[Skip Fix]

So planning a new build. Collecting parts for a while. I have a eagle forged 4.25 stroke crank SCAT 6.8 rods. Some ported High Ports Manley Nextek springs, T&D shaft 1.75/1.65 trying to get the IA/Camaro in the 9s . Not sure current E head 500" will get me there.A buddy is pushing me to go ahead and spring for a 4.5 crank to get more CI to where the rpm range will be a little lower, but that adds another grand to the project and I have the 4.25 crank. Cam selection open- something easy on valve train-too old to have the fun of changing springs all the time.

Thoughts from you all on crank and cams?

[JD]

I know this doesn't help with your current question but no interest in taking weight out of the car?

If all you want to do is drop .4 and get into the high nines that should be doable with the 4.25" stroke crank and a roller cam you can run multiple seasons.

[PAUL K]

4.25..... But Eagle offers A nice 4.35 crank and Molnar has a 4.375. We've had success using all three of the above.

[Elarson]

Our experience with The Grocery Getter, changing from 455 to 541 inch (without changing heads or cam) resulted in lots more low end torque (great for burnouts!) but no noticeable horsepower improvement and no appreciable ET improvement.

Then, changing from e-heads to Tigers added something like 150 hp with the corresponding improvement in track times.

So in my opinion, the 4.25" crank has the overwhelming advantage of being something that you already own.

Look to your heads, cam and other breathing components for your ET goals.

JMHO,
Eric

[Stan Weiss]

Originally Posted by Skip Fix

So planning a new build. Collecting parts for a while. I have a eagle forged 4.25 stroke crank SCAT 6.8 rods. Some ported High Ports Manley Nextek springs, T&D shaft 1.75/1.65 trying to get the IA/Camaro in the 9s . Not sure current E head 500" will get me there.A buddy is pushing me to go ahead and spring for a 4.5 crank to get more CI to where the rpm range will be a little lower, but that adds another grand to the project and I have the 4.25 crank. Cam selection open- something easy on valve train-too old to have the fun of changing springs all the time.

Thoughts from you all on crank and cams?

Skip,
Do you have a flow sheet for the HP?

Stan

[Scott65]

Put the Camaro on a diet! It'll be faster and easier on parts.

[Skip Fix]

Already got a glass hood. Minimal front urethane nose bracing, no front sway bar, Calvert Split leaf spring so lighter than 4-5 leaf packs. Light Prostar wheels, no tubes in slicks. Heck with those wheels and no spare my 78 TA was almost .5 seconds faster! Snowflakes radials, and spare have it right at 11.50s now! Crank windows. My skinny 150 lbs is in that 3595 weight. The High Ports are heavier than the E heads in it currently but new block will be lighter!

Current combo is running a decent mph but only mid 1.5 60 fts almost dead hooking with no chassis tuning. My 78 TA 200lbs heavier with only a 455 and those heads a smaller roller was hitting 1.51s with a smaller tire but only running 10.90s.

Stan I do have flow sheets, and we just sent them off to Dwayne Porter to flow them, at his shop and came up with pretty close numbers on his bench.Took pictures of the sheet as well as the Ehead numbers on the current 500 when they were freshened a few years ago. First line before the extra work.

JD I used to do some horse/cow work up in the Castro Valley area out of Danville back early 80s and autocrossed at Pleasanton Fairgrounds!

[Stan Weiss]

Originally Posted by Skip Fix

Already got a glass hood. Minimal front urethane nose bracing, no front sway bar, Calvert Split leaf spring so lighter than 4-5 leaf packs. Light Prostar wheels, no tubes in slicks. Heck with those wheels and no spare my 78 TA was almost .5 seconds faster! Snowflakes radials, and spare have it right at 11.50s now! Crank windows. My skinny 150 lbs is in that 3595 weight. The High Ports are heavier than the E heads in it currently but new block will be lighter!

Current combo is running a decent mph but only mid 1.5 60 fts almost dead hooking with no chassis tuning. My 78 TA 200lbs heavier with only a 455 and those heads a smaller roller was hitting 1.51s with a smaller tire but only running 10.90s.

Stan I do have flow sheets, and we just sent them off to Dwayne Porter to flow them, at his shop and came up with pretty close numbers on his bench.Took pictures of the sheet as well as the Ehead numbers on the current 500 when they were freshened a few years ago. First line before the extra work.

JD I used to do some horse/cow work up in the Castro Valley area out of Danville back early 80s and autocrossed at Pleasanton Fairgrounds!

Skip,
Thanks. I see in your signature the 500 is making 695 HP. Many years ago you sent me a dyno file where it made 635.3 HP @ 6100. Can I ask what changes you made in between.

Thanks,
Stan

[Scott Stoneburg]

Skip, do you have a 4.25 crank already for the new motor or will you have to take it out of your running motor? I would probably build the 505 since you already have the crank and that should make plenty of power to get you in the 9s with the high ports.

[steve25]

The 505 with 13 to 1 and 340 cfm heads should get you there easy !

[Gary H]

I'll go slightly against the grain here and say I'd go with either the 4.375" or the 4.5" stroke. I think the old saying there's no substitute for cubic inches is true. With the added ci you can probably keep the rpm's down lower and make the same power as the 505" Also, the 4.25' crank you already have will be easy to sell as that's the most common build on a 400 stroker combination. Not really a right or wrong answer but that's what I did for my race engine, 4.5" stroke.

[Skip Fix]

New crank I collected a few years ago for either a stroker in a 400 block or what ever.

Stan same motor maybe "corrected" vs non corrected HP?

500 is flat tops with about 75cc chambers around 11.75:1 4.350x4,21 billet crank-before forged cam out from P Dude.

[Tom Vaught]

Stick with the 4.25 crank. I had a new Bob and Frank 4.5 stroke crank and sent it down the road years ago.

Tom V.

[Stan Weiss]

Originally Posted by Skip Fix

New crank I collected a few years ago for either a stroker in a 400 block or what ever.

Stan same motor maybe "corrected" vs non corrected HP?

500 is flat tops with about 75cc chambers around 11.75:1 4.350x4,21 billet crank-before forged cam out from P Dude.

Skip,
Thanks. Yes I have the same file, but was looking at Page 1

Stan

[slowbird]

There is zero reason you current combo can't run 9s. 132mph is 9.9s without issue. Your 60ft are killing you! Get those sorted out and you're there. But if you truly want to build a new combo my vote is 4.25-4.375

[Dragncar]

Originally Posted by Tom Vaught

Stick with the 4.25 crank. I had a new Bob and Frank 4.5 stroke crank and sent it down the road years ago.

Tom V.

It was Frank who suggested I get that 4.5 crank.

slowbird is right, 60 foot needs taken care of.
If it does not 60 foot like a 9 second car its kind of hard to run 9s no matter what crank is in the engine. Just my opinion.

[steve25]

A 4.5 Crank would be taking your 60 ft times backwards with your current set up.
They need to be addressed first.

[Skip Fix]

3 different convertors one that was "loose" at 5000 in the 455 TA but only flashed the same with the 500. I have a new trans I think there may be something weird in the existing one to see if that fixes the 60 ft issue, but data recorder showing it is dead hooking and you would think at least a run or two it would spin. All three convertors flash close to 4700-5000.

[77 TRASHCAN]

4.25, keep the wrist pin out of the ring lands, and the skirts a little bit higher, safely in the block!

What gear?

What do you know about the Cam?

[grandville455]

If All your looking for is a solid 9, then do the 4.25 stroke and it will live a long happy life!