Squealing noise around stator and slow return to idles

Brickyard · Post by **Brickyard** » Mon Nov 09, 2015 5:20 pm

I'll get those number soon after the cases go back together.

LOUD MOUSE wrote:Micrometer. .....................lm

LOUD MOUSE · Post by **LOUD MOUSE** » Mon Nov 09, 2015 6:02 pm

Good deal. ...lm

Brickyard wrote:I'll get those number soon after the cases go back together.

LOUD MOUSE wrote:Micrometer. .....................lm

Brickyard · Post by **Brickyard** » Mon Nov 09, 2015 10:56 pm

LM,

Considering you can measure this more accurate with your eyes better than I can actually measure, take a look at the photos, but using a straight zip tie, sharpie and my harbor freight digital caliper, im reading:

TDC at the raised base: .7mm
BDC at the raised base: 50.8mm

excuse my non technical terms.

LOUD MOUSE wrote:OK.
I'll recommend you go with what TIM sold you as for the rings.
Question.
How do the new pistons MIC at the top and bottom?. ...............lm

LOUD MOUSE · Post by **LOUD MOUSE** » Tue Nov 10, 2015 12:00 am

I'm a little confused with your numbers.
I measure the inside bore at top then the middle of the piston (very top of piston is machined smaller than the rest of the piston) and compare the numbers.
I also measure the bottom inside of the sleeve/bore and the bottom of the piston and compare those numbers.
Some folks use feeler gauges at the top and bottom to measure the clearance.
I'm sorry but I can't even measure with just my eyes and feel perfect as to the actual clearance.
How bout you call me tomorrow and discuss this rather than the slow way on the computer. ....................lm

Brickyard wrote:LM,

Considering you can measure this more accurate with your eyes better than I can actually measure, take a look at the photos, but using a straight zip tie, sharpie and my harbor freight digital caliper, im reading:

TDC at the raised base: .7mm
BDC at the raised base: 50.8mm

excuse my non technical terms.

LOUD MOUSE wrote:OK.
I'll recommend you go with what TIM sold you as for the rings.
Question.
How do the new pistons MIC at the top and bottom?. ...............lm

Brickyard · Post by **Brickyard** » Tue Nov 10, 2015 12:57 am

I assumed you were talking about measuring the new pistons TDC and BDC from the base of the cylinder top, hence the photos.

Why did I assume this... I have no idea.

Now I believe you were talking about measuring the inner diameter of the cylinders at varying points with a micrometer vs a digital caliper.

I dont have a micrometer, and I will call you tomorrow.

LOUD MOUSE wrote:I'm a little confused with your numbers.
I measure the inside bore at top then the middle of the piston (very top of piston is machined smaller than the rest of the piston) and compare the numbers.
I also measure the bottom inside of the sleeve/bore and the bottom of the piston and compare those numbers.
Some folks use feeler gauges at the top and bottom to measure the clearance.
I'm sorry but I can't even measure with just my eyes and feel perfect as to the actual clearance.
How bout you call me tomorrow and discuss this rather than the slow way on the computer. ....................lm

G-Man · Post by **G-Man** » Tue Nov 10, 2015 2:08 am

Brickyard

Pistons are usually tapered (smaller at the top) and oval, widest at 90 degrees from the pin. The largest diameter can be measured near the bottom of the skirt at right-angles to the pin.

The taper is because the top gets hotter than the bottom, when running, and expands more. The ovality is to reduce friction as the side flanks do not do a lot of work but do contribute to friction.

The honda specs (the ones above the *) give the clearance between piston and bore. As LM says, you can push a bare piston in the bore and push a feeler between it and the sleeve to measure actual clearance. Maeasure between the skirt (at 90 degress to the pin).

Brickyard · Post by **Brickyard** » Tue Nov 10, 2015 3:19 am

G,

I cant accurately measure all areas in the cylinder as I dont have a micrometer, however, my digital caliper allows me to measure 1/4 inch from the top and bottom of the cylinder. My results are as follow:

Both new piston diameters: 59.4mm

Cylinder 1, bottom end: 60.0mm
Cylinder 1, top end: 60.0mm

Cylinder 2, bottom end: 60.1mm
Cylinder 2, top end: 60.1mm

Please see photos below:

G-Man wrote:Brickyard

Pistons are usually tapered (smaller at the top) and oval, widest at 90 degrees from the pin. The largest diameter can be measured near the bottom of the skirt at right-angles to the pin.

The taper is because the top gets hotter than the bottom, when running, and expands more. The ovality is to reduce friction as the side flanks do not do a lot of work but do contribute to friction.

The honda specs (the ones above the *) give the clearance between piston and bore. As LM says, you can push a bare piston in the bore and push a feeler between it and the sleeve to measure actual clearance. Maeasure between the skirt (at 90 degress to the pin).