22 replies to this topic

[Macker1]

Plugs are abit black on all, yes car was run upto normal and battery is new.

[MiniMadRacer]

If all plugs "match" colour wise I wouldn't have thought you have a "Gasket" issue, and figures to me suggest you don't have a Gasket issue.. interesting to see what others think

[Macker1]

I don't think it's the head gasket. Hopefully someone can advise me..

[cal844]

I think the valves can do with a relap and the head decoked but see what someone else says

[Macker1]

I think the valves can do with a relap and the head decoked but see what someone else says

I know this may sound stupid, but what to you mean by relap?

[sonikk4]

I would agree the figures do look ok with some potential piston ring/ bore wear on 3 and 4.

 

Several things here to look at. The carb itself, is it adjusted correctly?? possible bent needle, no oil in the dash pot, possible air leak making things go lean on initial acceleration?? All of these things can cause power issues along with timing.

 

Ref the valves. Re lapping is when you remove each valve in turn, look at the seat in the head and valve itself. If there are no signs of pitting etc, you then use grinding paste to lap the two surfaces together, the surfaces being the valve seat in the head and the contact face of the valve. When done correctly it should be a even grey finish.

 

If the valve seat shows signs of pitting / burning / damage then its time to have them replaced. The same applies to the valves. This is the time you also look at the valve guides for wear and of course the vale stem seals. Just to say doing it with a drill is quick but hand lapping will give you more leeway.

[Macker1]

I would agree the figures do look ok with some piston ring wear.

Several things here to look at. The carb itself, is it adjusted correctly?? possible bent needle, no oil in the dash pot, possible air leak making things go lean on initial acceleration??

Ref the valves. Re lapping is when you remove each valve in turn, look at the seat in the head and valve itself. If there are no signs of pitting etc, you then use grinding paste to lap the two surfaces together, the surfaces being the valve seat in the head and the contact face of the valve. When done correctly it should be a even grey finish.

If the valve seat shows signs of pitting / burning / damage then its time to have them replaced. The same applies to the valves. This is the time you also look at the valve guides for wear and of course the vale stem seals. Just to say doing it with a drill is quick but hand lapping will give you more leeway.

I have a new carb ordered, I will try that first before I strip down the engine, thanks for all your advice, I'll keep you posted on the result..??

[Macker1]

Well guys just a quick update and thanks for the advice, turned out it was the valve stem seals that needed replacing. No damage to the block. I had the head cleaned and skimmed and all new parts put in plus new unleaded seals. Car is back running and I'm now moving onto upgrading the drums to 10inc disks. Thanks again for all your advice and thanks to minifix in Dublin for helping me out..