2000 and newer

[Drednaut09]

Hi everyone. I’m getting ready to build a stroker and the question I have is.

-Is there anything different that needs to be done when building or installing a stroker for the coil pack era 4.0?

-Just wondering if the computer will be able to adjust the timing on its own? And is a upgraded fuel pump needed?

-And what’s the highest compression people are running on 87?

Sorry for the chain of questions. I’m jumping into this about 6 months sooner then I had previously intended due to the fact that I stumbled on a running 258 for 75$ tonight. Planning on pulling a 4.0 block from the upull this weekend from a 2001 Xj.

[Cheromaniac]

The process of building a stroker is the same regardless of the type of ignition system you have.
The ignition timing is programmed into the ECU and is non-adjustable unless you slot the bolt holes of the CPS and advance the timing slightly by moving it upwards. Otherwise the ECU would need to be reprogrammed with revised fuel and timing maps.
The stock 90lph fuel pump is good for up to ~300hp so there's no need to upgrade it for a mild stroker.
If you use the 4.0L rods and go for Russ' custom pistons, the static compression ratio can be set at ~9.5:1 with a tight quench height so that the engine can still run on 87 octane fuel.

[Drednaut09]

Ok what if I go with the 4.2l rods?

[Cheromaniac]

Ok what if I go with the 4.2l rods?

You'd have to use Silvolite 2229 pistons, mill the block to lower the deck clearance, and have the piston dish/combustion chamber volume increased to lower the compression ratio enough to run 87 octane. By the time you do all that and have the 4.2L rods reconditioned and balanced, you might as well use the 4.0L rods plus Russ' pistons and save yourself a lot of hassle.

[Tolemar]

B03BC296-AB84-4999-8A81-4F3961885425.jpeg

Ok what if I go with the 4.2l rods?

Why 4.2 rods? Imo longer rod is better. By the time you send out the rods to get reconditioned you could of just bought a way better rod from Russ. Imo these rods are really top notch. Pistons are also. Btw these rods were all exactly the same weight.

[Drednaut09]

Ok what if I go with the 4.2l rods?

You'd have to use Silvolite 2229 pistons, mill the block to lower the deck clearance, and have the piston dish/combustion chamber volume increased to lower the compression ratio enough to run 87 octane. By the time you do all that and have the 4.2L rods reconditioned and balanced, you might as well use the 4.0L rods plus Russ' pistons and save yourself a lot of hassle.

What is the part number for these Russ pistons?

So here’s where I am as of today. I have a completely disassembled 4.2.
Are these blocks or heads worth anything? The engine was in beautiful shape and I would hate to let such a nice looking block and heads go to waste.
And I have a 1999 short block that I just pulled from the yard today. Along with a 2005 head and and intake manifold.

I was thinking of going with the 4.2 rods because I assumed the pistons would be cheaper.

[Tolemar]

Contact Russ he’ll hook you up.

[Cheromaniac]

What is the part number for these Russ pistons?

So here’s where I am as of today. I have a completely disassembled 4.2.
Are these blocks or heads worth anything? The engine was in beautiful shape and I would hate to let such a nice looking block and heads go to waste.
And I have a 1999 short block that I just pulled from the yard today. Along with a 2005 head and and intake manifold.

I was thinking of going with the 4.2 rods because I assumed the pistons would be cheaper.

Send Russ Pottenger a PM for further information about his pistons and any other parts/services he can offer.
Your 4.2 block/heads & rod/piston assemblies won't be worth much but I'm sure there's a Jeep enthusiast out there who'd snap them up.

[Russ Pottenger]

Mr Dreadnaut just PM’ed me and I’ll be emailing him information and pricing.

Thanks for the referral Dino and Beau!