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Blew my 4.0
Posted: March 16th, 2008, 1:14 pm
by Matt99
So I have a 1999 Cherokee and it just recently blew. Im in a hurry to get it back up and running cause it is my dd but I also take it threw trails all the time. Soon I hope to make it just a trail rig but for know it is a dd as well. Ive been looking in to turning it in to a 4.5 stroker.
4.5L "Poor man's" simple stroker
Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Sealed Power 677CP standard bore pistons
9.2:1 CR
Stock 4.0 camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.088" quench height
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines, stock injectors with stock 49psi FPR for '96 and later engines
247hp @ 4900rpm, 300lbft @ 3500rpm
http://www.jeep4.0performance.4mg.com/stroker.html
Im on 32's with a 5 inch lift everything else is stock. So i was wondering if any of you had done this? If so how did it go and do you have any pointers. Also do you think my stock 5 speed and stock axles will hold up to it? Im up for any thoughts on this I will be starting on it this week so let me know asap.
Thanks
Re: Blew my 4.0
Posted: March 17th, 2008, 11:53 am
by oletshot
I'm in the middle of assembling my 4.5 poorman stroker myself, so can't really give you any tips or info on that, at least not yet. I've heard that the 8.25 axle (29 spline) is almost as strong as the dana 44, so I woudn't think you'd have a to big of a problem with it, especially with 32's. It got a bad rep in the 27 spline version that has lived with ever since. I had 31's on my 90 xj with the POS dana35 and it never failed me (just a matter of time though, I suppose). Sorry, I couldn't give any more answers.
Re: Blew my 4.0
Posted: March 17th, 2008, 1:15 pm
by Cheromaniac
Matt99 wrote:So i was wondering if any of you had done this? If so how did it go and do you have any pointers. Also do you think my stock 5 speed and stock axles will hold up to it? Im up for any thoughts on this I will be starting on it this week so let me know asap.
Thanks
I was the author of that recipe and mine is essentially a 4.5L poor man's simple stroker with a +0.020" overbore, pushing it closer to 4.6L. The engine runs great and has plenty of power (dyno numbers in my sig.). I run 24lb Ford Racing injectors and a homebrew MAP adjuster set at 5.1v.
The stock AX15 5-speed is bombproof and will handle the power. I'm not so sure about your 8.25 rear axle though. With 32's I think it should be OK; it'll depend on how you treat it.
Re: Blew my 4.0
Posted: March 18th, 2008, 7:31 pm
by Matt99
I decided to go with the 4.6. I was curious if anyone had any ideas on a clutch for it. Also what kind of gas do you run?
Re: Blew my 4.0
Posted: March 18th, 2008, 7:32 pm
by Matt99
Cheromaniac wrote:Matt99 wrote:So i was wondering if any of you had done this? If so how did it go and do you have any pointers. Also do you think my stock 5 speed and stock axles will hold up to it? Im up for any thoughts on this I will be starting on it this week so let me know asap.
Thanks
I was the author of that recipe and mine is essentially a 4.5L poor man's simple stroker with a +0.020" overbore, pushing it closer to 4.6L. The engine runs great and has plenty of power (dyno numbers in my sig.). I run 24lb Ford Racing injectors and a homebrew MAP adjuster set at 5.1v.
The stock AX15 5-speed is bombproof and will handle the power. I'm not so sure about your 8.25 rear axle though. With 32's I think it should be OK; it'll depend on how you treat it.
Are you lifted with tires? If so what size?
Re: Blew my 4.0
Posted: March 18th, 2008, 7:53 pm
by seanyb505
Matt99 wrote:I decided to go with the 4.6. I was curious if anyone had any ideas on a clutch for it. Also what kind of gas do you run?
Im in the process of getting everything together for mine. Stock clutch will work fine. I havent seen many people who actaully need to upgrade the drivetrain for a 4.6. What grade gas depends on a couple factors, compression ratio and quench. The higher the Compression ratio the higher grade you will have to run. If you keep stock quench or worse you will more than likely have to run mid to high grade. Im shooting for 9.13 CR and .047 quench in my motor and hoping to run low grade. Theres actually more to it than throwing a new crank and rods in. Im sure you know this, but its best to know what factors affect what result. You can mess around with the stroker calculator at the top of the page, that helped explain a lot to me.
Dino (Cheromaniac) is not lifted and I believe is running 225/70/15 bridgestones.
Re: Blew my 4.0
Posted: March 19th, 2008, 5:17 am
by Matt99
seanyb505 wrote:Matt99 wrote:I decided to go with the 4.6. I was curious if anyone had any ideas on a clutch for it. Also what kind of gas do you run?
Im in the process of getting everything together for mine. Stock clutch will work fine. I havent seen many people who actaully need to upgrade the drivetrain for a 4.6. What grade gas depends on a couple factors, compression ratio and quench. The higher the Compression ratio the higher grade you will have to run. If you keep stock quench or worse you will more than likely have to run mid to high grade. Im shooting for 9.13 CR and .047 quench in my motor and hoping to run low grade. Theres actually more to it than throwing a new crank and rods in. Im sure you know this, but its best to know what factors affect what result. You can mess around with the stroker calculator at the top of the page, that helped explain a lot to me.
Dino (Cheromaniac) is not lifted and I believe is running 225/70/15 bridgestones.
What is the casting number on your rods your putting in?
Re: Blew my 4.0
Posted: March 19th, 2008, 6:24 am
by jeepinwi
For the clutch Luk used to be, and still may be the manufacturer of OEM clutches for Jeep. They make a Pro Gold line of clutches that is supposed to have 25% more clamping power. Go with the Luk Pro Gold clutch.
Re: Blew my 4.0
Posted: March 19th, 2008, 9:03 am
by seanyb505
Matt99 wrote:
What is the casting number on your rods your putting in?
lol both...I dont have them in front of me but some are 707 and others are 352 I think.
Re: Blew my 4.0
Posted: March 19th, 2008, 9:30 am
by gradon
I have a centerforce df2 clutch that'll go into the stroker. I used it for about a year on my 94. After a fresh machine job on the flywheel, that clutch, and cleaning then greasing the throwout bearing shaft and fork, that was the best I've ever had a Jeep shift. My left calf is still bigger than my right from 10+ years of pushing them xj clutch pedals.
Re: Blew my 4.0
Posted: March 19th, 2008, 11:57 am
by Cheromaniac
Matt99 wrote:Are you lifted with tires? If so what size?
As seanyb505 correctly mentioned, I have stock height suspension and 225/70R15H Bridgestone Turanzas. My clutch is a Luk stock replacement and the rest of the drivetrain is also stock (including the 3.07 diff. gears).
I run 91 octane with no ping. I once topped up the tank this winter (55-65*F weather) with 87 octane when it was half full with 91 octane so I effectively had 89, and the engine still didn't ping.
Re: Blew my 4.0
Posted: March 30th, 2008, 5:28 pm
by Matt99
Where can i find a luk clutch?
Re: Blew my 4.0
Posted: March 30th, 2008, 7:11 pm
by gradon
I highly recommend the Centerforce DF 2 clutch.
Re: Blew my 4.0
Posted: March 30th, 2008, 9:16 pm
by Matt99
If i were to decide to do that where would you go to get that clutch?
Re: Blew my 4.0
Posted: March 31st, 2008, 8:08 am
by seanyb505
Centerforce:
http://store.summitracing.com/partdetai ... 294865886+
Luk: (You have to enter your vehicle information, but it will show you the Pro Gold series around the middle)
http://www.dialaclutch.com/DAC-DEMO/dosearch.asp