Cheburator

As per title, need a new one for sure... Anyone selling a good 2nd hand one, please pm me, alternatively is it worth getting a Moldex one? What is the waiting time on one of these? Any other sensible suggestions?

Thks in advance.

Jim M.

I didn't vote because I want to know more. What is wrong with your crank, did you spin a bearing or is it cracked? Can it be polished or turned down and go with 1st oversize bearings? Is it a rod or main journal? What was the failure mode, loss of oil pressure, debris or water in the oil?

GlenL

I voted "buy from Porsche" because I'm in a bad mood and can only imagine what they'd want for it.

Okay, I really want more information.

Cheburator

Crank is beyond salvation - 2/6 failure which left 1mm deep scouring on the journals and conrods 2/6 completely destroyed. By the looks of it no chance of a polish/oversize bearing job... Porsche want $BIG$ for a new one... Schoolboy error during measuring the oil level at the dry-sump tank starved the car of oil...

Jim M.

Wow, really sorry to hear that. Talk about a kick in the pants.
I think buying new from Porsche would be my last choice. What year is your car or more importantly what rods do you have. The early GTS rods must be replaced so you may be looking at rods, bearings and a crank. What is the general consensus on welding the crank journal and then turning it down to stock size? I admit I'm in over my head on something like that.

If you choose to go with the Moldex crank than for the little extra $ I think I would go for the 6.2 liter stroker.

Good luck with whatever you choose, and take lots of pictures and posts of your progress and all the steps. Help the rest of us learn.

Cheburator

The GTS engine was one of the last ever produced by Porsche - special pistons made by Kolbenschmidt with the oil holes drilled through, special sleeves made of alusil pressed into the block and 2R rods...

Any suggestions are welcome...

Moldex seems to be the way fwd, but I need to know the costs and the lead times...

TIA

Maybach_Man

karl ruiter

I think I heard somewhere that a S4 crank will work.

123quattro

I would seriously look at having it welded and machined. If you don't want to do that, I'd pick up a stroker crank.

FBIII

+1 on welding. If its a forging it can be welded. I had this done to a crank a long time ago and it was a viable solution monetarily on a crank that wasn't worth nearly as much as a GTS crank. They heat it up, weld it, straighten it and grind a new journal. Usually you end up loosing a tenth on the mains to get it perfectly straight.

GregBBRD

This is pretty tough. Since there were very few GTS models made and a large percentage of the automatics had "Thrust Bearing" issues...I'd guess that good used cranks are not common. I've got a customer with a complete engine (stroker engine going into the car), but I've suggested, to him, that he "store" the engine and not sell it.

New crank, from Porsche, is expensive.

Moldex takes 6-8 months to build a crank.

I try to keep 95.25mm stroker Moldex stroker cranks, in stock. This opens an entire new bag of worms....

I've got a GTS crank that had a terrible rod bearing failure, right now. We are currently checking to see if it can be turned to a more common rod bearing specification and thus be salvaged....

We've been talking to a crank builder about building a batch of GTS size (but not design) cranks, as replacements. Since the Porsche rod design and the rod bearings leave a bit to be desired, we are drawing up this crank in a different rod journal size. This will give a a larger selection of rod bearings to use, for high performance use. Obviously, the oiling design will get changed, also. This is months away, from having a product, so probably will not help you.

Vilhuer

Find some common smaller diameter bearing size and machine old crank to it. Then you need just custom rods and you are good to go. That is if main bearing surfaces are ok or at least can be saved with oversize bearings. Then again I do have one ok condition GTS crack around...

Silverback66

I voted for the stroker because that's what I would do if it were my car and you were paying for it. If it were my money, I wouldn't proceed until I knew the cost of welding and remachining.

How about reposting the poll with prices attached?

GregBBRD

Welding is a "used car lot" repair. No way to do that without all the associated stress risers from the beads of weld. It will break.

"Weld it only if you are going to sell it" is the phrase we use.

SwayBar

I know someone who has a good GTS crank they are not using; I will check.

Is this for the dry sump track car?