Carnage vol 3.

[DougsfastZ]

On this pass: YouTube - DougsfastZ 10.58 pass the fuel pressure regulator vacuum line came off and went lean, 13:1 AFR's. This was the outcome

#2 cylinder blew the RJC .019 stainless head gasket and melted the ringland

#3 piston has some detonation pitting but looks salvageable. Headgasket was stretched as well

Matching chamber

Block and other pistons look fine. I'll pull it down, check bearings, put in a new piston and get it back up and running.

 

[blackshoebox]

Damn Doug! Seen the pics on FB and was hoping it was not your new motor. That is racing though. S%$T happens!

 

[86brick]

Ouch, hope you get her fixed and back up and running!

 

[Squid4life]

What brand of pistons? How much boost was that run? Sorry to see that, sucks for sure!

 

[DougsfastZ]

Diamond's, 30 psi.

 

[turbot990]

They sell a vaccum block that bolts in the factory location with brass fitting to attach 3/16 brake line and a very short peice of hose thats how im setting mine just thought i would share i had the same thing happen to me afr went 15,0s smoked it because of the hose man that sucks sorry to hear that

 

[Squid4life]

They sell a vaccum block that bolts in the factory location with brass fitting to attach 3/16 brake line and a very short peice of hose thats how im setting mine just thought i would share i had the same thing happen to me afr went 15,0s smoked it because of the hose man that sucks sorry to hear that

You have a link or more info? Interesting info.

 

[Boost231]

here is the block. just add the brake line fittings of your choice and hook it all up.

Billet Vacuum Block

http://www.cottonsperformance.com/proddetail.asp?prod=ENG135

http://www.fullthrottlespeed.com/itemdesc.asp+ic+270billetvacblk+eq++Tp+

 

[turbot990]

YES thats the one cottons performance the price is right 39.95 thats me for sure my fuel pressure reg. has a screw in fitting im going metal line and fitting all the way no rubber hose to blow off or in too

 

[Squid4life]

Yep, the one from cottons looks like the way to go. Will have to keep that in mind. I have not had a hose blow off, but had one split because of the barb being a little too big, and hose dried a little.

Thanks for the info guys, much appreciated. Learn something new every day!

 

[DougsfastZ]

Looks like I found my knock issue. The pistons were contacting the heads. The long block is at the machine shop now. Going with the thicker .040 cometics.

 

[Squid4life]

How did you come to that? Could you see it on the heads or tops of pistons? Hard to tell, but I don't see any "contact spots" in the pics above. Good thing you caught it now though...

EDIT: Pic #2, on the far right side. Is that where it is contacting?

 

[NCTURBOS]

So the pistons were/are "proud" of the deck surface? Or it's a piston to valve issue? Was none of that checked when it went together the first time? Have you CC'd the heads as well?

I would take some measurements and do some math to figure the actual compression ratio while you're there...


K.

 

[DougsfastZ]

In the second picture, you can see the line running across the top of the reliefs, which is the edge of the chamber. I measured everything before putting it all back together, but I must of missed something. I didn't see any valve to piston contact.

 

[Squid4life]

In the second picture, you can see the line running across the top of the reliefs, which is the edge of the chamber. I measured everything before putting it all back together, but I must of missed something. I didn't see any valve to piston contact.

Ah, I see it now that you point it out. Clear as mud. :biggrin:

With that contact, is there reason to worry about possibly cracked pistons, beat up bearings, or bent rods? I assume you looked into that to be sure. Maybe it was just enough contact to slap that one side, just barely, and not enough to do any serious damage?

 

[DougsfastZ]

I'm hoping I didn't hurt any other parts. Everything is at the machine shop right now getting checked out. I'll install new bearings regardless.

 

[DougsfastZ]

Wow did I screw up on the last build.

All the machine work on the block is done, it had to go out to .030 (originally was .020 over). As I start doing calculations for a new set of pistons, I started inputing the numbers for my old setup. Sure enough, piston to head clearance was only .009". That explains the constant knock readings I had and the pistons smacking the heads. It was caused by a low deck height of 9.500", a thin head gasket (RJC's shim) sprinkled in with some oversights on my part.

Well you live and learn. I'll be going with off the shelf .030" over CP's, new static CR will be 9.3:1 and I'll run a cometic .040" headgasket.

It's only money, right?

 

[Squid4life]

Glad it didn't hurt more. That could have been pretty bad. All the rods were good to go?

 

[87we410877]

Awesome. My diamond peice of sh*t piston broke in the exact same location. NOT hitting the head. Check out "broken diamond piston" in the engine section