WJ Stroker build recipe.

[darkcorp]

Or maybe I should choose this one? Still a poor man's but with a tight quench.

4.6L Modified "poor man's" stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom forged +0.020" bore pistons, compression height 1.380", dish volume 26cc
9.25:1 CR
Stock 4.0L camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
Ford 24lb/hr injectors for '87-'95 engines, Accel 24lb/hr injectors for '96-'04 engines, '98 Chevy LS1 25.2lb/hr injectors for '05-'06 engines
248hp @ 4900rpm, 306lbft @ 3250rpm ('87-'95 camshaft)
245hp @ 4800rpm, 315lbft @ 3000rpm ('96-'04 camshaft)

Should I reduce dish volume to some 22cc to reach 9.5:1 CR?

Finaly I found way to open Bulltears's site (it doesn't open from my country) and see that the pricing for pistons is 475USD for set of 6.

[Cheromaniac]

Or maybe I should choose this one? Still a poor man's but with a tight quench.

Good idea! This is an evolution of the original poor man's stroker recipe that I have in my Jeep.

Should I reduce dish volume to some 22cc to reach 9.5:1 CR?

No. Leave it as it is in case you get stuck in an area with crappy gas so you won't run into pinging problems. If you run the engine all the time with LPG, you could consider this recipe instead:

4.6L Propane Conversion Special

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom forged +0.030" bore pistons, compression height 1.380", dish volume 11cc
10.9:1 CR
CompCams 68-231-4 206/214 degree camshaft
Russ Pottenger ported HO 2.00"/1.55" cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
266hp @ 4900rpm, 322lbft @ 3500rpm

Finaly I found way to open Bulltears's site (it doesn't open from my country) and see that the pricing for pistons is 475USD for set of 6.

That's a great deal.

[darkcorp]

If you run the engine all the time with LPG, you could consider this recipe instead:
4.6L Propane Conversion Special

Yes, engine runs LPG every day. It starts with petrol and after warm up (1-3 km) switches to LPG. But sometimes I travel to places where no LPG can be found so I run petrol.
If I rise the CR to 9.5:1 will I be satisfied?

[Cheromaniac]

If I rise the CR to 9.5:1 will I be satisfied?

It'll make too little difference to notice.

[darkcorp]

Thanks!

Will stock 4.0 camshaft and stock lifters work at CR 9.2-9.5?
Are ZJ and WJ blocks compatible?

[beiwulf]

Blocks compatible... several parts and fitment are interchangeable.

Cam retainer plate on WJ with screws upfront.
Cam retainer spring on ZJ (no screws upfront and no plate)

One of the major physical differences. Another is the WJ blocks came with coil packs vs. ZJ distributor (dizzy).
Fuel rails run a different pressure also 39-43 ZJ - vs. - 48-49 psi WJ.

pistons, rods, crankshaft, bearings, rings... yes - brackets for accessories will change based on some items. the WJ blocks moved the ac compressor bracket/mount point to below the intake manifold on drivers side. The ZJ's ac compressor sits high on passenger side of block and alternator under that. The holes on the block for these items are mostly the same (except for the driver side ac compressor). I would have to double check it on some blocks I have. I do believe the ZJ blocks have the mount studs cast into block but are not drilled/tapped out (don't quote me on that).

Brian

[SilverXJ]

ZJ Blocks are not compatible with WJ blocks. Engine mount bosses are in different locations, water pump mount is different, AC & alt mount are different. Dizzy/coil rail/fuel pressure are minor compared with the other issues & not really block related. Too much difference to attempt to make a ZJ block work in a WJ. Find a WJ or 00+ TJ block.. it will make life a lot easier.

[darkcorp]

SilverXJ, thank you!

[bellator50]

If you have assisted me before.. I need some more help.. So I have spoken to soon and 500 miles into it the engine began to knock. Long story short I took apart and found the 2 back pistons were marked up as seen in pic. Any ideas as how to resolve this from occurring again. I don't know if this has any thing to do with it, but I had just changed oil recently and when I took it off to take engine apart, I noted there was NO oil whatsoever on the flange with holes on it. there was oil inside it, but to me me appeared oil was not circulating. Could bad filter do this. It has standard pump and before removing it I fired up with valve cover off and oil was shooting out.

Any Ideas???


https://goo.gl/photos/TvFo8XKs44fgPYqv9

[SilverXJ]

What was the piston to wall clearance?

[bellator50]

What was the piston to wall clearance?

I was told it was .0050 by machine shop