OK you 2.7 geniuses...

Ho Hum 74 · Ho Hum 74's Garage

When Porsche changed the case casting to incorporate the oil bypass mod in about '75.5 what springs and end caps for the pressure relief pistons did they use?

The reason I'm asking is that my 2.7 has one of these cases and has the solid relief pistons BUT the springs are the same length. "The book" says that the springs are of differing length but mine are not. My end caps are also the old style where you need a monster sized flat head screw driver.

What is the consequence of using the same length springs in these types of cases?

Thanks

Tristan

Fishcop · Fishcop's Garage

I don't know the consequenses, but I'd be inclined to order the updated kit which comes with new springs/pistons/caps. It's relatively cheap and will give you peace of mind.

Cheers

markwemple · 03-15-2004, 03:37 PM

I would say it depends on oil pressure. If it is fine leave it alone. If not.....

Wayne 962 · Wayne 962's Garage

Right - different oil pressure - you may have problems if you don't use the updated springs. If you use the old pistons, you will have severe oil pressure problems...

-Wayne

markwemple · 03-16-2004, 05:58 AM

With Wayne here. If you change the pistons you must use the upgraded springs. I did the mod and my oil pressure went up. Up to the point that my brother-in-law borrowed the '76 and detonated the oil cooler as my '76 woul peg the oil pressure guage for the first couple of minutes after start-up. My car didn't need it. That is why I am suggesting taking a second look.

Ho Hum 74 · Ho Hum 74's Garage

Thanks for all the info. Maybe I didn't get my question out correctly. In no way am I thinking about going with the two old springs but I'm wondering if this was the cause of my lower oil pressure issues.

Tristan

markwemple · 03-16-2004, 06:16 AM

The old ones have the same length springs. If you are having low oil pressure, go with the upgrade wayne offers as his kit is complete.

As to the cause, that could come from many things but if it isn't drastically low the upgrade will help.

Ho Hum 74 · Ho Hum 74's Garage

Er...My engine already blew up! Lost the #3 rod bearing at the track. Just thinking about all the probable causes.

Tristan