996 3.6 piston ring gaps

Hi guys Building a motor at the moment and can't find anything in the workshop manual for ring gaps for new Porsche rings. Any help would be appreciated

We have discussed this issue here and never came to a definitive agreement. Part of the problem is bore taper & ovality. First you need to measure that very accurately - that too has been discussed here. If any bore is oval or tapered(try the hotter side first ?) ,measuring ring gap is moot.Ditto Scoring. And speaking of rings are you planning to 'pin' the #2 ring ? One conclusion was to mark/note the specific location of each gap on each piston and reuse the original rings .It seems the rings wear to the bore(to a degree) and rotate to a stable location and then remain there. New rings or muddled old rings will create more blow-by than desirable. Like so much with the M96 ,it is very exacting in every respect compared to typical engines.And unless you go to Flat 6 school, there are very few ways to learn all the details. The ring gap issue is just one of many such potentially disastrous details. The parts cost of rebuilding and upgrading an M96 is substantial.You will probably find you also need some very expensive,specialized tools/equipment. When I did mine ,it cost well over $7000. I spent an enormous amount of time researching and only time/miles will confirm if I got it right ! So it was a financial nonsense, but fascinating :-).

These specs do not exist from Porsche. New ring gaps can be anywhere from .014"-.025" out of the box, too. In my experience, the sweet spot is around .018", but remember that the second rings have anti- rotation dowels. There are two different types of dowels, and two different types of rings that match these dowels. Its imperative that you have matching dowels, and rings. As Schnell said, almost every bore will need more than just rings, as the taper and out of round factors are a real concern with these engines, even at extremely low mileage points.

We've had some interesting Posts about M96 engine failure after a rebuild. One member had his engine rebuilt twice by a highly regarded Porsche 'expert' in S.California. Of relevance is that this company , despite much hoopla here ,showing their facility full of expensive looking road and race Porsche's is not a Preferred LN IMSB Installer. The member's engine failed after both rebuilds on the first Track outing . Suggests there was something wrong with the rebuild technique . The post above about the dowel/ring issue is a hint at what kind of issues there are when enthusiastic amateurs (like me !) rebuild these engines. The fact that the amateur has an impressive workshop is irrelevant if the rebuilder does not know ALL these arcane M96 details.And even the self-proclaimed experts like the company above are ignorant of these little details. So enthusiasts like me spend a large amount of money($7000+) on these engines and it is potentially wasted.This despite great care in technical research . You may get lucky but you are clueless about which details you missed and why they do/don't matter.And there are dozens of such details and quirks. Now compare the $7000 amateur attempt(like mine) with the cost of getting a used engine or a rebuild by a real expert. I have watched every M96 rebuild video/photo diy/account I could find. The only mention about dowels/pins/rings is this thread and the prior one I mentioned. Trying to discover the complete list is probably impossible outside the M96 Engine rebuild class - which I am unable to attend due to family commitments. So until the M96 book is published ,I suggest holding off on a diy rebuild.Meanwhile I am just hoping for dumb luck on my rebuild :-).

Quotes source post: 12787379

Well said and that's one of the major reasons I enrolled in the engine rebuild school.

You can never know it all. The most important 6 inches in the shop is between your eyes. Most of this is all common sense, paying attention, and situational awareness. Thats how I take things apart when they are brand new, with no manual, and start my manipulation with them. If you pay enough attention, take enough notes, and try your best, you'll succeed. The most recent enthusiasts level "101" engine class online had Tony and I shocked with the knowledge that the attendees had compared to technicians. Two questions were answered in the last session that have NEVER been answered by a technician correctly in any class. Over 3000 techs have been asked that question over the years, and none have ever gotten it right. An enthusiast nailed it verbatim in 2 seconds. Remember, its not what the shop knows that counts... Its what they apply. The way that most repair shops work, by paying employees on commission, promotes negligence, speedy work, and etc. The faster the pace, the less is applied. You won't find a clock here. Not one.

this dowel....I don't recall seeing these on the JE pistons & rings. am I correct to assume the JE set doesn't have a dowel?

Quotes source post: 12791639

JE only have dowels if custom designed.