Re: What do these sleeves fit?
Posted: Thu Dec 10, 2020 12:09 amStock Scout bore is 2-7/8". My KHK had Scout pistons in it when I got it in the '70s. I think I still have them. 
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Posted: Thu Dec 10, 2020 12:09 amRe: What do these sleeves fit?
Posted: Thu Dec 10, 2020 12:16 amApparently using the Scout pistons in the KHKs is not uncommon. What got me looking for K sleeves is I wanted them as an option if I can't make what I have work. I discovered when I went to do a top end on my 54KHK motor that it also has Scout pistons, standard bore.
Re: What do these sleeves fit?
Posted: Thu Dec 10, 2020 1:17 amJerry, Are there any other modifications or is it as simple as using scout pistons to go 0.100 in the stock cylinder?
Re: What do these sleeves fit?
Posted: Thu Dec 10, 2020 10:21 amCommon sleeve nomenclature: OD, length, wall thickness
W/r/t Scout: too small, too long
Sleeves are certainly not meant to be both lathed to make the OD and bored to make the ID.
What to watch for using std. Scout in KH?
The compression distance is close to a 45, which means it's far too short for any K, KH etc., no pop-up means no quench.
W/r/t Scout: too small, too long
Sleeves are certainly not meant to be both lathed to make the OD and bored to make the ID.
What to watch for using std. Scout in KH?
The compression distance is close to a 45, which means it's far too short for any K, KH etc., no pop-up means no quench.
Re: What do these sleeves fit?
Posted: Fri Dec 11, 2020 9:02 pmThanks again for getting back to me on this gang. Maxcapacity my mechanic says he had to machine the Scout pistons to take the Sportster wrist pins. Panic can you say more about the benefits and draw backs of using the scout pistons in a KHK? You talk about popup and quench?
Re: What do these sleeves fit?
Posted: Sat Dec 12, 2020 9:27 amFlathead engines (H-D, Indian, Ford, Triumph, Pontiac) REQUIRE very tight piston to head clearance, about .035" minimum @ TDC.
K, KH, KR, WR and all Scout and Chief Bonneville engines have pistons that rise above the deck @ TDC and enter a recess in the head.
The same clearance is necessary in all cases. No sidevalve engines were built without this design feature in the last 100+ years (although the production tolerances tend to be a bit looser).
This has nothing to do with the compression ratio, it's anti-knock protection.
Hemispherical chambers (H-D single-cam big twin, iron Sportster), Triumph, Chrysler) have almost no quench surfaces and do reasonably well with very loose clearances. It's still a good idea.
What happens if I use a zero or slightly negative deck piston (such as a 45, Scout, Atlas) with a head that requires a dome (K, KH, KR, WR)?
Overheating, knocking, low power and eventual piston failure.
K, KH, KR, WR and all Scout and Chief Bonneville engines have pistons that rise above the deck @ TDC and enter a recess in the head.
The same clearance is necessary in all cases. No sidevalve engines were built without this design feature in the last 100+ years (although the production tolerances tend to be a bit looser).
This has nothing to do with the compression ratio, it's anti-knock protection.
Hemispherical chambers (H-D single-cam big twin, iron Sportster), Triumph, Chrysler) have almost no quench surfaces and do reasonably well with very loose clearances. It's still a good idea.
What happens if I use a zero or slightly negative deck piston (such as a 45, Scout, Atlas) with a head that requires a dome (K, KH, KR, WR)?
Overheating, knocking, low power and eventual piston failure.