Topic: Motor Differences

[DodgeMudder]

The 4 popper in my '95 YJ is suffering from serious blow by and needs rebuilt.  I plan to do a major rebuild on it that will push the power up conciderably, should be around 200hp when I'm done on '87 octane.

But anyway to the point of the post, I'm looking to find out if there is differences between different blocks and heads that make them better to build to get more power or not.  I have several different motors sittinng here and want to put one together to drive on while I'm building the motor out of my YJ.  I have '94 YJ motor with a good head and cracked block, an '86 Xj motor with good bottom end and bad head, I have a '89 YJ TBI motor missing the intake and exhaust, but the block and head are supposed to be good.  What I think I would like to do is put the '94 intake and exhaust on the, '89 motor and get a EFI motor to drop into my '95YJ, if that will work, or would I be better off putting the '94 head on the '87 motor, is there adifferent combo that would be best to build and just keep pouring oil in my '95 while I build the other parts tobe my power motor?

I guess the main point to my question is what if any are the differences between the different year 2.5l's?

[Jeffy]

There were two different heads used but there is nothing on which is better.  There should be a post someplace about them though.  Blocks for the most part are the same.

[Jeep_Lust]

The 4 popper in my '95 YJ is suffering from serious blow by and needs rebuilt.  I plan to do a major rebuild on it that will push the power up conciderably, should be around 200hp when I'm done on '87 octane.

Just curious; what are you planning on doing to the engine to get 200 hp on Regular?

[jrollings]

yea id like to know as well because a rebuild is the near future for me as well. any specs on what your doing for your build and what not would be appreciated. that would be sick for 200 horses on regular 87 from 150ci motor

[DodgeMudder]

I'll be posting about what I do, after I get it built, hopefully that will be sometime around spring of '09.  I'm still working on where to get all the needed parts to make it work the way I want and how to find the $$$ to do it.  It should be a reasonably cheap (for what I'm doing) build, but I don't have a big enough budget right now for it.

My best advice to anyone looking into doing something like this is to start off talking to places like Cliford performance they hae lots of good parts and info for you.

[stan98tj]

There were two different heads used but there is nothing on which is better.  There should be a post someplace about them though.  Blocks for the most part are the same.

there are 2 (if not 3) different heads used from YJ to TJ 2.5l. there are a few differences, one being the size on the TJ heads and  the YJs head (YJ is a hair thicker) and the YJ head had some sort of "dummy hole" near the #4 piston on the driver side.  I just went through replacing a head and the one they sent me was a YJ 2.5l, i ended up buyin a freeze plug from home depot, wrappin teflon around it and plugging the hole to prevent antifreeze leak, the head is identical though except for being a hair thicker. Dunno if this helps at all--didnt help me cause the whole motor ended up needing to be replaced lol...but that had nothing to do with the head. :)