cylinder head

[trevor_ford]

OK, so I'm at the stage of trying to start the engine again. I have tightened down the head to the specified torque, prior to starting, but when I connected up the hoses and filled it up with water, I'm getting a leak between the head and the block. Any advice - tighten the head more ? Or is it a sign that the head needs to be skimmed ?

[donsayers]

Re: cylinder head

What engine please?

[trevor_ford]

Re: cylinder head

Good point Don - 1700 Ital.

[CABRIOBOB]

Re: cylinder head

I am not familiar with the 1700 Ital engine but I have a lot of engine experience.
What was the problem with the engine for you to replace the head gasket ?.
Have you got the correct head gasket ?. Check the gasket on the block and head to see if all the oil and water holes line up prior to fitting the gasket.
Are the head bolts/studs stretched and are bottoming out in the block ? and no oil or water in the block thread holes stopping the studs to tighten. You can fit a washer under the bolt heads or nuts if to long.
Make sure the block and cyl head are flat and is very clean prior to fitting, if a alloy head it may need skimming.
Make sure the cyl head bolts/studs are tightened in the correct order and setting.
Depending on the gasket material I would use a small smitching of sealant (wellseal) around the water holes on both side of the head and use 2 guide bolts if required when refitting the head.
If you have not ran the engine I would remove the head and start again checking as above and you could clean and reuse the gasket if not damaged.

[trevor_ford]

Re: cylinder head

Thanks Bob. The head gasket was replaced along with all the other seals when the engine was out of the car. I think I will be taking the head off again as you suggest and finding someone to skim it.

[bbeech50]

Re: cylinder head

This may sound facile, but is it possible to put the c/head gasket on back-to-front? I did this once on a L/Rover engine. I have no idea if this is possible on the 'O' series, but if it is........! Tell me, are the inlet ports in the head the same size and location as on a B series head? Just idle curiosity on my part.

[bbeech50]

Re: cylinder head

An old 'Imp' trick (alloy head) was to use two gaskets. Imps would pop their gaskets regularly, and two gaskets was considered to be a rally modification by those who could not afford Wills Rings. Alternatively you could try a copper gasket of suitable thickness. These are easy enough to make given suitable raw material

[macdonald.dm]

Re: cylinder head

Hi Trevor.

I'm not familiar with that particular engine either.

However, if the head has been torqued correctly, and unless there is something else obviously amiss (such as grit caught on one of the surfaces, or wrong/faulty gasket used, etc), then a leak occurring BEFORE the engine has even been started and pressurised suggests a fairly significant warp, I'm afraid.

[cameronfurnival]

Re: cylinder head

I suspect that the head is warped. Its an alloy head on an iron block. The O is largely reliable save for frequent oil leaks! So unless you have got the wrong gasket, fitted it wrongly or torqued down in the wrong order, its likey to be warped. How did you get it off? did you undo it in the right order? was it hot when it came off? has it ever overheated?
I suggest it needs to come off for inspection. It might be something daft like a bit of the old gasket not completely removed - but come off it must. clean up bothe faces (block and head) and with e astraight edge try to get a feeler blade under it. there should be no more than a 3thou gap - check both head and block. Hope this helps

[macdonald.dm]

Re: cylinder head

In which case it will need skimming - double gasket (that's clever!) will only be a temporary solution, and will also lower compression ratio a little.

[bbeech50]

Re: cylinder head

Donnie. The double gasket idea is certainly not recommended. I only mention it because I have known it used. The significant clue to all this is that the engine leaks water before being fired up. That would indicate a significant warp. Dismantle, inspect and if necessary, skim. When rebuilding an engine it is also good police to have the block faced as well just to be sure.

[bbeech50]

Re: cylinder head

Donnie. For 'police' read 'practice'!

[dogoncrazy]

Re: cylinder head

Trevor
Had the same problem when I took the head off my Pinto engine to overhaul. New gasket [of unknown manufacturer!!!] bloo--- leaked as yours has. Took it apart and replaced with Quality gasket[ Payens] with no further problems.The moral in my case was don't buy cheap tat!

[donsayers]

Re: cylinder head

The blocks sometimes distort where the studs screw in, leaving a small raised area around the stud which prevents the head from seating. Unscrew the studs and check with a straight edge. Lightly counter-sink any that look as if they need it.

There are some dodgy pattern gaskets out there too, make sure you use a good one.

[trevor_ford]

Re: cylinder head

WOW, you go away for five minutes - OK - a day - and look at the response. Thanks for all your advice. Took the head back off. Cleaned it and block, again. Cleaned gasket. Torqued it down - leak now gone ! Couldn't get the engine started yesterday and its pouring with rain today - single garage full of lawnmowers, bikes etc., means I have to work on the driveway. Roll on summer. Looks like a new battery is the next thing.