It started with a pop

[AndrewSlater]

I recently took my 912 for it's MOT and as usual ( touch wood ) it passed with no advisories.

On the way home I heard a couple of pops and bangs so decided to investigate.

Having recently adjusted the valve timing I expected that to be the culprit but after dropping the valve covers and checking everything was spot on.
Maybe I had an exhaust leak, so promptly hooked up my recently purchased smoke machine to the exhaust and soon had the answer - an exhaust leak.

Dropped the exhaust off for closer inspection and found the corrosion had taken hold in a few places.



I believe the exhaust is an original Eisenmann. I have all the receipts for the car from the first owner from 1966 through to 2008 and I can't find any reference to a new exhaust - so possibly this is the original!

Resigned to the fact that it was past its best I decided to look for a replacement.

Thanks to fellow DDK'r Doug ( Flat ) I now have a solid one to use.

[neilbardsley]

I think you can do this with the engine in. Just remember to put paste on the joints with the tubes. I didn't and it continued to pop

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[newto912]

how leaky is it?
they look weldable?

[AndrewSlater]

Yes I realise I could replace the exhaust with the engine in, I took it off with the engine in situ.

The exhaust itself has a number of perforations, so decided to go for a solid one. I expect the original one could be saved by someone with some welding skills and a little time.

When I removed the exhaust I noticed there was a bit of soot on the head exhaust flanges which suggested I probably didn't quite torque them up well enough the first time around.
If that was the case then it was likely that the J tubes might be similar - so worth a check

After a lot of consideration, I decided that I should drop the engine so that I could tackle a few other jobs whilst I was there.
The engine has been back in for 7 years or thereabouts, so a good opportunity to double check the car over whilst everything is easily accessible.

Jobs on my list include:-

Check the j-tube gaskets.
New clutch release bearing - the original one has always been slightly noisy at times so time to treat the car to a new one.
Gearbox leak - the MOT man always points out a small drip on the bottom of the gearbox - probably time to investigate further.
Paint and fit the new exhaust.

As always I expect this job might grow

Time to drop that engine.

[wildtexas]

Neat looking engine dolly Andrew.

[neilbardsley]

Andrew I'm guessing you don't have to MOT the car? If it does fail do you have to correct?

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[AndrewSlater]

The motorcycle lift works well as a 912 engine lift, I've also used it for the 911 engine but you have to be a bit more careful as to where to sit the engine.
You still need a trolley jack for the gearbox end, but I'm planning on making a scissor jack jig on wheels for that end when I put it back in.

As for the MOT, I like to keep my classics MOT'd so at least I get an independent pair of eyes checking over the car every year.
I've always wondered if it was to fail, could I just ignore the report as the car doesn't need to be MOT'd - the new rules aren't very clear to me.


So the engine came out OK although I tend to find it takes me forever as I like to check everything over and over and go slowly slowly.


The engine still looks pretty much pristine, but I'll still give it a good going over.

Looks like my started motor has rusted a little since fitting - so will add to the list of things to tidy.

Separated the gearbox from the engine and remembered I'd reused the clutch release plate last time around - add that to the list of replacement parts needed.

[AndrewSlater]

Looking at the gearbox carefully I think it has more than one leak.

Firstly one axle stub had the correct cap fitted but no retaining spring and the other side had the correct spring but fitted first with an aftermarket seal on the outer.
As a result both sides had leaks to one degree or another.

I now need to source a replacement cap and spring - anyone got a spare one lying around?


Another potential leak was from the speedo drive.

The problem with these leaks is that I can't see how they would end up back on the bottom face of the gearbox so possibly there is also a tired seal somewhere.

So the plan was to change all the seals and gaskets!

[neilbardsley]

Wow that all looks super clean. I wish my look half that good.

Try calling Mike Bainbridge for the gearbox part?

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[AndrewSlater]

Hi Neil, thanks for the advice.
Mike rebuilt my 915 gearbox so would highly recommend him, I've already PM'd and emailed him with regard to the cap but not heard from him yet.

If this was a gearbox rebuild I would be sending it to Mike without hesitation, but as it's only changing the seals I thought I would tackle it myself.

When I got the car I never opened up the gearbox, only externally cleaned it and treat it to new oil.
When I drained the oil this time it was pretty much still clean.

The engine was supplied as a restored short motor with all the other parts in a non restored state. I restored all the ancillaries and tinware and rebuilt the engine - which is why it looks pretty clean.


The gearbox came apart pretty easily and I have now cleaned all the internals and refitted all the seals.
I was impressed at how good a condition all the internals are in with really no signs of wear or problems.

I think the gearbox has been rebuilt previously as there seems to be a little damage to the differential cage when something bad once happened, but everything looks great now - which is a relief.







The gearbox is currently all back together awaiting a source for the axle stub caps - even the gears seem to still work so hopefully a success.

Now I need to move on to the engine.

[AndrewSlater]

Hi Neil, thanks for the advice.
Mike rebuilt my 915 gearbox so would highly recommend him, I've already PM'd and emailed him with regard to the cap but not heard from him yet.

If this was a gearbox rebuild I would be sending it to Mike without hesitation, but as it's only changing the seals I thought I would tackle it myself.

When I got the car I never opened up the gearbox, only externally cleaned it and treat it to new oil.
When I drained the oil this time it was pretty much still clean.

The engine was supplied as a restored short motor with all the other parts in a non restored state. I restored all the ancillaries and tinware and rebuilt the engine - which is why it looks pretty clean.


The gearbox came apart pretty easily and I have now cleaned all the internals and refitted all the seals.
I was impressed at how good a condition all the internals are in with really no signs of wear or problems.

I think the gearbox has been rebuilt previously as there seems to be a little damage to the differential cage when something bad once happened, but everything looks great now - which is a relief.







The gearbox is currently all back together awaiting a source for the axle stub caps - even the gears seem to still work so hopefully a success.

Now I need to move on to the engine.

[AndrewSlater]

When I bought the car as a project in 2012 the previous owner had got the engine up to the short engine stage, case + heads, and I built it up from there.
In hindsight I should have stripped it back down to see what I actually had, but I was assured it was all good, however I didn't actually know what I did have, I guessed it was a big bore kit but didn't know that for sure.

On inspection of the engine this time I found the following:-

The end play is just out of spec .
There is a small oil weep from the pulley seal
The spark plugs seem a bit oil fouled ( a recurring theme over the years )

I decided it was time to find out once and for all whether I had a big bore kit fitted so time for the engine stand to take a head off and explore!



Tinware stripped and carbs removed ready for the engine stand.

[neilbardsley]

The end play out of spec isn't good but normally can be solved by spacers?

What distributor is that?

Difference between you and me. When I thought I had a leak from the pulley seal I replaced. You crack the case

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[wildtexas]

Andrew, they look like cast iron cylinders not Biral ones. Off the top of my head I can't recall what a 66 should have. An AP marking on the barrel side would denote an AAperformance product. Likely a 1720 if so.

Matt

[neilbardsley]

Andrew, they look like cast iron cylinders not Biral ones. Off the top of my head I can't recall what a 66 should have. An AP marking on the barrel side would denote an AAperformance product. Likely a 1720 if so.

Matt

Yes you are correct Andrew has already indentified as NPR set

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