Been away, forgot my password. :badidea:


But I'm finally starting to work on the engine again....

Found out the source of the blow-by this morning.

every piston on the pasenger side was cracked, and one drivers side. :mad:

http://superbike.dyndns.org/superbike/DSC01939.JPG

http://superbike.dyndns.org/superbike/DSC01940.JPG

http://superbike.dyndns.org/superbike/DSC01941.JPG

http://superbike.dyndns.org/superbike/DSC01942.JPG


So I'm out shopping for parts now. There's a seller on ebay that has a set of clevite pistons for $150 right now. No rings though. There's also another seller that sells mahle pistons with rings for $345. I've got an entire turbo setup off a 6.5 that I plan on running with a spring waste gate limited to 10psi boost. My IP was rebuilt prior to the engine damage. But could it have been misadjusted to cause this? I assume that the past owner's crew is the one at fault for the engine damage. The engine had been rebuilt ~30K miles prior. And it shows, other than the cracks. It's the cleanest engine I've ever torn down!

But back to the shopping issue, the engine ran fine prior to this except for blow by. Which piston should I run for what I plan? Also with how much gas is running these days, I'm thinking about only keeping it 2wd. My truck currently has the 4l60e transmission, is there a way to adapt it to work behind the diesel? IIRC the trans is computer controled, needs the stock speed sensor, and a throttle position sensor. Is there a way to adapt my 6.2 IP to a TPS sensor? Also does the trans need to know engine RPM as well? And how could I wire the truck to use the stock tach?

OK looking at prices, even if I did buy the pistons from the ebay guy for $150, the cheapest place I've found rings is about $190 so I'm already at the same price as the piston ring kit for $345.

Whats the better piston? Mahle or CLEVITE ?

Is it worth while to fork the extra $200 for the marine low comp pistons? Like I said, I don't plan to go over 10psi boost.

anyone?

Im listening, I just dont know the info you need, sorry. I do hear Mahle pretty often around the board, especially with the guys in the 6.5LTD area, the ones making 18:1 engines.

shame with all the cracks, that ones nasty looking

I'm thinking I'm just gonna go with the mahle pistons.

Here's the sellers webpage....

http://www.diesel-direct.com/product.php?prod_id=027480

how does that happen?...the cracks?

i dont have any personal dealings with them but Dieselchick has been having trouble with them, concerning her 18:1 6.5 rebuild.
http://dieselplace.com/forum/showthread.php?t=39124

dont they crack from overheating?

She sent her engine to be rebuilt, not buying parts? They have good ebay feedback except for two negitives, and those were over a year ago.

It's the same price on ebay as well, maybe I should buy via ebay, pay via paypal, and charge that to my credit card. Then I should have plenty of ways to secure I'll get them?

Yeah I noticed the ebay auction with the same prices. I would think that would give you some extra security going that way.

I coudl be wrong, but I thought I heard mentioned somewhere that Kennedy has them as well? something to look into.

Cracked pistons on a 6.2 can be caused from several things, 1) to much advance on injection pump, 2) poor quality aftermarket pistons. The military sued Silvolite for inferior pistons quality due to failures. I have also suffered failed pistons from silvolite(not pretty) Either mahle or clevite should be just fine. I noticed that the clevites that were listed, had an armoured top ring groove, that is a good thing. It also appears that your engine was driven with failed glow plugs(all the little dings on the top of the pistons):eek:

I vote for poor quality pistons too.

The pistons you have now are .020" oversized pistons, You might get lucky and go back with the .020" pistons again. To find this out you'll need to mic the new pistons and then mic the cylinders carefully to determine if you've got the right clearance, not too much, and not too little.

I vote for poor quality pistons too.

The pistons you have now are .020" oversized pistons, You might get lucky and go back with the .020" pistons again. To find this out you'll need to mic the new pistons and then mic the cylinders carefully to determine if you've got the right clearance, not too much, and not too little.

There's still a nice cross hatch on the cyl. No gauling or slap from the pistons, the rebuild only has 30K on it. I think poor pistons, and misuse was the failure.

I'd measure the bore, feed it some pistons & rings and go again! Like Dave said, it looks like glo-plug damage on some of them.

It also appears that your engine was driven with failed glow plugs(all the little dings on the top of the pistons):eek:

Can you explain? thats new to me and would like to understand how little dings in the piston are caused by glow plugs not working right.

only thing I know happening is unburned fuel.

Can you explain? thats new to me and would like to understand how little dings in the piston are caused by glow plugs not working right.

only thing I know happening is unburned fuel.

I Think its from the actual tip of the plug breaking off and falling into the cyl.

Correct! It's from that glo-plug you pulled out that didn't have a "tip" on it! That tip is what made the dents in the piston as the piston chewed it up and spit most of it out the exhaust.