Pelican Parts Forums

Pelican Parts Forums (
-   911 Engine Rebuilding Forum (
-   -   factory 7r racing case prep? (

lvporschepilot 12-19-2017 06:19 AM

factory 7r racing case prep?
Hey all, someone had told me recently the 7r cases were never shuffle-pinned by the factory when run in race motors, rather pinning was only necessary for the earlier cases with less strengthening. I didn't know the 7r case was ever raced as it was my understanding when it came out in 73.5 the factory was then using aluminum 3L cases, can anyone confirm either?

faapgar 12-19-2017 07:19 AM

To shuffle or not
I have never seen any that were pinned.I had a factory 2.5 that was not pinned.Starting with the RSR engines the factory had the through bolts with a shoulder where the case halves met.There was a flat side which allowed oil flow but it was the shoulder that kept the case halves from moving hence a pinning effect.Ciao Fred

lvporschepilot 12-19-2017 07:31 AM

And that was a factory set up 7r race case? I would think there would be a market for those bolts with shoulders.

faapgar 12-19-2017 07:54 AM

Shouldered bolts
It was not a 7R case but 2.8-3.0 RSR.Looked into making them but it was just easier to pin.I would use the hollow dowels that hold the case at the flywheel end and install them in the through bolt holes.Simple and no movement.

lvporschepilot 12-19-2017 08:10 AM

I've seen them pinned that way, but it seems the shouldered bolts would be the most simple solution. Why on earth hasn't someone made these?

lvporschepilot 12-19-2017 11:43 AM

Is anyone else able to comment about web cracking around pinned areas after use? I'm hearing a lot of that here from the machine shop across from Road Atlanta. Seems, at least a this shop, they are not advocating it as the cracking at the webs totally destroys the block whereas when they're not pinned at least the block is savable when the webs aren't cracked. Interesting real-world stuff.

Steve@Rennsport 12-19-2017 04:31 PM

I've seen web cracking on mag cases regardless whether they have been shuffle-pinned or not. Its always in the same places, too.

Extended high RPM use is what does it.

MBEngineering 12-20-2017 02:31 AM

HI lvporschepilot

there you go, have just fitted a set to a 3.4 Turbo engine.

"I've seen them pinned that way, but it seems the shouldered bolts would be the most simple solution. Why on earth hasn't someone made these?"

BS Motorsport

you could contact Neil as he is often across in the USA, for more info'

regards mike

lvporschepilot 12-20-2017 06:05 AM

That’s really outstanding. Glad to see someone did this.

faapgar 12-21-2017 04:13 PM

Cool through bolt
So 102 Euro for 12?Cheaper than the pin job.I was quoted $95 apiece in the early 80,s.for 100 units at that time.Ciao

faapgar 12-21-2017 05:08 PM

11 bolts my bad.Ciao Fred Merry Xmas to all.

All times are GMT -8. The time now is 05:14 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.