Removing/replacing cylinder heads
Rennlist Member
Joined: Jul 2008
Posts: 3,098
Likes: 1,456
From: Near Hamburg-Germany
My friend Jochen says CIS euro engines fail because the vacuum ignition timing mechanism doesn’t work properly.
Than ppl in an recent Facebook discussion are arguing their S don‘t need high octane fuel, no wonder a lot of the engines are broken.
Pinging destroys the pistons.
Than ppl in an recent Facebook discussion are arguing their S don‘t need high octane fuel, no wonder a lot of the engines are broken.
Pinging destroys the pistons.
Last edited by Darklands; Apr 14, 2024 at 04:44 AM.
Archive Gatekeeper
Rennlist Member
Rennlist Member
Joined: Sep 2002
Posts: 18,866
Likes: 4,084
From: Irvine, CA
If you bore that block oversize, then you need oversize Porsche pistons- I'm not sure that Porsche has any 97.5 mm or 98 mm Euro pistons available. So the other option would be sleeving and running aluminum pistons.
For the time and money involved, I'd probably go find another good (I know that's a tall order...) M28.11/12 short block and build up a motor around that. I think James Izzo may(?) have one. Or you can check with 928Intl but I'm not sure Mark has any right now.
For the time and money involved, I'd probably go find another good (I know that's a tall order...) M28.11/12 short block and build up a motor around that. I think James Izzo may(?) have one. Or you can check with 928Intl but I'm not sure Mark has any right now.
Thread Starter
Racer
Joined: Sep 2017
Posts: 288
Likes: 20
From: San Francisco
If you bore that block oversize, then you need oversize Porsche pistons- I'm not sure that Porsche has any 97.5 mm or 98 mm Euro pistons available. So the other option would be sleeving and running aluminum pistons.
For the time and money involved, I'd probably go find another good (I know that's a tall order...) M28.11/12 short block and build up a motor around that. I think James Izzo may(?) have one. Or you can check with 928Intl but I'm not sure Mark has any right now.
For the time and money involved, I'd probably go find another good (I know that's a tall order...) M28.11/12 short block and build up a motor around that. I think James Izzo may(?) have one. Or you can check with 928Intl but I'm not sure Mark has any right now.
I’m open to sleeving and running different pistons. Are there drawbacks to doing that? Does it open up more options for pistons?
Archive Gatekeeper
Rennlist Member
Rennlist Member
Joined: Sep 2002
Posts: 18,866
Likes: 4,084
From: Irvine, CA
Yes, cast iron sleeves allows the use of uncoated aluminum pistons. Dry iron liners plus aluminum pistons modeled after the originals, with the same compression height would allow you to use the original rods. Not sure about how lighter pistons would affect balancing the motor.
Drifting
Joined: Mar 2010
Posts: 2,605
Likes: 360
From: Holden Beach, NC
Are you saying you were driving the car and it was just running a little rough with several broken piston ring landings? I don’t see how it wasn’t just pouring out smoke with oil blow by and no compression/no start and GB says all the Euros pistons have broken ring landings? Does not seem possible. Gunar
Thread Starter
Racer
Joined: Sep 2017
Posts: 288
Likes: 20
From: San Francisco
Are you saying you were driving the car and it was just running a little rough with several broken piston ring landings? I don’t see how it wasn’t just pouring out smoke with oil blow by and no compression/no start and GB says all the Euros pistons have broken ring landings? Does not seem possible. Gunar
I did a compression check before the tear down and the two worst cylinders were at 120psi while all others were 135 or so. The gauge is old, so I was only looking for correlation between cylinders. After seeing the pistons I bet the compression numbers were actually correct.
Last edited by camelman; Apr 14, 2024 at 04:37 PM.
Thread Starter
Racer
Joined: Sep 2017
Posts: 288
Likes: 20
From: San Francisco
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
Thinking of Buying a Porsche? Do These 10 Things First
Joe Kucinski
Pixar Pals Turned Into 1-of-1 Porsches!
Michael S. Palmer
Theon Goes Full Carbon Fiber With Stunning New Build
Verdad Gallardo
Genius Porsche-Themed Gifts That'll Make Any Dad or Grad Smile
Joe Kucinski
10 Used Porsches Are Selling for Way Too Cheap
Joe Kucinski
Tuner Is Converting Porsche 911s Into Shooting Brakes
Verdad Gallardo
This Coachbuilt Creation Is A Modern Take on the Legendary Porsche 917
Verdad Gallardo
Is This Convertible Cayenne A Steal, Or A Returnless Investment?
Verdad Gallardo
10 Best Non-Flat Six Porsches You Can Buy For Under $100K
Joe Kucinski
Archive Gatekeeper
Rennlist Member
Rennlist Member
Joined: Sep 2002
Posts: 18,866
Likes: 4,084
From: Irvine, CA
Greg can certainly repair this engine, you'll end better than new- Bore the block, Nikasil plate the cylinders (Nikasil is a plating process, not a spray process), spec custom pistons (and rods, and crank, and cams, and valves, depending on your WYAITitis), then rebuild the whole motor. The slippery slope is that you end up with a full-on stroker motor . Nothing wrong with that.
Thread Starter
Racer
Joined: Sep 2017
Posts: 288
Likes: 20
From: San Francisco
Greg can certainly repair this engine, you'll end better than new- Bore the block, Nikasil plate the cylinders (Nikasil is a plating process, not a spray process), spec custom pistons (and rods, and crank, and cams, and valves, depending on your WYAITitis), then rebuild the whole motor. The slippery slope is that you end up with a full-on stroker motor . Nothing wrong with that.
Thread Starter
Racer
Joined: Sep 2017
Posts: 288
Likes: 20
From: San Francisco
Rebuild or replace my smog pump
My smog pump is shot, and I want to replace it with a new or rebuilt one. I can only find them on eBay. Does anyone have experience running one of these?
https://www.ebay.com/itm/33408502746...3ac5ac465451cd
https://www.ebay.com/itm/36150095048...9aceeb0f431c19
https://www.ebay.com/itm/33408502746...3ac5ac465451cd
https://www.ebay.com/itm/36150095048...9aceeb0f431c19
Archive Gatekeeper
Rennlist Member
Rennlist Member
Joined: Sep 2002
Posts: 18,866
Likes: 4,084
From: Irvine, CA
Not familiar with the Oregon rebuilder. Mark has good rebuilds in stock: https://shop.928intl.com/Rebuilt-Smo...13%2D017%2D00/
RE: engine rebuild, you don't really _need_ to change anything other than having the block bored and Nikasiled, and get custom pistons that match the original rods (I imagine Greg is very familiar with the specs for replacement Euro S pistons). Everything else could get bolted back together. The question is always A) what other wear items will you discover along the way while you're that deep in the motor, and B) what upgrades do you talk yourself into while you're there?
RE: engine rebuild, you don't really _need_ to change anything other than having the block bored and Nikasiled, and get custom pistons that match the original rods (I imagine Greg is very familiar with the specs for replacement Euro S pistons). Everything else could get bolted back together. The question is always A) what other wear items will you discover along the way while you're that deep in the motor, and B) what upgrades do you talk yourself into while you're there?
The Parts Whisperer
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Joined: Nov 2002
Posts: 7,249
Likes: 542
From: Anaheim Ca
Thread Starter
Racer
Joined: Sep 2017
Posts: 288
Likes: 20
From: San Francisco
Not familiar with the Oregon rebuilder. Mark has good rebuilds in stock: https://shop.928intl.com/Rebuilt-Smo...13%2D017%2D00/
RE: engine rebuild, you don't really _need_ to change anything other than having the block bored and Nikasiled, and get custom pistons that match the original rods (I imagine Greg is very familiar with the specs for replacement Euro S pistons). Everything else could get bolted back together. The question is always A) what other wear items will you discover along the way while you're that deep in the motor, and B) what upgrades do you talk yourself into while you're there?
RE: engine rebuild, you don't really _need_ to change anything other than having the block bored and Nikasiled, and get custom pistons that match the original rods (I imagine Greg is very familiar with the specs for replacement Euro S pistons). Everything else could get bolted back together. The question is always A) what other wear items will you discover along the way while you're that deep in the motor, and B) what upgrades do you talk yourself into while you're there?
