One For The Pro's. A Skim To Far? (xu9 8v)

[MerlinGTI 3]

I have a heavily modified XU9 8v head here that im intending on rebuilding soon.

 

Its being sent off for a re-face, 3 angle seats, and of course a hot pressure test. Before I do could one of the pro's give me some advice please?

 

Ive just measured the head to check how much has been skimmed off in the past and heres what I got:

 

157.41 mm. Nominal value of an unskim'ed head being 158.931.

 

Its going to need another reface before I use it. What sort of CR will this give? Will it be ok to proceed?

 

Many thanks

[whizzer71 0]

I have a heavily modified XU9 8v head here that im intending on rebuilding soon.

 

Its being sent off for a re-face, 3 angle seats, and of course a hot pressure test. Before I do could one of the pro's give me some advice please?

 

Ive just measured the head to check how much has been skimmed off in the past and heres what I got:

 

157.41 mm. Nominal value of an unskim'ed head being 158.931.

 

Its going to need another reface before I use it. What sort of CR will this give? Will it be ok to proceed?

 

Many thanks

 

Hi There fella, I havent got the answer to your Q' but I notice that you are in Kent, R u far from Canterbury theres not that many 205 afficionados round here lol, I think the other important bits of info you have left out are size of pistons u are using ie are they overbored, also the measurement in cc's of the piston and head dishes if any, also I believe that head gasket thickness plays a part in the eqaution also, there are calculators on line that will work it out for you, I seem to remember seeing something on Puma Powers site about working out comp ratios might be wrong tho ?, although this will help

 

http://www.chainganger.co.uk/Page2/Page2.html

 

Regards

 

Tris

[Miles 331 1 Cars]

+ it depends on how much has to come off, a very light cleaning skim would be fine, A skim to remove corrrsion could be a different matter

[petert 589]

Max skim is 2mm, but you will also need to elongate the hole in the engine mount.

Edited December 5, 2010 by petert

[MerlinGTI 3]

Whizzer71, Im in medway mate

 

Miles, No corrosion. Im hoping a very light skim is all thats needed.

 

Petert, you the man thats what I wanted to know.

 

Thankyou very much everyone

[welshpug 1,661]

will need a vernier pulley to get the timing right too

[MerlinGTI 3]

Got one sitting here mr wp