any 2.5l out there w over bore and head shaved?
- Thread starter woodie92
- Start date
The head on mine was shaved a little just to clean it up after some other work was done to it. You have to be careful with these engines as they already have a little over 9:1 compression ratio in stock form, and you will get into trouble with pre-ignition on low octane pump fuel if you cut too much. If you decide to play with it some, take a couple of nights with a die grinder and do a mild port job on it while it's off. You don't have to go crazy and hog a pile of metal out of each port and I wouldn't do much reshaping in the bowls, just clean the castings up a little bit.
As far as camshafts go, Hesco makes a couple of off the shelf models if I'm not mistaken, and you can always have one ground to suit your engine. If you can find any NOS Mopar Performance cams, they have/had two or three off the shelf grinds, and they are fairly mild. You can make decent gains before changing the cam though, as the stock one pulls pretty good up to 5500 rpm. Plus, you have to remember this is a really small displacement engine when you consider the loads being put on it. Running too much cam is worse than running too small of one. Excessive duration and overlap for the application is going to kill bottom end power and response, and you'll basically have an engine that isn't good for much except WOT acceleration.
As far as camshafts go, Hesco makes a couple of off the shelf models if I'm not mistaken, and you can always have one ground to suit your engine. If you can find any NOS Mopar Performance cams, they have/had two or three off the shelf grinds, and they are fairly mild. You can make decent gains before changing the cam though, as the stock one pulls pretty good up to 5500 rpm. Plus, you have to remember this is a really small displacement engine when you consider the loads being put on it. Running too much cam is worse than running too small of one. Excessive duration and overlap for the application is going to kill bottom end power and response, and you'll basically have an engine that isn't good for much except WOT acceleration.
Bounty__Hunter
Super Moderator
36" TSL's and 5.38 gears and I'm pulling between 15 and 18mpg. I run a Mopar Perf. Cam but they're next to impossible to find anymore.
There's several members who built performance 2.5L's over at 4BangerJP.com - Index .
Don't forget the electric fan swap, FirePower ignition kit, 62mm throttle body (which I sell cheap), and other 2.5L mods that make for a decent power package.
There's several members who built performance 2.5L's over at 4BangerJP.com - Index .
Don't forget the electric fan swap, FirePower ignition kit, 62mm throttle body (which I sell cheap), and other 2.5L mods that make for a decent power package.
Hey Bounty, do you know any of the user names for the guys over at that 4 banger forum that have built serious engines? Any dyno info? I'd like to read the write-ups. I've checked it out a couple of times when you've posted it before, but there are just too many threads about mufflers and TB spacers to search through. What kind of special stuff are the heavy hitters over there doing?
woodie92
New member
lookin for an 88 to 94 cherokee to rip the motor and drivetrain out of so i can do a conversion. u changed my mind on the v-8. as for the cherokee later.... thats a different story.
jfrabat
New member
YJMechanic did some nice work on his over a year ago from what I have read there, and about a month ago he told me it is still running strong. MPG were on the low side if I remember correctly, though. Some other people have left the compression as it is and installed a turbo (Garrett T3) to increase pressure slightly and gain power. Or, you can always buy an Avenger Supercharger... There is a guy on that site selling one (with everything you will need to install it) for $2300... That is not a bad deal if you intend to go with the Supercharger way...
Felipe
I was really looking for info regarding internal engine mods. Are all of the guys over there just trying to put some snap in their trail Jeeps, or are there people over there actually trying to wring big power out of them? I've never seen a full-tilt AMC 2.5L, and I was hoping there might be one floating around over there.
Bounty__Hunter
Super Moderator
Interesting. He is running more compression than I would have thought you could get away with. Mine would experience pre-ignition with regular fuel, and he's running at least a half point higher than I was. I'd like to see his cam card.
jfrabat
New member
According to him, that engine is still runing strong more than one year later (I talked to him about it about a month ago). If it works, it is an interesting option... And a not so expensive one for the power he is getting out of it (power/investment relation).
Felipe
