I did a search, but didn't find it... can someone provide the link?

 

There's no chance the one's on the ebay source are knock offs is there???

 

Not really, they are a reasonably well known source for race componants

 

Can someone confirm the procedure for installation of these? Does it require you to assemble and install the engine, turn it on, get it to temp, turn it off and let it cool, and then pull the top off it to get back to the ARP's just to re-torque them? This seems excessive and expensive. About 6 hours labour the next day?

 

Raceware does indeed specify a re-torque after heat cycling. I've done it several times, and only once found a nut very slightly under-torqued. Now I just torque them all above what they specify and leave it -- haven't had a problem.

 

The threads on my Raceware head & main bearing studs were wrong - didn't fit my block - total waste of money.

 

In the interests of fairness, Raceware are fine, but their standard kit only covers 951's up to '88 inclusive & therefore the threads were incompatible with my UK 1990 car.

Apparently their stud kit for '89 - '91 Porsche 951's are special order only.

 

Sounds like you just got the wrong ones. I've used them in plenty of cars, and have never had a problem. I think all the 951 studs are the same through '89, inclusive. When I called Raceware for '89 2.7 studs (twice), they shipped them almost immediately and they fit like a glove, so "special order" wasn't really a big deal.

 

The 44.52 engine was manufactured 1988- 91 but apparently the stud threads changed at some point in '89.

I was stupid enough to think the the studs described as working in any 944 83'-88' and 944 Turbo would be fine in my '90 - WRONG.

I've never seen anyone mention this - if your 951/952 is MY 89 - 91 the existing Raceware studs will not thread - you need to place a special order.

An expensive mistake.

 

Porsche lists the same part number, 944 101 197 00, for the M44.51 and M44.52, at least in the US-version of PET. I can't speak to the post-'89 turbos outside the U.S., but I've never seen or heard of a US-spec 951 with different threads, regardless of year. What part number or threads did your '90 need, if not 944 101 197 00?

 

Probably they sent studs for different car altogether. I had all versions of blocks and same thread is used on all of them.

 

It turns out that some of 1990-91 951/952 blocks used 968 main bearing studs with a 12 x 1.75mm thread pitch compared to the standard 12 x 1.50mm thread pitch.
Unfortunately mine was one of those!

I've got the factory main bearing studs back in now but have sourced the Raceware 968 studs.
There's a strong argument for using new OEM head studs as they're a stretch fastener which does well accommodating the expansion & contraction of the block & cylinder head.

 

Ah, main studs.... My comments were limited to the head studs, which I believe are the same on all US-spec 951's. If you say the main studs are different on the '90 and '91 turbo motors, I have no basis to doubt you. We don't have those here, unfortunately.

 

Correcto mundo - the '90-'91 head studs are same as for all the 944's but it seems they transitioned to the 12 x 1.75mm pitch thread on the main bearing studs
in advance of adopting this thread size for the 968 which would have been nearing the end of its development.

 

I’m surprised no one has mentioned race wares spec of 65 ftlbs vs arp that calls for 100ft lbs? And the fact that arp have the nice Allen head on top to turn the stud... I’ve used both, I like arp. As far as the mains, not needed.. I do wish someone made a bottom end nut and washer kit and the small bolts.. cause I keep losing them in my parts bins..