How much for timing chain replacement?

[Elu]

I've done a few searches but nothing is coming up. I took my '74 911 in for the chain tensioner upgrade because #1 my timing chain was making "the noise". He said it would cost about $1200. I didn't worry too much about that, however I had this thing in the back of my mind that the timing chain might be stretched as well. I never told him about that....He called back a couple days later and said the timing chain was stretched to the point that it was about to jump a link. He said he has to drop the engine and remove the timing cover, replace the chain, adjust the timing, adjust the heads, replace the gaskets, replace the rear engine mounts because they are really bad, and the oil pump gasket was leaking pretty good too so he wanted to replace that as well. And last year the engine block had a minor weld where the oil send unit screws in because it was leaking, there was a small crack in the block. The repair was done proper and was re-threaded without incident and it doesn't leak. I knew about the weld. I'm just hoping it is smooth enough to get the new oil lines put in without additional labor. Everything for a price of about $3200. Does this sound fair, the price and the work involved? I just don't know.

[Gunter]

Elu:
First: I am totally against just changing the chains and not change the chain-sprockets on the intermediate shaft. See this:

New chains without new sprockets? Read this!

Just changing the chains without new sprockets is a short-term solution.
Adding hydr. tensioners is good and the revised oil lines should cause no problem.
That said, $3200.- seems high for the work you describe.
Some things are not clear:
Adjusting heads? Do you mean a valve job?
I suspect that you have high mileage and that translates into a total rebuild meaning: The case is split, new head studs with case-savers installed, P/C's are checked for specs, new rings, valve job, etc.
A total rebuild is involved and costly and some people would not spend a lot on rebuilding a Magnesium case 2.7 liter. Instead, they'll spend the money on finding a 3.0 or 3.2 liter engine.
Ask the mechanic about details on what exactly is planned.
Split the case?
Install case-savers for new head studs?
Re-ring?
Valve job?
And tell him about the problems related to just feeding new chains onto worn sprockets.
What is the mileage?

[Elu]

Originally posted by Gunter
Elu:
First: I am totally against just changing the chains and not change the chain-sprockets on the intermediate shaft. See this:

New chains without new sprockets? Read this!

Just changing the chains without new sprockets is a short-term solution.
Adding hydr. tensioners is good and the revised oil lines should cause no problem.
That said, $3200.- seems high for the work you describe.
Some things are not clear:
Adjusting heads? Do you mean a valve job?
I suspect that you have high mileage and that translates into a total rebuild meaning: The case is split, new head studs with case-savers installed, P/C's are checked for specs, new rings, valve job, etc.
A total rebuild is involved and costly and some people would not spend a lot on rebuilding a Magnesium case 2.7 liter. Instead, they'll spend the money on finding a 3.0 or 3.2 liter engine.
Ask the mechanic about details on what exactly is planned.
Split the case?
Install case-savers for new head studs?
Re-ring?
Valve job?
And tell him about the problems related to just feeding new chains onto worn sprockets.
What is the mileage?

He said re-align the heads and adjust the timing. As far as the engine it was re-built 42000 miles ago and all the other parts seem to be in good shape. Sprockets and shaft appear to be in good condition.

[Gunter]

"He said re-align the heads"
I wonder what is meant by that? Adjusting the valve clearance?
If it was rebuilt 42k ago, it shouldn't need new chains unless the old ones were re-used?
When the hydr. tensioners are installed, it requires different chain covers; that's part of the expense. $1200.- o.k.
I can see a cam timing check when the chains are replaced and setting the valve clearance. Also, new points etc. as part of a tune-up.
Don't see where the additional $2000.- comes in?
Must be missing something.
As long as you feel it's worth it, go for it.

[Elu]

It just seemed a little high to me....He believes they used the original chain on the rebuild. But how much could it be for a new chain? I can see $2400 max...not $3200. Errrr!!!

[Gunter]

Ask your mechanic to break it down so you can understand what is being done.
Especially the "Re-align the heads" would be of interest to me.