Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: mtngoat on July 27, 2010, 10:54:49 PM
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I have recently purchased a 87 yj. It is currently running a 4.2l engine and I am looking to get alot more power. I have done some reading about the different mods that
a guy could do. I have found another jeep that is running a 4.0l ho engine that I could use do either a stroker build or just take the head and fuel injection system and install it on the 4.2. Depending on what block I use both would get a full rebuild. I would like to achieve about 10:1 compresion for the build and would like to go .060 over. Both heads would get a full rebuild as well along with new cams. So hears my dilemma, I have a extra 4.2 engine on the stand right now that is ready for the rebuild. All I would have to pull of the other jeep would be the head and FI system. Or do I pull the other engine and go to the lengths of building the stroker. I will be using the jeep mostly for the trails it will see very little town or highway driving. The other option would be to take the 4.0 head and keep the engine carburated, and add a new intake, header and carb. I would like to get around 225-250hp. Any that have gone down this path and could shed some light on these choices I would greatly appreciate your feed back.
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Man you have a YJ just swap in a V8 and be done with it. You can spend all your time and money on a 4.0 and still now come out with what some V8s will be producing without touching it.
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Was thinking the same thing...
"Is it worth all that work?"
Depends what you want.
think of the $ and time invested, Vs. HP gains and/or weight gains, power at what RPM's, tourque, etc...
What do you want out of it, what do you want to invest into it.
To me, a stock Chev 350 has more potential then a 4.0 stroker with less investment. However, being a stubborn old man, I decided to stick with AMC engines...bolted in a 360, I'm almost equivilent to a tired, stock chev 350 now...
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I hear you on the v8 conversion. I have built two full size trucks about 7 years ago 1 with a 350 and the other a 454 loved the 454 tones of torque. The 350 was great, the thing would still run great even if you thought it was half full of dirt and water. I do want to keep this project fairly simple, not going to extreme so that I would be fixing drive line issues due to the extra power.But I am just worried that I will spend the time and money and be disappointed. The jeep is running 35" tires right know, and the main problem is that if you want to take it anywhere as soon as I come to a hill on the highway I literally have to be in 3rd or fourth 4 to maintain 75-80kph. It would be nice to maintain 100-110. I would be doing a lot of the work myself when it comes to the assembly on the rebuild. My budjet would be around $2000.
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The jeep is running 35" tires right know, and the main problem is that if you want to take it anywhere as soon as I come to a hill on the highway I literally have to be in 3rd or fourth 4 to maintain 75-80kph. It would be nice to maintain 100-110. I would be doing a lot of the work myself when it comes to the assembly on the rebuild. My budjet would be around $2000.
if you want to keep it simple, gut the 4.2 of all its power robbing emission BS, regear the axles to 4.56 and call it good.
if you have a 4L/tranny combo, swap that in, and regear...........
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In this case you are probably better off doing a small block.
4 litres and strokers are only woth the effort if you already have all the wiring and instrumentation in place to use it. Unless you are really, really, skilled with wiing, and have a lot of patience.
A carbed platform is the best candidate there is for a sbc conversion.
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$2000 doesn't go very far when rebuilding an engine. Machine work is expesnive!
Also IMO .60 over on a 4.0 is lot and asking for cooling problems.
I agree with the V8 option.
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I agree with not overlooking the gearing.