identification help...cam nuts, oil pump, and...

[speedo]

Most of my experience with engines is 2.7 and smaller. I just picked up a (supposedly) twin plug 3.0 MFI electromotive engine. What I do know...
930/16 case, S MFI pump, "stepped" 38mm exhaust ports, and raceware studs. Engine was supposedly built up years ago off an 81 3.0 CIS stock engine. Driven for years and then sold to Canada. New owner experienced broken lower head studs which were repaired by a shop up in Nova Scotia. With the engine back in the car, it never ran well again. I bought it and planned to go through it. A friend and I started to take the engine apart this afternoon and found some things we didn't recognize. The cam towers look normal 930-105-111-OR
. But the business end of the cams don't look like I am going to be able to use my standard Porsche tools. Sprockets look normal, but are these 3.2 cam nuts? I am used to a 46mm nut, not a bolt?


Is there another special tool needed to hold the sprocket while the nut is tightened? And is it torqued to the same 170 ft/lbs?
Rockers look normal, although the adjustment screws look like they are really turned in... not much meat protruding


And I couldn't really tell much about the cams, but the lobes looked pretty aggressive.
We next flipped it over and looked in the sump...looked like a standard sump plate but I have never seen this kind of screen before


Does this look like a 3.0 or carerra pump?
And the exhaust prts should be 34mm, not 38 and they look to have a "step" and they measure 38mm which would be correct for a carerra.


If you can help me with identifying some of this stuff, I would appreciate it.

Speedo

[speedo]

A few pics before it gets torn down....







Thanks for looking

Speedo

[Flat6pac]

The cam nuts were replaced with bolts in 1981 or 2 and run through 964
The oil pump screen is an update from the early SC that the engine lost oil pressure so the scavange pump needed this screen for the later SC.
The heads with the step are actually 80 to 83 using inserts blowproof for the heat boxes
The pump is SC but the Carrera is still the same size pump itself but just a different pickup for the scavange pump.
Youre looking good for some fun after getting it running but the key for MFI is all the accelerator links are to spec from the spec book.
Bruce

[echrisconnor]

speedo,

As previously stated, cams look like they have hardware from the 3.6 engine. See attached photo. Not sure how you hold them still while removing or setting cam timing. No special too listed on Pelican... hmm.

chris

[jbell959]

Everything looks consistent with a late SC engine... Looks like a fun project.

[TibetanT]

Hello there:

I use this tool for the late SC engines.

PEL-TOL-P237

Our host sells them. Link below

Pelican Parts - Product Information: PEL-TOL-P237

[speedo]

Thanks guys! With the cam holder tool...is the nut still torqued to 170 ft/lbs? I had expected to find an early S cam....and identify it by the makings on the end. Is this cam likely a "built" cam?

Speedo

[TibetanT]

If my memory serves me right, more like 89ft-lbs with the M12 bolt that is pictured here.

[speedo]

I was of the impression that usually when twin plugging, 12mm smaller spark plugs are used on the bottom side to avoid interference with the lower head stud nuts. The lower plugs however are Bosch W3CS and are 14mm. I learned that if raceware nuts are used however, due to their smaller diameter, a 14mm plug can comfortably be used . The cam towers are 4 bearing so the cams are not factory S cams as those would have been 3 bearing. So they must be a DR or Elgin special 4 bearing grind matched to the engine. I presume the only way to find that out will be to pull the cams. I need to remove the chain housings anyway to re-JB weld a few things, and replace the seals.
One thing I don't get is the exhaust ports. It appears they are "stepped". The outer-most diameter is 38mm. Exactly 10mm into the port, there is a step where the size drops to 35mm which would be correct for a 3.0 CIS port. Anybody got a guess why this is?
I am curious to see what the cams are...and to either borrow a borescope, or buy one and pull a plug to try to get an idea on the pistons. I have no idea what the bore of the pistons are...without pulling a head. I suppose I could fill a head with oil at BDC and measure how much oil comes out as the piston moves to TDC. That will give me volume and I suppose I can calculte the bore that way presuming stock 70.4 stroke...seems to be a sloppy alternative. Suggestions?

Speedo

[gtihop]

Do you know what shop in Nova Scotia did this build? There are only maybe 3 places that could.

[speedo]

Was "done" with the engine. Not happy and wanted it to go away.I am of the impression it was done in New England and landed up north. I have noticed some sloppy exterior "things" as I have torn it down...wrong bolts, missing bolts, bolts not torqued...little attention to detail. I think the original build was done correctly, but the head stud rebuild was lacking

Speedo

[tom1394racing]

Lars

The "step" in the exhaust port is normal for the late SC heads that use the thick flange heat exchangers.

[speedo]

My leakdown tester screwed up tonight...I got frustrated trying to get it to work. My cam holder showed up and I wasted little time in tearing it down to the semi-shortblock. We have 95mm pistons with nice valve pockets. Anybody want to wage a piston ID guess? I still don't know if it is a 66mm or 70.4 crank...I think that would tell me whether this was built as a 2.8 or 3.0 engine


Heads measure out with valves 49/41.75 so they are stock valves at least.


I need to pull the cylinders and formally identify the pistons (compression ratio)and evaluate the cylinders and rings. I'll also yank the cams and see what the profiles look like as there were no conspicuous markings on the ends.
So far, no bad surprises

Speedo

[tom1394racing]

Lars

A familiar sight.

Mahle 10.5 CR RSR

[911Freak]

Originally Posted by tom1394racing

Lars

A familiar sight.

Mahle 10.5 CR RSR

Shwing!! I love threads like this

Isn't the 930/16 an 1981 Euro SC 3.0 engine?

Also, why is one of those pistons so much cleaner then the others? Maybe indicative of a poor running engine/cylinder as a result of improper A/F ratio or MFI set up?

I ask b/c I'd love to build this motor, the best of both worlds...high compression 3.o l, twin plugged AND MFI!

sub'd


Way to go Speedo

[speedo]

I checked with EBS today and the Andial/Mahle 95mm 10.5 are not cheap. Looks like this engine was built well, but the shop that did the stud replacement was lacking. I found that 3 of the 4 studs on #4 were loose...haven't pulled the cylinders off to see why ( the studs are raceware ). and to ID the cams. Still need the twin plug dizzie...and nobody seems to want to swap for an Electromotive HPV-1...yet.

Thanks for the info guys...I would still like to find out who built the engine.

Speedo

[JFairman]

Those look like ARP headstuds because of the rounded ends. From all the pics I've seen Raceware headstuds are machined flat on the end and only ARP are like that.

[speedo]

Originally Posted by JFairman

Those look like ARP headstuds because of the rounded ends. From all the pics I've seen Raceware headstuds are machined flat on the end and only ARP are like that.

I called Pacific Injection and probably confused Gus as much as he confused me. He thinks the MFI pump is a 2.2 S pump, but told me to get the pump numbers off the plates. The top plate has stamped 90630378 and underneath those...0408 126 009. The side plate has EP RLA 1/28R.
I took another closer look at the stacks 911 110 303 1R and the throttle bodies 911 110 101 2R. However, something caught my eye when I was looking at the side of one of the throttle bodies...there was a dremeled set of numbers under some grease. I cleaned the grease off and this is what appeared...the numbers 0291 and underneath "S->40/42" which I am going to guess has something to do with the TBs being opened up to 40mm at the bottom.

Feeling like I was on a roll, I decided to pull the left cam. I am no expert in identifying cams, or deciphering the part/casting numbers.Everyone I talked with today agreed that to pull the cams with the rockers in place ...all I had to do was loosen up the valve adjustment screws all the way...nope. Would come out. The bearing surfaces were hanging up on the rockers. NBD, so I pulled the rockers and then the cam slid right out. Heres what I got off the cam...930 105 143 1R and a couple lobes to the side "3501". However, under the MFI sprocket are stamped "AN 123" and under that either 8 90...or if I was reading it upsidedown "06 8". The cams are 4-bearing, so they are not early cams. Not sure if this is enough for someone to ID the cams. Interestingly enough, the cams don't look like the MFI drive was welded (added). They look one-piece. So my question is...does Porsche make the bare billet cams available for grinding with the cam sprocket extension? I guess a call to DRcamshafts and Elgin to see if they recognize anything would be in order....or if someone cares to weigh in?

Speedo

[tom1394racing]

Lars

That would be a late turbo cam.

Carquip, Porsche 911 Camshafts

These did have the scavenge pump drive on the LHS cam that could be modified for the MFI pump drive.

[speedo]

Talked with John at DR Camshafts and the number on the camshaft end "AN 123" designates an Andial grind. I called Andial and the guy told me they never kept track of their grinds and to go somewhere and get the cam profiled....less than helpful. Looks from the other stamp that the grind was August of 1990...20 years ago. I posted on Early S registry to see if the AN 123 was familiar to anyone...nothing yet.

Tom1394...does your engine use MFI? Are you 66mm or 70.4 with the mahle 95mm 10.5-1 pistons. What cam profile are you running? Twin or single plug....dizzie or electronic? BTW...thanks for the info and input.

Speedo