28 replies to this topic

[The Matt]

You could try to find out why it's had what looks to be about 50 thou taken off the top surface.

I have no idea personally. I am going to get the underside skimmed before I fit it to the engine, do you think it'll be worth while asking to get the top done too?

The top has already had a shed load skimmed off it, hence the lack of a clear ID and the machining marks.

[Dog]

You could try to find out why it's had what looks to be about 50 thou taken off the top surface.

I have no idea personally. I am going to get the underside skimmed before I fit it to the engine, do you think it'll be worth while asking to get the top done too?

The top has already had a shed load skimmed off it, hence the lack of a clear ID and the machining marks.

Was thinking along the Gasket seal line mainly, like Dan says, I could have a bad seal due to the rough surface but it doesn't "feel" rough

[miniboo]

mine looks like that and it seals fine

[RacingGreen]

Was thinking along the Gasket seal line mainly

You cant just skim a part of a surface, the whole thing has to be done.

[minimole]

I have an mg metro head at my garage if ya want i will take some pics for you tomorrow to compare.

[Dan]

If it feels smooth then it will be fine, just looks like it was done with a chisel fitted in the mill rather than a proper tool! Although there's almost nothing other than the gasket holding the oil in. It'll pour out every time you take the rocker cover off!

If that much has been removed it may have been removed from both sides if it was done to correct warping. I'd get it looked over by someone who really knows what they are doing with heads. There's only so much metal you can remove before it becomes scrap, it may not take another skim. This head is already pretty thin.

Edited by Dan, 17 April 2006 - 05:49 PM.

[Sprocket]

the exhaust ports look like theyhave been opened out to me

[Dog]

If it feels smooth then it will be fine, just looks like it was done with a chisel fitted in the mill rather than a proper tool! Although there's almost nothing other than the gasket holding the oil in. It'll pour out every time you take the rocker cover off!

If that much has been removed it may have been removed from both sides if it was done to correct warping. I'd get it looked over by someone who really knows what they are doing with heads. There's only so much metal you can remove before it becomes scrap, it may not take another skim. This head is already pretty thin.

Thanks Dan.
Been chatting to MMM, and what I am going to do is stick it on the engine, see what happens. If it goes from bad to worse, then I'll use as surchrage agaist the head I want for my other 1330.

[RacingGreen]

surely, if it is no use to you, then no-one will take it in exchange as it will be no use to them either?

[Dan]

Remember that if it's already been machined so much that it won't take any more machining then it's no good as core, it's scrap. If that is the case it won't be accepted against surcharge.

[Dog]

Dam, there goes that idea then

[Dan]

It might not be too far machined yet for you to rescue it, that's why you need to get a head specialist to check it out. They will know for sure, but they really only want untouched heads as exchanged core.

[Dog]

It might not be too far machined yet for you to rescue it, that's why you need to get a head specialist to check it out. They will know for sure, but they really only want untouched heads as exchanged core.

Ok will do.

Thanks For your input Dan

[Sprocket]

Right

The casting will be 12G940, all modern 1275 heads are this casting irrespective of valve size, that is a machining operation

Standard unmodified head measures roughly 69.85mm face to face (measured against the three standard ones i have in the garage)

And for everything else read here http://mlmotorsports... head modifying