Jim H.

I have an 04 GT3 street car and haven't yet had the fittings welded or pinned.

Thinking about a 6 cup this year...do they also need the fittings pinned or welded?

Thanks,

Jim H.

bgiere

I had mine done...They were fine upon inspection...I know a few people that have had them pop on 996 cup cars though. I'd do it.

spiller

My understanding is there are a less fittings on the cup compared to street so less points of failure. Most if not all people in my location run water with a slight (1-2%additive) so it's not common practice. I've had three different coolant hoses fail on two separate occasions and each time it was a rubber hose, not the aluminium fitting. I replaced every hose with new but did not do the fittings. As an experienced Porsche mechanic said to me once, "could it happen, yes, but your tyre could do flat too".

Phokaioglaukos

The 996 cups need need welding (pinning is not as effective, IMHO). Same adhesive used in the coolant manifold as in the street car, and both fail with track time.

The dealer replaced the failed part under warranty on my 996 street car and my shop welded the part on the 996 cup car after it failed during qualifying, ending the weekend early. The welding of thin to thick aluminium is not easy, so make sure the part is pressure tested before re-installation.

rbahr

Jim H. 996 GT3 based engines (street or track) need the lines pinned / welded (I happen to think both are effective) ESP if you track them

Hi Chris,

I would like to understand why you thins pinning is not as effective as welding

Thanks

Ray

Phokaioglaukos

See the attached article about the issue and the options. If the bonding agent fails with a pinned joint it seems to me that leakage can occur. I believe good quality welding is a permanent solution, and worth the work so that dropping the motor to do a second repair is not necessary. That, and it's what I did on the cup car so I have to defend the decision! :-)

rbahr

Thanks, I did see that article. I pinned mine for a number of reasons - that was ~10,000 track miles ago. Still going strong. That said, if you have a good welder, welding works very well.

Ray

fstockcarrera

Pinned 5 years ago no problems.

Rob S

My understanding is that PMNA does not weld or pin any cup engines during rebuilds: if the coolant fittings are factory original, they disassemble, clean, and re-glue, using green epoxy that they claim has never failed. It's 3M Scotch Weld 1838. With what has been many hundreds or maybe thousands of rebuilds since this became an issue, that's likely to be pretty solid footing.

rbahr

And here are the instructions, kinda looks easier to just pin or weld :-)

https://multimedia.3m.com/mws/media/...e-1838-b-a.pdf

Ray

EMGT3

The local PCA ( not sure if that is nation wide )will not allow a GT1 Mezger on the track without having the welded or pinned.. I agree the welding IS the way to go. The pin can still have a failure..

Ed@Demonspeed

The reason, I suspect, we see less failure on the cup motors than the street cars is that they see less heat cycles than the street cars. You will get maybe 300 heat cycles out of a cup motor before it is rebuilt (a high number considering 1/2 hour sessions and 100 hours to rebuild) . A street car can see 1000 every 10,000 miles (based on an average trip of 10 miles)

The failure still happens on cup cars. I have personally seen it many times.

EMGT3, that is local to your region. It is not part of the PCA DE min standards.

Thanks
Ed

MSTACH

I pinned my 9 years ago without any issues after 10k track miles

EMGT3

Hi Ed,
Yeah, I wasnt sure if that was a standard or not, just required for our region

rbahr

I am unaware of this requirement in the NER or NCR regions - although I think it is a good idea, having watched someone in front of me dump a bunch of coolant on a very fast part of the track

Ray