Rebuild Update
 

OK, the engine came out a few weeks ago. Finally got around to the intial teardown last weekend. Thanks to Marc, who came over to marvel at how truly nasty a water cooled Porsche could be.

The backstory is this:
- Blew a head gasket.
- No other mechanical problems/noises/issues
- Figured I'd drop the engine and have a good look around, do the clutch, timing belts etc. Basically filling in the gaps that existed in the documentation I got with the car.

The picture got a bit nastier during the engine drop. Removed the oil drain plug, and found a large chunk of mystery metal attached.

Once the head came off, all was revealed. All four outer intake valve springs were broken. There were bits of valve spring everywhere. Fortunately, none had gone anywhere nasty. Seems they mostly just dropped down the return oil galleries into the oil pan.

The miracle was that the piston tops were pristine - not the slighest sign of valve kiss. That's even more remarkable when you figure that I will often stretch a gear to 7000 [6200 redline] in order to avoid an upshift/downshift in the heat of racing.

So, all is well. Assuming there is nothing nasty lurking under the bearing caps, it will slowly start to come together over the next two weeks. Shoudl have all the macjhine work back by the end of next week. Will be busily cleaning parts and preparing the ground before then.

For those who care, these are beautiful engines. Trouble is they are buried in two tons of turbo & coolant plumbing and around 100 sensors everywhere. Back to the parts cleaning......

We need pic's!

Glad to hear things didnt take a turn for the worse. I've read the clutch was the first part used to assemble a 944, everything else is suspended around it. Good luck brother.

Wow... sounds like an ordeal. And Dave Riley makes working on these sound so easy, too. Good luck.

It always happens that way....you dig in to take care of one issue, tidy things up, then you get smacked in the face with another (BTW: same resaon the SC engine had to come apart, broken outer intake spring). It's amazing how these cars can be abused, on the verge of mechanical disaster and still run like a top.

Good find and good luck with the build!! :twisted:

I've been taking documentary pics with my cell phone camera. The quality is not great, but it is certainly convenient and good enough for the job. The busted valve spring pics are lousy - taken from inside the focal range of the little lens. Here's a couple for kicks. All four outer springs are broken on the inlet valves. The inner springs are fine. In fact, they saved the engine by preventing Mr Valve meeting Mr Piston. Don't know how long this has been going on, but I'm sure it had nothing to do with the head gasket failure. Rather be lucky than good, right?

Tony,
From the pictures you posted, it looks like the inner valve springs saved the valves from hitting the pistons. It that your thoughts also? It just may be that those occassional journeys to 7000 rpm broke the outers.
Cheers, Rich

Rich,
The little guys certainly saved major piston to valve collision. The scary thing is that there is really no way of telling how long one or more of the outer springs have been broken. The first piece of broken spring came out with the drain plug while removing the engine, but there could have been broken pieces lurking in there for a while.

You can bet that my mental limiter is now set rock solid at 6500.

Until some upity serf tries to knock you off the Super Cup throne ... :twisted: :lol:


It'll probably go something like this...

6,500, OK, gotta stop, 6,600 no really, motor can't take it, 6,700 He is still gaining / getting away, 6,800 it's not yet 7K and I know I can risk it this one time, 6,900 I almost got him, next lap a couple more rpm is all I need, BINGO magic 7000 ... here we are again ... :wink: :lol:

Of course ... speaking from experience on the high banks of Daytona as I sat there counting mississippis at 7,400 rpm :cry: watching my "classmates" run it up / away to 8,000. Not this year though :twisted:

Jase

Watching and listening to you suffer those bastards who could run to 8000 was one of the high points of Daytona, Jase. Great to hear you will have a righteous lump for this season. Keep it fresh for when you need to top end.

You're probably right about the temptation to stretch it a bit, but now that I've seen the results it would be pure driver abuse. No excuses.

BTW:

I feel your off-sea$on pain ... motor and transaxle refresh. Thankfully, no pieces fell out when I drained the fluids .... how is the 951's transaxle holding up? Do you have a T-biasing / Quaiffe, other LSD in there?

Jase