Topic: Is this anyone's rebuilt 2.5L?

[Jeffy]

Found this picture while I was browsing images.  The description says:

AMC/Jeep 2.5L four cylinder, ported head, YellaTerra roller tip rockers, MP cam 248/248-32-.440/.440(Phase II), Banks Torque Tube header, '95 MPI intake, will run '93 OBDI MPI, built by Duffin Engine Service, SATX.

[FourbangerYJ]

I wish.
Needs to port the TB intake.

[dwtaylorpdx]

We only deflashed the intake on mine, and I did not pop for the yellow terras. Hopefully a new job comes along and I can fix that... :)

Dave

[sharpxmen]

We only deflashed the intake on mine, and I did not pop for the yellow terras. Hopefully a new job comes along and I can fix that... :)

Dave

if you do get them go for the 1.7 as apparently yella terra makes them (might need to order them in but that's what i heard).

[Jeffy]

if you do get them go for the 1.7 as apparently yella terra makes them (might need to order them in but that's what i heard).

Yella Terra does make them and anyone who sells them can order any other ratios.  I talked to them a while back...

[dwtaylorpdx]

I've got too much cam to go to 1.7's... 

Id come darn close to the pistons if something went wrong. Mine are already cut for valve clearance...

At the time the builder wasn't too keen on the roller rockers due to the price, but the flexible nature of the stock rockers had not been documented as well back then... We didn't find any rocker flex when we degreed the cam. I suspect its an inertia thing with the motor wound up where it starts to matter. We did cut teh spring seats to get the height correct, I suspect not everybody does it and that will abuse the rockers... If you ev er have the valve cover off its good to make sure the coils on the valve spring do not touch each other.

Dave

[sharpxmen]

I've got too much cam to go to 1.7's... 

Id come darn close to the pistons if something went wrong. Mine are already cut for valve clearance...

hmm, i tested close to .600 lift and the valves were not touching the piston, but depending how much lift you get with you cam you might need longer valves and higher rate springs.

[dwtaylorpdx]

I'm running a .470 lift cam, the heads are milled the block is milled and the pistons are small wedge units, I've got about .150 clearance right now... We clayed them before final assembly, I probably could get away with it, but if I ever broke a chain or stuck a valve it would be nasty...

Dave

[frhrwa]

great looking 2.5L  wish it were mine, someone told me months ago not to bother trying to boost a 2.5, I wondered about that..  don't know why not, you can get tons of horsepower I guess with a V-8, but you also get all that front end weight..  the 2.5 should be a great building block..  turbo, or supercharged, headers, flow enhancements, and so on..  anyway, that one looks real nice..

[chitchc2]

That's What my motor looks like right now only it is actually on the mounts and in the engine bay.
I noticed one user is stating they are running a built motor already.
Do we have any dyno numbers for it?
I'm hoping to get on the dyno this weekend.

[jfrabat]

That's What my motor looks like right now only it is actually on the mounts and in the engine bay.
I noticed one user is stating they are running a built motor already.
Do we have any dyno numbers for it?
I'm hoping to get on the dyno this weekend.

I guess that would be YJmechanic, but he's not been on the forum for a while now...  He did not dyno it as far as I know.

[chardrc]

yj mechanic had his dynoed but didn't have specific numbers, this is what he said.

sorry guys its been awhile again but my life seems to get crazy and then i loose my self in other stuff,  but i always come back to my true passion.  yes it was dynoed a long time ago when the engine was initially installed and was sitting close to 200  hp/tq split.  i have played around a little lately with it and now it should pull well over 200.  and torque should be even higher with my gears going a step lower.  anymore i dont waste time with dyno tuning and such just the butt dyno.  sadly to say i drive it so little anymore i cant tell the differance unless i drive it for a week and then do something.  i am happy with the motor all together and will not dyno it again (the first time it was just messing around with a local car show i was donating my time to,  and they said lets see what it reads and i said i bet youll be surprised)  i think i answered most of youre questions in pm's but if i missed some let me know and hopefully i will get back to you soon as i can

thread: http://4bangerjp.com/forums/index.php/topic,6007.15.html

[chitchc2]

The Hemi and the Supercharged V6 barely broke 200 WHP/TQ

He must be running 16+:1 compression on top fuel or something.

[sharpxmen]

The Hemi and the Supercharged V6 barely broke 200 WHP/TQ

He must be running 16+:1 compression on top fuel or something.

he said it was 200 at the crank but even so i don't think his numbers were very accurate.

[Yella Terra]

Hi Guys,

We have the following JEEP rockers for the 2.5

1.6 Hydraulic
1.7 Hydraulic

Jim
Yella Terra

I've got too much cam to go to 1.7's... 

Id come darn close to the pistons if something went wrong. Mine are already cut for valve clearance...

At the time the builder wasn't too keen on the roller rockers due to the price, but the flexible nature of the stock rockers had not been documented as well back then... We didn't find any rocker flex when we degreed the cam. I suspect its an inertia thing with the motor wound up where it starts to matter. We did cut teh spring seats to get the height correct, I suspect not everybody does it and that will abuse the rockers... If you ev er have the valve cover off its good to make sure the coils on the valve spring do not touch each other.

Dave