Mystery Engine Condition - What To Do?

[Bristol]

So I got Wayne's book on engine rebuilding... and read through the section on when to rebuild. A question though: I just purchased a 1975 911S with the original 2.7L. It's been sitting since roughly 1991. I'm thinking there's nothing major wrong with the engine, but of course it's not running right now after having sat for so long. The plan is to drop the engine out and freshen it up at minimal cost. So the question - is there an advantage in trying to spin the engine and compression test it before removing it from the car? Am I over-reacting by jumping into a rebuild or should I try to at least get it running first to determine what needs work? I was thinking of tearing into it more just to play it safe than anything. Thoughts?

[JJ 911SC]

Originally Posted by Bristol

... The plan is to drop the engine out and freshen it up at minimal cost...

Be aware of the very expensive "while you are in there" domino effect

[Eagledriver]

Here is the slope you are on. If you take apart the engine, you'll have to timecert the case headstuds and have the case alignbored. You'll also need a valve job most likely. If you are a DIY kind of guy you might get away with 6 grand or so for the above with gaskets, tools, etc. If you pay to get this done the sky is the limit. Then you'll need to get the CIS working again.

Better options to me are to buy a 3.0 or correctly rebuilt 2.7, or try to get your motor running without taking it apart.

-Andy

[Bristol]

I'm definitely a DIY type of guy and had planned on doing most of the work myself. I'm okay with putting maybe $2,000 into the engine just to get it freshened up (89K miles on the engine).

As another option... I also picked up a '73T 2.4L engine with the car. Again, it's a mystery though as to the condition. I've already had the car inspected for the Communist State of California, so I'm now free to use either engine (smog exempt). Theoretically it's probably cheaper to revive the 2.4L, I think, assuming similar states of condition. Or maybe I use the 2.7L as a donor for any parts I need on the 2.4L. Thoughts?

I have other Porsches - '03 C4S, '00 Boxster S, and '72 914-4. So I already have speed and handling to satisfy me. From the '75 911S engine I'm mostly looking for cheap and reliable. I'm hoping to get this car back on the road, safe, and reliable for under $6K total investment. Then use it as a daily driver.

[JJ 911SC]

Originally Posted by Bristol

I'm definitely a DIY type of guy and had planned on doing most of the work myself. I'm okay with putting maybe $2,000 into the engine just to get it freshened up (89K miles on the engine).

As another option... I also picked up a '73T 2.4L engine with the car. Again, it's a mystery though as to the condition. I've already had the car inspected for the Communist State of California, so I'm now free to use either engine (smog exempt). Theoretically it's probably cheaper to revive the 2.4L, I think, assuming similar states of condition. Or maybe I use the 2.7L as a donor for any parts I need on the 2.4L. Thoughts?

I have other Porsches - '03 C4S, '00 Boxster S, and '72 914-4. So I already have speed and handling to satisfy me. From the '75 911S engine I'm mostly looking for cheap and reliable. I'm hoping to get this car back on the road, safe, and reliable for under $6K total investment. Then use it as a daily driver.

Well, you fooled us with your Post numbers

6K for a DD sound good to me

[TimT]

Trollish

[Alan L]

Run it - what have you got to loose, unless you are desperate to throw $s at it. If it has issues, much easier to diagnose while is running.
Alan

[euro911sc]

I'm with Alan. Leave it in the car, pull the valve covers and look for pulled studs. If no obvious bad studs, do a valve adjust and seal it back up. Obviously, if the crank doesn't spin while doing the adjust you know you have some bigger issue.

After that follow the long term storage revival plan:

1) replace all the vacuum lines on the CIS. $10/m at the local VW dealer.
2) drain the tank. refill w/ gas and injector cleaner.
3) soak your injectors in something strong
4) change the plugs
5) change the oil... obviously it will be empty after the valve adjust anyway
6) change fuel filter
7) air filter
8) check all fuel and oil hoses for signs that they will fail and replace as needed
9) Make sure the clutch and throw out bearing are not seized
10) Look for signs you have critters nesting on the engine
11) get a nice new battery
12) make sure the CIS fuel metering plate swings freely
13) Add all the stuff people mention after this post

Hand rotate the crank when its all buttoned up and get some new oil in there. pull the fuel relay and crank w/ starter to check that you are getting oil pressure. If all is well put the relay back and turn the car to on (not Start) and let the fuel pump run for a second. Then see if it starts

PS: Have at least 1 extra buddy present with fire extinguisher in case a fuel hose blows and catches fire!

[jonesb930]

+1 on what Michael said! Check it then run it! After you have it running do a leak down and compression test to see what the state of the motor is.

I would also add this:
After removing the oil filter use that tool ( Longacre Oil Filter Tool ) that cuts open the filter to see whats inside. After you get it running do the same thing on the next oil change.

[lucittm]

Bill,
Seriously? $53 (your link at Amazon) for a device that spins around your oil filter and cuts the top off? I just jam an old pair of tin snips in the top of the filter about a 1/2 inch from the top and cut the thing open. I bet my method is faster too.

Mark

[jonesb930]

I guess I just love tools. There are cheeper versions, I prefer to buy tools that last. If your method is working for you than stick with what works. The only issue I would see with your method would be that if you got the thing open and saw a small piece of metal on the filter, how would you be sure it was not from all the jamming and cutting. Just my observation.

Bill

[Cupcar]

Run it, but have a fire extinguisher just in case a fuel lines goes nuts.