Dan87951

Well I finally got the stupid engine out of the car wow is that torque tube long!! I think when the engine is done I will be putting it through the bottom! Anyways I found out why the engine was locked when we started the disassembly of the motor. The #3 piston and cylinder are several scored (see pic) also the ring on #3 piston is cracked or broken. However all the other bores look to be in good shape other than some light scoring here and there. The with all the pistons out the engine will spin freely and feels very tight. I guess my question is what are my options now that I have a scored piston? How much can I expect a bore and hone job to cost me? I’m aware these blocks need a special bore process done to them so who do I bring it to?

Mike B

Eeek...bad luck...I just went through a similar process...Oversize pistons (100.5 mm) cost me $1400 US from the dealer here...Boring, honing, polishing, etc the cylinders cost me about another $450 US or so...I found a place locally and it came out great...I now have a perfect block...unless I screw up the assembly, and i probably will, all should be good soon...

Ian had a set of 100.5 mm factory pistons a while ago for about $1250 if you're interested...Best of luck Dan..

John Anderson

that has to sting! Dan, I'll email you tomorow. As to your questions you asked me...I can do something for you...we need to talk about this and get you going.

Take Care

Perry 951

Dan, that scrape where the ring let go is very deep. Depending on how much material you need to remove will depend on piston size. IMHO, that is too deep for 1st over. You may need some custom pistons.

My origional block had a bad thrust face on the crank, and we needed to go to 102mm to get them round. The largest factory pistons availible are 100.5

All you can do now is send it out and hope for the best. I feel for ya! Good luck.

Dan87951

If it's to many $$$$ then I can comprehend I will scrape the block. Man this sucks...

Deepice

look at the bright side if you have to bore it go for the xtra displacement.

Dan87951

I can't because the pistons are special order which means $$$$$$$$$$$ that I don't have.

Bones944

Dan, contact me if you need a block, I think I know where one is for a very reasonable price.

John Anderson

Dan,

We have the pistons for a 106mm over bore, and a block....we can deliver asap...its not as expensive as you think :-)

Dan87951

John,
Please email me off the list I would like to discuss options. I was led to believe by many vendors that anything over 100.5mm is a “custom job” and would cost big money if I wanted to keep the current cylinders. I was also led to believe that I must use factory Porsche pistons (biggest is 100.5mm) in my block because of the special coating with the factory cylinders. So if my #3 cylinder can’t be rounded out by 100.5mm I’m screwed and would be considered needing a “custom” piston.

keith

couldn't you run 3.0 liter pistons (104mm?) ? to keep the costs down?

...but that would require custom rods, huh?

John Anderson

Dan,

YOur server keeps returning my mail...at least thats what I get back...are you getting my replies??

Dan87951

John wow returning your mail?? I will PM you.

smokey

If only one bore is damaged, another option is to sleeve the bad cylinder with a special aluminum insert and use a standard piston. The other three cylinders can be left as is. Henri Costa at Refined Motorsports in Toronto (416-248-9777) did this on his own 951 after the number 2 rod bearing blew on the track and the cylinder was damaged. There is a process for inserting an aluminum sleeve that brings the block back to spec. Henri can advise you and probably do the block if you want. It would be a lot cheaper than going oversize on all cylinders if none of the other cylinders is scored.

Wachuko

Dan, I just saw this post... man!! Sorry to see this happen.

Good luck with the repair!