build a high HP 4.0?

[chrisja77]

Hey fellas, got a question or 2 for ya. My 95 XJ has over 188,000 on the clock now, and I was wanting to start preparing for when the 4.0 finally kicks the bucket. I have found a 93 4.0 with high mileage for cheap, so I'm gonna wrench on this engine while I'm still driving the XJ. I was looking heavily into stroking the new engine, but the numbers are getting me worried. I want this project to be worth it when complete, so my question is how much could I get out of the 4.0 without stroking it? I'm talking about whatever it takes....boring it out, big ass cam, boring out TB, headers, whatever I can do to it. I figure if I'm gonna be out the money to stroke one, I can't be out nearly as much to build a performance 4.0. Or should I just bite the bullet, build the 4.6 and hope for the best?

 

[JNickel101]

Dont forget port matching/polishing, 99+ intake manifold, better injectors (Ford Mustang), some type of chip/programmer, hi-flow cat and exhaust, hi-flow intake/snorkel, roller rockers, headers...

I'd imagine you could get up pretty high, maybe 230-240HP with every mod possible? Thats just a WAG though...

 

[Larrythedog]

FYI

http://www.mallcrawlin.com/forum/showthread.php?t=6355

 

[bigdaddyjlove]

Don't be scared of the stroker. It's as easy as building a standard motor.

That being said, all the usual trick apply
Bored
High compression pistons
Camshaft
better intake (2000 and up)
Better exhaust
bigger injectors to keep up with the above
performance computer chip
turbo
supercharger
nitrous
Mr Fusion

An indy car in the late 60's ran a AMC inline six de-stroked to 3.0 liters. He made +- 750hp. so the skys the limit

 

[5-90]

Don't be scared of the stroker. It's as easy as building a standard motor.

An indy car in the late 60's ran a AMC inline six de-stroked to 3.0 liters. He made +- 750hp. so the skys the limit

You're thinking of Barney Navarro - I believe he ran a destroked 199 or 232 with some heavy boost. Otherwise, production parts.

If you can find an even earlier block (RENIX is best,) you'll have a heavier casting - but there's no reason whatever that a stroker won't last anywhere near as long as a production engine - and probably longer than most other engines. AMC just used heavier castings, so you've got more room for a "fudge factor." (There are RENIX blocks out there that have been bored out to 4.000" - or +.125"! They still need to be ultrasonically checked for core shift, but the typical maximum for boring other engines is +.060", or about half of that. N.B. You'd have a hard time doing this with 1991-up blocks, since lightening the cylinder walls was one of the first things ChryCo did. 1991-up blocks will only got +.060")

Also, the already relatively low compression of the 242ci six is rather "boost friendly" - you might need to get custom slugs made if you stroke the engine, but if you're working with an OEM crank and a mild overbore, you shouldn't need much. If you want to build a blown stroker, you're going to want to get an older 258ci crankshaft (earlier AMC stuff was built tougher than the later stuff.)