luke87 Posted March 25, 2008 Share Posted March 25, 2008 is there any such thing? can it be done and are the cyclinder walls to thin? if anybody has every heard of of one these kits please let me know. Link to comment Share on other sites More sharing options...
jeepthing07 Posted March 25, 2008 Share Posted March 25, 2008 Stroke comes from the crank not the bore. there is no engine family for the 2.5 its all alone so there are no cranks that will stroke it. i guess you could have it offset ground but it wouldn't get you much. just put a turbo on it they have been doing that for years on the 2.5. you can use a turbo off a dodge daytona there are write ups for it. this is a pretty good site for 2.5 performance http://www.4bangerjp.com/forums/ Link to comment Share on other sites More sharing options...
Pete M Posted March 25, 2008 Share Posted March 25, 2008 Chances are good that if you have the AX-5 behind your 2.5, it won't last long behind any additional power. :( The best thing to do is to regear the axles for more perceived grunt and to make better use of the power you've got. :D Link to comment Share on other sites More sharing options...
Tracker Posted March 25, 2008 Share Posted March 25, 2008 A long time ago, in a galaxy far, far, away...... No, actually it was in Long Beach, California in the '70's, there were a couple shops that made welded-up stroker cranks for several different kinds of racing motors. In this process they actually welded multiple layers of passes on the rod journals of the crank, then ground new journal surfaces at a different stroke length. Then, different length rods and / or pistons were used to get the deck height back. It worked on small block Chevys and Fords- quite well I might add. :brows: This would be incredibly expensive to have a shop do as a one shot deal- Especially when it came to the rest of the parts needed to make it all work. But- If the 2.5 is or was ever used in any kind of racing, the stuff may be out there for a reasonable price. The first step would be to find a class of racing that used the 2.5. Then poke around and see if strokers were ever used and / or practical on that motor. Link to comment Share on other sites More sharing options...
LEAD_NOT_FOLLOW Posted March 25, 2008 Share Posted March 25, 2008 Don't quote me on this, but the rod journals on the 2.5's are a little larger than Chevy rods. A good machine shop that specializes on crank grinding can probably "off-set" grind your crank about .110 to use Chevy rods. If this is the case, you should be able to stroke a 2.5, use Chevy rods and pistons for a cheap price. I would go to your local machine shop and see if anybody there can crunch some numbers to make it work. You will also have to figure the proper piston pin height for proper deck and crankshaft counterweight clearance. Balancing shouldn't be too much of a problem as Chevy rods and pistons come in a variety of weights, and 4 bangers balance easy. And an increase in .110 is stroke will be very noticeable. To the best of my knowledge I have never heard of a 2.5L stroker crank. Link to comment Share on other sites More sharing options...
luke87 Posted March 25, 2008 Author Share Posted March 25, 2008 is the ax-5 the 4 speed manual tranny? Link to comment Share on other sites More sharing options...
brigarpeon Posted March 25, 2008 Share Posted March 25, 2008 Nope. That would be an AX4. The AX5 is a 5 speed Link to comment Share on other sites More sharing options...
Pete M Posted March 25, 2008 Share Posted March 25, 2008 They are identical transmissions except for the 5th gear in the AX-5. SCCA back in the day used the 2.5L, but they were stock cranks as far as I know. Link to comment Share on other sites More sharing options...
pingpong Posted March 25, 2008 Share Posted March 25, 2008 Do a search on the net... I know there is a class of racing for 4 cyl at the local dirt track, so I am sure there are plenty of ways to get some serious power out of them. Keep in mind the 2.5 has been sold for yrs... and came in just about every configuration possible.... I even had one in a Fiero... that car was way fast even though all it had was a 4 popper Link to comment Share on other sites More sharing options...
luke87 Posted March 26, 2008 Author Share Posted March 26, 2008 what transmission would work for that then? the ax-5 could hold up to the added power? Link to comment Share on other sites More sharing options...
luke87 Posted March 26, 2008 Author Share Posted March 26, 2008 ..would any stroker kit for a 2.5 work with my jeep 2.5? Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 26, 2008 Share Posted March 26, 2008 ..would any stroker kit for a 2.5 work with my jeep 2.5? Check out the Yahoo Groups Stroker forum. There's been an ongoing discussion the last couple of weeks regarding stroking the 2.5; apparently many on the forum have done it, but I have no idea why :nuts: . Might give you some ideas. Link to comment Share on other sites More sharing options...
Eagle Posted March 26, 2008 Share Posted March 26, 2008 Stroking the 2.5L is one of those things best undertaken only by those with a lot of time and money. There is no easy way to do it. The 4.0L stroker is easy because the block is the same basic layout as several other, older engines in the AMC line, so the 4.2L (258 cubic inch) crankshaft is a drop-in fit and provides an instant and inexpensive source for the heart of a longer stroke engine. The 2.5L engine is built on the same basic engine design, but it is the only displacement Jeep ever built as a 4-cylinder. That means there's no other engine that can be used as a source for a cheap stroker crankshaft. Messing around with offset-ground journals is expensive, and each attempt becomes a one-off prototype. IMHO, the best way to get more power out of the 2.5L is a camshaft. The factory cam has the same specs as the 4.0L engines of the same years, which makes them very mild for a smaller displacement, higher-revving engine. A slightly more aggressive cam will really wake up the 2.5L and it's a lot cheaper than trying to stroke it. Link to comment Share on other sites More sharing options...
aemsee Posted March 26, 2008 Share Posted March 26, 2008 Do a search on the net... I know there is a class of racing for 4 cyl at the local dirt track, so I am sure there are plenty of ways to get some serious power out of them. Keep in mind the 2.5 has been sold for yrs... and came in just about every configuration possible.... I even had one in a Fiero... that car was way fast even though all it had was a 4 popper You don't think that the 2.5 in your Fiero is the same a s the AMC 2.5? They are totally different engines. Link to comment Share on other sites More sharing options...
luke87 Posted March 26, 2008 Author Share Posted March 26, 2008 whats a good company to get a camshaft from? I'm new to rebuilding the internals , how agressive would it be? is there a certain degrees it has to go to? and is the camshaft the only thing you have to change when installinga new camshaft? Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 26, 2008 Share Posted March 26, 2008 Again, search and read as suggested above by others. You have not posted one thing that did not end in a question mark. Help yourself first, then ask intelligent informed questions. :cheers: Link to comment Share on other sites More sharing options...
pingpong Posted March 26, 2008 Share Posted March 26, 2008 I know they are different, but they are based on the same thing, and a good machine shop can make it work.. if you wanted to spend the money Link to comment Share on other sites More sharing options...
Eagle Posted March 26, 2008 Share Posted March 26, 2008 whats a good company to get a camshaft from? I'm new to rebuilding the internals , how agressive would it be? is there a certain degrees it has to go to? and is the camshaft the only thing you have to change when installinga new camshaft? The Mpoar Performance Catalog offers two or three different cam kits for the 2.5L Jeep engine. I think they are still available. I'd look for a Stage 2, but a Stage 3 would probably still be streetable. Link to comment Share on other sites More sharing options...
aemsee Posted March 26, 2008 Share Posted March 26, 2008 I know they are different, but they are based on the same thing, and a good machine shop can make it work.. if you wanted to spend the money There is nothing similar between the GM 2.5 Iron Duke and the 2.5 AMC engine, other than approximate displacement. Link to comment Share on other sites More sharing options...
Eagle Posted March 26, 2008 Share Posted March 26, 2008 I know they are different, but they are based on the same thing, and a good machine shop can make it work.. if you wanted to spend the money aemsee is correct. You are perhaps confused because AMC did buy GM "iron duke" engines for a few years. But those were used in Eagles and Concords, they were never used in the Cherokee/Comanche. The Jeep 2.5L engine is based on the Jeep 6-cylinder engine, it is not based on or developed from the GM engine in any way. Good luck trying to use Iron Duke parts in a Jeep engine. I hope you have deep pockets ... Link to comment Share on other sites More sharing options...
beaterjeep Posted March 26, 2008 Share Posted March 26, 2008 There's an old saying that would fit perfectly in this thread. I'd rather be blown than stroked. :D I say just go with a turbo setup (I'll be doing this in the future) or go the supercharger route; both are good for HP gains and minimal to no internal work needed. Just my 2¢. Link to comment Share on other sites More sharing options...
mvusse Posted March 26, 2008 Share Posted March 26, 2008 I don't know about internal work. How much boost? Can the stock rods and pistons handle the extra HP? Is the compression low enough to not get detonation under boost? I think the 2.5l and 4.0l both are 9.2:1 compression. That is quite high for a turbo or supercharger setup. Link to comment Share on other sites More sharing options...
beaterjeep Posted March 27, 2008 Share Posted March 27, 2008 I don't know about internal work. How much boost? Can the stock rods and pistons handle the extra HP? Is the compression low enough to not get detonation under boost? I think the 2.5l and 4.0l both are 9.2:1 compression. That is quite high for a turbo or supercharger setup. Sorry to the O.P. for the temporary hi-jack first of all. I was planning on running a T3 turbo with 26lb injectors and only running around 5lbs of boost. I've been doing a lot of research on it lately, and from what I've been reading (not to say that it's all accurate) the lil 2.5L Jeep motors can handle up to 175ish HP with stock internals. Link to comment Share on other sites More sharing options...
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