What do these sleeves fit?

All things K & Sportster

Re: What do these sleeves fit?

Postby Rubone » Thu Dec 10, 2020 12:09 am

Stock 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. :shock:
Rubone
 
Posts: 117
Joined: Thu Oct 26, 2017 6:48 pm

Re: What do these sleeves fit?

Postby JerrryR » Thu Dec 10, 2020 12:16 am

Apparently 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.
User avatar
JerrryR
 
Posts: 440
Joined: Sun Jul 20, 2014 9:39 pm

Re: What do these sleeves fit?

Postby Maxcapacity » Thu Dec 10, 2020 1:17 am

Jerry, Are there any other modifications or is it as simple as using scout pistons to go 0.100 in the stock cylinder?
Maxcapacity
 
Posts: 35
Joined: Thu Jul 28, 2016 10:30 am

Re: What do these sleeves fit?

Postby panic » Thu Dec 10, 2020 10:21 am

Common 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.
[url="http://victorylibrary.com/L-BK.htm"]The Linkert Book[/url]
User avatar
panic
 
Posts: 132
Joined: Mon Jul 29, 2019 5:33 pm

Re: What do these sleeves fit?

Postby JerrryR » Fri Dec 11, 2020 9:02 pm

Thanks 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?
User avatar
JerrryR
 
Posts: 440
Joined: Sun Jul 20, 2014 9:39 pm

Re: What do these sleeves fit?

Postby panic » Sat Dec 12, 2020 9:27 am

Flathead 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.
[url="http://victorylibrary.com/L-BK.htm"]The Linkert Book[/url]
User avatar
panic
 
Posts: 132
Joined: Mon Jul 29, 2019 5:33 pm

Previous

Return to General K / Sportster Discussions

Who is online

Users browsing this forum: No registered users and 16 guests