Factory Piston Pin height

[GregO]

I’ve tuned 3 sc combos at 9.5/1 and one turbo setup at 9.5/1. The weakest one made 950 rwhp where it ran out of 2650.

What combo base 5.0 or 5.2 ?
The 2650, was it ported for the big TB ?

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[engineermike]

What combo base 5.0 or 5.2 ?

One sc was a predator with a 3.8 Whipple, the other two were 5.0

The 2650, was it ported for the big TB ?

Odin, so a big tb.

 

[Oakley]

i don't have the measurements but it should definitely be below the head and valves.

if its above those you got a real problem.

 

[tdstuart]

If the point is to boost the motor, is the 0.2L really worth the effort?

Take a look at FFRE where they keep the engine at 5.0L to have a stronger cylinder wall, they just chuck in a ton of boost haha. Their 5.0L on bretts car has gone low 6s 1/4 mile. I think they are turning 9k+ maybe even over 10k rpm.

For an engine making a lot less than 2000+hp it would probably be just fine to have the cylinder walls thinner to get the 5.2L. Just not sure if it's worth it to increase the stroke to get another .2L when you could just add a little more boost.

This setup: https://rpgracingengines.com/product/rpg-max-effort-n-a-5-5l-short-block/
Would be a sick N/A motor.

 

[Decible]

If the point is to boost the motor, is the 0.2L really worth the effort?

Take a look at FFRE where they keep the engine at 5.0L to have a stronger cylinder wall, they just chuck in a ton of boost haha. Their 5.0L on bretts car has gone low 6s 1/4 mile. I think they are turning 9k+ maybe even over 10k rpm.

For an engine making a lot less than 2000+hp it would probably be just fine to have the cylinder walls thinner to get the 5.2L. Just not sure if it's worth it to increase the stroke to get another .2L when you could just add a little more boost.

This setup: https://rpgracingengines.com/product/rpg-max-effort-n-a-5-5l-short-block/
Would be a sick N/A motor.

It would actually be a bit over .4 total and on the low end side it probably would be worth it. Not using a factory block, I’ll be using the Bear Block.

 

[Decible]

If the point is to boost the motor, is the 0.2L really worth the effort?

Take a look at FFRE where they keep the engine at 5.0L to have a stronger cylinder wall, they just chuck in a ton of boost haha. Their 5.0L on bretts car has gone low 6s 1/4 mile. I think they are turning 9k+ maybe even over 10k rpm.

For an engine making a lot less than 2000+hp it would probably be just fine to have the cylinder walls thinner to get the 5.2L. Just not sure if it's worth it to increase the stroke to get another .2L when you could just add a little more boost.

This setup: https://rpgracingengines.com/product/rpg-max-effort-n-a-5-5l-short-block/
Would be a sick N/A motor.

The compression is way to high for what I’d use it for but I bet at 14:1 that thing make 670+ to the wheels. We did a 13.1 sbc 377 back in the 90’s and that thing made over 700

 

[tdstuart]

The compression is way to high for what I’d use it for but I bet at 14:1 that thing make 670+ to the wheels. We did a 13.1 sbc 377 back in the 90’s and that thing made over 700

Ya they say it can do over 700whp with the right heads, cams, intake, etc.

Way too high compression for boost though.

 

[tdstuart]

It would actually be a bit over .4 total and on the low end side it probably would be worth it. Not using a factory block, I’ll be using the Bear Block.

So would it be 5.4 or 5.6 (5.2 block + 0.4 stroke) total?

 

[Decible]

So would it be 5.4 or 5.6 (5.2 block + 0.4 stroke) total?

So the 5.2 and 5.0 use the same 3.65 stroke. The only difference is the bore. The 5.2 has a 3.7 bore and the 5.0 has a 3.6x bore. 3.7 is a max bore on these blocks due to the bore spacing. That’s why the only way to gains and cubes is to increase the stroke. That motor uses a 3.9 stroke with a 5.85 rode with a 3.7 bore to get to 5.5L or 335 CI. I don’t like the idea of having the piston above the deck and having to run an extra thick head gasket with boost. I’d rather lose 4 cid and keep the piston slightly below the deck and make it up with boost so to answer your question it would be going from a 5.0 to a 5.43 or 331 CI with a 3.7 bore and 3.84 stroke. So a total increase of .43 CI for an extra 25 CI with much more low end torque due to the stroke. A Centri would love this motor.

 

[engineermike]

Technically the 5.2 is 3.66 stroke…worth a whopping 1 cid.

 

[engineermike]

I fantasized about 5.4 badges on the fenders….

 

[tdstuart]

I fantasized about 5.4 badges on the fenders….

I looked into doing a stroker when first building my motor and had this same thought. Couldn't find any though haha would need to get some custom made

 

[engineermike]

Challenge accepted.

 

[engineermike]

https://www.npdlink.com/product/emblem-fender-54/129077

 

[K4fxd]

Y'all are worried about piston speed rod ratio ect..... I'm just going to throw this out there. We were building 4-5/8ths inch stroke twin cam HD's for YEARS. Spinning the max effort one's to 7500-8000 RPM

The pistons, pins and rods are beyond good.

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