Allegro Club International

[Chris Williamson]

Can someone shed any light as to a solution to a leak that is driving us barmy? I wont bore you with the back ground to it, suffice to say Brian spent sometime awaiting an engine rebuild. So the great day arrived, my mechanic friend began the assembly, original head and block, new gasket, got to the point we just needed to refit the air cleaner, added water and it promptly oozed out between the head and block, both sides of the engine!

So engine stripped again, head and block checked, gasket examined ,all was well so assembly began again. This time we got just the essentials on, added water, which promptly oozed out again, this time only at the front of the block!!

Disassemble again, send spare head off for a skim, refits with first the original and then the new gasket, once again water oozing each time! Head was tightened to 55psi so increased in 5psi steps to 70, as far as we dare go and by this stage the leak had virtually stopped. I say virtually as on the expose flat strip behind the distributor a faint weep was just to be seen. I was content to live with it and add Radweld but my mechanic insisted on yet another strip down. At this point, due to a turbo failure and subsequent expensive rebuild on our everyday car I had an uphill job explaining throwing more money at Brian to my better half and so it sat for 3 months untouched in the garage until last week when once again the rebuild process began. Original head, block and gasket, correct torque, more leaks! Remember too up till now all these leaks are without any pressure what so ever in the engine.

Best we could get was just a slight weeping in the same spot again but this time we got to the point of actually turning the engine over. OK the battery was stuffed and managed only 6 revs before dying but the result was water actually collecting on and dripping off the strip behind the distributor!

He is coming back on Tuesday or Thursday for yet another go at it but if we cant stop it with all these combination of heads and gaskets what are we to do. It didnt leak, or if it did then only slightly before the strip down, the head and block have been checked as far as possible and are flat, the head gaskets are both reasonable quality, we have checked none of the bolt bottom out or there is any water in the threads, has anybody else had such a bizarre experience with such a simple job and how was it cured?

[Graham]

Its possible that the head studs have "pulled" the thread up out of the block, easily done when over tightening the head bolts. You have most likely damaged the head gaskets also by over tightening.
That means the block isn't flat and preventing the head sitting down properly on the block.
Another possibility is that the block and/or head are cracked, unless you have had the head checked?
I think you're going to have to get the block out of the car and get it checked.
Sorry, but I can't think of anything else (easier) that would be causing this problem.
Good luck,
Graham

[Chris Williamson]

Thanks for the suggestions Graham. They are all worth checking out though there was no evidence of leakage before stripdown and to have 2 cracked heads would be extremely unlucky. We have certainly examined both heads and the block and there is nothing to suggest any cracks or failures in them and while we may have done subsequent thread damage it was torqued to the correct figure a couple of times and leaked then.

To be honest my money is still on the head gasket itself, the old one would have been shaped through use and the new one may not have been top quality but for either to leak even without any pressure in the engine is still odd.

He is back Thusday with a new gasket and we will endevour to get it right this time, I'll update you then. Thanks again.

[Chris Williamson]

Well had I put my money on it being the gasket I would have lost!

Bought a brand new gasket, checked the surfaces of the head and block to eliminate any bits, fitted the head , tightened to the correct torque, poured in a pint of water, - -and out it dribbled again above plugs 2+3 and behind the distributor as usual

As this is now the 3rd gasket and 2 heads, one skimmed, one not, then the finger of suspicion now points at the block. I can only assume, as it is a Silver Seal one, that somewhere during refacing maybe a sliver too much was taken off the edge facing the front of the car.
It is fortunate I do have a spare block but my current mechanic is in his mid 70s and officially retired and certainly not up to hauling engines in and out of cars so I am going to have to contract this out, anyone any idea what the reasonable cost for geting an engine out, separated, refaced and reassembled would be likely to run at?
What - - -that much

[Graham]

Sorry to hear that Chris. It shouldn't cost too much to get the engine out. If you disconnect everything you are capable of, which sounds like most/all of the top end if you're changing heads, then it's just a couple of bits underneath. Hire/borrow a crane, get someone to help, could be very cheap. Machining the block? I really don't know. Maybe around £200?

How much of a rush are you in to get it done?