First build

[jason_alex_2009]

Hey guys,
Been reading on this site for a while and just now getting ready to take on the task. If you guys don't mind reading over what I have and let me know if you see any problems
This is the first time I have attempted to rebuild a engine and I think I want to build a stroker. I have a 2001 Jeep GC with a 4.0.

My main goal is to stay burning 87 fuel and keep it reliable. (top end is where I am lost)

Here is what I am thinking,

Im not going to deck to 0 just get get square.
258 Crank out of a 1990 Wrangler 4 counter weight
4.0 Rods
Forged Pistons KB944 .030" over
Ford 24 Lbs/hr injector
I was wondering if I should go back with the factory cam? or a comp? any input for the power? and valves and springs?
and I am thinking about using my 0331 head is this wrong or is there a better head to use?

What programing needs changed on the ECU?

What type of hp would I be looking at getting?

Thanks,
Jason

[jason_alex_2009]

No input?

Anything would help.

[Retlaw01XJ]

I'm new at Jeeps, but here's what I've learned in my 60 day crash course.
0331 heads are crack prone. Look for a 2002-2006 version with 'TUPY' cast in it.
Ford 24 lb injectors are rated at a lower pressure, so when installed in a 49 psi Jeep, they will flow a lot more than 24 lbs! There are some choices in the 22 lb range (43.5 psi) that will give approx 24 lb flow at the Jeeps 49psi pressure.
I'm still researching valve springs. The extra lift (over .450" or so) makes the choice more difficult and expensive. Couple of guys mentioned using LS1 valves and springs which can be found for a good price.
A mild cam generally improves performance over 4000 rpm.
The ECU should be able to compensate for a mild build UNTIL you really get on it. Then it'll go lean and this is where the bigger injectors should fix the issue.
What is your budget?

[jason_alex_2009]

I havent really put a budget together yet I am wondering about running the factory cam and what that will do or what my choices are?

Thanks,

[herbiehind]

http://www.jeep4.0performance.4mg.com/index.html

[Retlaw01XJ]

You can use the factory cam if it's in good condition.
A mild performance cam from Crower or CompCams might gain you 10-15 hp at 4500-5000 rpm. Below 3500 rpm, there is very little hp gain over stock. If you are planning other mods like low-restriction air filter and exhaust system, might as well go with the cam too.
Disclaimer..... I'm using Dyn0 2003 software to do simulations, not a real engine on a dyno!

[jason_alex_2009]

Thats what im thinking.... Modified poor man stroker I think is what I will go with.

[Cheromaniac]

Thats what im thinking.... Modified poor man stroker I think is what I will go with.

Good choice. Here are the specs for your particular stroker build:

4.6L modified "poor man's" stroker

Jeep 4.2L 3.895" stroke crank
Stock 4.0L 6.125" rods
Keith Black UEM-IC944-020 pistons
9.25:1 CR
Stock 4.0 camshaft
Stock unported #0331 cylinder head
Mopar/Victor 0.043" head gasket
0.070" quench height
Accel 24lb/hr injectors with stock 49psi FPR for '96 and later engines
222hp @ 4400rpm, 307lbft @ 3000rpm

What programing needs changed on the ECU?

With a simple build like the above, none whatsoever.

[jason_alex_2009]

I was thinking of going with pistons 30-40 over just to up the size a little more is this a bad idea?

Would you guys look at porting the head yourself or leave it unported and why?

[crusher242]

I say do the head. There's a linkfrom Dino about doing a DIY P and P. There's power to be had from a little work to the head. There no reason to choke out your performance gains.

[jason_alex_2009]

Ill check the site out some more.... might as well make it my home page for my computer...

Will i have a problem running 87 with this compo.... i will probly have the block squared and the head machined as little as possible but i want to get it flat...

[Cheromaniac]

I was thinking of going with pistons 30-40 over just to up the size a little more is this a bad idea?

There's no harm in overboring the cylinders a little more but the advantage is negligible so why bother?

Would you guys look at porting the head yourself or leave it unported and why?

Port the mutha. Do it right and you could gain as much as 20hp. Read as many articles as you can find about DIY head porting so you can avoid the pitfalls.

[jason_alex_2009]

Also I am buying a 2002 block to build the stroker out of... it has a knock in the engine what all should I have the machine shop do to it?

Magniflux the block?
Bore and hone
Line bore and hone ?
square the deck ?
Balance the rotating assembly?

surface the head
have them do the valve work

Just want to make sure they dont take me to the cleaners.

[Cheromaniac]

Also I am buying a 2002 block to build the stroker out of... it has a knock in the engine what all should I have the machine shop do to it?

Magnaflux the block? Definitely
Bore and hone Definitely
Line bore and hone ? Probably unneccesary but definitely have the alignment of the main bearings checked.
square the deck ? Have the deck checked with a straight edge and mill if necessary
Balance the rotating assembly? Probably overkill but at least have the connecting rods weight-balanced

surface the head Same advice as for the block deck, and also have the head magnafluxed
have them do the valve work Yes

Just want to make sure they dont take me to the cleaners.

[SilverXJ]

They won't balance the rotating assembly using bob weights as they would a v8. They should weight match the pistons and rods (big and small end) and spin balance the crank alone. Balancing the harmonic balancer and flex plate are good options as well.