Advice on a 'garden find'

[dlacey]

All, 

Here's an update:

The body is still under repair, no significant concerns ...  I expect to get it back in a few months.

 

I dismantled the engine, what I found confirms its low miles but abused!

The documents indicate 30k miles, the pistons and bores confirm this: standard size, no wear ridge. The cylinder head same: cam looks perfect, rocker shafts show no wear, just a slight polish on the load bearing side.

At first I was worried that the exhaust valves were damaged as I could see irregular edges, but it turns out that was just a buildup of crud and the underlying valve is fine.

All the major castings are dated 1974. Both block and head plus water pump and water distributor show serious corrosion due to lack of corrosion inhibitor in the coolant: core plugs rusted out, alloy turned to mush. Luckily the head waterways aren't too bad and the other parts are same as Tii and I have spares. Block itself cleaned up fine with a set of new core/freeze plugs.

The crank is a replacement, casting date '78 and the baffle in the sump is bent and broken. After some discussion elsewhere here, I think this is racing damage...oil surge causing starvation on the crank... resulting in need to replace the crank. The broken baffle is probably just brute force accident trying to remove sump with engine in the car.

I will start reassembly over the Ramadan holiday in June... Still waiting to the injection pump to be ready, will need to travel to UK to pick it up.

 

Exhaust Manifold: I obtained an original-but-cracked example of the turbo manifold to use as a pattern...my foundry says the manifold is Spheroidal Graphite Ductile Iron of the "FCD" alloy specification family. They are currently fabricating wood patterns to enable casting of a sample.

 

The turbo itself is in a bad way, as a far as I can see there's no parts available to rebuild it... Still searching for a specialist in Asia who may be able to make parts... Maybe Singapore.

[Tommy]

Incredible find and even more incredible story. From the main board I knew you had a turbo but just found the story from the turbo discussion.

Thanks for sharing and congratulations! Keep it up :)

[dlacey]

OK, next challenge. I stripped the head, its the correct original Turbo type...cast early 1974, 121T

 

I found a small crack...

 

Thats not the valve seat that's cracked, this is just a machining mark on the alloy casting, lower part of the pic is the exhaust valve, the valve seat is out of sight below valve, and OK.

 

Can something like that be repaired??

 

Other course of action would be to fit a different head: I have, [dunno why & where i got it from, but I have] a 1972 121 head (no 'T' or 'Ti' casting marks), it's in good condition, same size valves.

Has anyone machined a turbo-like combustion chamber into a straight 121 head??

[Einspritz]

Check some other postings regarding the combustion chamber shape before the additional machining was done as well as the valve size.

 

I do think that you can have it repaired, though you would have to find out how deep that crack is e.g. goes all the way to the water jacket.

[dlacey]

You may recall the injection pump was completely missing from this car.... i had to source a replacement. Advice here & elsewhere directed me to Mike Lucas of Lucas Development in UK. He has now built and calibrated a complete pump for me....not sure if it's the heart or brain of a 02turbo engine... but it's certainly one of the most important parts of the puzzle...It's on its way to Malaysia now.

 

Edited June 13, 2018 by dlacey

[Preyupy]

That is not an uncommon issue with M10 heads,  I have had a number of them repaired over the years and they have held up just fine.  Normally on a completely stock head it is not cost effective to repair them because you can get a good head for less than the repair would cost.  In the case of race heads with a lot of $$$ spent on porting and other modifications it is worth trying to save the head.  The same goes for your Turbo head, the cost to repair may well be less than the cost to machine the combustion chambers on another head.  It really depends on how deep the crack is and the condition of the rest of the head.  I'm glad you and Michael could come up with an Injection pump. 

[dlacey]

Thanks for the advice, as predicted the crack is more of a surface defect than a deep fissure. With the valve seat out we can see it's very shallow mark in the surface of the head. I will keep this as backup I think, it's thickness is 128mm, on the low side already.

We machined the 'Spare' 121 head to match the combustion chambers, and re-tapped to exhaust flange to suit the 10mm turbo studs. This head is 129.5 thick, I think that's the high end of spec.

 

Modified 121 in the foreground

[dlacey]

Exhaust Valves:

 I seem to have an unmatched set.. they appear to be made by ATE and two are marked 1123 and two 1149. AFAIK the 1123 is the standard 02 exhaust valve. I guess 1149 is the sodium cooled turbo valve. Can anyone confirm/decode these numbers??

 

Edited June 22, 2018 by dlacey

[Preyupy]

Weigh them, the turbo valve is heavier (I can't remember by how much but you can tell just by holding them in your hand)  I did not look at the numbers on the valves that I got from BMW

[dlacey]

1149-1  = 86g

1149-2  = 86g

1123-1 = 83g

1123-2 = 81g

As you can see in the pic above the 1123s are not identical - the 'font' is larger on one....so can assume they were produced at different times...explaining the weight variation between the 1123s ?

It appears the 1149 (turbo valve) may be ~5% heavier

 

Externally they look identical...seems weird to me that the hollow/sodium valve is the heavier one

[Bibm5]

Awesome story!
Very much subscribed!

Sent from my SM-G960U using Tapatalk

[dlacey]

All,

I am in the middle of body restoration, in the engine bay on the left side under the brake booster there's a bracket welded to the body that seems to have been bent flat... Is it meant to be there? What's it for? Clutch hydraulics?

At the bottom of the pic is the chassis rail, to the right one of the oval holes for the brake lines. I am talking about the bracket in the lower centre of the pic. 

Any ideas?

Sorry, my experience is only RHD cars...and this will return to LHD as it is meant to be.

Dave

Edited September 3, 2018 by dlacey

[Einspritz]

If that is the Left hand side, then it appears to be the mounting for the brake proportioning valve.

 

I will have to look on my car to be sure, but this was not on standard 2002s.

 

It is the same part as the CS coupes.

[wkohler]

Yes, proportioning valve.  There’s a notch in the top that the tab fits into and a single screw holds it in place.  

[Einspritz]

Yes, but you have to bend the tab horizontally. A bolt from the top secures the valve.