Hello guys,

Well.. I finally had my engine out today... I disassembled everything...

I found out that after just 3-4k miles the engine was a bit beaten up to my taste....

I have change the oil more than 6 times, to say a number....

I have use Mobil 1 10w-30 each time.

I found out that the wear on the piston skirts and cylinder walls was more than what I thought... I found a heavy sludge of metal with oil on top of the pump pick up and the such...

I am a bit concerned with the wear on the piston skirts and cylinder walls...I went to a friend who has a shop and he told me that the piston wear is normal and that this is a Hi-po car and its not a 300rwhp car. He also told me that high power cars he had done were the same and that his car was the same in that situation (he has a probe GT 89 that we are aiming for 400rwhp). Im going to send these pistons to be coated top and skirt.... so I would hope that the wear is less.

I found that the bearings were extremely worn out and I didn't like the way they looked... They looksed really worn and not indicative of a 3k mile engine... I thought that with the proper maintenance this could be avoided.

I was unable to take pictures of the walls, but here are the skirts

These are the pics of my piston #3

http://netdial.caribe.net/~highland/piston1.JPG
http://netdial.caribe.net/~highland/piston2.JPG
http://netdial.caribe.net/~highland/piston3.JPG
http://netdial.caribe.net/~highland/piston4.JPG
http://netdial.caribe.net/~highland/piston5.JPG
http://netdial.caribe.net/~highland/piston6.JPG
http://netdial.caribe.net/~highland/piston7.JPG
http://netdial.caribe.net/~highland/piston8.JPG

They are big...

Let me know what you guys think and what things to look for...

Thank you as always!!!

 

Those pistons look like they had 300k miles on them, I pulled apart my old blown 355 that was having some detonation and had about 25k miles on the trw pistons and they looked brand new with no wear on the piston skirts or anywhere else. What kind of parts did you use? It's kinda hard to tell from the pics but the rod bearings look a little tore up too. You shouldn't have any wear with that many miles even if it is high performance. I don't think I would have those same pistons coated and I would talk to another engine builder.

 

Well.... There seems to be a lot of wear residue in a form of sludge...

There is something strange there.. it looks like it was ran w/o oil at some point or something... not sure there. Not really sure what I should do...

It could have been when it was on the paint shop that I had to remove the supercharger for some body work and I had VERY LOW OIL PRESSURES.

and it looks REALLY recent that sludge...

My question is.. why not coat those pistons? i dont see anything "harmful" in those pistons there...

Anyways... Might as well get a complete new engine then! which means $$$$$

 

Don't do anything before you find out what went wrong with this one.

 

My only guess is this:

When I sent my car to the body shop from some body damaged I was requested to remove the Supercharger to clear space...I took the oil feed line and re-returned to the return pan.

Now.... The thing is that I began to see extremely LOW OIL pressures... around 10-15psi and lower... this was due to the fact that my oil feed to the supercharger didn't had the restrictor or jet on it... that is the ONLY guess.. because it looks recent...

Are new pistons REQUIRED????

Might as well get a new engine.. I do not like the idea of boring this thing over 30.

 

Low oil pressure was probably due to the worn main and rod bearings or sludge in the oil pump pick-up. As far as the pistons go they don't look like anything I'd put back in a motor Boring .030 over that won't hurt anything.

 

The low oil pressure was ONLY SEEN when I removed the supercharger.. never ever before... The bearings were perfect(I assume) as did a very good break in and I did all the required meintenance.

What im saying is that my engine is bored to 30 over and i dont want to bore it more than that.

 

My 385 is .040 over and have not had any problems , I've seen some people go .060 over but that maybe on the ragged edge.

 

What about overheating??? etc etc etc? I am a bit concerned about the boring at 0.040 when I want to put a lot of power in there. My goal is in the 700rwhp range... I dont want to build a time bomb...

 

I've actually seen much worse run fine.

I would sand the damaged areas radially with course-grit sandpaper to put the small machining grooves back in it. These tiny ridges serve to retain oil.

After sanding, measure the OD of the piston near the bottom. It should be around 4.024" - 4.026". If it's down to 4.022" or less, they're probably dead. You can probably get a better spec' from an engine rebuilding manual, Chilton's/Haynes, or the piston manufacturer.

I'd bet the damage was done with the low oil pressure. Joe Bob at the body shop probably rev'ed it up a few times to hear "them pipes on that there hot rod".

The bearing damage especially indicates this. If an engine has oil pressure, the bearing will never actually contact the crank. Any wear you see on a bearing occured without oil. I've seen 100,000 mile bearings look like new. We run gas turbines at 3600 rpm for 10 years straight producing 90,000+ hp, take the bearings out and they're untouched.

Have you measured the bore? If it's still 4.030" - 4.032", you could consider honing it and putting new .030" over pistons back in. Anything over 4.032" after honing is probably too much.

Mike

 

That is exactly what we are trying to check out now...

The pistons were checked today by my "local" machine shop and he told me that it was really NOTHING on those pistons... he was going to mesure the bore and mesure the pistons and see if the clearance is fixable... there is only one cylinder really #7 that did the most damage...

They couldn't have reved it because I reprogramed it with a max RPM of 2krpm.

Anyhow... for some reason the open loop tables were way off and it was extremely heavy with fuel and that liquified the oil.. which did the work...

My local shop told me that even the bearings were "ok" and the crank suffered 0.

So... they will measure everything up and "hone" it IF the tolerances are ok... The wear you see on the pistons appears to be augmented by the pics...

I'll keep ya posted.

 

Perhaps I'm missing something ... but what was the reason to pull the motor?

 

The reason to pull the motor was because I dented my oil pan jacking the car up...

Since I had the heads removed and I had the tranny out for a clutch change etc...I dented the oil pan jacking it up and I decided to remove it to upgrade my rod bolts while im at it and found all the crap i posted.

 

Sounds and looks like it was a good thing you dented your pan! Someone was looking out for ya.

 

I have to be honest... someone is always watching on me... someone likes my car very much and that is the personality I attribute to it

I am wacko.. i talk to my car and all.. and I always say it listens to me!! JAJAJAJAJJAJJAJAJA...