dville_gt

iTrader: (5)

Car has been running hot since I put it together. Tried a few simple fixes with no luck. Pulled the heads off and found a couple of oddities.

First of all, the old motor popped #7. The plug for number 7 always looked a little off to me, but the car ran great. When I pulled the heads off to do the motor the combustion chamber for number 7 looked like it does in the following picture, but I figured that was because I lost a piece of that piston and who knows how that cylinder was running. Now that it's got a fresh short block I expected that combustion chamber would look like the rest after 50-100 miles. Nope, look for the exhaust valve that doesn't look like the rest:

I've got both the heads at the machine shop getting checked out.

On to the short block. I am running a 370ci forged lq9, with Wiseco coated pistons. The coated seems to have transfered to the cylinder walls on a couple of the cylinders, but the number 1 cylinder is the worst. It seems like these cylinders transferred the coating where they had been sitting for a week or so after I pulled the heads off. Not every cylinder has this, but at least 3 do. On the number 1 cylinder there is some extra transfer towards the bottom of the bore that almost looks like a cracked sleeve. I can't tell for sure, I can't feel it but the way the coating transferred to the wall sure looks strange to me. I did a leak down on the motor but obviously that won't tell me much about the health of the cylinder that low since the test was done at TDC. Motor is .030 over and the piston to wall clearance was checked by the machine shop and motor was torque plate honed. Motor has been run pretty hot (due to the cooling issues), but never over 235*.



I did my best to clean the cylinder walls but that coating is tough, I got some off, but not nearly all of it.

Any ideas what might be going on in this motor?

Jontall

The first thing I see is that the spark plug tips are white and running too hot. What plugs/ heat range are you using? If the piston coating is transferring to the cylinder walls, I'd say the cylinder taper is wrong. They probably kept it tight to prevent piston slap, but it's too tight and probably causing extra heat to build up. What machine shop are you using? I think it's time to find a new machine shop.

dville_gt

iTrader: (5)

The plugs are br7ef's. What is real odd about the transfer is how it seems to have occurred where the piston was in its stroke when I pulled it down. See how the transfer is high on that number one cylinder, the transfer on another cylinder is low where it was in the bore while it was sitting for a week or two.

hellbents10

iTrader: (10)

What did you do to the tuneup or the cooling system to change the condition when it popped #7 before.

dville_gt

iTrader: (5)

well, the motor popped number 7 @17psi and somewhere around 800rw (was doing 120mph in the 1/8th). stock pistons, a little greedy with the timing (16*), pump gas, semi-hot lapped, etc. So, really I didn't change too much this time around, put some good pistons, rings, and rods in it, bored it .030 over, new bearings/gaskets, and bolted it back together.

i did pull some WOT timing out of it, but this motor has only seen the wastegate so far (~5psi). plan is to run race gas in it now when i turn on the c02 controller. in an effort to cool it off i replaced the water pump, installed an aux filler neck at the highest point in the system, moved the trans cooler from the front of the intercooler, opened up the front end a lot to promote the airflow.

dville_gt

iTrader: (5)

talked to my buddy and he said he's seen the top marks before from water sitting between the rings and staining the block. the stuff in the bottom is still confusing though.

mike13

iTrader: (27)

Have you had your injectors tested and flowed? You have so much money invested in a build I would consider having them tested just for piece of mind. Hope you get it figured out.

dville_gt

iTrader: (5)

funny you mention that, they were sent off last week to be flowed and cleaned. going to call today and see what they found. heads are at the machine shop and going to call him today as well.

SPRAYED 01

iTrader: (22)

Do you have the rear stem ports in. the heads?

dville_gt

iTrader: (5)

yup, all four ports are connected with an ls1 style cross over (and they were when the motor popped number 7 as well).

was running 93 and 14gal/hr 80/20 meth injection. 17psi @ 16*, chipped a piece of #7 off, motor still ran fine, went a couple of 6.0x's like that, but started making a little noise. drove it home, did a leak down (it passed), put a scope in and found the issue. pulled it apart at the beginning of june and had the work done, got it all back together around mid july but have been fighting it getting too hot since then.

Old Geezer

iTrader: (3)

From the color difference in the entire surface of the 2 heads, the dr side is considerably hotter than the pass.
Is this a twin turbo arrangement?
How is the wastegate set up plumbed?
What kind of manifolds are U using?

dville_gt

iTrader: (5)

single t6, dual 38mm gates off each cross over pipe, truck manifold on the driver side, c6 manifold on passenger side (running a/c)

SPRAYED 01

iTrader: (22)

Do you have a build thread? Id love to see how you set up your rad/condensor/ fan setup with a t6 turbo.

JAX04

iTrader: (17)

https://ls1tech.com/forums/forced-in...85-118mph.html

Old Geezer

iTrader: (3)

have a flex joint in the dr side pipe?
Both gates working properly? Tied together with a common boost signal source?

dville_gt

iTrader: (5)

both gates working good (bench tested), all vacuum/boost is sourced from a single vacuum block. no flex join in the driver side (only in the passenger side, running solid engine mounts and frame mounted turbo).

got the heads back from the machinist today, they were about .004 warped, had them decked .007. showed him pictures of the cylinder bore and he said it's rust from water getting between the rings and the motor just sitting like that.