Engine failure update

[AHM]

You can just make out the radiused edge of the welch plug which then goes very flat - so it looks like machined in situ. The area around the welch plug is not in contact with the head you would set the machine-up so that the tool rotated off the head by the welch plug.

The Random marks look like 'deburring' like scratches on paintwork they look worse than they are - check between the cylinders and you see the milling marks - also the imprint on the gasket.

[jono]

I agree with what you say, the photos do not show the full picture and the 'scratches' are very fine indeed (accentuated by the camera flash) as if the head has been rubbed lightly with a very fine stone immediately after machining, probably just to take of any raised burrs.

I'm not an engineer but I have some understanding of materials and I know that copper is soft and will deform into any minor imperfections so, at least to my untrained eye, I do not feel that the 'scratches' are of significance.

You can indeed see the curved lines from the cutter as it has passed over the head.

Jon

[jono]

"Professionally Rebuilt"??

Yet they used the wrong sized gasket?

And machined the head with a plug in place.

Doesn't sound very professional to me.

Thanks for this John - I started the thread to try and resolve the problem I'm having with my engine not as a free platform for criticising my engine builder who is not here to defend himself. I have no intention of naming the builder concerned nor am I at all convinced that he done anything wrong. Suffice it to say he was very well respected and had built many, many hundreds of engines including BDA's, modern Cosworths, big yanks and including many race winning units. The hardest part was getting him to work for you as he was always flat out with work.

And incidentally, I bought a new vernier at lunchtime and on re checking the block with an accurate device my bores are in fact 83.5mm and the compressed fire ring 84mm ID. The Welch plug question has already been commented upon by AHM which appears entirely sensible, even to an non engineer such as myself.

I would be grateful if we could avoid negative or critical comments and focus on the main event which is getting me back into my Elan and enjoying driving it.

Thanks

Jon

[Chancer]

Given the pressure differences between the combustion chambers, the oil galleries and that the water is not contaminated by oil I am wondering if it is a leak from somewhere in the pressurised water system into the head or crankcase.

Can a water pump seal problem leak coolant into the crankcase? Maybe a front cover gasket?

The final question is for me, can a water pump problem allow engine oil to be out radially?

My old engine was run last year just to flush it through before storage once again, I could see that the water pump was dribbling, no surprise there but when it got up to temperature a thin film of oil was thrown around which settled on the rack, crossmember etc and made an oily band across the open bonnet, it seemed to be coming from the waterpump area and not the crank pulley but it was so fine and went everywhere its hard to say, it was definitely thrown around by the belt and pulleys though.

[AHM]

Jon,

It is somewhat the nature of internet forums that you get a variety of comments - Sit back and marvel at the assumptions about your head gasket overhang - and you didn't even show us the block side of it!

The people doing this kind of machining have usually been doing the job day-in day-out for years - They know what works and what doesn't so I wouldn't worry too much. The only way to test the roughness is with anRa meter or an experienced hand. If the Welch plug didn't leak before it is unlikely to - Change it and it might

What I would do from here:
As Chancer mentions check the leak is not somewhere else.
Check that the Head bolts will go into the block far enough.
Check that the head is still flat
Put a new gasket on - I wouldn't normally suggest wellseal but this is 1960's technology + Mr Wilkins uses it and the Man knows what he is talking about!

QED sell gaskets and give good advice. The Gasket is specific to the T/C

You will have it all together in time for the bad weather on Sunday

Keep in mind that if you were doing this job in the '70's you would have been working in a carpark and the only attention the head would have seen would be a sheet of emery on a wooden block.

[Johnfm]

I didn't assume anything. I just read this sentence:

"When fitted and compressed should the fire ring edge meet the edge of the bore exactly. overshoot slightly or sit back slightly? The reason I ask is that this gaskets appears to overhang slightly the edge of the bore"

It wasn't an attack on the anonymous engine builder, merely a comment on the evidence provided by your posts.

I was unaware that people in the Lotus fraternity take umbrage on behalf of their engine builders so readily. Good luck with the rebuild.

[Jeff@Jae]

A standard head gasket is only good up to +.030" overbore. You should look for a head gasket good for +.40" (83.5mm) bore sizes and they are available from your favorite Lotus parts specialist. Use ARP Ultra Torque lube on the head bolts for the best torque up and be sure the head bolts are the later KMax bolts or better yet use ARP fasteners. Always be sure the torque wrench is a good one and accurate. I suspect this is all down to the head gasket/improper torque issue.

[bob_rich]

Hi Jon

Sorry 2 hear about your problems. As U R seeking comments and there appears no blatantly obvious gasket failure I too was wondering if oil and water had mixed by another route. I dont think U need 2 much water to produce the dreaded "mayo". My sons old metro (K series common problem with that engine series )had a oil water mix but the engine performance was not noticeably changed and oil water levels did not appear to be very different to normal but the coolant and the oil both looked really yuk

As U have the head off a look down into the camshaft drive train front cover may be worth look

Hope U fix it soon looks like U got your MOT done though so thats a plus!!

best of luck

Bob

[AHM]

I didn't assume anything. I just read this sentence:

"When fitted and compressed should the fire ring edge meet the edge of the bore exactly. overshoot slightly or sit back slightly? The reason I ask is that this gaskets appears to overhang slightly the edge of the bore"

As it would when it is squashed into place ... or slightly misaligned due to tolerances in the bolts - He didn't say the builder had "used the wrong sized gasket"

John, That is the problem with conducting a conversation over the net. If you were in the Garage with Jon discussing engine rebuilds over a cup of tea you probably wouldn't have rubbished his engine rebuild.

I can't see anything that represents sub-standard work. From all of the evidence we have here we can't even say why the bolts were not tight, but we can suggest that that is why the head gasket failed.

[Johnfm]

AHM

I agree. The written word doesn't convey 80% of a message.

I wasn't rubbishing anything, but can see how it could read that way. As you say, over a beer or a era it would have merely been conversational.

[jono]

No offence taken and certainly no umbrage on my part John,

Cheers

Jon

[Johnfm]

In that case, a virtual pint is in order.

[Galwaylotus]

Here you are!

[jono]

What,...Guinness?

..I'm strictly a Timothy Taylor's man

[Galwaylotus]

"A pint of plain is yer only man!"