Technical cylinder head work.

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Technical cylinder head work.

trissy

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Aug 23, 2005
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hi again,

Im just wondering what sort of work to do on the head while I have it off the car. Obviously there is the skimming an shimming, is it worth whipping out my black and decker version of the dremel and doing some basic polishing and porting? I have no experience of this, but is it just a case of taking off rough edges and smoothing things up? Also its an 82, so what processes make the car run on unleaded, hardened valve seats? Is this pricey?


tris.
 
Hi there, you could have a go on the porting and polishing, but all you would be realy doing is poilishing, as to do a good job porting you normaly need to drill, or mill the ports out and then you hand polish them to smooth things off. To change the valve seats it would be recomended for an expert to do that , and then you could get some new bigger valves and valves seats while you are at it.
Bottom line if you dont want to spend much money then just get the head skimmed clean it and all the valves, have a go polishing it ( it cant hurt just to polish but not to reshape), and stick with using a fuel additive for the valve seats, but if you have the money then the 1500cc head responds very well to an increased intake valve (38-40mm), and a port and polish. If you want any more info just ask,
Slapper
 
The head is *designed* to run on unleaded so no specific work is needed. Fiat do have some reservations about aggresive use of revs while running on unleaded but this appears to be more to do with avoiding legal problems than mechanical issues.

Agree on the intake valves, best way to get some extra grunt from the engine without going for a loopy cam profile.

Clean the ports up to remove mould lines but do not polish them to a mirror finish - best gains here are from matching the ports. CC the combustion chambers if you want to be pedantic and then attempt to balance them up so they are all identical. This is of limited use without working the bottom end but while you have the head off it is one job you can then forget about.

Do you want me to see if I can pull the head of the junker so you have something to play with?

On that subject the whole lot is going to the scrap heap at the end of the month so don't wait too long...
 
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