that is very interesting. ^^^

 

Another good write up....

Engine Basics: Detonation and Pre-Ignition

http://www.streetrodstuff.com/Articl...tion/index.php

 

In all my reading I have yet to read where detonation cause the ring land area of the piston to fail and break. It's usually this....

" The Keith Black pistons unique thermal conductivity, ring location and varied end use requires special attention be paid to top ring end gap. KB pistons make more HP by reflecting heat energy back into the combustion process and, as a result, the top ring runs hotter and requires additional end clearance. Increasing ring end gap does not affect performance or oil control because normal end gaps are realized at operating temperatures. Failure to provide sufficient top ring end gap will cause a portion of the top ring land to break as the ring ends butt and lock tight in the cylinder. The broken piece may cause further piston or engine damage. Safe top ring end gaps can be found by multiplying the bore diameter by the appropriate ring end gap factor from the clearance chart below.

Example: 4" bore "Street Normally Aspirated" = 4" bore x .0065 = .026 top ring end gap. NOTE: Second ring end gaps do not need extra clearance. Dyno and track testing has shown that 34 degrees or less total ignition timing makes the best HP and time. Excessive spark advance, lean fuel mixture or too much compression for the fuel and cam used will make heat sufficient to butt piston rings with as much as .060" ring end gap. The entire top land can expand enough to contact the cylinder walls, when close to melt down temperatures are reached."

 

Turn the crank and look to see if the ring gap changes substantially from top to bottom of the cylinder. If you can see a change in ring gap chances are they never bored the cylinders.

 

makes sense to me.

 

Well, engine is out and on the truck. Hopefully can get it to the machine shop tomorrow!! Pics below....


Lonely Vette again........



Loaded up and ready!!





Miscl. shots of different cylinders....notice the markings....

 

[QUOTE=MsVetteMan]Well, engine is out and on the truck. Hopefully can get it to the machine shop tomorrow!! Pics below....


Lonely Vette again........[QUOTE=MsVetteMan]

 

Is that one of the cylinders with a broken piston? If not I'd be curious to find out the cause of those vertical wear marks.

 

It may just be the angle of the picture, the ring 'gap' peeking thru the broken piston land does not look perpendicular to the cylinder wall, which would mean it is actually a break in the ring, and not the gap.

 

MsVetteMan I just hope everything works out well for you. Please keep us posted as to your results with the warrenty. I in no way can see how it is your fault or your cause for the failure. It would be impossible for the timing to be off that much and that soon to cause detination.
Wishing you luck with the outcome.

 

I thought I read in your other thread "Pull the motor with the tranny"? I see the tranny still in the car? Why the change of mind?

 

Batsy....It was quite easy to get to the bellhousing bolts with both the heads off, that is why I left the tranny again!! With the heads on, you can only inch the bolts a little at a time, and can't get your hand on them.

Came out much quicker this time!! Nothing like experience.



Other questions.....the vertical marks are on the #3 cylinder which had the broken piston top, but no break in the cylinder wall.

Thanks once again for the support guys, and it means more than you realize!!

I was a novice vette owner just a year ago who knew how to do nothing more than change the oil. With the help and encouragement of members of this board, I have now pulled two engines, replaced one, and will do a second reinstall shortly!! Bottom line, this board is awesome!! I'm still learning, but I went from a looking at a head swap as a major task, to now it would be a piece of cake.

Nothing like hands on experience!! Oh....I have had some help from some good friends that have guided me as well, and one in particular who was riding shotgun when the engine misfortune happened.

For you new wrenchers.....don't be afraid to jump in and just "do it". Read this board, ask questions, and be willing to take advice. You would suprised at the $$$$$ you can save by doing some of your own major projects!!

Hopefully this message thread has educated a few, as I know it has me!! Still learning, and wondering what the next project will be?? Tranny? (way to many parts!! ).

 

ever notice that the bolts come out easier the 2nd time around, MS? (sorry man, ya gotta be able to laugh in times like this!)

 

So very very very true!! Hey, I am now over the dissapointment with the failure, and looking forward to dropping some new power in again!! Out with busted, in with the new!!

 

I have been following along now, and can't wait to hear what your independant examiner has to say. Have you called that brother in law yet to start cashing in on those freebies?

Let us know as soon as you have more info.

DR. Jay

 

Most likely all Marshall will want to do is send you a replacement engine. Are you going to accept that or insist on a refund?

 

It's the thought of having to pull that motor out again in such a short period that really kills me. I firmly believe your gonna make out just fine as far as the warranty goes. Then your gonna have to install the new one , in an out twice in a short period makes my back hurt just thinking about it? Now lets look forward a little and think positive! Does the warranty say whether you get a refund or a replacement motor? If you get a choice are you considering maybe buying a motor elsewhere?
ESU

 

What a great thread! We're all behind you MsVetteMan! The Forum is one awesome place. I've got Chilton's, the Assembly Manual, and the Shop Manual and I know I've learned more from you guys on the Forum than all three combined! Good luck!

 

......Following closely here in Canada

 

Cant wait to hear what they say monday. Hope it works out, They better take care of you or they are gonna have a heck of alot of bad press!!