I am changing the heads on my 1916
I really dont want to turn it into a major rebuild.
To be honest - I dont want to turn it into a minor rebuild, but #3 is "pssst-ing" when you start it up.
Seems to be a crack in the thread area as the plug has a carbon V on it

Anyway - should I put a gapless top ring on it when I pull the motor.
Was going to hone the barrels.

Motor has done about 80,000kms

yep u MUST hone and take the lip of the top of the barrell other wise the rings wont bed in as such and it will b pissssing again

The gapless rings usually go on the second groove, let the std first ring take the brunt of the work and have the second ring set seal the blowby in

The pssting is coming from the crack at the spark plug i reckon

The pssssst is usually the head to barrel seal but a badly burnt head at a plug crack could obviously do it too. Why do you think it needs new rings? Gapless on second is more the go if you want to, or just hone and rering with a quality set of rings, beware, some are junk and luck to make it onto the piston!!!

Matt

That is exactly the point

I am throwing up between
1) taking the heads off and putting the new ones on
2) step 1) + honing the barrels and putting them back on
3) step 2 + new rings
4) step 3 + a new mortgage

due to the carbon mark I am pretty sure of the source

just put the heads on.

If it's not burning oil and the barrels are relatively clean externally and on disasembly not disturbed, I'd setup CR and throw on the new heads. Sometime it's necessary to remove the p&b's just for cleanup, decarbon and check over. The thing is, it'll really depend on what you find on disassembly, at 80k km things may be more worn than you think and need to be replaced or be fine and a clean is all they need.