Is it alwas cylinder 2 or 5 that goes?

911st · 03-10-2009, 04:36 PM

Has any one ever seen any cylinder fail on a 930 other than # 2 & 5?

The thought is they have the most direct air path so they might get more air flow and thus run a little more lean and that they are the only cylinders in the middle so they might run hotter.

bahnzai · 03-10-2009, 05:24 PM

Yep, mine was cylinder #1. Although #2 also had shattered compression rings, #1 is the one that let go...

jwasbury · 03-10-2009, 06:17 PM

I've heard number 6 runs hot since its right next to the oil cooler.

Speedy Squirrel · Speedy Squirrel's Garage

This is an interesting question that I would like to hear more about. I could swear that I saw a picture once that showed 930 cylinders with some of the fins removed, mainly on one side. I believe the intention was to make some of the cylinders run hotter so that, for emissions purposes, all the cylinders would run the same temperature. Has anyone ever seen a 930 motor (3.0 or 3.3) with this feature?

JohnJL · 03-10-2009, 11:12 PM

I have a CHT on each cylinder. #4 always around 10 deg hotter.

snbush67 · snbush67's Garage

I wonder if running different heat rated plugs would make a difference or maybe too much of a difference. Just a thought...

911st · 03-11-2009, 06:33 AM

John,

Excellent on monitering each jug.

Have you done a fuel quantity test to see it it is getting the same amount delivery as the others?

equality72521 · 03-11-2009, 06:37 AM

Quote:

Originally Posted by Speedy Squirrel

This is an interesting question that I would like to hear more about. I could swear that I saw a picture once that showed 930 cylinders with some of the fins removed, mainly on one side. I believe the intention was to make some of the cylinders run hotter so that, for emissions purposes, all the cylinders would run the same temperature. Has anyone ever seen a 930 motor (3.0 or 3.3) with this feature?

All 930 cylinders (at least 3.3, not sure about 3.0) have fins only on the bottom side.

911st · 03-11-2009, 06:43 AM

With the 91 C2 Turbo the fins returned.

The 3.4, 3.5 and RUF performance cylinders were all fined. Porsche took the fins off and went to small intake ports mostly for emissions.

JohnJL · 03-11-2009, 03:46 PM

No, I dont have a method for testing AFR on each cylinder. 10 degrees could also be within the instrument tolerances.

911st · 03-11-2009, 03:58 PM

Here is a great thread on checking that fuel deliver is the same to each cylinder.

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/461843-meter-head-flow-adjustment-question-post4536761.html#post4536761

mooney265 · mooney265's Garage

Quote:

Originally Posted by JohnJL

I have a CHT on each cylinder. #4 always around 10 deg hotter.

john,

what is the operating temp. range [average] you see with your CHTs?

I have one sensor installed and see 285 - 300 F

Shannon

mark houghton · 06-12-2009, 07:13 PM

By my count from feedback so far, suspected cylinders are 1, 2, 4, 5, 6. I guess that leaves just #3 as being safe. I bet if we wait long enough, someone will come up with that one as well, which means that none are more prone than any others to "fail".
This after my own statistical regression and probability analyses of available data, of course

930gt-40r · 930gt-40r's Garage

Quote:

Originally Posted by mark houghton

By my count from feedback so far, suspected cylinders are 1, 2, 4, 5, 6.

hahaha
I have heard (not scene) that number 1 and 4 get hit the hardest because of the vents for the heat taking away cooling for those two cylinders. I am going to post another thread on this issue because I need advice as well...