blown engine salvage

C

Campbell

New member
I had an engine blow the #2 rod thru the block and make a mess. I want to salvage all I can from it, anything to watch for? Anything that automatically should be scrapped? Thanks
 
The entire bottom end... If that was worn enough to fail then I would be worried the other parts are not far behind, but that is just me.

The head I would send to a machine shop and have rebuilt and checked for cracks/warping ($300 or so). Find a new bottom end cheep from a running car ($50 - $100), change the crank bearings, rings, and hone out the cylinder walls... you now have a new well built motor and a spare head!!!

Raymond
 
Yes, I will have the head checked - the piston did slap it and crack. I am savings all the flanges, sprockets, oil pan, etc. It looks like the other 3 piston heads are okay - not sure if the rods were affected. I am going to take the oil pump apart and check it out, it was new. The windage tray has a hole ripped through it where the rod cap hit, it's trashed I guess. Just wondering if I should trash all the internals (rods, pistons, oil pump) or try to keep them. thanks
 
Why keep any of that? If you are going to get another new/used motor it will have all that stuff on it. If you are going to get new/new parts to replace the ones that failed you are into big $, so do all of it or none of it. I can see keeping the oil pan just incase you damage another one.

This summer we have had to move everything, and we are saying over and over, why did we save that? If you need those parts, then you again have bigger problems and will be starting from scratch anyhow...

Raymond
 
VW motors are cheap enough. Take any of the stuff that bolts to the block (flanges, pulleys, etc.) off and junk the rest. No point in spending $300 at a shop on an essentially stock head when you can buy a whole motor for that much, and you need a new bottom end anyway.

BTW, let me know what you need, and I might be able to help you out. I have several motors for sale.
 
I used to save oil pans and valve covers, but it's pretty rare that you ever get a engine, aside from a crate deal, that doesn't have them. I guess that's why I've got a big stack of both, after recently digging out from under piles of used parts, I've started re-evaluating what I keep and what gets tossed, or put into the big bin of "hey dude buy all these parts for only $1 and you pick them up and take it all." I'm happy to say that I'm now pretty much De-Junked! :023:
 
Bigger quesiton, is why did it ventilate the block? Normally the weak link in the VW motor is the #3 rod bearing, not the #2.

Did you notice low oil pressure in the turns? Funny sounds before it blew? Engine "straining" or loss of RPM's or power prior to the ventilation? Did you zing the motor and stretch the rod bolts?

I'd figure out what happened before you rebuild, so you can avoid the same situation again.

Loss of oil pressure, un-torqued bolts, poor bearings, etc. all might point at what caused the failure.

I've never ventilated a block, but have spun the #3 rod bearing twice, before I realized that I was starting the oil pump without a baffled oil pan. This was back in 1993-1994. Once I got a good pan and a high capacity Melling oil pump, the problem solved itself.
 
Tim, it was a very uneventful failure - going down the back straight at high rpms in 5th, started to lose power at the end and when I braked and downshifted to turn the car quit, but no noise. Let the clutch out and thats when it started to bang a bit, I put the clutch in and rolled to the side with smoke coming through the the hood cracks - again not much. My first reaction was that a half shaft broke till I saw smoke. I think it was the bearing - the oil pump had one season on it. I already picked up a donor motor and am having it bored out for new pistons. thanks
 
Started to lose power at the end and when I braked and downshifted to turn the car quit, but no noise.[/b]
Click to expand...

Loose power or loose RPM's? When I spun the bearing, I did feel the the engine was "straining" and lost RPM's going up the hill from Turn 6 at Laguna Seca.
 
Tim, good way to describe it - I did lose rpm's and started slowing so - was wondering what was happening. The crank journal for #2 was dark grey and gouged while all the others were still shiny. Sounds like a bad bearing.

Tim, good way to describe it - I did lose rpm's and started slowing so - was wondering what was happening. The crank journal for #2 was dark grey and gouged while all the others were still shiny. Sounds like a bad bearing.
 
We just went through the same thing on the Gprod car at Grattan. Spun #3..you're better off starting over with a new block and save the head as a spare. What do you have? I have a couple spare engines and am in your neighborhood (northwest suburbs) Lots of leftovers from 12 years of IT racing.
 
If you had a lot of scrapnel in the motor, toss the oil cooler and lines. Same thing if you use an Accusump.
 
remove the head.. look at teh combustion chambers.. see if you see any piston to head contact. check teh valves.. bring the bottom end to a recycle center to get some money back.
 
A common cause of rod bearing failure can be from detonation. This can be caused by a lean mixture in one cylinder, too much timing with a poor octane fuel, or by an engine that has a cylinder passing oil through the rings or valve guide. This slight amount of oil can add BTU's to your mixture causing detonation. Beside detonation not being good for the pistons, it can cause the rod bearing shell to start to close in on itself and actually squeegy away the oil from the journal leading to failure. Think of it this way. Set a rod bearing shell on the bench. Start tapping the center of it and you can see the ends start to move in. Some engine builders will actually thin this area of the rod bearing shell to help avoid this. Sorry for your engine loss. Most likely the there is an imprint of the piston crown in the head that will show up with machining. If you want to put the head into service, have the valves checked to be sure they were not bent as well. If so, replace the guides. Don't ask how I know. Regards. mark
 
I was able to salvage the head - a bent exhaust valve was all. The block and crank were ruined and I removed and cleaned everything else. Not sure why it happened but it was a mess in there.. thanks
 
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