[performerrpm]

just curious, my shortblock still isnt assembled but the parts were for a n/a build originally. but now i have the dyers 871 i wanna use so.


with my 310 72 cceheads and ross flat tops my 455 is 11.6ish cr which is less than ideal but i wonder, with pulleys to make 6 psi could i get away with it.

with e85 and a bug catcher converted to fast xfi and a good blower cam" solid roller" could it be done or should i figure on ordering a set of dish pistons to get back around the 9.1 mark?

[JSPONT]

That is a bit much for boost, were the rings file fit? Were they filed for boost? Boost pistons have the ring lands set down a bit too. I used regular forged pistons in a turbo build and lifted 2 ring lands. That was at 9 to 1 on 12 psi (pump gas)

[tom s]

Talked to a couple boost guys,quench not that important,put a thick gasket and run it.Tom

[GTOGEORGE]

Originally Posted by tom s

Talked to a couple boost guys,quench not that important,put a thick gasket and run it.Tom

I’d go with a thick head gasket also! Also keep timing down.


GTO George

[73 TRANSAM]

If the Procharger was the best combo out there. Do you think people will be running turbos? Also not everyone has unlimited funds when it comes to heads. You don't need all this special heads to make power with turbos. I would love to have the warp 6 heads on my combo but I don't have unlimited funds. Big Chief and Butler are well over 2800 hp with eheads. It cannot be that bad but I know u can do better with better heads? Thanks.

[GTOGEORGE]

Originally Posted by 73 TRANSAM

If the Procharger was the best combo out there. Do you think people will be running turbos? Also not everyone has unlimited funds when it comes to heads. You don't need all this special heads to make power with turbos. I would love to have the warp 6 heads on my combo but I don't have unlimited funds. Big Chief and Butler are well over 2800 hp with eheads. It cannot be that bad but I know u can do better with better heads? Thanks.

I could make more hp with better heads just like a turbo would those 481x turbo engines don’t have e-heads on them, there’s a reason!
It’s pretty simple the better flowing head the more hp NA or PA!

[performerrpm]

file fit is the plan for the rings and the ring lands are set down i was gonna use with nitrous, everythings still in boxes. i seen butler sells cometic gaskets in different thickness but wasnt sure.



i wonder what the effective cr of ur 9.1 cr was vs what mine would be with 6 psi and 11.5/6

[GTOGEORGE]

Originally Posted by performerrpm

file fit is the plan for the rings and the ring lands are set down i was gonna use with nitrous, everythings still in boxes. i seen butler sells cometic gaskets in different thickness but wasnt sure.



i wonder what the effective cr of ur 9.1 cr was vs what mine would be with 6 psi and 11.5/6

With 9 to 1 compression and 6 lbs of boost your compression would be around 12 to 1 with 11.5 compression your looking at about 15 to 1.
Roots blowers are not turbos asking the wrong/right questions will get you the wrong answers!

GTO George

[JSPONT]

Stan Weiss would be the one to ask on here.

[73 TRANSAM]

The bigger the turbo would make more power per psi. Charlies turbo is tiny compare to ur blower. I made almost 1265 hp at 15 psi and my turbo was on the smaller size which is a 91.5 mm with a 1550 hp rating. I need a 98 mm for my 482 and that is rated at 18-1900 hp. But I want to drive it on the street so I wanted a small one. If I wanted to make a big power on lower boost, I just need to put a 106 mm on it and I believe it will match ur combo but that is just an example. But the turbo shines when u up the boost! Not a lot of hp loss driving it unlike the blower combo. Not arguing but stating the facts. Look at Daddy Dave at SO! He said he will never put a turbo on his car and look at his combo now. Twin turbo just like everyone else. The only one left is Megalodon and just a few guys and few nitrous cars. But turbo is the way to go for big power based on the cars running it. But what do I know. Converting to Turbo is just hard on a Pontiac due to the head design exhaust we have. This is why a lot of people are converting to LS.

[GTOGEORGE]

Originally Posted by 73 TRANSAM

TLook at Daddy Dave at SO! He said he will never put a turbo on his car and look at his combo now. Twin turbo just like everyone else. The only one left is Megalodon and just a few guys and few nitrous cars. But turbo is the way to go for big power based on the cars running it. But what do I know. Converting to Turbo is just hard on a Pontiac due to the head design exhaust we have. This is why a lot of people are converting to LS.

Daddy Dave switched to twin turbos because he needed more HP and could not fit a BIGGER pro charger on it (no front end room if there was he would have seeped with the procharger) he didn't want to get a different car so he had no choice but to go to twin turbos.
As for Pontiacs head design we have the Warp 6 and DCI's RA5 heads!


GTO George

[GTOGEORGE]

Originally Posted by 73 TRANSAM

The bigger the turbo would make more power per psi. Charlies turbo is tiny compare to ur blower. I made almost 1265 hp at 15 psi and my turbo was on the smaller size which is a 91.5 mm with a 1550 hp rating. I need a 98 mm for my 482 and that is rated at 18-1900 hp. But I want to drive it on the street so I wanted a small one. If I wanted to make a big power on lower boost, I just need to put a 106 mm on it and I believe it will match ur combo but that is just an example. But the turbo shines when u up the boost! Not a lot of hp loss driving it unlike the blower combo.

With my small blower set up (compared to a 12-71 or 14-71) all I can make (boost wise) is 11.5 lbs and I have to spin it almost 30% over (which is a lot for a roots blower of that size) to do that, even with that I'm making upwards of 1,400HP. So boost wise I'm maxed out...........i need a BIGGER blower. I couldn't imagine what my engine would make with a 12 or 14-71 on it......well over 2,200HP! Remember its not the size of the blower or how much boost can make its what you can do with what you have.....ive been working on my combo for a while! A lot of people just turn up the boost as oppose to working on a certain combo....not always the best thing to do.


GTO George

[performerrpm]

i hope he chimes in here......i cant get the search function to work on the phone version

[73 TRANSAM]

This info came from Tom V. and he doesn't like the .090-.120 clearance. He said it tends to cause detonation. I ran .145 down the hole plus 35cc dish with Marty's sealing ring with a 61cc heads to get 8.8 to 1 compression.

[Tom Vaught]

Assuming the below engine parameters: Wallace Racing Calculator.

Engine Bore = 4.181"
Engine Stroke = 4.210
Deck Height = .004
CCs in the head = 72
Valve Reliefs = 6.6
Head Gasket Thickness .041"
Head Gasket Bore Diameter = 4.250"

Wallace Racing says you would be at 11.64 Compression Ratio.

So to get to 9 to 1 compression ratio you would need a (Wallace says 8.96)
you would need a Head Gasket that was .170" thick.
FOUR TIMES AS THICK AS THE .041" THICK GASKET THAT HE HAS RIGHT NOW.

RIGHT, BET THAT SUCKER WOULD REALLY SEAL UNDER BOOST. NOT.

Personally I would stay closer to 8.5 or 8.75 to 1 compression ratio and be able to add boost at a later date by using the PROPER parts vs a bandaid super thick head gasket.

Tom V.

[GTOGEORGE]

All you would need is to get the compression in the 10’s with e-85 and you’ll be fine!


GTO George

[blueghoast]

Originally Posted by Tom Vaught

Assuming the below engine parameters: Wallace Racing Calculator.

Engine Bore = 4.181"
Engine Stroke = 4.210
Deck Height = .004
CCs in the head = 72
Valve Reliefs = 6.6
Head Gasket Thickness .041"
Head Gasket Bore Diameter = 4.250"

Wallace Racing says you would be at 11.64 Compression Ratio.

So to get to 9 to 1 compression ratio you would need a (Wallace says 8.96)
you would need a Head Gasket that was .170" thick.
FOUR TIMES AS THICK AS THE .041" THICK GASKET THAT HE HAS RIGHT NOW.

RIGHT, BET THAT SUCKER WOULD REALLY SEAL UNDER BOOST. NOT.

Personally I would stay closer to 8.5 or 8.75 to 1 compression ratio and be able to add boost at a later date by using the PROPER parts vs a bandaid super thick head gasket.

Tom V.

What he say's
I'm running an 8-71 with 7:98:1 on pump gas with 10 LBS of boost.
I pop a couple head gaskets but now I have a timing boost controller
that will make the difference and I plan on spraying mine too.
If you want some of my info call me 269-832-8122 and I'll help as much
as I can. Charlee 66 has good info too.He give me some good information.

GT.

[73 TRANSAM]

I respect your combo as u r going round after round with it. If it makes u happy and not breaking anything. That is the best combo especially if ur not setting the world on fire. U only need urself to be happy at the end of the day. Daddy Dave was breaking his Procharger every time he race before. U dont see turbo guys burning up their turbo on a pass do you? I'm sure Daddy Dave knows more than what hes telling us on the show.

[GTOGEORGE]

Originally Posted by 73 TRANSAM

I respect your combo as u r going round after round with it. If it makes u happy and not breaking anything. That is the best combo especially if ur not setting the world on fire. U only need urself to be happy at the end of the day. Daddy Dave was breaking his Procharger every time he race before. U dont see turbo guys burning up their turbo on a pass do you? I'm sure Daddy Dave knows more than what hes telling us on the show.

I’m just repeated what he (daddy Dave) said if he had the front end room he would have stayed with a pro charger.


GTO George

[73 TRANSAM]

I'm glad u did not take it the wrong way. It is a lot of good info if u didn't think of negative on the posts. Good luck with your build.