M50 bad leakdown test

[gudgeon]

Just been into the garage and done the leakdown test I've been meaning to do on my M50, which I was hoping to start transplanting next weekend.

Basicly I've got 80-100% leakage on every cylinder at TDC.
Obviously the engine is cold and hasn't been run for years, but still this seems disastrous to me. The air is leaking out through the valves, both inlet and exhaust. I've even dropped a teaspoon of oil into each port and I can see the air bubbling through it, pissing through it really.

I've tested at 60psi 90psi and 140psi.

Just before I remove the head has anyone got any tips on what else I could try to make sure the valves are seated properly?

How common is this problem?

How much trouble am I going to have re-timing the Vanos after I've had the valves done?

I notice that the valve seats are all inserts, is this an easy job for an engineering shop to do?

Thanks

Jon

[gudgeon]

Crap! I need a special tool just to remove the cams!
This is going to cost a fortune.

Anyone thing the valves are just a bit dirty (carbon buildup?) and need to run a bit to bed back in?
An experienced view on this would be very helpful.

[DanThe]

You dont need a special tool for standard cams
You say the engine has sat for years, if its been damp there could be corrosion stopping the valves closing properly
A better way to test it would be to bolt on a gearbox/starter and spin the engine over with a battery, you will then see how much compression the engine produces

[gudgeon]

I'm a bit confused about the cams, do they come out on their carriers? Maybe removing them from the carriers is what requires the special tool. Anywy, that's what it says in Bentley.

I've decided to stick it in anyway, after a good deal of trolling around on the interweb I've decided to be optimistic and put the valve leaks down to carbon deposits, which there do seem to be plenty of. From what I can see with the valve cover and sump off the engine is pretty tight, it's allegedly only got about 60000 on it. I don't have much to lose from puting it in anyway.

[DanThe]

The special tool is to press the cams in evenly against the valve springs, tightening the cams in unevenly will snap them

The only engine ive had that the valves wouldnt shut properly on had sat in a scrap yard over a winter and had inlet ports full of snow/water/ice, so there was massive amounts of corrosion. It cleaned up fine though, the head was reconditioned and the alloy block now lives in the form of a 3 litre in my track car

[kerrie]

Sounds to me like rusty valve seats from standing, should be fine after a few miles, I wouldn't worry, do the conversion and if after a bit of mileage test it again/ repair if necessary.

[gudgeon]

The engine doesn't look corroded, and in theory was stored in a garage, although it was stiff to turn over the first time I tried. I hope it doesn't need valve cutting as it's likely to cost £600 - £700 (£15 each valve, plus sundries and a full head gasket/bolt set) - If the valves or guides need replacing it could be twice as much.

The exhaust ports have always looked very coked up, and the inlet ports were home to assorted crud as they were upwards as the engine was stored. In fact before I started the leakdown I squirted carb cleaner in the closed ports and blew it out with air, but I had already turned it over a fair few times.

My hope is that running it for a bit (maybe with some fuel additive) will sort the problem. If not I'll have to get the manifolds off and take the head off after it's installed. Not much to lose as I now have a daily runner to keep me mobile while I sort this conundrum out.

Thanks for your help

Jon

[DanThe]

If you can get it running a can of carb cleaner sprayed into the intake will clean the ports/valves up a bit

If they are fooked it would be more cost effective to buy a second hand recon head, I usually have one about

[gudgeon]

What work is done on your recon heads and what price do you charge (including/excluding core)?
Reassure me that you don't just hand-lap the valves