Pontiac GTO Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
Alright guys, need some help on my next step in my new engine build! I got a 455 bored .030 over at 462ci, forged crank, eagle h beam rods, and ross racing pistons. Im wanted to make a 700hp(or close to it) pump gas engine, been looking a lot at the TIN builds and possibly going with a northwind intake, harland sharp rockers, kauffman or edelbrock aluminum 85cc heads to keep the compression low enough, what do i need to do to get 700 hp out of it? How much should i port the heads? 340cc is max that kauffman does on their heads. Am i going in the right direction? Still havnt made a decision on cam yet, they confuse me lol what lift and duration do i need? Just need some pointers guys! Thanks!
 

·
Registered
Joined
·
1,611 Posts
700 gross hp "on the motor", on a pump gas 462-469 with 85cc alum heads...good luck with that!

Head over to Pontiac Street Performance site & ck out what Steve Coombes had to do to make right under 700hp with his 450 cube Pontiac build. Steve's build was nearly a dozen years ago & used a custom 4 1/8" forged crank. A good friend followed Steve's build but used an offset ground "990" 421 crank. A few years later I picked up the rotating assembly, when he changed direction (IAII build) & I assembled a 448.
 

·
Registered
Joined
·
634 Posts
My engine guy made 755hp @ 5900 rpm, with a 400 block 4.5 stroke build. But it was high compression on E-85. It ran strong in a modified dirt track car.

Won't be easy to make 700hp with 85cc heads & pump gas. But, you can easily make 600 +.

http://www.krepower.com/Pontiac Street Engines.htm


If you go with higher octane fuel, you can use KRE High Port heads, a nice solid roller cam, and a 1050 Dominator type carb. That's what my engine guy did. He used unported High Ports, and a Northwind intake. The HP's flow 330cfm out of the box. They'll port 'em to 380, without a rocker shaft---over 400, with a shaft.

Kauffman Racing Equipment

By the way, my guy built another similar engine, and put it into a street '69 GTO. He drove it to our local car show one year. :smile3:

PS: If you'll be doing much street driving, I'd consider going with closer to 600hp, or less. That way you can build with lower compression, and a reasonable HR cam.

http://www.sdperformance.com/viewProduct.php?productID=1817

http://www.sdperformance.com/viewProduct.php?productID=1786

http://sdperformance.com/customerCars_01.php?carID=121

A 700hp long stroke Pontiac engine will be a real beast to handle, on the street. Even 600hp will be scary, with hard street rubber. We're talkin about 10 sec 1/4 mile power, with slicks.
 

Attachments

·
Registered
Joined
·
18 Posts
Discussion Starter #4
Thanks for the info! I know 700hp is kinda unrealistic, and i would be very happy with 600+, but i really just wanna try to push the limits if ya know what i mean!! I dont necessarily need 85 cc heads, the 75cc heads could still keep the compression in the 11:1 pump gas range! What compression is optimal for E-85? And based on what power im wanting, what choice of cam would be best? I already got a set of solid roller lifters, just waiting on a cam to use them with and im clueless on what to get.. i understand with this much power, the idle quality is terrible, but im not worried about that
 

·
Registered
Joined
·
3,759 Posts
Thanks for the info! I know 700hp is kinda unrealistic, and i would be very happy with 600+, but i really just wanna try to push the limits if ya know what i mean!! I dont necessarily need 85 cc heads, the 75cc heads could still keep the compression in the 11:1 pump gas range! What compression is optimal for E-85? And based on what power im wanting, what choice of cam would be best? I already got a set of solid roller lifters, just waiting on a cam to use them with and im clueless on what to get.. i understand with this much power, the idle quality is terrible, but im not worried about that

Rather than guess or accept opinions, why not simply email Kauffman or Butler to get a list of build parts, or better yet, just buy a $25K ready to run engine? Seeking to get those kinds of numbers will require matched/blueprinted parts where everything flows.

You will want to have your block sonic checked, squared and all cylinders correctly bored/honed with a torque plate. Bottom end will have to be beefed up. Lifter bore braces with a roller. Even then there will be no guarantee the block won't grenade at that HP level. That's why they make the aftermarket MR-1 and IA II blocks. They sell for about $3,200 and can handle the HP you are looking to get. Kauffman or Butler can put this together in any form you want to include a short block: Kauffman Racing Equipment or Butler Performance Online

Why not go turbo or supercharger?
 

·
Registered
Joined
·
18 Posts
Discussion Starter #6
I already have the beefed up crank, rods and pistons. Its been zero decked, honed, and bored. Just need help choosing the best parts to get the power i want. Just looking for opinions and what other people have used to get the most power. I know its possible, and im not gonna spend 25k to have them build me an engine when im already halfway there, and wont even be close to 25k in the end
 

·
Registered
Joined
·
3,759 Posts
I already have the beefed up crank, rods and pistons. Its been zero decked, honed, and bored. Just need help choosing the best parts to get the power i want. Just looking for opinions and what other people have used to get the most power. I know its possible, and im not gonna spend 25k to have them build me an engine when im already halfway there, and wont even be close to 25k in the end


Here is a 700HP recipe that you might follow: Pontiac Takes The Win at 2015 Engine Masters Challenge - Hot Rod Network
 

·
Registered
Joined
·
634 Posts
Here's more places to get some big power parts & advice.

http://www.spottsperformance.com/

http://www.dcimotorsports.com/services/pontiac-v8-engine-builder/

pontiac crate engines


"...What compression is optimal for E-85?..."

As much as you'd want, for a street driven car. I've read that it has up to 106 octane. Also runs cooler.

http://www.hotrod.com/articles/hrdp-0801-e85-ethanol-alternative-fuel/

You can Google up lots of E-85 info.

"...what choice of cam would be best?..."

You can use the solid rollers on a HR cam. If you stay with a reasonable lobe, you won't need lifter bore braces. The Road Paver I linked is in the ball park.

http://www.sdperformance.com/viewProduct.php?productID=1817

I'd try a smaller cam, similar to this. Then, if it doesn't produce the high rpm power you want, try something a little bigger. Used roller lifters can be used on new cams. So, you'd only have to replace the cam, unless the new cam was enuff bigger to require stronger valve springs. I say try to get by with a smaller cam. I think you'll be much happier with it, at lower street rpm.

And if you have a popular cam, such as the SD cams. you can probably sell it & get most of your money back, to help pay for the bigger cam. But, if you go with a big cam 1st, then have to go smaller, it will probably be harder to sell the bigger cam, especially if it is a solid roller grind. There are lots of guys running smaller HR cams on the street.
 
1 - 8 of 8 Posts
Top