So, this past weekend I dropped the 6 to look for a compression leak on the number three cylinder. As soon as the cooling shroud came off it didn't take long to find it.

It doesn't look too bad and now I will finally know for sure what pistons and cams I have. Also have to take care of an oil leak on the front somewhere. (or rear depending on what car or book )

Check it out.

here's the close up #3

compared to the others

Is that a 2.0? See the nice rusty barrels :-)

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

Wow. I thought it was the head gasket, but damn. Well, get in there...

If it is a 2.0, that "head gasket" really doesn't help seal against that level of leakage, it's just more to reduce the combusion by-products getting blown into the stale air heat, or at least that's what I was told by an engine builder who does lots of 2.0 race engines.

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

Yes, the head gasket of a SB chebbie won't seal that level of leakage, either. It's just more there to keep the combustion products out of the water jackets. I read this somewhere, but may have lost something in the translation.

Unless it has to be 2.0 , Get some 2.2-2.4 heads and cylinders.gotta have 2.2 pistons for comp. if its short stroke still
Bigger valves, better head gasket ,more CC's

Mag case witth 66 dated heads, its been around . mag late 68

Case is a 1970 2.2, everything else is earlier. I'll post more pics this weekend after the heads come off. And if they are still 2.0 p/c's, then 2.2's will be going back on.

A couple of things bug me about this leak. Two different Pro Porsche mechanics diagnosed the noise as something completely different. One of the guys here that told me it might be a vac leak (closer). It was the very same day (the last so cal fun run) that it blew out for good.

Maybe it still has 2.2 Cylinders and someone cut the heads to accept the 2.2/2.4 stlye cylinders and did a poor machining operation. Heads have different thinkness. (blown head gasket)

Kinda scarey about the diagnossis you got.
Know you'll know what you got.

Mike, do you have any rubber vibration isolation pieces between the engine mount bar and the body mount?

Have any photos?

I'm using the stock 911 enging mounts. They are round with a rubber center similar to the 914 Trans mount. (but not)..
They work great, and fit perfectly in the 914 engine mount space. see pic...

Yep, I am using the same mounts on the front of my 914-6 with a cross bar. Kerry, make sure you also get the big washers that go on top of these. They fit and work great. Like they were made for the 914.

Do the washers come withi t or are they listed seperatly? I see the mounts listed on PParts..I'll check for the washers too.

Cheers

got the heads off today. The head gasket was totally blown out of one corner. the engine also had two different brands of head gasket. What the?? It's also a confirmed 2 liter. 80mm p/c's. Valves: intake 39mm, exhaust 35mm. So nothing special there. I pulled out one of the cams to check part number, and I'm not sure what I've got maybe someone can shed some light. Part #901.105.139 OR... I found the number on this carquip web site and it says 911L, but I did not find anything listed as 911L in Bruce Andersons book. I have 3 distributers, T, E & S, and need to know which one is best suited to this cam.
I also found lot's of carbon, probably more than I should have.. <_<

check it out...
-Mike D.

close up pistons

different head gasket

inside the heads...

the cam, can sort of see the part number.

mike..it sounded good on the funrun! sorry to see it apart

Oh, and today I had some help in the garage. It made things that much faster...

They dont just lap those in like the type 4's? I hate blown head gaskets, they make such a mess.

yeah it is quite a mess, Now I have to decide what to do. should I pull the other side and have everything cleaned. I was thinking I would just be able to put new head gaskets in...but know...???

The cams are 130HP set 3.0-3.3mm 911/911L USA
E cams = E distributor. On these old motors use should check the lift at overlap , in case they have changed or reground to a different profile than the P/N Hope this helps

It doesn't look like much overlap if any. Is overlap measured in degrees of rotation, or in mm of valve travel at overlap?

mm valve lift at top dead center ,when exhaust is closing and intake is opening . zero at TDC comp. (intake valve.)
Its porsche's measurement for timing the cams. not the cams grind spec .

typical cam timing specs S 5.0-5.4
T 2.3-2.7
Carrera-6 6.7-6.9

OK, I did this measurment before the engine went in the car the first time. it's 3.2mm I think. I had to replace one of the chain tentioners and the chain slipped, so I measured the other side, about ten times with a stanard dial gauge and came up with .129". So I set up the other to the same.

Does this make sense?

exactly , p/n , your measurement , and the book , all match.
are the head gaskets just on in different directions (flipped to each other) ?

Thanks For The Info!
So everything is to the E spec, right? I found more info that said the cam p/n was 68 911L Sporto with smog pump. Was the 911L just an E with a sporto, I'm assuming that L was for Luxury, maybe.
Not sure about the head gaskets being flipped. did you notice in the pics how one has dots around the sealing edge and the others do not?
What about all that carbon? I've only had the engine in the car for about 500-600 miles.

an L is an L but the cams are the same as an E . The term E is used because it is used more years and easier to identify with.
Was the motor rebuilt ? did it smoke ? did it use a bunch of oil ?
Do you drive like a granny ? (That was meen I apoligize)
It definantely looks oily wet, but if it does not exhibit any of the above its ok. Valve job and rings would be nice right now , but if the case leaks so would a total rebuild. Budget Time (Money)
Its all Fun

Yeah Inoticed the dots thats why I think the one without is flipped.

I got this engine from Brad about two years ago, and the PO from him had the engine rebuilt. He ran it very little before I got it. At that time we knew it was a older rebuild and the work was probable done a few years before he had it. The engine is a bit of a frankenstein. with the '70 case and '68 everything else (oh, and a 2.7 shroud and fan housing).
It only smoked on start up, (unless you count the smoke burning off the headers. ) and not every time, but moreso after the addition of an external oil cooler. I attributed that smoke to the fact that there is now 3.5-4 more qt.'s of oil.
It only "used" oil because it was leaking. Left chain cover, both bottom valve covers (6 bolt), int. shaft cover on front, oil sump plate, maybe the rear main, have to check. Oh, and it is dripping from that fabulous Vellos oil tank, not sure where but I plan to check it everywhere.

I have new silicone vavle cover gaskets and new sump plate and silicone gaskets for that too. Plan is to definately get everything sealed up tight.

The carbon is very soft and comes off easily. I spent alot of time trying to dial this engine in myself. It has seen tuning time with three others. All of this could have helped produce the carbon mess.

Hey Sixnotfour...

'68 911S couldn't meet US emissions with Webers, so plus or minus a little, an L is a 911S (Luxe...) with a T engine so they could still have an 'entry-level' and an upscale 911. E cams came in the next year with the first of the fuel injected (MFI) cars, and the T/E/S lineup returned.

i'll recheck my sources on cam specs tonight once i'm back home with the library ...

If it doesnt exhibit any of the before mentioned symptoms,
then fix the head gasket and runner.
Does the Head look like it needs to be recut ? so it will seal.

I had play plumber today