Broken Piston tear down

[jub jub]

Great news. Thanks for the update!

[Dperreault]

So my buddy and I determined the lift of my cam and also checked the Bore tolerance.

First the lift on the cam is .340 super high lift. We were not able to determine the duration but Im going to call Comp Cams tomorrow and hopefully with the push rods that I have and the lift I might be able to get the direction from them. The push rods are Comp Cams parts so I'm assuming the cam is also. It's worth a try.

I'm so happy that the cylinder walls are nice and smooth and are all with in the rebuild specs. Now I don't have to remove and machine the block. I'm going to order 8 new pistons tomorrow. More to come.

[Dperreault]

UPDATE!!!

Here's what I found last weekend out about my engine last weekend. It has...

Custom ground_Cam
Lobe lift .340 x 1.7 = .578
Rocker ratio 1.7:1
Total lift .578
Still working on determining the diration.

Push Rods by Competition Cams
P/N 7955_
7.400 length
.080 inside diameter oil hole

Roller Rockers_
Yella Terra Ultra Lights
1.7:1

Valve Springs
Possibly_SLP
But I'm pretty sure they are after market that will Handle upto a .600 lift cam._

Purchased these yesterday.
Mahle LS1340898F04
Flat Top Pistons
Mahle Chevy PowerPak Piston Kit
Forged 4032 High Silicone Low Expansion Aluminum Alloy
Bore: 3.898''
Pin Diameter: .945''
-4cc Dome Volume
Comp. Ratio @64cc: 10.4:1
Precision Ring Grooves for Included 1.5, 1.5, 3.0mm Rings
Stroke: 3.622''
Rod Length: 6.098
Compression Height: 1.340
Weight: 394g

My pistons should be in on Friday. Need to de-glaze the cyclinders and plastiguage the Rod Bearings and then it's time to install. I can finally start reassembly.

[YumaZ06]

The only concern that I have about this whole deal is that the engine was not flushed out or the front timing cover removed and oil pump and associated areas cleaned. But that is just me....any residue filings or junk would definitley find their way into bearings (rod and main) through the oil galleries and I would hate to see you have to do this all over again. I really don't know any other way to completely clean out the block other than remove it and have it flushed. Maybe I am anal about this, but I'm from the old school and that is the only way to completely ensure that nothing remains to cause problems.

[fcar]

Anal and prudent are not necessarily the same and both can be wise. The correct/right procedure(s) are usually cheaper, more long lasting and better performers than the alternative.

[SRK]

Originally Posted by YumaZ06

The only concern that I have about this whole deal is that the engine was not flushed out or the front timing cover removed and oil pump and associated areas cleaned. But that is just me....any residue filings or junk would definitley find their way into bearings (rod and main) through the oil galleries and I would hate to see you have to do this all over again. I really don't know any other way to completely clean out the block other than remove it and have it flushed. Maybe I am anal about this, but I'm from the old school and that is the only way to completely ensure that nothing remains to cause problems.

I agree completely. In addition the "de-glaze" should be done with an expanding hone and produce a plateau finish, and that type of hone assembly is not normally available to the home mechanic. The old spring loaded type hones are not suitable, and even the ball hones, which are better, are still not good enough. Modern piston rings require extremely smooth bores.
And then there is cleaning the bores with the engine assembled....

[Dperreault]

You guys are killing me. I'll talk to my buddy. You are all probably right. I just hate to do it. I'm sure I'll end up breaking some line or a vac tube or something like that but it make sence for the long term. CRAP!

[XFordGuy]

I'd think the risk of debris is pretty minimal if only the upper ring area of the piston was damaged. Nothing very big could have passed the piston and got to the oil. The concern over the quality of the hone is quite valid.

Just my $0.02

[Dperreault]

So you guys are saying there is no good way of de-glazing the cylinders without taking out the engine and giving it to a Machinist?

[racingvette]

You'll kick yourself if within a couple of months you find you should have taken the easy path with all this ripped down and not checked the condition of timing chain and doing that also allowed clean out all that carbon buildup oil as that piston was not a new failure

Did you find all the pieces from the broken piston ?
if not clean and assure nothing will clog up oil pump.

If pulling timing chain cover means then taking crank pulley off, long term best you then key the pulley to crank snout

[jub jub]

Just to deglaze, I would go with a simple set-up like this since you're using stock size pistons.



If I were going with the .005" oversize, I would use this, increased uniformity in the honing process.

[Dperreault]

Originally Posted by YumaZ06

The only concern that I have about this whole deal is that the engine was not flushed out or the front timing cover removed and oil pump and associated areas cleaned. But that is just me....any residue filings or junk would definitley find their way into bearings (rod and main) through the oil galleries and I would hate to see you have to do this all over again. I really don't know any other way to completely clean out the block other than remove it and have it flushed. Maybe I am anal about this, but I'm from the old school and that is the only way to completely ensure that nothing remains to cause problems.

Originally Posted by jub jub

Just to deglaze, I would go with a simple set-up like this since you're using stock size pistons.



If I were going with the .005" oversize, I would use this, increased uniformity in the honing process.

Thanks Jub, I planned on using the ball hone method. The rest of the folks on the forum have me second-guessing leaving the engine in. Also with the ball hone method I've been told it doesn't work quite as well as Hard stone hone. Since I'm going with the stock piston size I really can use the stone hone. Have you used the ball hone with success in the past?

[YumaZ06]

Originally Posted by XFordGuy

I'd think the risk of debris is pretty minimal if only the upper ring area of the piston was damaged. Nothing very big could have passed the piston and got to the oil. The concern over the quality of the hone is quite valid.

Just my $0.02

That may be true for bearings, but not checking the oil pump and cleaning out that area is just asking for trouble. And like racingvette mentioned, it is a good idea to key the pulley to the crank snout (if it hasn't been done already) to ensure the pulley doesn't walk and cause other problems.

[Dperreault]

Here's another update.

Who ever worked on my car last not only destroyed the engine but the broke the fuel rail valve stem. Here's a shot.


Also, I received my new forged pistons. Ya baby!

[jub jub]

Originally Posted by Dperreault

Thanks Jub, I planned on using the ball hone method. The rest of the folks on the forum have me second-guessing leaving the engine in. Also with the ball hone method I've been told it doesn't work quite as well as Hard stone hone. Since I'm going with the stock piston size I really can use the stone hone. Have you used the ball hone with success in the past?

Yes, it works fine for deglazing.