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-   -   Head Clearance (https://www.rctech.net/forum/nitro-off-road/257019-head-clearance.html)

franklucas 11-30-2008 05:51 PM

Head Clearance
 
Could I please have detailed directions on measuring head clearance? thanks I do have a digital calipers

chunk t 11-30-2008 06:07 PM

Frank,

pull the back plate but leave the head bolted in place. turn the crank to TDC (top dead center) then pull the head and shims. (if you turn the crank with the head removed there is a good chance you will cause the sleeve to slide in the block and this will affect your first measurement.)

1. Measure from the top of the sleeve to the piston face with the probe on the butt end of the caliper. (write the number down)
2. measure the length of the portion of the head that inserts into the sleeve.(again w/the probe on the butt end of the caliper)
3. measue the thickness of the shim(s)

take your answer from #1 - #2 + #3 = your head clearance (aka. deck height).

hope this helps

chunk

sickboy 11-30-2008 06:36 PM

way easier method.
remove glowplug
get a 4" long piecethin piece of solder
bend the solder into an "L" shape 1/4" from the bottom
stick the solder into the head button
slowly spin the crank one revolution
pull the solder out and use your calipers to measure the thickness of the flattend solder.
done..........

jpalessi 11-30-2008 07:04 PM


Originally Posted by chunk t (Post 5110503)
Frank,

pull the back plate but leave the head bolted in place. turn the crank to TDC (top dead center) then pull the head and shims. (if you turn the crank with the head removed there is a good chance you will cause the sleeve to slide in the block and this will affect your first measurement.)

1. Measure from the top of the sleeve to the piston face with the probe on the butt end of the caliper. (write the number down)
2. measure the length of the portion of the head that inserts into the sleeve.(again w/the probe on the butt end of the caliper)
3. measue the thickness of the shim(s)

take your answer from #1 - #2 + #3 = your head clearance (aka. deck height).

hope this helps

chunk

+1 Just make sure your at TDC when taking your measurements. when measuring from the top of the sleeve to the top of the piston, take multiple measurements in multiple locations, just to make sure your getting an accurate reading. Good Luck ;)

franklucas 12-01-2008 06:08 PM

i get a .30 reading woth no shims? does this seem acccurate? so with the .30 shims that came on the engine that makes a total of .60 head clearance?

mugenb46 12-01-2008 06:21 PM


Originally Posted by franklucas (Post 5115291)
i get a .30 reading woth no shims? does this seem acccurate? so with the .30 shims that came on the engine that makes a total of .60 head clearance?


.60? are you measuring in mm or thousanths

franklucas 12-01-2008 06:23 PM

mm

franklucas 12-01-2008 06:26 PM

duh sorry new at this thousands would be .024?

mugenb46 12-01-2008 06:29 PM


Originally Posted by franklucas (Post 5115361)
mm

here is your DH in thou 0.02362204724412

mugenb46 12-01-2008 06:31 PM

Thats the high side of 23 so figure 24, thats a good starting point, what motor are you measuring?

franklucas 12-01-2008 06:35 PM

axe rossi x1 comp. 30% fuel


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