apitts73

ill pull the head today and take a look at the gasket....ill take a couple pics too!

Tom M'Guinn

The reason I asked is because the Mahle pistons sold by Andial produce a higher than advertised compression ratio. LR tends to use other pistons from what I've gathered though.

lart951

Yep, remind me of this one;

https://rennlist.com/forums/944-turb...-an-offer.html

Thom

- headgasket?
- head studs?
- torque applied on the studs?

schip43

I think they are asking about the compression ratio because the tune/timing would be different for a Hi comp turbo vs a low comp one.
But yeah if the motor was built for you, you would have had to specifically ask for a Hi comp motor, I'am pretty sure.

Honestly though if the chips were lose in there, I don't believe that anything you saw on the AF gauges could have been accurate! I think this motor is fine but yeah with that history, I understand your concern!

7 to 8 head-gaskets and a backward WG! Holy crap, how did you find that out? Yeah that would have been a lot of beer!

apitts73

i understand why the question about pistons and comp ratio now...sorry....i know they arent mahle pistons, i cant remember the name of them right now.

so when the chip was loose it might not have given me the right AFR #s??

yup...the wife calls the car "THE GOLD DIGGER", "THE MISTRESS" or "THE GOLD DIGGING MISTRESS" because i spend so much time in the garage and so much $$$ on her....yet she has no idea how much $$$ is into her!!
the guy i bought it from had the WG on backwards on a brand new motor without a boost gauge too. i didnt even know what a wastegate was or what it was for until i blew the second motor and smartened up and started learning about turbo cars and my beautiful Gold digger!!.......sooo many beers and medical mari jane definitely helped(or maybe not, more confussion??)
thanks so much for all the help and suggestions guys,
adam

racerxrick

sorry to hear it...hopefully you'll get some answers when you inspect the head gasket

docwyte

Ugh, so sorry to hear this Adam!

jmj951

2nd that. Could have just been a weak head gasket, a broken stud, or a few that were not tight enough. 2-3 cylinders with water? That sounds really unusual. 1-2, I can understand. 3 is a huge failure. Just out of curiosity, before you remove the head, try tightening all of the head bolts with a torque wrench. Not sure what kind of torque wrench you have, but do it in such a way that you start low and increase the torque until you can get a reading on the amount of torque it takes to further tighten each one. See if there are any significantly different values on any of them.

I really hope a loose chip didn't start any deterioration, because I had the same issue in December. However, I was never boosting when the motor cut out on mine, I was still test-driving when this problem was showing up for me. I really don't think this could have caused a problem because the result is the absence of spark when the problem appears. When the chip loosens, the coil loses its signal.

Very sorry to hear this. Good luck.

Mike Lindsey

Adam,

I understand you and Mike have been talking through email today. I'm sorry you're having problems but
we are always here (not here, but you know what I mean) to help and offer advise.

Since it's a unknown at this point whether the shop that installed the head re-torqued the gasket as we advise on cometics (don't think they ever called us as to our prodecures and cautions), it would be useful as jmj951 says to check the torque before you remove the head as a FYI.

What you should do is position the torque wrech facing a exact direction you can remember. Say 90 to the cam or whatever. Then with the wrench still on the nut, set the direction of the wrech to loosen. Back off on the nut until it comes loose being careful not to remove the torque wrench from the nut or allow it to move when changing directions on the CW/CCW dial. Now change the wrench to tighten, and take to 67#. See if the wrench ends up in the same place, or if it goes further around before it makes torque. We usually see 1/8 to 1/4 additional rotation on a re-torque on a cometic. Even when we just let them sit overnight. You can see more if heat cycled. We like to do both. Never all the studs, average say half of them take more rotation. If you get rotation, then the torque was low and that didn't help the gasket. If it was good, then you can probably eliminate torque as a reason.

Trying to cram a 450 RWHP @ 15psi capable 3.0L motor through a stock down pipe and 3" exhaust is in my opinion is the most likely reason your gasket failed. Back Pressure. And lots of it. Too bad you didn't install the pressure kit before it blew. It would of been nice to see how much.

3" TDP and 4" or 5" Big Flow Exhaust will fix that back pressure problem.

Can't speak for the tune as it's not our stuff on there.

Good luck and you should be up and runnin again soon! Hopefully not with the same exhaust though!

- Dave

Mike Lindsey

We don't buy our pistons from Andial. We order everything custom to our specs. We give the customer the exact compression ratio they want.

Adam has a 59cc head, 40cc dish, and with his bore, the gasket thickness, the gasket bore, and calculating in the area around and above the top ring,
he has 7.95:1 compression.

Tom M'Guinn

Sounds ideal to me. In contrast, the Andial/mahle pistons produce 8.7:1 or so with a 2.7 head or closer to 9:1 if the head has been surfaced a few times (and using a widefire gasket). With my motor, using Raceware studs, my ability to hold boost is a direct function of the amount of torque on the studs.

apitts73

thanks guys,

for sure i will do the torque test later today or tomorrow(waiting for tool to get cam off)
as for the back pressure kit....it is installed but the gauge isnt installed yet....ill get the shop to hook it up when i get running again....try it with this exhaust, and check out the back pressure @ 15psi boost......if too much then ill go the rest of the way and go with the 4" exhaust and the 3" down pipe.

after i saw the smoke out the back in the rear view mirror i shut it down and coasted to the side of the road. opened the hood and checked the engine bay....all good...so i started it again and it smoked out the side this time so i shut it down again(only ran for less than a minute.

would this cause all cylinders to fill up??

Mike Lindsey

Yes. This is how you bend rods, crack cylinders, pump coolant all around the oil system. Let's hope
it's OK. With no cylinder pressure, and 14 or so psi on the coolant system, it doesn't take long to fill a cylinder
beyond the clearance left with the piston up. Not much. In your case, not much more then 100cc's.

Bri Bro

Adam, I sure hope you get this sorted out. I am sure it is very frustrating getting a new engine and having issues with it right out of the gate.

I would suggest that after you get the HG problem resolved, you dial in boost a little at a time starting with dialing no boost and stepping it a couple of Lbs at a time. That way, when you run into problems, you don't run as much of a risk of doing damage to the engine. You also need to find ways to measure the pressures in the exhaust and log some of your engine perimeters so you can see if you are trending toward a potential issue as you raise the HP (boost) of the engine. Slow and easy tends to be the best path. If things are not running right, stop right away and go looking for the cause. Just my thoughts.