Dreaded oil and coolant water mix! guidance required please

[0005K]

Thanks Mike -
I'm thinking the issue is in the water pump / timing case sealing (lack of). I'll dip paper towel test strips into cylinders to insure no water on tops of pistons which could indicate a head crack. (I saw no steam from the tailpipe when I last ran it a few weeks ago, and the old copper head gasket didn't show signs of a leak.) I'll try to paper towel-test pump area inside of timing chest for indication of water weep. I think water level in radiator is dropping to water pump height. It is likely that the OEM water pump replacement I did 40+ years ago was done incorrectly or did not age well. The engine had not run from then until a few weeks ago. When I did start it, it ran fine but I found water in the sump.
I'll again read the Lotus service manual on water pump repair in situ - which Lotus says can be done, but this forum recommends against. The oil pan gasket and new water pump has been in place 40+ years with only 20 minutes of running, but the upper timing chest cork doesn't even have one heat cycle on it and may come apart from the timing case intact. I don't have a Spyder chassis so I'll at least have to try to raise the engine a bit to be able to drop the pan a little.
Dick

[ericbushby]

Hi Dick,
You are not going to like this but here goes.
I recently had water in the oil just like you with the radiator level dropping significantly in a short run.
I had the head skimmed because it needed it anyway, but that did not look to be the cause of the problem.
Removed the block and fitted a new water pump along with all the `while you are there` jobs.
it may be possible to change the pump in situ but I cannot imagine it being worth all the extra struggling.
Just to fit the sump gasket in that position seems impractical to me. The block needs to be inverted to have any chance of it fitting neatly. If it is not done carefully enough it will have to be done again.
The amount of care required to fit the pump parts properly needs good access and good light.
Sorry, but I think you should take the engine out.
If you do manage it in situ please let us know how you get on.
Eric in Burnley
1967 S3SE DHC

[0005K]

Thanks Eric
I fear that you are absolutely correct.
However, we found these articles online:

GOLDEN GATE LOTUS CLUB - Elan Waterpump Replacement (gglotus.org)

A guide to rebuilding the Lotus twin cam water pump, part 1 - dismantling and inspection (lotusmarques.com)

I've little to lose by trying it in situ.
I will also investigate the removeable crossmember modification.
Dick

[bitsobrits]

Twice in 40+ years of owning Elans I did a water pump R&R in situ. Though both times I was nominally successful, both times I wished I had pulled the motor as I chased significant oil leaks until the next time I removed the motor for a proper reseal.

[0005K]

Brian
Pressure checking it with coolant pressure pump confirmed your experience. There was a geyser down at the water pump in the timing chest. It has to come off....
Dick