'91 964 Turbo motor rebuild

turbo ride · 12:06 PM

Since I bought this car over five years ago, I have been chasing an oil leak that drips onto the muffler and heat exchanger - causing some smoke at shut down, and worse, burnt-oil smelly heat in the winter. No bueno. I did the power steering seal and o-ring, valve cover gaskets, checked rocker shafts (one seemed a little off)...and came to a conclusion that it was leaking from the cam tower seal behind the chain pulley. Fixing that would require timing the motor which I just didn't feel comfortable with. Plus realistically I just don't have the space to do big projects - I live in an urban neighborhood with a "1.9-car garage" and don't like leaving my daily driver parked outside on the street at night. So I decided to use a professional.

Honestly I feel a little guilty not doing this project myself...but I do know I made the right decision. I'm having a local guy whose day job is caretaker of a 50+ Porsche collection (that gets used/raced) do the engine work. He has done the Porsche dealer and Indy shop thing - and has a nice garage with all the tools where he rebuilds air-cooled sixes.

Here's the car at a shop where he removed the motor...and then the motor in his home garage. And the car back at my house where I'll replace a few lines, filters, etc.

turbo ride · 01:21 PM

Couldn't get those photos to post correctly....

Turns out the leak was actually coming from the head/barrell junction [EDIT - leak was between heads and cam tower] - so heads had to come off. Top end reseal. Once he got the motor stripped further he showed me where it has small leaks at the thru-case bolt seals. It was not necessary, but I decided to go ahead and have him split the case. Here we go. The car has 95,000 miles and the engine had never been apart. There were a few funny things - like fuel line banjo bolts and intake bolts that were finger tight - I guess 27 years of vibrating can do that. Injector blocks were perfect still (but yes replacing them).

At this point the motor is totally disassembled. He has put the parts through his ultrasonic parts cleaner and they are looking great - especially the heat exchangers - lots of oilly goop in there from years of oil leak. The injectors are out for cleaning. The heads are getting uprated springs - just a safety measure and the only upgrade I'm doing. Keeping it stock otherwise. Exhaust valve guides were shot - and really that is pretty much the only thing that has shown any wear. The piston rings, cylinder bores, wrist pin, cams, rockers, rocker shafts, main bearings, journals, even the turbo - everything looks great. No pitting, no scratching, no nothing. I won't say brand new because it has 95,000 miles - but virtually no signs of wear on anything. Really a testament to the quality of materials in this motor. And the motor oil that has been used. So basically this is an expensive fix of an oil leak because other than the valve guides, no reason this motor wouldn't have gone another 95,000 miles or more. But it will be so nice to have it all clean and [virtually] leak-free. Several new oil lines, clean injectors, removal of air pump...

turbo ride · 02-16-2018, 11:59 AM

wow - that's annoying - if somebody can tell me how to fix the pics that would be great. I tried rotating them on my computer and they still posted like this.

turbo ride · 02-16-2018, 12:01 PM

Engine removal was four weeks ago - here's where we are today:

turbo ride · 12:08 PM

A few more - heads should be going on today

turbo ride · 12:44 PM

I'm keeping the car stock. My daily driver Audi is over the top mod'd - I like this car just fine the way it is. 1 Bar boost. We did put in upgraded valve springs tho.

somoney311 · somoney311's Garage

That engine looks so nice now. Congrats on fixing the leak.

Sent from my iPhone using Tapatalk

356911930 · 356911930's Garage

Beautiful job...will be great to get it back in the 911 turbo.

Rahl

turbo ride · 02-16-2018, 06:27 PM

Yeah I can’t believe how clean it is! Wish I could take credit. His ultrasonic parts cleaner is awesome. I’m most excited about the heat exchangers. They are perfectly clean inside and out.

timc · 02-16-2018, 07:54 PM

Did you install new pistons/cylinders? Mahle?

turbo ride · 02-18-2018, 07:50 AM

Quote:

Originally Posted by timc

Did you install new pistons/cylinders? Mahle?

No. Everything is in incredible condition - from contact surfaces to cylinder walls (no ovalizing and cross hatching looks great)...everything. The only thing that showed any signs of wear were the exhaust valve guides. They were done.

Here’s how it looked yesterday. Still need the tins back from powder coat and injectors back from testing/cleaning.

Tippy · 02-18-2018, 09:46 AM

Man, that's a fast turn around! Great job.

heliolps2 · heliolps2's Garage

Ok.. take pictures with your phone sideways, that should fix it, I have the same car but a 92

mikedsilva · 02-19-2018, 01:43 PM

Would be cool to see a photo of his ultrasonic cleaner... how large is it?

turbo ride · 02-20-2018, 10:17 AM

By my recollection outer dimensions are about 4 ft wide, 3 ft tall and 3 ft deep. About. Maybe a little bigger? My headers/heat exchangers fit in it, fwiw.

flightlead404 · flightlead404's Garage

Quote:

Originally Posted by mikedsilva

Would be cool to see a photo of his ultrasonic cleaner... how large is it?

There were some on ebay a couple years ago big enough to take a case half. Lots of guys in the engine rebuilding forum were snapping them up.

IDK if they are still around though. I've been toying with the idea of getting one (or maybe I just need a new tool lol)

Oh krap, I said tool........

turbo ride · 02-26-2018, 08:47 AM

No new [sideways or upside lol] pics - hopefully soon - but making progress. The engine had developed a funky cold start condition last year where if the didn't catch/start on the first attempt it would flood. I'd have to unplug fuel pump relay, crank over, let catch and then install relay before dying. Then I'd be good all day. Easy with a kid to help - hard by yourself. I thought the CSV was dumping fuel. Well it turns out the CSV is perfect - BUT one of the other injectors was bad. Leaking gas and spraying to much. So we're replacing that injector. Nice to find a problem. I think it's still on target for reinstall back into car this weekend.

Can't wait to road trip to Rennsport this fall.

Alan L · Alan L's Garage

Quote:

Originally Posted by flightlead404

There were some on ebay a couple years ago big enough to take a case half. Lots of guys in the engine rebuilding forum were snapping them up.

IDK if they are still around though. I've been toying with the idea of getting one (or maybe I just need a new tool lol)

Oh krap, I said tool........

Try this ......

http://forums.pelicanparts.com/911-engine-rebuilding-forum/988593-ultrasonic-cleaning-engine-parts.html

Alan

turbo ride · 02-26-2018, 01:38 PM

Just a couple new pics - getting pretty close. Picking up engine tins from powdercoat today. The new injector should be here any day, too.

FYI - You can see his ultrasonic cleaner in the background of one of the pics for those who have been interested in that.

Alan L · Alan L's Garage

looks great. But you left a timing sprocket out. It is lying on the bench below the motor :-)
Just thought i would mention it :-)
Alan