FBIII

I ran a welded crank in an LT1 a long time ago. Spun that bugger to 7K without a concern. Outlasted me and the next owner. Devore's early 928 strokers had welded cranks. Nothing wrong with them if done correctly. Welding and hard chroming journals was the old state of art.

blown 87

Big if, and not sure of that, I am not willing to take a chance when I know of some that have failed.
Pretty simple math for me.

cold_beer839

Poll has the stroker vote nearly lapping the field.

BIG 928

hi alex, sorry to here about the crank. ive got a spare standard gts crank, someone from italy is interested in buying my gts race car. if the deal goes through ill sell you the crank, otherwise ill keep it. just need some new tyres and i can do a few rounds of the cscc future classic meetings. kinda hope it doesnt sell. ill let you know asap

thanks mark

Cheburator

Quick update...

Here is a picture of the offending 2-6 journal:


Spoke to Moldex, they claim that the journal can be fixed without a problem by grinding it down, welding it up, grinding it back down to size and then nitriding it. All in for $375 + shipping to the US and back

Also spoke to a British company, who claims that can grind it down, weld it back up to size and then grind to standard, but claimed that even if they nitride it, it would never be as good as the original. Costs $750 all in.

Finally, Farndon Engineering in Coventry, who work with Aston Martin and Bentley will make me a billet EN40B crankshaft drilled like a Chevy for $3000 and DEFINITE 12 weeks leed time. They also supply custom rods

Have been offered several 2nd GTS cranks, but I keep on thinking that I am almost better off repairing mine or going with Farndon.

Stroker sounds nice, but if I go down that route, it will mean that I will not race this season. I don't know where to start:

- which block is good for boring out? My GTS one is no good since it has liners already. I have a perfect GT one, but that has 4 liners on one side
- what stroke/bore do I need - my max allowed displacement is 6.2ltrs
- am I better off by going with steel liners pressed in, which would allow me to run pistons made by pretty much anyone?
- what mains/rod bearings should I use

US guys have the luxury of Greg, Mike and a few others, while in Europe we have to discover the hot water and the wheel at the same time so to speak...

Any advise / opinion gratefully accepted...

Jim M.

I believe that most prefer the 85-86 block because the walls are thicker. Also don't go to steel sleeves the different expansion rates cause problems.
I think I would be going with Moldex from what you describe.

docmirror

OPM is the best kind.

Lots of probabilities that we just don't have the sample size to quantify:

Failure rate of the welded crank
Failure rate of a new Porsche crank(yes, they have)
Failure rate of the Farndon crank(? a non-zero number)

We are supposing that the first has the highest failure rate. But how much higher? And at what cost do we avoid that 'potential' differential failure probability? If it were an aircraft where peoples lives are at stake, no question - new crank with full inspection. It's not aircraft, it's a car. Worst case, the block is destroyed and he sources another block and goes back again. Even with that, the price of going with the welded crank is still lower than the price of the new Porsche or new Farndon crank.

So, the cure is worse than the disease in this case. Go with welded, if it breaks, oh well.

Jim M.

Moldex is a well recognized company, they have been around for a lot of years and have an excellent reputation. They are in business for the long haul and have no reason to lie or sell you a bill of goods. Even for a track car I would trust their repair. Every thing in life is a crap shoot.

Cheburator

That's precisely what I am thinking - Moldex does not really need my miserly $500. In fact they should be better off that I need a GTS copy made by them at a cost of $2750. They have been in business for a while, so I guess they know what they are talking about... If all else fails, I have been offered a few GTS cranks, S4 blocks are two a penny... And I have an excellent GT engine on a pallette in my garage

Cheburator

In a bizzarre twist, Official Porsche Centre Reading in the UK has come up with the goods... They received a reconditioned GTS crank from Germany with 24mths waranty - std journal size at a cost, which makes all the 2nd hand options too expensive. I have to exchange the old toast crank, which is a shame as I would have loved to be able to try the Moldex repair, but at this price I cannot be a choser. Thus I have gone ahead and bought it... Keep your fingers crossed that the rest of the car built goes well.

Jim M.

Good choice, fingers crossed.

FBIII

Porsche wanted the damaged crank in exchange? Are they then in the business of doing the repair work themselves? Could a "reconditioned" crank be a fixed spun bearing crank?

123quattro

Hmmm..... Used crank sent to Moldex for $400 repair. Porsche warranties it and charges a premium to cover their possible liability? Not a bad deal for all involved.

Cheburator

I have been told on the QT that the crank is actually brand new... My initial plan was to pay the surcharge - $300 - and keep both cranks
However, Porsche AG appear to be smarter than I gave them credit for and said - no old crank with us, no new crank with you...

The price is not cheap, cheap, but I figured out that there is a new gasket set, new big end bearings, new crank bearings, two new rods and labour at risk. Moldex by all accounts are great, but there is uncertain lead time and the nagging doubt - would it hold and survive the main straits at Snetterton,the Nurburgring or Spa where the engine is really hammered like at no other track... The Porsche option offers immediate availability and a warranty to boot.

I doubt that Porsche are offering exchange cranks, which have been as badly damaged as mine, but what do I know...

Before the crank goes in, I think I will have it drilled like a Chevy...

P.S. I got it for 50% off list price of a new one, including the robbing basterds' 20% Value Added Tax

AO

Cool. Keep us updated.