Which cam to go with? Crane?
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Model: Cherokee
That thread you quoted, he made a few assumptions and used the wrong numbers for his calculations.
Seat to seat duration is not useful, not a true look at a cam. That is why everyone looks at the 0.050" duration. The new cams have more aggressive ramps and more 'area under the curve' with respect to time and duration of valve lift.
The 'stock' cam he used 270* which looks aggressive but only has 191* duration at 0.050". And a DCR of 6.97
The 231 cam has 250*/256* seat to seat which 'looks' smaller but has 206*/214* duration at 0.050". Clearly a more aggressive cam. And a DCR of 8.06. It will have more area under the curve that the stock renix cam. He did not take that into account when he ran his numbers.
He also used a 4.6L stroker and 9.44:1 CR.
Seat to seat duration is not useful, not a true look at a cam. That is why everyone looks at the 0.050" duration. The new cams have more aggressive ramps and more 'area under the curve' with respect to time and duration of valve lift.
The 'stock' cam he used 270* which looks aggressive but only has 191* duration at 0.050". And a DCR of 6.97
The 231 cam has 250*/256* seat to seat which 'looks' smaller but has 206*/214* duration at 0.050". Clearly a more aggressive cam. And a DCR of 8.06. It will have more area under the curve that the stock renix cam. He did not take that into account when he ran his numbers.
He also used a 4.6L stroker and 9.44:1 CR.
You seem like you know a lot, change and make them correct. Are they based on math or dyno?
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Joined: Dec 2011
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From: PA KOTUFU!
Year: 1998
Engine: 4.0L 162,000
He said that they were from his 'desktop dyno', a computer simulation program. I have it and have used it for many years but it is only as good as the data you give it. It can use details like head flow mumbers and intake manifold flow numbers and if these are not known, then it makes some assumptions.
So if you want a good recommendation, I go back to, from mild-just a bit more than stock to mid-mild, which will idle, run well with the ecu, good mileage and trail manners and nice street pull and give good performance, just for what the Jeep 4.0 is, a low tech, non-crossflow head engine, low reving 200,000+ mile reliable engine.
1-Mopar 28 with stock springs
2-Mopar 29 with mopar performance springs, keepers and locks(stock will coil bind)
3-Comp 231 with mopar perf springs
4-Comp 232 for a stroker 4.6L with mopar perf springs.
For you, follow the above cam selection, dump the Hypertech, get a good header and get your ecu tuned by a guy named chris at christunned.com for about $250. He is the best and 1 of only about 2 in the country that can actually tune the jeep's ecu. Easier yet is just add the 1.7 roller rockers, headers and ecu tune along with all the other goodies you already have.
So if you want a good recommendation, I go back to, from mild-just a bit more than stock to mid-mild, which will idle, run well with the ecu, good mileage and trail manners and nice street pull and give good performance, just for what the Jeep 4.0 is, a low tech, non-crossflow head engine, low reving 200,000+ mile reliable engine.
1-Mopar 28 with stock springs
2-Mopar 29 with mopar performance springs, keepers and locks(stock will coil bind)
3-Comp 231 with mopar perf springs
4-Comp 232 for a stroker 4.6L with mopar perf springs.
For you, follow the above cam selection, dump the Hypertech, get a good header and get your ecu tuned by a guy named chris at christunned.com for about $250. He is the best and 1 of only about 2 in the country that can actually tune the jeep's ecu. Easier yet is just add the 1.7 roller rockers, headers and ecu tune along with all the other goodies you already have.
Thread Starter
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Model: Cherokee
He said that they were from his 'desktop dyno', a computer simulation program. I have it and have used it for many years but it is only as good as the data you give it. It can use details like head flow mumbers and intake manifold flow numbers and if these are not known, then it makes some assumptions.
So if you want a good recommendation, I go back to, from mild-just a bit more than stock to mid-mild, which will idle, run well with the ecu, good mileage and trail manners and nice street pull and give good performance, just for what the Jeep 4.0 is, a low tech, non-crossflow head engine, low reving 200,000+ mile reliable engine.
1-Mopar 28 with stock springs
2-Mopar 29 with mopar performance springs, keepers and locks(stock will coil bind)
3-Comp 231 with mopar perf springs
4-Comp 232 for a stroker 4.6L with mopar perf springs.
For you, follow the above cam selection, dump the Hypertech, get a good header and get your ecu tuned by a guy named chris at christunned.com for about $250. He is the best and 1 of only about 2 in the country that can actually tune the jeep's ecu. Easier yet is just add the 1.7 roller rockers, headers and ecu tune along with all the other goodies you already have.
So if you want a good recommendation, I go back to, from mild-just a bit more than stock to mid-mild, which will idle, run well with the ecu, good mileage and trail manners and nice street pull and give good performance, just for what the Jeep 4.0 is, a low tech, non-crossflow head engine, low reving 200,000+ mile reliable engine.
1-Mopar 28 with stock springs
2-Mopar 29 with mopar performance springs, keepers and locks(stock will coil bind)
3-Comp 231 with mopar perf springs
4-Comp 232 for a stroker 4.6L with mopar perf springs.
For you, follow the above cam selection, dump the Hypertech, get a good header and get your ecu tuned by a guy named chris at christunned.com for about $250. He is the best and 1 of only about 2 in the country that can actually tune the jeep's ecu. Easier yet is just add the 1.7 roller rockers, headers and ecu tune along with all the other goodies you already have.
Location to buy?
231 can use stock springs? Did I read some said yes, while others said no?
His chart says 39T and 11H gain. What do you say?
Last edited by CrawlerXJ; Dec 15, 2012 at 01:09 PM.
CF Veteran
Joined: Dec 2011
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From: PA KOTUFU!
Year: 1998
Engine: 4.0L 162,000
Stock springs are good to .440-.450" with a little extra clearence to prevent coil bind. Mopar performance springs are good to .500" lift.
39TQ and 11HP ? that could be a little optimistic but close. It is the head and manifold flow that limits the HP gain. Even with 7 pounds boost I only gained 60HP but 100 TQ. These engines do not post big HP numbers. You will definately feel the 25-30 to ?39 TQ gain.
39TQ and 11HP ? that could be a little optimistic but close. It is the head and manifold flow that limits the HP gain. Even with 7 pounds boost I only gained 60HP but 100 TQ. These engines do not post big HP numbers. You will definately feel the 25-30 to ?39 TQ gain.
CF Veteran
Joined: Dec 2011
Posts: 1,777
Likes: 22
From: PA KOTUFU!
Year: 1998
Engine: 4.0L 162,000
Here's a few threads with good spring info.
http://www.jeepstrokers.com/forum/vi...rmance+springs
http://www.jeepstrokers.com/forum/vi...=mopar+springs
http://www.jeepstrokers.com/forum/vi...rmance+springs
http://www.jeepstrokers.com/forum/vi...rmance+springs
http://www.jeepstrokers.com/forum/vi...rmance+springs
http://www.jeepstrokers.com/forum/vi...rmance+springs
http://www.jeepstrokers.com/forum/vi...=mopar+springs
http://www.jeepstrokers.com/forum/vi...rmance+springs
http://www.jeepstrokers.com/forum/vi...rmance+springs
http://www.jeepstrokers.com/forum/vi...rmance+springs
Thread Starter
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Model: Cherokee
Update: Pulled the trigger on the "231" cam. I also got the timming set, and lifters. Couldn't beat the price! Comp Cams offers Military/LEO discount.
Ill keep thread updated as it goes along.
Ill keep thread updated as it goes along.
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Model: Cherokee
Weird, it says not for fuel injection, but Rep said it was fine. He knew my year/make/model.
http://www.compcams.com/Company/CC/c...x?csid=10&sb=2
Update:
Looks like it is fine.
http://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm
http://www.jeepstrokers.com/forum/vi...fuel+injection
http://www.compcams.com/Company/CC/c...x?csid=10&sb=0
http://www.compcams.com/Company/CC/c...x?csid=10&sb=2
Update:
Looks like it is fine.
http://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm
http://www.jeepstrokers.com/forum/vi...fuel+injection
http://www.compcams.com/Company/CC/c...x?csid=10&sb=0
Last edited by CrawlerXJ; Dec 18, 2012 at 01:31 PM.
CF Veteran
Joined: Dec 2011
Posts: 1,777
Likes: 22
From: PA KOTUFU!
Year: 1998
Engine: 4.0L 162,000
Finally, good choice for your combination. After your engine is done, try it, but I would still dump the hypertech and go with a tuned ecu. You could probably sell the hypertech on ebay for $100 towards the ecu tune which will tie your whole combination together.
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Model: Cherokee
Agree. Ill try it. I have used Hypertech since I can remember. I usually buy them for $100 and sell them once car is sold for $100. So, no loss.
Now, just have to wait for machine shop to get back with me. Seems to be very slow. Oh well, its the holidays. No rush I guess.