Topic: 2.5 rebuild

[warro]

I'm new to the forum and in the process of a rebuild. I have a 93 wrangler 4 banger. I have never rebuilt a motor before so I wanted to learn how.

I picked up a spare motor, transmission and transfer case as a set for $300. Sold the tranny for $300 and was even on the purchase.I have sold the intake w/all the EFI on it also.

I disassembled the motor, pretty easy. Took it to the machine shop and went to town. The block was bored out 60 thousands past stock, the block was decked, magna fluxed and all. The crank was reground and balanced. The connecting rods were resized. Valve job, new springs and lifter and the valve springs were balanced/equal spring pressures on all. I choose an RV2 cam from a local cam grinder company. I pick it all up today and will start the assembly soon.

Ok, let it rip with advise.

[jwrape]

I'm new to the forum and in the process of a rebuild. I have a 93 wrangler 4 banger. I have never rebuilt a motor before so I wanted to learn how.

I picked up a spare motor, transmission and transfer case as a set for $300. Sold the tranny for $300 and was even on the purchase.I have sold the intake w/all the EFI on it also.

I disassembled the motor, pretty easy. Took it to the machine shop and went to town. The block was bored out 60 thousands past stock, the block was decked, magna fluxed and all. The crank was reground and balanced. The connecting rods were resized. Valve job, new springs and lifter and the valve springs were balanced/equal spring pressures on all. I choose an RV2 cam from a local cam grinder company. I pick it all up today and will start the assembly soon.

Ok, let it rip with advise.

Shoot sounds like you got it all except polish and poring of the head and intake. What is the lift and duration of the cam?

[Jeffy]

Hmm, didn't someone say earlier that the block could only take .030" without going into a water jacket?

[jwrape]

Hmm, didn't someone say earlier that the block could only take .030" without going into a water jacket?

That's not what I read here. There is that thread about the performance 2.5L build up. He did .60 over.

[jwrape]

Here we go. He bored his .60 over
http://www.4bangerjp.com/forums/viewtopic.php?t=662&highlight=

[YJmechanic]

I don't know how this 30 and over thing is staying in everyone's minds.  My motor is 60 over and obviously it didn't hit a water jacket.  If over 30 hits the jacket then even 30 wouldn't be safe to do.  For that matter if 30 was max, I be afraid to touch the block at all.  My motor turned out fine and I have had no problems with heat or anything else.  And by the way,  nice to here other people are trying this buildup.  Let me know how you turn out.

[YJmechanic]

Also, I forgot to mention that you better know what that cam is capable of.  If you are over a 400 cam,  then you should be changing the springs to doubles and using stronger pushrods, locks, retainers,  and lifters not just new oem stuff.  I had all my stuff custom made from clifford.  The now sell it as a kit.  And if you are over  a 400 you better have a manual tranny.  I just put a 476 cam form hesco, I think ,  in a tj for one of my customers and it stumbles and falls because of the auto, now I have to run a stall converter for him and I don't know anyone with that application.  Not trying to be rude, just a warning before you are all done and have to redo something.

[jwrape]

Also, I forgot to mention that you better know what that cam is capable of.  If you are over a 400 cam,  then you should be changing the springs to doubles and using stronger pushrods, locks, retainers,  and lifters not just new oem stuff.  I had all my stuff custom made from clifford.  The now sell it as a kit.  And if you are over  a 400 you better have a manual tranny.  I just put a 476 cam form hesco, I think ,  in a tj for one of my customers and it stumbles and falls because of the auto, now I have to run a stall converter for him and I don't know anyone with that application.  Not trying to be rude, just a warning before you are all done and have to redo something.

So I couldn't put my Stage 3 Mopar performance cam in without upgrading my valve train? Just clarifying..

[50highlander]

What was the cost of this rebuild?  Or would buying a crate 2.5 been too cost prohibitive?

[dwtaylorpdx]

Bottom line you have to sonic check the bores to make sure you have the
iron in there to support the thermal and mechanical stress. You do not have
to actually punch through to the water jacket to be too big.

My engine had two thinner spots between 2&3 so my builder said 40 was it,
plus we found some really good pistons in 40 over that were not available in
.060 over. so it worked out.

I used the Hesco cam and springs due to the lift on my cam. The stock springs
will not take the over 400 cams, and there are things to do to make the valves
close when they are supposed to. Stem height, valve length and the depth the
seats need cut to. Just like having a machinist machine the block, its a good idea
to have one assemble the head properly clearanced and setup for the cam profile.

Just another .02 bucks worth on it...

Dave