Nelson's KZ1000 Fighter? build

Nelson wrote: the other one.

.

what did the piston outer edge to head clearance measure. it is best to measure this over the wrist pins to avoid rocking.
i have never owned a stock motor but if your deck is level with the pistons, i would bet it has been milled.
Larry, how much down the hole should a stock piston be ?

good progress nelson.

mark,
larry bailed,he is not a member here any longer.

leon

531blackbanshee wrote: good progress nelson.

mark,
larry bailed,he is not a member here any longer.

leon

WTF.
Since when ?

few weeks back,took his advertising and all.

leon

Bummer.

I think the plugs were all about the same, not sure tho. Of course the carbs are all jetted the same...so...? The only diff I can think of is that the center cyls always run hotter.

Deck height measurements were:
1 .46mm
2 .49mm
3 .48mm
4 .35mm

I did not think of the rocking issue, I'm sure I did not measure above the pins.

is this how far the piston is down below the deck ?
how thick is your compressed head gasket?

mark1122 wrote: is this how far the piston is down below the deck ?
how thick is your compressed head gasket?

yes. 2 stroke guys call that "deck height" and we adjust it with base gaskets.

I think it's a stock head gasket, I haven't measured it.

i just asked to make sure we were on the same page.
so u need to remeasure at the pins to get an accurate #. then add the compressed gasket thickness.
u can adjust the deck height to get a total of .040" for the piston to head or squish clearance, a street ride. a stock head gasket will compress to about .040" but u can measure the old 1.this will get u less squish,and decrease the likelihood of detonation if u decide to mill the head.u were asking about milling for compression earlier.
compare the deck height on #1 and #4 to make sure everything is square.

so you're saying .040" is the minimum safe piston to head clearance?

Nelson wrote: so you're saying .040" is the minimum safe piston to head clearance?

Yes ,u can go lower on the track , but this is fine for the street. but remember to use compressed gasket #s in your equation.
if u mill the head the chamber will get smaller , and closer to the outer edge of the piston dome. i have no data on this, but it is something u need to measure. a set of 1075 pistons would be better all around than milling the head.
larger pistons give u a larger squish area, and give u the compression u want without complications. If u mill the head u cannot use it later with 10.25:1 pistons.

i would just go 1075CC's.
even if u plan a build over time. u can get the crank welded now, later u can buy a spare block and have it fitted for new pistons when u get them. then u just have to pull the top end and change out the pistons and block.