89cherokeexj
NAXJA Forum User
- Location
- Victorville
I seen a head from a 90 4.2l motor for sale. Would it fit on my 4.0? What would it do for it? Would I need to put a 4.2L crank in it also??
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4.2l head on 4.0??
- Thread starter 89cherokeexj
- Start date
XJPhoenix
NAXJA Forum User
- Location
- Guelph, Ontario, Canada
IMHO it's not worth it. If anything, you'd lose power, economy & gain nothing. I'm thinking you're interested in a stroker, right? In which case, it's the crank-shaft & connecting rods you'd be after. Or are you thinking of a carb'ed 4.0?
What year of vehicle would be the intended recipient?
What year of vehicle would be the intended recipient?
89cherokeexj
NAXJA Forum User
- Location
- Victorville
I'm just looking to pull soem more power out of my motor. The intended jeep is 1 91 4.0l HO XJ. Stroker, I'd love to have, but thats a while down the road. I just figured I'd ask since the dude only wants 60 bucks for the complete head...thanks
itbrokeagain
NAXJA Forum User
- Location
- Amelia Ohio
Nope its the other way around. 4.0 head on a 4.2 is a pretty good power increase. Its not a bolt on swap. some work has to be done to make it work right.
4wdParakeet
NAXJA Forum User
- Location
- Olathe, Ks
If you don't want to stroke it, you can always upgrade the head the 98 style I think. I forget the casting number but if you go to jeepstrokers.com they have a good head FAQ that has the listings of casting numbers years and most desirable.
Also looking in to the 99+ intake, ported and polished head, bored TB, 24lb injectors, intake kit and 2.5" exhaust w/ high flow cat and flowmaster 44. You do all that and you are halfway to a stroker and only gained 25 to 50 horses. Realisticly probally closer to 25.
A 4.5L stroker will get you close to the 200 range and that's just adding the crank and rods out of a 4.2L. If you decide to have it bored to the 4.7L range (.060 overbore) you will be close to the 250-275HP and 325-350TQ.
Building a 4.6 or 4.7 you will need to get a hotter cam and lifters, maybe an adjustable Fuel pressure reg, and possibly a adjustable map sensor.
So cost to HP ratio of swapping the top end vs swapping in a stroker didn't make sense for me. I built a 4.6L and couldn't be happier with it. Making the step from tired 89 4.0L that had been rode hard to fresh stroker infront of a metallic button clutch it's no suprise that I'm happy.
Oh and on the primitive dyno program I used it consistently gives me 200 RWHP. I say that not to brag but to give you perspective.
Parakeet
Also looking in to the 99+ intake, ported and polished head, bored TB, 24lb injectors, intake kit and 2.5" exhaust w/ high flow cat and flowmaster 44. You do all that and you are halfway to a stroker and only gained 25 to 50 horses. Realisticly probally closer to 25.
A 4.5L stroker will get you close to the 200 range and that's just adding the crank and rods out of a 4.2L. If you decide to have it bored to the 4.7L range (.060 overbore) you will be close to the 250-275HP and 325-350TQ.
Building a 4.6 or 4.7 you will need to get a hotter cam and lifters, maybe an adjustable Fuel pressure reg, and possibly a adjustable map sensor.
So cost to HP ratio of swapping the top end vs swapping in a stroker didn't make sense for me. I built a 4.6L and couldn't be happier with it. Making the step from tired 89 4.0L that had been rode hard to fresh stroker infront of a metallic button clutch it's no suprise that I'm happy.
Oh and on the primitive dyno program I used it consistently gives me 200 RWHP. I say that not to brag but to give you perspective.
Parakeet
