown which direction they were intending to go with the hemi 427. IT WAS NOT BASED ON THE STRATOSTREAK DESIGN, it was a clean sheet of paper design. If it had not been a great design, I doubt ford would have adapted it to their V engines 35 years later.

I really don't see why moving the bore centers is such a big deal, most likely if Pontiac had been restricted by GM to keep the Stratostreak design they themselves would have moved them. Afterall when GM said, "Pontiac you have the chevy big and small blocks to work with now for performance applications" Pontiac made 2 cylinder heads that were superior to what chevy already had in both the big block and small block applications. Even when they had to use another divisions engine they one upped the competition and beat them at their own game. I really think if GM had told them you have to work within the Stratostreak design, they wouldn't have had a problem moving the bore centers for a performance application to be competitive and put the hurt on the competition.JMO.......

One question to the serious Stratostreak stock bore center fans, If Pontiac engineers were willing to think outside of the basic Stratostreak design (which has been demonstrated by their actions and designs including improving both the small and big block chevy engines and the 427 hemi), why wouldn't you be willing to move the bore centers and make one of the best advancements yet in the maturing of the original Stratostreak design, yet still keeping the identity and much of the original architecture of the 1955 design?
BTW this change is only going to affect .01% of Pontiac racers trying to be competitive in pro series racing, everyone else it's still business as usual. I know I'd rather see a stretched Statosteak engine between the fenders of a Pontiac pro car than a pig block chevy.

THINK OUTSIDE THE BLOCK!!!!..................

DCI Home of the LONG INJUN BLOCK ????????

[PONTIAC DUDE]

Stretch the block. 4.500" bores 1400 hp N/A.

[BILL BOWMAN1]

Originally Posted by PONTIAC DUDE

Stretch the block. 4.500" bores 1400 hp N/A.

Ken, do you offer in house block stretching?

[triathlonx13]

[Brian Baker]

Originally Posted by Dragncar

If the BBC boys can call their engines BBCs with the bores and ports moved all over the place Pontiacs can too.
Its that kind of thinking, thats its not a Pontiac if you move something that has held us back.
Sometimes you have to move something.

Move to the other camp.

[John Langer]

Originally Posted by PONTIAC DUDE

Stretch the block. 4.500" bores 1400 hp N/A.

ahhhh, no! There have only been 2 engines that have eclipsed the 1100hp n/a mark (both by the same engine builder). Where are all of the other ones??? Many have tried and can only make around 1040ish tops. The guru's can't make 1100, what makes you think by opening up the bore to 4.500 they can make 1400??? I don't think you can make anywhere near 1400n/a with a BBC with a 4.500 bore.