G80CS Top End Rebuild Advice

[Iron Head]

Although I got lucky freeing my ‘54 G80CS engine off, stuck for many years with Castrol R gum, after about 300 miles of road use compression was down to 80psi and so I pulled the head and barrel. +20 Hepolite piston fitted and bore is perfect albeit slightly glazed. Plenty of bean oil crud on the piston crown! Top ring broken into 3 and luckily all pieces retrieved.

No head gasket fitted just the spigot joint, can I fit a G80 Cu gasket bought from AMC Classic Spares if I open the head bolt holes out? Do I anneal it first? Got rings sorted. I prefer the chamfered bottom push rod tube seals rather than ‘O' rings are these still available? Is bottom cylinder gasket just paper as per the gasket sets I have?

Many thanks in advance.

Iron Head

[cbranni]

I fitted a copper gasket also annealed it, I can't remember what O rings I used and the cylinder gasket was a paper one.

Colin

[dave16mct]

I also fitted the copper head gasket and annealed it. O rings were the correct ones from AMC Classic spares. No pushrod tubes on mine but I would fit the 4 O rings at the top or you could cut the rubber sleeve in the middle and fit one O ring. Just cut the thickness of the O ring out from the middle. This was the original advice from John Allen in the early 90's. (edit actually July '88 Just seen it again after working my way through all the old Jampot mags! - thanks Rob H). It'll leak if you just use the sleeves.
Dave.

[SPRIDDLER]

No head gasket fitted just the spigot joint, can I fit a G80 Cu gasket bought from AMC Classic Spares if I open the head bolt holes out? Do I anneal it first?

Always anneal solid copper gaskets as even new ones age harden quite quickly.
When I worked in a plumbers' merchants the old boys wouldn't take slightly dull copper pipe as they said it was problematic to bend it.

[Marty]

No head gasket is correct for CS. Lap head to barrel. No gasket problems ever. Why make it complicated ? Marty

[39speedtwin]

Marty is correct, my 1953 G80 CS on +30, has no head gasket, was lapped in with fine paste, then rubbing compound, no leaks.

[GOLDSTAR]

I think the chap in the west country supplies a gasket for the s/s G80cs can't think of his name, but yes no gasket originally fitted,

By the cringe 'Marty' aint that poor critter dead yet?

kind regards

stay safe

[dave16mct]

Blimey, I didn't think there would be a lynch mob chasing me for fitting a head gasket! Does this mean I'll have to remove the DVR2 regulator, LED bulbs, stainless nuts and bolts, stainless rims, ball end levers, cyclon battery, fuses, Rob Swift centre stand, spin-on oil filter, Thorspark electonic ignition and QD seat??
Dave.

[Iron Head]

Thanks guys. Seems the jury is split 50/50 on gasket or not. If lapping works perhaps I'll give it a go. Will certainly give a slightly better ‘squeeze' on the pushrod tube ‘O' rings I guess?

Iron Head

[ajscomboman]

Blimey, I didn't think there would be a lynch mob chasing me for fitting a head gasket! Does this mean I'll have to remove the DVR2 regulator, LED bulbs, stainless nuts and bolts, stainless rims, ball end levers, cyclon battery, fuses, Rob Swift centre stand, spin-on oil filter, Thorspark electonic ignition and QD seat??
Dave.

I'm with you Dave, a lapped joint was ok when these were used in anger and it was the norm to strip clean and then lap the head. Today they just potter and get hot and the sleeve nut by the exhaust pipe always seems to be the first to relax and a weep develops. I've had it happen despite hrs lapping. Since I've taken to using copper gaskets, not a drop! I think you'll find even Ken De Groome recommends the gasket if they are going to be road based.