how do you check head clearance?

[socco72]

would like to know how to check head clearance on my outboard and inboard .21 engines??

 

[Jerry Dunlap]

I'll show you tomorrow.

JD

 

[socco72]

cool thanks jerry

 

[DonSoper]

I'll show you tomorrow.
JD

Hey, what about the rest of us?

 

[Mike Hughes]

Well I think if you want to make the trek to Tacoma WA, then Jerry would show you too.

 

[camaroboy383]

Dustin, hmmm i woulda thought you wick boys would know how to check that.lol..

Take a dial caliper and measure from top of piston (on tdc that is) to the top of the sleeve.

Now measure the head button from where the sleeve would mate, to the top of the squish band (the part that protrudes into the sleeve)

Now subtract the button number from the number you took from the sleeve.

Example:

Piston on tdc to top of sleeve = .048

Sleeve mating surface of button to top of squish = .042

.048-.042= .006 head space

Tell your brother too..lol.

Alden

 

[Bill Britton]

Super easy...

Small piece of solder in the plug hole, turn it over at tdc a few times, mic the solder. There ya go.

 

[john v]

got a set of head clearance feeler guages from gary pruesse and they work great to .010

 

[camaroboy383]

Super easy...
Small piece of solder in the plug hole, turn it over at tdc a few times, mic the solder. There ya go.

Ahhhh, the old imitation plastigauge,,lol..

Alden

 

[TUNLBOTR]

Invest in a dial indicator for your most accurate measurments, through Speedmaster Products or check with Glenn Quarles .Once you set and dial in and use reference points on dial, you can periodically check to see rod stretch and rod bushing wear. The dial doesn't lie.

 

[Bill Gibson]

Super easy...
Small piece of solder in the plug hole, turn it over at tdc a few times, mic the solder. There ya go.

Thats a GREAT IDEA! Even a dumbass like me could do that!! (MAYBE!)

 

[Tunnelbill]

Alden,

What do you do if you have a dished piston?

TB

 

[TUNLBOTR]

Alden,
What do you do if you have a dished piston?

TB

Bill,

Take your head button and zero it on a sheet of glass with the dial indicator. Then press the piston up to the head button. Dial will give your dish depth.

Randy

 

[GRoth265]

OK Dustin if Jerry doesn't show you I will. If you hand me OS outboard I'm going to laugh because every one ive seen is the same. Just take the head shim out and feed it its Nitro. Greg

 

[socco72]

wow so many good ideas i like the one where you use solder to check it that's so clever.

 

[moparbarn]

a few thoughts on checking head clearance with solder. solder comes in 3 types acid core, rosin core, & solid. you don't want to use acid core, for all the obvious reasons.............rosin core would probably be ok, but no flux/solid solder would be best. also, we're only checking .006 to .010 (average), so a thick solder isn't needed. get the thinnest solder you can find. radio shack should have what we need. silver solder or a solder with a high tin content is MUCH harder than lead solder. stick with lead solder, it compress' easier, gentler on internal engine parts . hope this helps.

 

[mark james]

I use a dial guage too from bill m but,,..my sleeve goes into the head button to sit flush inside..

I used a dial caliper and measured from the top of the sleeve,down to the top of the piston and came up with .004

Does this sound rite? I pulled a .008 shim out of a new motor

I tried the solder thing but my motor would not turn to tdc with the solder in it ???

 

[Bill Britton]

I tried the solder thing but my motor would not turn to tdc with the solder in it ???

Then your head clearance is way too tight.

 

[Norm Doerr]

Height guage and a surface plate, granite countertop etc etc. You need top of liner to top of piston at TDC then measure the flange to the highest point on the squish.. OR get a McGraw gauage

 

[TUNLBOTR]

I tried the solder thing but my motor would not turn to tdc with the solder in it ???

Then your head clearance is way too tight.

OS XM 21 Outboard, if it is right, can't be checked with solder. No way Billy Bob.................