Hi,
My engine builder selected the bearings last time. I can't recall (it was built in 2015) what brand he selected. Can you point me to the mod to help the thrust bearing live longer?
On the injectors, yeah, that was kind of surprising about the variations in volume. The text indicated they were indexed for their testing but they are not visibly numbered/lettered now they're in my hands so that I know which one(s) flowed the least.

 

Ah, thanks for the link. Interesting. I'll hit up my machinist tomorrow about that mod. I took the block and crank over to him today. He felt like, at first look, the damage to the top of the cylinder might clean up easily. Hope so. He'll give me measurements so I can order the new slugs and rings. Looking at the Summit LS Pro piston series.

 

If this was caused by running too hot of plugs I would expect more of the pistons would be affected not just the two. Something else must be going on here. That chalk white color in the exhaust headers on 4 and 6 needs to be explained. Maybe head gasket so bad coolant was getting sucked in there?

 

That seems to be the supposition of a lot of folks. I've had blown head gaskets before of different engines over the years but they always had one or more of the following....

1. Overheating
2. Oil in the coolant
3. Coolant in the oil
4. Pushing coolant out of the overflow onto the ground.

This time, it wasnt running hot or even above normal (just under the first quarter mark on the dash gauge. About 185 degrees.
No coolant in the oil, but the coolant did have brown particles in it. Still mostly green and certainly, not the oil floating on top of the water like I've seen on other engines.



Looking at the head gasket for those cylinders, it still doesn't leap out to the eyes that an area was overtly affected. On some bad head gaskets, there were actually channels where you could see the route. Maybe these LS9 shim gaskets don't leak that way, perhaps just weeping between the 'multi layers' (speaking of which, those shims are razor sharp. I was putting a new one back in the plastic sleeve, brushed the side of my thumb against a tab on the gasket and it flat unzipped my thumb. Blood everywhere). I'm going with Cometics and a true 3.780'ish hole in them. Placing the LS9 gasket on the block showed me how much gasket surface I was giving up.

I'll take off the passenger side fuel rail and inspect that and then the wiring harness to see if anything stands out for #4 and #6.

 

I like that you're trying to find the root cause of this failure. Sometimes there's just no smoking gun, just a pile of broken metal. Good luck!

 

My good buddies pile of smoking metal.





hard to do postmortem sometimes.

The missing data log may have provided clues.

My damage has just been bearings. But being old and slow, it messed me up for a couple of years.

Keep up the good work.

Ron

 

BadApache - Thanks. I'll do all the research I can.

Ron - Good God. What a catastrophic failure!

On a side note, I was looking for some youtube info/experiences on Youtube for the Bosch 210cc injectors. I found a Matt Happel (sp?) video where he was replacing some 160's with the 210's but as I listened/watched, he spoke about mentioning this swap to his buddy at FIC (Fuel Injector Clinic, the facility that just serviced my Bosh 127's). His buddy (and I'm typing what I remember, not necessarily word for word) "Oh? Did they fix the problem with the seats sticking when they get hot?". Matt asked him for details and FIC indicated that either the pintle or the seat for the CNG category injectors is made from a material different from the true gas/e85 style injectors that may 'stick' (closed) when they are hot. Matt went on to remark that if he just got into the vehicle and drove that they were fine, but driving say 2 hours to a track then racing, he ran into weird lean A/F issues. He said that even when he tried to fatten up the fuel, the resulting behavior was still erratic because the issue isn't linear. That is, the sticking appears to be hit and miss when hot so you can't eradicate or 'tune out' the effect. This behavior is exactly what I ran into in every respect.

Well, that may not be my problem but it may be too. My twin setup routes the two 2.5" down pipes on the passenger side, stacked like an over/under shotgun barrel, under the flipped cast Truck manifold. So I have 3 sources of heat concentrated in that channel/cavity between the block and the inner fenderwell. Those two plugs, #4 and #6 are in the middle of the block (as you know) so that area would suffer the most heat concentration since #2 gets some residual/collateral coolant fan air and the rear has some air between the block and the firewall. I'm wondering if that is something to look at. I don't think the Bosch 127# have that same CNG style pintle/seat but I'm sure curious about this possibility in the absence of bad injectors, bad wiring harness, bad pumps, dirty filter.

I

 

Took my PRC Stage 2.5 heads over to the machinist to clean up chambers #4 and #6 and get some info on the block. He said he can keep me where I am on my current Wiseco 3.80 bore pistons. The cylinders were still in good shape. We were thinking I could just buy two replacement pistons so I was pretty happy about that. But, .... when I got to the house, I pulled out one of the other pistons to look for a part number. That's when I noticed that at least two other pistons had an ever so slight breakoff on the outer perimeter of the valve reliefs. Since the individual pistons are around $100 each, I said, F-it, I'll just buy a brand new set. I looked at the compstar rods I have and noticed they are 6.125". Seeing as I wasn't there when my original machinist assembled this engine back in 2015 (he's a good hour away) I thought that the bore was stock and the rods were stock length. Ah well, I'm better informed now. I ordered the pistons from Tick and ordered some Cometics Head Gaskets with a 3.91 bore and .051 compressed height. That will likely yield a 10.25:1 static compression ratio. I think I'll opt for a cam with more duration to bleed off some of that compression. My Triple 12 has 212/212 @ 0.050 and approx .576 lift 112 LSA. The Summit Stage 2 Turbo cam has 226/230 Dur @ 0.050., LSA 113+4, .600/.575 Lift

 

Are you on pump fuel?

 

Yes. Just normal 93 octane. I'm going back to E85 for this refreshed engine.

 

No worries with compression on E85.

 

Do the other damaged pistons line up with the lower flowing injectors?
- it's possible the timing was one the edge and the leaner cyls had detonated , the tr7s and and fresh tune should cure that. If you're going to continue with pump or flex fuel definitely start with a little less timing.
- it's too bad you weren't logging fuel pressure, quite a few on here have had the low voltage at high rpm which leads to low fp, again effecting the cyls with the lower flowing injectors first. If this is the case disregard the timing comment. Definitely something to watch for when tuning the new build.
- hard to believe that the injectors were sent back unlabeled, would be good to put the higher flowing ones in the rear cyls - just a cushion as those tend to be the cyls that melt down in a majority of cases.
I'm sure you'll be in the 9s the next time out !!

 

Thanks for the input. I have a high output alternator and the hot wire relay kit powered right off the alt. post with 10 ga. wire. But who knows. I'm just going to go through the whole set up just be as sure as I can.

Picked this up today to help move the engine around..

 

That’s a nice piece! Wish I had that when putting my engine on the stand.

 

The Summit Turbo Stage 2 Cam arrived along with the Cometic 3.91 bore Head gaskets. The block has been honed and trued up And is ready to go but I have to measure the journals to see what size bearings I need for the mains and the rods.

 

The new Wisecos arrived this morning.
I'd weighed one of the still pristine pistons I took out of my engine, having stripped out the spiro-locks, wrist pin and rings. My digital kitchen scale displayed .420 grams. My intention was to weigh one of the new Wiseco pistons when they arrived

They arrive...

Opening the box...

Spot on...
and see what kind of the weight differential there might be. As I took the pistons out of their bubble wrapped bags, I noticed that each one had written on the bottom of the wrist pin boss, "418". Sure enough, each one i put on my scale displayed ".418".
Is that common practice nowadays to balance the pistons before they're delivered? If so, that's outstanding.

 

Notes for anyone looking.

1. Compstar Rods are directional. One side of the main journal has a bevel. The other side is flat. The beveled side faces the crank counterweight, the flat side faces the rod beside it on the journal
2. Compstar connecting rod bolts for the 6.125" are torqued to 80 ft lbs.
3. Stock, GM, OEM Torque to yield main cap bolts
   1. Inner bolts 1st pass: 15ftlbs 2nd pass: 80 degrees
   2. Outer bolts 1st pass: 15ftlbs 2nd pass:51 degrees
   3. Side bolts: 18 ftlbs
4. Recommended (by my original engine builder) ring gap on these Wisecos (Wiseco Piston Kit LS1 Vortec 5.3L FT -2.2cc 10.25:1, Part #K474M965)
   1. Top ring: .025
   2. 2nd ring: ,028

 

I've long felt like putting ends on my braided steel lines (Fuel, Turbo drains, Transmission cooler lines) where the devil. Not so much now that I finally bought the Koul Tools. But I've discovered the devils evil twin today. Spiro lox on my Wiseco pistons. The first three caused all manner of cussing but by the 4th piston, I kinda settled into a method that went much better. Fingertips sure are sore though....

 

The Mahle clips are worse!

 

Really? I'll have to look those up. Last time I had full floating pistons that *I* put in where in my old LT1. They were what I would call traditional Cir-clips.

Got that last remaining bits and pieces for my rebuild today. Hoping to make a lot of progress over the weekend. UPS brought...
1. Piston Ring filing machine
2. Rod Bearings (Clevites)
3. Cometic 3.810 bore (custom set and $$$) head gaskets. I'd ordered and received some Cometics earlier that were 3.910 but I didn't know my machinist had ordered these 3.810's Ah well, I have an extra set now
4. LS7 Lifters and trays

I now have 3 sets of heads.
1. PRC stage 2.5 CNC ported (they were on the engine when the pistons got burnt. They've been completely cleaned up, one new valve was all that was needed, valve job, new seals.
2. RPC Heads 2.0 intakes. Dual valve springs good to .660 lift
3. Stock 5.3 heads. Cleaned, new valves, new seals, Valve job