What is known about KS Aluminum Blocks?

I am dangerous. I'ben surfin' the net again... o oh.

I understand the 997.2 blocks are all KS low-pressure casting. Is this corrrect? All 911s? All Boxster/Caymens?

[www.kspg.com]

[www.kspg.com]

I also understand that my 2000 Boxster S had a high-pressure casting by the same company and this high-pressure system is faster, cheaper, and not as good. At least it wasn't good enough for the turbo and GT3 models. Is this true?

Any insights into this and Porsche recent history of engine design. Where can I look to read more?

Maybe I just need therapy.

Peace
Bruce in Philly

...were a totally different motor - the old, pre-water cooling "metzger" motor. They had water sleeves added (which had its own problems BTW).

So i don't know about the casting techniques, but as to whether it was good enough for turbos and GT3s - irrelevant. Totally different, dry-sump, hyper expensive, 20 year old, motor design that may or may not have had a different block casting technique.

its also why turbos and GT3s occasionally dump their coolant all over the race track causing multiple crashes.

G

Grant

gee-lenahan-at-gee-mail-dot-com

It's not a block issue with the GT3's and turbos. A couple of the coolant hoses on the engine are too short and they separate or split.There are new, longer replacement hoses There is also one ore two aluminum coolant manifolds that are epoxied together. The epoxy fails, dumping the coolant. The NHTSA is investigating this.

Ed B

Those blocks, the GT-1 motor, were air cooled. They added water jackets. To feed them the added metal coolant pipes. These pipes are fitted (7 fittings) using a sealant. Porsche claimed it was an adhesive, but the manufacturer disagrees. The sealant dries, and under pressure the fitting fails.

The important part of my post in the context of the OP's question is that the reputation of the GT1 (turbo, GT3) block is not necessarily due to some casting difference, but that it was an entirely different block, derived form the good old days of over-engineered motors. It was also a air cooled block, ergo the problem.

regardless of what NHTSA writes, that's the issue.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

Some personal observations as head of our PCA region's safety committee.
I've seen a number of failures of the coolant systems at DE events. (GT3, Turbos, 944s, BMWs Corvettes and others) The majority of the failures on GT3 and Turbos are with the rubber hoses at the rear of the engine at the water pump,
It is thought that there is enough movement of the engine on it's mounts to over stress the rubber hoses and cause them to split or come off the metal pipes. This has been confirmed by a Porsche dealer tech. The new longer hose fixed this. There is some thought that the strain on the sealant, glued, epoxy fastened aluminum "Y" fittings may be due to the stress from the short hose. I have not witnessed a "Y" fitting failure. Porsche has a "new" sealant, glue, epoxy that claims to fix the problem. Other fixes include pinning the pipes or TIG welding the joints.

While I haven't tracked my GT3, i guess I should update the hoses anyway.

Ed B.

We've *only* seen the metal tube come out of the water jacket. Most people here are, when other work is scheduled, TIG welding all the metal tubes. I have not (yet) seen the rubber hoses come off. I'll note it with safety.

We've debated a lot of potential rules (I run DE pre and on- track tech for NNJR PCA) - but have been re;luctant tpo place too many burdens on our members. One idea was to require water, not coolant (a typical true race requirements BTW), require inspections (but even on a lift you have access to at most 3/7 connections).

For now we simply asked every owner to discuss and dow what inspections are feasible with their shop. How much good that will do is debatable.

Thanks for the additional tip. Didn't know you ahd a GT3. Lucky you. Go on, take it otu and let it stretch its legs. You cant cage up a greyhound....

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

Grant,,
The hose coming off is rare. The split hose is the most common failure here in New England. UC region requires the tubes to be TIG welded.We warn everyone to change to the latest hoses.
Out west a couple of years ago, I did have the GT3 cruise control set on a three digit number. Felt great!

Ed B

"its also why turbos and GT3s occasionally dump their coolant all over the race track causing multiple crashes."

Our PCA DE had this happen last year at Mid-Ohio. Wipped out two cars, not the GT3 that dumped the coolant.
A 930 and a Cayman.

Not fun to explain to the insurance company.