Topic: The engine differnces between the yj and tj engine

[mikeb]

I understand that over the years there have been several changes between the yj and tj engine... But what are they? (I know about the fuel injectors) I am going to be rebulding my tj engine and I was wondering if a 95 yj  head would swap onto my tj. As far as I can remember my 97 head looks just the same as my old 91. My concern is not only with the fuel rail but also the head gasket. Any help woudl be greatly appreciated.

Thanks

MikeB

[lanulos89]

97 and 95 are noth the 2.5's, they are the same jut 97's are obdII .  in the newer tj's they put the crumby neon 2.4's then you wil have differences.  but heads are the same, other stuff is deff changed tho.

[zworld]

97 and 95 are noth the 2.5's, they are the same jut 97's are obdII .  in the newer tj's they put the crumby neon 2.4's then you wil have differences.  but heads are the same, other stuff is deff changed tho.

What the heck did you say? Please a little more time on the spelling

[dexetr30]

97 and 95 are noth the 2.5's, they are the same jut 97's are obdII .  in the newer tj's they put the crumby neon 2.4's then you wil have differences.  but heads are the same, other stuff is deff changed tho.

 

[mikeb]

Can anyone second that?  The reason I ask is  because when I check parts numbers for a head gasket set for a 97 and 95 they are different.  Not to second guess what has been previously said, but I just cant figure it out. Maybe its just the people that make parts numbers wanted to differeciate the two models of wrangler...

Keep then comming...

Thanks

MikeB

[lanulos89]

yea haha sry guys  was kinda tired.  what i said was the heads are the same.  all the ports for intake and exhaust are the same.  difference is the pre 97 is obdI  and 97 and new is OBDII  which is just the computer system

[Liljeepz]

Yes, and in 2003 is when they switched over to the German 2.4L for better emissions.

[mikeb]

Thanks guys that really made my day!

[chardrc]

97 and 95 are noth the 2.5's, they are the same jut 97's are obdII .  in the newer tj's they put the crumby neon 2.4's then you wil have differences.  but heads are the same, other stuff is deff changed tho.

 

  finally someone other than me is being yelled at for bad spelling...

[lanulos89]

chard wasnt my spelling just had grammer and logic issues in there too

[chardrc]

close enough for me...lol

[damon54]

I was looking at ordering a new set of pistons today and ran into an interesting find.  I was on ebay and talked with a parts dealer and they said that a 1992 2.5 and a 1996-2000 2.5 had different compression heights on the pistons.  Wouldn't that mean the stroke was different too?  I thought all that stuff was the same on the 2.5.  Need help.

[mikeb]

Thats funny because I just learned what the differences are between the two as I was ordering a rebuild kit. The pistons on the pre95s are .5 of a point of compression higher than the 96 and above. Also the camshaft in the 95 and below have a slightly higher lift and duration. I ordered my kit with the 95 pistons and cam for my 97. Between those advantages and the better fuel injectors it should make a little more power.

[damon54]

On mine I am gonna go with the newer pistons because you can get the hyperutectic pistons which are a little stronger than the original cast ones and a lot less expensive than forged ones.  I' ve got the engine out and torn down to go to the machine shop but I'm gonna wait til I get the new pistons so the cylinders can be matched to them.  The Hyperutectic are better if you gonna raise the compression.  All the other threads on here talk about the forged so I am hoping to get by with these.