Piston to plug

[thackers]

I recently had a cyl head re-profiled to a new piston (tzr) now with this conversion you need to have a packer plate to allow for the height of the piston crown. So i fitted the barrel plate and all the gaskets only to find the piston hitting the plug slightly so i added an extra base gasket and all seems well (ticking over anyway). My worry is this, is the gap still too close ? Could the piston expand in it's length when under running temp? I thought perhaps i could add an extra seating washer to the plug, or am i being a little paranoid

[Knowledge]

Your conrod will stretch at high revs, but will it stretch enough for the piston to obliterate itself on the plug hole?

I wonder why you are adding gaskets to the bottom of the barrel, and not fitting them as a head gasket? Your solution is legitimate, but each gasket you add alters the port timings. Head gaskets have no effect on the port timing, but it does space the piston away from the plug. Both solutions lower the compression ratio.

[sean brady scooters]

who did the head for you dave..........?

[thackers]

Martin at Chiselspeed, i'm not laying any blame here, i have used the same piston as others have with the tzr conversion and when i had just the one base gasket and packer the piston came up to the top of the barrel and looked right, the squish was about right at 1mm strong but hit the plug, so i thought an extra base gasket would be ok and not alter the port timing too badly(but then what do i know). Would i be better off removing the extra base gasket and adding the plug washer or go with the earlier idea of an extra head gasket, either way though is there enough space between plug and piston? Also, thanks for your help

[tony]

I would speak to Martin mate. Dont mess about. He did the job and is a professional. If there's a problem, whether his fault or another issue, he will help put it right.

[sean brady scooters]

i do of course agree with tonys answer.................
ask martin...........and tell him your probs..............firstly
i.m sure he will sort it what ever..................

[thackers]

I v'e spoken to Martin and his advice is to use extra washers on the plug, so i guess that's the problem sorted, as to how many i think probably 2 and remove the extra base gasket.