what internals for 2.3l stroker?

[jayiszraw]

so i was wondering what internals would make a decent 2.3l stroker also since i will be replacing the crank and all bearings will that eliminate the chance of crankwalk on a 7bolt? would i be better off stroking a 6bolt? i have done some searching but it gets a bit confusing. would i be best off just buying a stroker kit or the internals seperately? any input would be appreciated

 

[jayiszraw]

There are a lot of threads out there regarding piston compression ratio. In short, if you want to run high boost go with lower compression. If you want lowend torque, you go with higher compression pistons, but you can't boost as high. Higher compression pistons are harder to tune for as you will need to reduce timing a lot. Also, remember the higher final compression ratio you have, the higher octane fuel (or use meth/alchy/water injecton) you will need to keep knock down.

Final Compression Ratio = (Boost/14.7+1)*PistonCR

how do you calculate that?

 

[blazebolt]

how do you calculate that?

The final compression ratio is the total compression ratio that the engine sees.

Let's say you are boosting 18psi on stock 2G pistons (8.5CR) your FCR would be
(18/14.7+1)*8.5=18.91

Now say you changed to a 9.5 CR pisons. To get the same FCR you need to run 14.5psi
(14.5/14.7+1)*9.5=18.87

If you kept boost at 18 psi you get
(18/14.7+1)*9.5=21.13
See how you can't boost as high with higher compression pistons? In increases your FCR and your more likely to knock

Your FCR, timing, and octane rating determines your knock.

 

[jayiszraw]

The final compression ratio is the total compression ratio that the engine sees.

Let's say you are boosting 18psi on stock 2G pistons (8.5CR) your FCR would be
(18/14.7+1)*8.5=18.91

Now say you changed to a 9.5 CR pisons. To get the same FCR you need to run 14.5psi
(14.5/14.7+1)*9.5=18.87

If you kept boost at 18 psi you get
(18/14.7+1)*9.5=21.13
See how you can't boost as high with higher compression pistons? In increases your FCR and your more likely to knock

Your FCR, timing, and octane rating determines your knock.

so if i am understanding this correctly the only other factor is how advance the timing is?

 

[blazebolt]

so if i am understanding this correctly the only other factor is how advance the timing is?

To reduce knock you want to do one or ALL of the following:

1. Decrease FCR (lower boost)
2. Decrease Timing
3. Increase octane (E85, race gas, etc)
4. Water/meth/alchy Injection

 

[TunaTalon]

Danger Will Robinson.

On an engine with an intercooler you cannot just add up the static compression ratio with the boost pressure. Bad things can happen to the tops of your pistons.

The compression that takes place in the cylinder (static compression) does not have the heat of compression removed and the actual increase in pressure is increased by a exponential power of 1.4.

The compression that takes place in a turbo passes through an intercooler before entering the engine. With a (very) efficient intercooler one bar of boost does indeed add only 14.7 pounds of cylinder pressure.

For example a new ZR1 Corvette has 11.1:1 compression and is already on the verge of detonation with 91 octane fuel.

To prevent detonation you need to control the pressure and temperature of the intake charge. The fuel/air mixture doesn't know or care how the charge got to the point of auto-ignition.

 

[toxicity883]

heres a full kit everything you need, no misinformation Eagle 2.3L Stroker Kit 7 Bolt Eclipse/Talon 4G63 93-up

 

[TunaTalon]

That's pretty much what's in my Talon. I went with the Eagle crank and rods with Wiseco pistons and ACL race bearings.

I didn't think I knew enough about engine theory to go off of the reservation of tried and true.

We should all push the limits of our understanding. However when we are just starting to learn the limits are, ... well limited.

 

[dSmgs-T]

That’s pretty much what’s in my Talon. I went with the Eagle crank and rods with Wiseco pistons and ACL race bearings.

I didn’t think I knew enough about engine theory to go off of the reservation of tried and true.

We should all push the limits of our understanding. However when we are just starting to learn the limits are, … well limited.

i went with that exact same build up as you also. i went with wiseco 8:8.1 pistons though. didnt have enough money to shell out for custom ones for lower CR

 

[TunaTalon]

My first choice was the 8.8:1 CR. My plan was to make all compromises in the direction of better low end and off boost torque while staying with proven components.

It worked for me. The 2.3L stroker with 264/264 cams, the E3 16G turbo, and high stall torque converter has turned my DSM into a fun daily driver.