UPGRADE MY 86 3.2 to 10.5 COMPRESSION

El_Mecanico · 01-13-2012, 03:25 AM

Since I have already torn apart my engine for a thorough inspections I would like to upgrade it. Has anyone upgraded to EURO specs? What needs to be done to install JE 10.5 compression? I assume this would add about 20 HP. Any thoughts in benefits? Would I need to dual plugs. In my area 93 octane is available. Please your thoughts and If you found it to be beneficial?

Andy

drola · 01-13-2012, 05:39 AM

I've often wondered the same thing. someone out there must have done this

Tippy · 01-13-2012, 06:18 AM

Search engine rebuild section

LakeCleElum · 01-13-2012, 06:38 AM

My Max Moritz pistons (3.2) are 9.7. I use good fuel and total advance of 29 degrees. I'm fine, but make sure I don't drive in in such a way to cause it to detonate.

With 10.5, twin plugs might be a good idea.

IROC · IROC's Garage

I have 10.3:1 Mahle pistons in an '88 3.2 with single plugs. 93 octane is right on the ragged edge. I've had a tank of bad gas result in detonation and I use race gas at the track...

lonewolf · lonewolf's Garage

Mahle pistons only for me .
Never use JE. seen too many problems.

A lot of factory hipo engines from the 426Hemi to the 911 euro 3.2 use 10.23 to 1 comp ratio.
I think the factory euro 3.2 is the best choice for a strong hp and relliable motor.

El_Mecanico · 01-13-2012, 02:27 PM

I was tginking go euro spec but what exactly do I need to do

Canada Kev · 01-14-2012, 09:44 AM

My '87 RoW obviously has the Euro pistons/cylinders and single plugs. I don't have any issues with detonation on the 91 octane that we can get here. Mind you, our summer temperatures are usually lower than what you'll experience there. My elevation is about 2200 ASL, so that'll make a difference as well. Whenever I get out to the BC coast, I make sure I fill with 94.

Steve@Rennsport · 01-14-2012, 11:05 AM

Quote:

Originally Posted by syzygy

My '87 RoW obviously has the Euro pistons/cylinders and single plugs. I don't have any issues with detonation on the 91 octane that we can get here. Mind you, our summer temperatures are usually lower than what you'll experience there. My elevation is about 2200 ASL, so that'll make a difference as well. Whenever I get out to the BC coast, I make sure I fill with 94.

Wise man!!

Its a bit of a balancing act running high (over 9.5:1) compression, reasonable ignition timing, and dealing with hot weather using less than optimal fuels to avoid broken rings and pistons.

The rule is "Less is More",..

El_Mecanico · 01-14-2012, 05:15 PM

I guess I will than re-use my Mahle pistons and cylinders...they are in great shape. WOW these engines are so darn expensive. I split the case and completed a thorough cleaning and my curiosity decided to check out the oil squirter's in the process I was able to manage to jam 3 of them. I will need to find a local Porsche mechanic. Anyone know of a reputable Porsche Machine shop in Mobile AL or Pensacola FL?