Engine problem 911 2.7 1976

[fdeville]

Hi, I'm starting to rebuild a 1976 911 targa, 2.7 engine. The numbers are matching but that's about all that is still good about the car. But I love it and I know that is will take time and effort (and $$$) to bring it back to live.
I already dd a few things before starting the serious work: the engine. It is losing oil (they all do), but it is not running well at all. It makes a kind of 'clapping' noise. Difficult to describe so I posted a short video on youtube where you can crearly here that there is something seriously wrong. So I already know that I'll have to take the engine out of the car to have it rebuild, but does anybody can 'guess' what the problem is that causes this noise ? So I know a bit more in advance how bad it is...
Link to the video: Porsche 911 2,7 1976 - YouTube

[itsme]

Sounds like either rod knock or the valves hitting a piston, frequency goes up with rpms. Either way I would not run it anymore before tearing it down. You'll likely cause more damage.

[rodoredas]

Applause!!
I'm no expert but the frequency of the clapping increases with engine rpm, so I guess it could be valve adjustment/broken/damaged rocker arm noise. Maybe loose cam chain guide rail, really need an expert opinion.

I too have non running 2.7 Targa, slowly working on 3.0L to swap in sometime, good luck
cheers

[pors1968]

Sounds like rod Knock like ITSME i would not run that engine.

[Daves911L]

Sounds to me like a rocker arm that has either broken, or just fallen out.
DG

[G50911]

i have the same knock but only when i start the motor. it goes away after a few seconds. i hope it isn't a rod cause i just bought this motor and had it put in!

***update: i checked my oil level and it's barely registering on the stick. going to add some oil tomorrow and see if it goes away***

[Evans, Marv]

I absolutely wouldn't have run that engine even long enough to do the video. If it's a rod, it's at a pretty advanced stage of failure and your crank is probably trashed now. I'm no expert, but I don't think anything in the valve train would make noise matching the tempo of the crank like that. Maybe somebody who in in the business will chime in. Rebuilding a 2.7L can be pretty big money. If you open it up & see there are really big problems, it might make economic sense to put a different/larger engine in. Good luck with it.

[gearjam]

Sounds to me like you have broken heads studs. The noise is usually worse when the engine is cold. It's usually noisiest when you rev it up. We always called it flapping because the heads are actually bouncing off the cylinders. Get under car and look at where the heads and cylinders come together. Look for black oily or sooty leakage at the joint.

[fdeville]

Very very very late reply to this...sorry about that.
Engine has been entirely rebuild, about everything is new. Done by a Porsche specialist over here in Belgium. Cost was around 25.000 euros.... Including (of course) upgrades like carrera chain tensioners and so on.
So now the engine is entirely new. Also have rebuilt of the gear box, done by a gearbox specialist in the Netherlands.
The car body has also been renewed entirely - it was also in very bad shape) so now I'm in the process of putting the pieces back together.
Not finished at all as I don't have much time but (as you can imagine ) I'm not in a hurry.
Total cost until now (engine + gearbox + bodywork) is already above 45.000 euro's.
So think before you begin

[Street_Lethal69]

Do you have any before and after pics?

[Porsche 2]

So what was the engine noise problem?

[fdeville]

See pictures, I think that was one of the problems.
And one of the cilinders came loose, the well know problem of the 2,7 engines.

[fdeville]

This is the engine now (a few months ago), being tested. The only thing that hasn't been replaced (yet?) are the heat exchangers & the silencer.
https://www.youtube.com/watch?v=XlOfXH6njCE

[zedsn]

Nice test stand.

[Street_Lethal69]

Originally Posted by zedsn

Nice test stand.

Agreed. Did you build it?

[fdeville]

No I didn't, the guy who has rebuilt the engine had one.