4 replies to this topic

[coopersmate]

Model: City E with a stage 3 head and stage 1 kit
Year: 1989
Description of problem (please be as in depth as possible):

Hello People

What a lovley bank holiday weekend it is. Right so I thought I had blown the head gasget so stripped it down today to find this.



So I was wondering should I be worried about that lump of metal being somewhere in my engine and also what is the cause?
Oh and do you think I will need the head skimming or can I just replace the valve and be done with?

Thanks

Lloyd
Any non-standard parts that might be involved with the problem? See above

[Cooperman]

Who knows where that little bit of steel may be! It has probably gone down the exhaust pipe. If not, check the piston top for damage. if it isn't damaged you have no problem.
All you need to do as a minimum is to get the valve seat re-cut and fit a new valve, making sure you lap it in properly. Total cost about £5 for seat cutting plus the cost of the new valve.
That's the cheapest solution.
Then again, whilst it's in pieces, it would be a good idea to renew all the exhaust valves, clean up the head and e-lap all the old inlet valves. Inlets rarely go and you can change for new ones if you wish. Then again, as it's going to need the seats re-cut, it could be wise to fit new valve guides and have them reamed out to reduce oil consumption. Do inlets and exhausts and fit new valve stem oil seals too.
The choice as to how far to go is yours. It's unlikely the head will need skimming, but a skim of, say, 0.025" would increase the comression ratio a bit and thus improve performance.
Fit a top quality head gasket when re-fitting the head.
I hope this helps.
P.S. That head doesn't look very 'Stage 3' to me!

Edited by Cooperman, 24 May 2009 - 07:07 PM.

[coopersmate]

P.S. That head doesn't look very 'Stage 3' to me!

Thanks that helps a lot. I will go talk to my machine shop and see what sort of money they want.

I know the head looks very standard but with the stage 1 kit I get 50 hp at the wheels so its doing something.

I was concerned about the standardness when I first got it so posted so on here and this is what got said.

Thread about my head

Thanks

Lloyd

[WiredbyWilson]

that is more than likely caused by using unleaded fuel when the head is a leaded one - just a thought as i had a mini in the other day that had done just that!

luckily the seat was fine so fitted a new valve and it ran sweet.

[Cooperman]

No, it won't be the petrol. The worst thing that can happen with using unleaded in an engine without the modified valve seats will be higher wear on the exhaust valve seats. The seats 'recess' with time and the valve seems to sit further into the seat. The valves themselves are the same for leaded and unleaded - unless you are going for a higher performance valve for very high revs.