Slight Cylinder Score
Thread Starter
Rennlist Member
Joined: Nov 2009
Posts: 8,659
Likes: 426
From: Dubuque, IA
Slight Cylinder Score
In inspection of my engine with the heads off there are several very slight, as in feel with your finger nail, scores in one of the cylinders.
score.jpg
So, do I leave them be? Compression check out as pretty darn good when Greg Brown did the PPI 2 years ago.
Pistons are covered with carbon. Gonna brush that off with brass brush and sea foam then shop vac out. You can see it at the bottom that I scratched off with fingernail.
This is the cylinder bank that didn't have the blown head gasket but did have a gasket that was gonna blow.
Suggestions?
score.jpg
So, do I leave them be? Compression check out as pretty darn good when Greg Brown did the PPI 2 years ago.
Pistons are covered with carbon. Gonna brush that off with brass brush and sea foam then shop vac out. You can see it at the bottom that I scratched off with fingernail.
This is the cylinder bank that didn't have the blown head gasket but did have a gasket that was gonna blow.
Suggestions?
Team Owner
Joined: May 2004
Posts: 31,236
Likes: 4,221
From: Philly PA
The cylinder will fine the way it is,
when you clean it out,
dont use aggressive chemicals on the pistons as they could damage the cylinders,
put in new HGs and run it.
to clean the head gasket surfaces use a fresh razor blade held perpendicular to the surface this will neatly scrape off the old materials without damage to the mating surfaces
when you clean it out,
dont use aggressive chemicals on the pistons as they could damage the cylinders,
put in new HGs and run it.
to clean the head gasket surfaces use a fresh razor blade held perpendicular to the surface this will neatly scrape off the old materials without damage to the mating surfaces
Nordschleife Master
Joined: Apr 2003
Posts: 9,601
Likes: 39
From: Abbotsford B.C.
Just to add to this.
The razor will not damage the surface of the block due to the high silicone content.
However I did have a cam tower gasket on a car that I just did that took HOURS to get off as it had to be scraped off in layers. It was like someone used superglue that permeated the gasket too..... bloody PITA!
The razor will not damage the surface of the block due to the high silicone content.
However I did have a cam tower gasket on a car that I just did that took HOURS to get off as it had to be scraped off in layers. It was like someone used superglue that permeated the gasket too..... bloody PITA!
Thread Starter
Rennlist Member
Joined: Nov 2009
Posts: 8,659
Likes: 426
From: Dubuque, IA
I am doing a new 02 sensor and the MAF was replaced in 2000 or so by Porsche. Nothing showed on the hammer last June when Sean hooked it up. Would that show on the MAF. Just put rebuilt injectors in.
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Thread Starter
Rennlist Member
Joined: Nov 2009
Posts: 8,659
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From: Dubuque, IA
Apparently sometime in the past this engine ate something. That would explain the scoring and dings in the cylinder wall. The top of the piston is beat to hell also. Was hidden under all the carbon.
Goes to show you these are tough engines.
photo-1.jpg
Goes to show you these are tough engines.
photo-1.jpg
Former Vendor
Joined: Feb 2005
Posts: 15,228
Likes: 2,530
From: Anaheim
Apparently sometime in the past this engine ate something. That would explain the scoring and dings in the cylinder wall. The top of the piston is beat to hell also. Was hidden under all the carbon.
Goes to show you these are tough engines.
Attachment 556151
Goes to show you these are tough engines.
Attachment 556151
Three Wheelin'
Joined: Sep 2003
Posts: 1,526
Likes: 0
From: SF Bay Area
Small scratches will not be a problem. But that piston looks like crap. It might not be for damage but from being fried. Over heating can do that. Be sure to check the deck.
Porsche makes over sized pistons that can be replaced individually. The bigger piston is engineered so you can bore out imperfections and not increase the displacement or compression ratio.
Porsche makes over sized pistons that can be replaced individually. The bigger piston is engineered so you can bore out imperfections and not increase the displacement or compression ratio.
Thread Starter
Rennlist Member
Joined: Nov 2009
Posts: 8,659
Likes: 426
From: Dubuque, IA
Yes, you can see the small dings around the top of the cylinder, from the foreign object. I'd pull that piston and look at it carefully....no, I'd find one that was the same size and the same weight and replace it. There are "standard" pistons for these engines sitting everywhere...why mess with it?
If I am gonna do that, I might as well do the silicone pan gasket and stud kit.
Waiting for your reply