- Location
- Grand Junction, CO
At this point, I'd be leaning towards a head gasket leak between the combustion chamber and coolant passage.
The Rubi Q Build
- Thread starter UNSTUCK
- Start date
UNSTUCK
But stuck more often.
I ordered a leak down tester so I'll know for sure, but I'll be pretty surprised if that's the case.
In the mean time, I ran across a local guy selling (4) 16 inch ORI remote reservoir struts. They were used for a suspension build on a large truck, but never ran. The truck was too heavy. They switched to coilovers. I'm pretty temped but I think 16" would be too long. Ride height should have half the shaft showing, right? I doubt I could get 8" of up travel, and if I don't get that then I would loose the bump stop. Just estimating I would say they would need to have 5-6 inches of shaft showing. The price is really good. I was planning on these same shocks, but in 14" so if I could make 16" work these would be great. I wont cut through the hood to make them fit.
Anyone else running 16's on a TJ/LJ? How do they fit? What's your belly height and your tire size?
In the mean time, I ran across a local guy selling (4) 16 inch ORI remote reservoir struts. They were used for a suspension build on a large truck, but never ran. The truck was too heavy. They switched to coilovers. I'm pretty temped but I think 16" would be too long. Ride height should have half the shaft showing, right? I doubt I could get 8" of up travel, and if I don't get that then I would loose the bump stop. Just estimating I would say they would need to have 5-6 inches of shaft showing. The price is really good. I was planning on these same shocks, but in 14" so if I could make 16" work these would be great. I wont cut through the hood to make them fit.
Anyone else running 16's on a TJ/LJ? How do they fit? What's your belly height and your tire size?
Pile of parts
Well-Known Member
- Location
- South Jordan
I run 14s (on a YJ frame) with only 5-6 of shaft showing, and that last 5/8 or so is not travel. I haven't had any issue with that little uptravel. However, I don't really run high speed. Maybe you'd want more for that.
rholbrook
Well-Known Member
- Location
- Kaysville, Ut
You are chasing a problem I had on a motorcycle. It ended up being a cracked cylinder. I’m with Greg
UNSTUCK
But stuck more often.
I believe you need to have half the shaft showing at ride height to make use of all three stages of valving. Not really sure what that means or if you’d notice a difference? I assume it’s just progressive.
Pile of parts
Well-Known Member
- Location
- South Jordan
Interesting. I'll have to look into that. I've been very happy with them, as is, but I came from leaf springs to this. I'm sure someone familiar with them could give me a lot of advice and probably improve upon what I have.
UNSTUCK
But stuck more often.
Find this.
Right side of the chart shows your shaft length. The bottom explains it a bit.
UNSTUCK
But stuck more often.
Leak down test complete. 
3 was the worst, but only about 5%. I won’t loose any sleep over that.
I can’t remember if I mentioned it or not, i replaced the thermostat. I boiled it and it did not open. I’m sure that was my main issue. Today I installed a new temp sending unit. The resistance readings were slightly different between the old and new. I took it for a very spirited drive. Maybe 2 or 3 miles and then back to the house. My temp gauge stayed right on 210. I plugged my scan tool into it and it was reading 219. I need to check the temps at the top and bottom of the radiator. I think at this point my ten amp fan is worthless.
I also replaced the spark plugs while they were out. Each one had a different gap, but looked fine otherwise.
Mileage to date.
3 was the worst, but only about 5%. I won’t loose any sleep over that.
I can’t remember if I mentioned it or not, i replaced the thermostat. I boiled it and it did not open. I’m sure that was my main issue. Today I installed a new temp sending unit. The resistance readings were slightly different between the old and new. I took it for a very spirited drive. Maybe 2 or 3 miles and then back to the house. My temp gauge stayed right on 210. I plugged my scan tool into it and it was reading 219. I need to check the temps at the top and bottom of the radiator. I think at this point my ten amp fan is worthless.
I also replaced the spark plugs while they were out. Each one had a different gap, but looked fine otherwise.
Mileage to date.
UNSTUCK
But stuck more often.
Let the fun begin! I started the tear down of the L92 that will be going in the jeep. I didn’t think to take pictures until I was a bit in to it.
This engine has definitely had a hard life, at least towards the end. The sludge around the rocker arms was pretty deep and nasty. There was a bit in the valley and more in the pan. You can’t change oil too often. The weight saving over the iron block LQ9 I tore down a month or so ago is obvious. Fully dressed with exhaust manifolds this one comes in at 458 pounds. 430 without manifolds. I weighed it myself.
Gross sludge.
I drilled and tapped the pass side coolant port for the jeep coolant temp sender with it was easy to do so.
Nothing obviously wrong with this thing. Just high mileage wear. No cross hatch left and almost polished smooth bores.
Crank and rod journals look perfect.
Not sure if this a unique way to check bore wear or not but I like it. I set my mic to 4.0650 and then zeroed my bore gauge in the mic. I was then able to quickly check each bore in three spots while my daughter, Ashlee recorded my findings.
Overall there was no wear at the bottom of each bore. Then 1 to 1.5 thousandths in the middle and and 3 to 5 thousandths at the top. Each bore had a taper. There’s no scratches or any issues with any of the bores. I’ll let the machine shop decide how to proceed from here.
With this torn down I can drop it at the machine shop so I can start building the LQ9 that’s going in the project Bronco that is coming home from the Rocky Point body shop this week. Which mean I need to wrap up the project Camaro this week to make room for the bronco. 🤪
This engine has definitely had a hard life, at least towards the end. The sludge around the rocker arms was pretty deep and nasty. There was a bit in the valley and more in the pan. You can’t change oil too often. The weight saving over the iron block LQ9 I tore down a month or so ago is obvious. Fully dressed with exhaust manifolds this one comes in at 458 pounds. 430 without manifolds. I weighed it myself.
Gross sludge.
I drilled and tapped the pass side coolant port for the jeep coolant temp sender with it was easy to do so.
Nothing obviously wrong with this thing. Just high mileage wear. No cross hatch left and almost polished smooth bores.
Crank and rod journals look perfect.
Not sure if this a unique way to check bore wear or not but I like it. I set my mic to 4.0650 and then zeroed my bore gauge in the mic. I was then able to quickly check each bore in three spots while my daughter, Ashlee recorded my findings.
Overall there was no wear at the bottom of each bore. Then 1 to 1.5 thousandths in the middle and and 3 to 5 thousandths at the top. Each bore had a taper. There’s no scratches or any issues with any of the bores. I’ll let the machine shop decide how to proceed from here.
With this torn down I can drop it at the machine shop so I can start building the LQ9 that’s going in the project Bronco that is coming home from the Rocky Point body shop this week. Which mean I need to wrap up the project Camaro this week to make room for the bronco. 🤪
Make sure it has one of these in the pan when it goes back together. If not it'll spray the oil pump relief pressure directly on the back two cylinders and cause some nasty issues. 
GM Genuine Parts 12639759 Engine Oil Pressure Relief Valve Deflector https://a.co/d/hdw7eS1
GM Genuine Parts 12639759 Engine Oil Pressure Relief Valve Deflector https://a.co/d/hdw7eS1
UNSTUCK
But stuck more often.
So while we’re on the subject, help me with the build plan on this one. I guess I have a goal of 350hp to the ground, which should be pretty easy to do. I figure I’ll loose 20-25% through the drivetrain (6L80e transmission and 241 case). This engine should have around 420hp in stock form. A stage 1 truck cam should get me around 45-50hp and tuning should get me some more. I’m actually not sure what block hugger headers do for HP. Help or hurt, anyone know?
I keep going back and forth on a VVT cam or deleting that system. This engine does not have AFM. I see no reason to use a forged piston. I will upgrade to a better spring and upgrade the trunnions. What else am I missing?
I keep going back and forth on a VVT cam or deleting that system. This engine does not have AFM. I see no reason to use a forged piston. I will upgrade to a better spring and upgrade the trunnions. What else am I missing?
UNSTUCK
But stuck more often.
From the conversation we had before about the deflector I was looking forward to removing the pan to see if it had one in place. It did not have one. I studied the TSB and other GM info regarding the issue. I was sure the rings on 7 and 8 would be packed with sludge and the cause of this engine burning oil. I pulled those pistons and the rings were clean. They were some of the most worn bores though. With 8 being the most worn at the top.
I’ll be sure to put a deflector in when it goes back together.
- Location
- Grand Junction, CO
Factory exhaust manifolds flow pretty well, shorty headers look nice but can be a little tighter to fit in some place. Its really up to you.
A decent cam will gain you more than 50 HP on a L92 IMO... really depends on which cam though. With the rectangle port heads and TBSS/NBSS intake that came factory on that engine and a half decent tune, I bet you'll be close to 500 HP at the crank.
I'd delete the VVT, it can be problematic over time.
Get a valve spring with pressure to match the cam, a matching set is ideal IMO.
Yes, upgrade the trunions for sure.
Hypereutectic pistons are a good compromise between cast and forged, that's my usual choice.
I like a standard pressure, high flow oil pump.
Bearing tolerances on a LS are much tighter than an old SBC, I'm sure your machine shop knows that though.
UNSTUCK
But stuck more often.
Speaking with Texas speed a while back they told me to keep the intake under 220 if I want to keep the stock torque converter. In my mind I want to keep the stock low stall converter so the cam will stay under 220.
For the LQ9 I’m building I ordered their stage 1 truck cam, but received their stage two cam by mistake. I’m going to run that instead. I’m hoping it won’t have a noticeable lope and be smooth running.
I have not began looking into specific cams for the L92. Is one brand better than another? I also want it smooth running for low speed crawling. A flat torque curve above 500 lb/ft starting at 1000 up to 5500 rpm’s would be ideal. 😂
For the LQ9 I’m building I ordered their stage 1 truck cam, but received their stage two cam by mistake. I’m going to run that instead. I’m hoping it won’t have a noticeable lope and be smooth running.
I have not began looking into specific cams for the L92. Is one brand better than another? I also want it smooth running for low speed crawling. A flat torque curve above 500 lb/ft starting at 1000 up to 5500 rpm’s would be ideal. 😂
- Location
- Grand Junction, CO
I think as long as you use a reputable company to source your cam, it'll be fine. I used a Comp Cam in my L33 and plan to use a BTR for my LQ4.
@RockChucker has a nice aftermarket torque cam in his 6.0 that sounds good, decent idle.... I don't remember what cam he used or his stall converter.
If you decide to keep VVT I would get a complete Texas Speed kit. They include all the cam information for running the VVT. The Comp cam I had in the last L92 was great, but it took a lot of searching thru HPTuners repository and tweaking the tune to get it to initially start and idle right. I've read with TS the information provided for the VVT tables eliminates 99% off the problems.
RockChucker
Well-Known Member
- Location
- Highland
350 hp to the ground sounds hard to me ha. I have a pretty mild cam and volumetric flow numbers during tuning say my engine is right around 500 horse and 500 lb-ft of torque. The Dyno used for tuning everything said it put down 250 at the tire. Granted my jeep is quite different from yours. The engines are close. Mine is an LQ4 bored .030 over, stock crank, L92 heads/intake manifold, flat top pistons and a 10.5:1 compression ratio. I’m running a 6L90 controlled by a stand alone PCS controller. That might have a little more parasitic loss vs a 6L80 but I’d expect they are pretty close. But then we diverge heavily from there. I have a 3 speed hero that I’m sure is a huge power suck, running through a d60 rear end with 5.38s and 40s. There certainly is some question in my mind about the dyno’s accuracy. The guy that tuned it mentioned that this particular dyno is ready for a some maintenance. I’ve never gotten super hung up on the numbers because it pulls like a freight train. This 6.0, ok 6.1, coming from a 5.3 was a bigger jump in power than it was from the 4.0 to the 5.3. I got the loosest OEM gm converter that I could find, which supposedly is out of a CTSV with the 6L90. Rumored to be a 2200-2400 ish stall. It works great for me. Very driveable, smooth idle and lays down the power when I want to. When we were doing trans shift point tuning at WOT, I was driving while my tuner was passenger and data logging. I’d come to a complete stop and then stand on the throttle. It barks the 40s at every shift all the way into 4th gear. I’d be curious to run it on a 1/4 mile track but with RMR gone it will probably never happen.
UNSTUCK
But stuck more often.
That’s got to be a bit frustrating to see such a low number on the dyno. I don’t think they always tell the full story though. I built a JK back in 2008-2009 for a guy that wanted more power. It’s the only time I’ve dynoed a vehicle. He wanted before and after numbers. I did all the bolt ons we could do at the time, as well as regearing and a hand held tune. The dyno numbers actually went down over stock, but the jeep was way quicker.
350hp is really just a number I pulled out of the air. I do know it will have way more power than it does now. I’m actually more interested in the performance of the 6L and the fun to drive factor it will give.
350hp is really just a number I pulled out of the air. I do know it will have way more power than it does now. I’m actually more interested in the performance of the 6L and the fun to drive factor it will give.
RockChucker
Well-Known Member
- Location
- Highland
The 6 speed trans with tap shift is rad. I love mine.
- Location
- West Haven, UT
Ditto.