Block damage What would you do?"
08-08-2010, 01:18 AM
#1
Rennlist Member
Thread Starter
Block damage What would you do?"
During the DFW tech session on Sat. we started working on John Leidel's white 88. While attempting a pan gasket change we discovered that the car had severly bottomed out at some time in it's life, cracking the block lower girdle in two places (see pics). Both damage areas were repaired with JB Weld (DAMN PO's). Both areas were a source of an oil leak at the pan gasket.
After all the sobbing was stopped we came up with several different action plans. The DFW crew has done a lot of wrenching, but we've never run into this problem and need the wisdom of the Rennlist group.
Plan "A" - JB Weld the thing back together and drive it like you stole it until it dies from old age.
Plan "B" - Get a "Pro" welder in there with the engine installed and build up and repair the two area. Don't know if that is possible but we're going to have a welder look at it.
Plan "C" - Replace the lower girdle only (?) with new main bearings and hope for the best. Can this be done, is the girdle and block line bored as an assembly?
Plan "D" - Replace the entire engine with either a short or long block.
Here are the pics. Who has "Been there Done that"??? AND what would do if it was your car?
After all the sobbing was stopped we came up with several different action plans. The DFW crew has done a lot of wrenching, but we've never run into this problem and need the wisdom of the Rennlist group.
Plan "A" - JB Weld the thing back together and drive it like you stole it until it dies from old age.
Plan "B" - Get a "Pro" welder in there with the engine installed and build up and repair the two area. Don't know if that is possible but we're going to have a welder look at it.
Plan "C" - Replace the lower girdle only (?) with new main bearings and hope for the best. Can this be done, is the girdle and block line bored as an assembly?
Plan "D" - Replace the entire engine with either a short or long block.
Here are the pics. Who has "Been there Done that"??? AND what would do if it was your car?
08-08-2010, 01:42 AM
#3
Team Owner
you cant swap out the girdle its bored as part of the block assembly, This repair will depend on the welders skill .
I dont know if the girdle is made of the same material as the block as it does a different job and when its cleaned it looks different than the block.
I have seen some welding jobs on the girdle so it may be possible to repair this in position
I dont know if the girdle is made of the same material as the block as it does a different job and when its cleaned it looks different than the block.
I have seen some welding jobs on the girdle so it may be possible to repair this in position
08-08-2010, 01:46 AM
#4
Nordschleife Master
That's a tough one.
A full engine replacement will be a lot of money.
Replacing the lower girdle is the same thing plus machine shop work. The girdles are machined to the blocks and are not readily interchangeable.
Welding it might warp the girdle. It may be a weird alloy, too.
Plugging the hole, putting cardboard on the garage floor and being happy is probably the right approach. Wait for something major to happen and then swap the engine.
A full engine replacement will be a lot of money.
Replacing the lower girdle is the same thing plus machine shop work. The girdles are machined to the blocks and are not readily interchangeable.
Welding it might warp the girdle. It may be a weird alloy, too.
Plugging the hole, putting cardboard on the garage floor and being happy is probably the right approach. Wait for something major to happen and then swap the engine.
08-08-2010, 02:10 AM
#5
Three Wheelin'
Welding this won't be easy. Is the cradle the same alloy as the block? I would think so for the same expansion rate? You would need someone that
has done these before. Also, with the high silicone content once heated, the cracks could travel.
I think this alloy is Reynolds 390?
A possible solution might be looking into something like this:
http://www.devcon.com/prodfiles/pdfs/fam_tds_101.pdf -Worth a phone call to see if they recommend it around hot oil etc.
If you could get it patched & maybe bond a thin piece of aluminum larger than the patch area to the inside/ outside it should seal up.
Any chance of making some braces to go from under the head of the alt & a/c comp mounting bolts to a bolt or bolts in the area to spread out the stress & take the load off this area so that all it has to do is seal up?
No easy solution - hope it works out for you
has done these before. Also, with the high silicone content once heated, the cracks could travel.
I think this alloy is Reynolds 390?
A possible solution might be looking into something like this:
http://www.devcon.com/prodfiles/pdfs/fam_tds_101.pdf -Worth a phone call to see if they recommend it around hot oil etc.
If you could get it patched & maybe bond a thin piece of aluminum larger than the patch area to the inside/ outside it should seal up.
Any chance of making some braces to go from under the head of the alt & a/c comp mounting bolts to a bolt or bolts in the area to spread out the stress & take the load off this area so that all it has to do is seal up?
No easy solution - hope it works out for you
08-08-2010, 02:20 AM
#6
Rennlist Member
Damn!! ... that must have hit hard! Imagine what the sump and everything else low slung looked like.
Sounds like you've already started to explore the best first step.
If it was me this is what I'd be thinking about each option ....
Plan A ... I personally wouldn't' bother going down the path of bogging it up with JB weld as it'll likely just lead to the same leak problems again. JL might consider this as an option though to buy some miles till the motor eventually comes out. It would give some time to source a motor and then refresh it before it eventually went in.
Plan B .... Nothing to lose in seeing if a good welder can do anything. He'd have to be a pretty good welder to build it up in situ though ... and then you have the issue of machining a flat face. Nothing ventured nothing gained ... and that would be the easiest relatively and cheapest more permanent solution ... as long as the girdle hasn't got any other hidden cracks .... ???
Plan C .... Wouldn't even think about it as you'd have to line bore the assembly and then fit oversized outer mains ... and I can't see them as an option in PET
Plan D ... If welding isn't possible .. replace it.
Hope the welding's possible
Sounds like you've already started to explore the best first step.
If it was me this is what I'd be thinking about each option ....
Plan A ... I personally wouldn't' bother going down the path of bogging it up with JB weld as it'll likely just lead to the same leak problems again. JL might consider this as an option though to buy some miles till the motor eventually comes out. It would give some time to source a motor and then refresh it before it eventually went in.
Plan B .... Nothing to lose in seeing if a good welder can do anything. He'd have to be a pretty good welder to build it up in situ though ... and then you have the issue of machining a flat face. Nothing ventured nothing gained ... and that would be the easiest relatively and cheapest more permanent solution ... as long as the girdle hasn't got any other hidden cracks .... ???
Plan C .... Wouldn't even think about it as you'd have to line bore the assembly and then fit oversized outer mains ... and I can't see them as an option in PET
Plan D ... If welding isn't possible .. replace it.
Hope the welding's possible
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08-08-2010, 02:33 AM
#9
Nordschleife Master
The lower girdle is a cast piece of aluminum and is line bored to the block.
It is not a special alloy and can be welded.
HOWEVER that said, you will have to remove the motor from the car for ANY fix to be attemted.
The damaged areas will have to be very very clean and free of all oil.
You do not need to worry that much about warping due to the fact it can remain bolted to the block.
This should also ONLY be attempted to be welded with TIG.
The cast piece will need some heat in the area, so it will want a little weld, then to cool for a moment before adding more. But it will keep the parent metal warm enough to ensure penetration.
After the welding has been performed, do not remove any of the weld from the outside or inside of the welded area.
The proper way to fix the mating surface is to have it milled. This will be difficult though without full disassembly.
Cleanup would also be a real nightmare.
I would use a NEW flapper disc on a grinder, and with only really the edge showing use the flapper wheel to smooth the surface. I would also have an assistant blowing compressed air to keep the particulars out of the inside of the block.
Then I would bolt it back together with the silicone OPG and hope for the best.
It is not a special alloy and can be welded.
HOWEVER that said, you will have to remove the motor from the car for ANY fix to be attemted.
The damaged areas will have to be very very clean and free of all oil.
You do not need to worry that much about warping due to the fact it can remain bolted to the block.
This should also ONLY be attempted to be welded with TIG.
The cast piece will need some heat in the area, so it will want a little weld, then to cool for a moment before adding more. But it will keep the parent metal warm enough to ensure penetration.
After the welding has been performed, do not remove any of the weld from the outside or inside of the welded area.
The proper way to fix the mating surface is to have it milled. This will be difficult though without full disassembly.
Cleanup would also be a real nightmare.
I would use a NEW flapper disc on a grinder, and with only really the edge showing use the flapper wheel to smooth the surface. I would also have an assistant blowing compressed air to keep the particulars out of the inside of the block.
Then I would bolt it back together with the silicone OPG and hope for the best.
08-08-2010, 02:48 AM
#10
Racer
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It just has to be Plan A. Nothing else for it, but to bodge it up and send it on it's way. At least it is not a structural part. Bog it up with some devcon etc. and drive it like you stole it knowing that at some time you MAY need a replacement motor.
N.B. this is exactly what I would do if it were mine, if it aint f#%&*d don't fix it !
At work right now, we have a $190 000 engine in pieces because someone thought they would fix a problem that had no effect on the performance of the machine. We are spending over $60 000 to fix something that was operating perfectly before it was pulled apart!
Cheers Roy
N.B. this is exactly what I would do if it were mine, if it aint f#%&*d don't fix it !
At work right now, we have a $190 000 engine in pieces because someone thought they would fix a problem that had no effect on the performance of the machine. We are spending over $60 000 to fix something that was operating perfectly before it was pulled apart!
Cheers Roy
08-08-2010, 02:57 AM
#11
Three Wheelin'
Lizard has the correct solution, mine was for an in car repair.
Have a look at Devcon, it's not retail store junk.
Worth calling them & discussing the repair.
If you do it, stuff a lot or rags in there to keep the grit out & cover the oil pickup.
If you get everything as clean as possible & really push it in to bond it, it will work.
Have a look at Devcon, it's not retail store junk.
Worth calling them & discussing the repair.
If you do it, stuff a lot or rags in there to keep the grit out & cover the oil pickup.
If you get everything as clean as possible & really push it in to bond it, it will work.
08-08-2010, 03:29 AM
#12
Rennlist Member
I would JB weld it again as a temporary fix to gain some time. Meanwhile I would look for a beaten S4 with an OK engine, extract it and rebuilt it. I would than sell the rest of the parts on Ebay to get some cash back.
I'm amazed that this JB weld trick worked for so long. Theses cars are very sturdy.
Except for another JB weld repair, the engine has to come out anyway.
I'm amazed that this JB weld trick worked for so long. Theses cars are very sturdy.
Except for another JB weld repair, the engine has to come out anyway.
08-08-2010, 03:30 AM
#13
Rennlist Member
I had my block sucessfully welded when the alternator bracket broke off a few years ago. This was easily done by a local welder in the back blocks of NZ.
I would think that welding it should not be too much of a problem for a good welder and this may even be able to be done with the engine in the car (mine was).
Your welder will be able to advise further.
Best of luck,
Myles
I would think that welding it should not be too much of a problem for a good welder and this may even be able to be done with the engine in the car (mine was).
Your welder will be able to advise further.
Best of luck,
Myles
08-08-2010, 04:03 AM
#14
Rennlist Member
A really good professional welder should be able to do it in situ. I've seen the work that professionals do at a shipyard here in Hobart where they build all alloy catamarans up to 100 metres plus long (some for the US military) ... it can be done overhead in situ by an expert welder who does that sort of work all the time. They can't put ships on a work bench ... that's the sort of welder you need.
