KH with KR heads

Production K Models

Re: KH with KR heads

Postby thefrenchowl » Sun Feb 17, 2019 2:51 pm

Do you care to enlighten me?

I'm always willing to learn sommat new if it makes sense (I'm still a youngster, been wrenching these beasts for only 40 years)

Patrick
Flat Head Forever
https://web.archive.org/web/20071011184353/http://www.harleykrxlrtt.com/index.htm
I'm the one who has to die when it's time for me to die so let me live my life the way I want to...
thefrenchowl
 
Posts: 611
Joined: Sun Jun 28, 2015 4:33 pm

Re: KH with KR heads

Postby LDB » Sun Feb 17, 2019 4:23 pm

The closer the plug is to the geometric center of the combustion space, the quicker and more complete the combustion process.
LDB
 

Re: KH with KR heads

Postby thefrenchowl » Sun Feb 17, 2019 6:38 pm

Theory also says spark should occur at hottest part of chamber...

So I wonder why it's always on top of the inlet valve on a side valve...

Quite away and offset from the "center" of the chamber by the way...

Wonder why they didn't know then sommat we now do... :D

Patrick
Flat Head Forever
https://web.archive.org/web/20071011184353/http://www.harleykrxlrtt.com/index.htm
I'm the one who has to die when it's time for me to die so let me live my life the way I want to...
thefrenchowl
 
Posts: 611
Joined: Sun Jun 28, 2015 4:33 pm

Re: KH with KR heads

Postby EKHKHK56 » Sun Feb 17, 2019 7:06 pm

The hottest spot in the Ricardo Combustion chamber is over exhaust valves. But not much air fuel hanging around there. KHK runs 36 total advance. Textbook. You can roll a golf ball through my intake ports, all the way almost. Haha. Guides? Chop them out of there. There's enough guide for a Cat Diesel. No goofy side load from rocker arms. Its all beautiful. The extra swept volume from the stroker loves any flow benefits regardless of RPM. 3 stroke...I run my race equipment for WFO. That's what. I've built hundreds of race engines, all great fun, low buck, successful, since 1974. Cheers, Flat Head Power. Erik
User avatar
EKHKHK56
 
Posts: 920
Joined: Fri Apr 18, 2014 5:20 am
Location: Fairbanks, Alaska USA

Re: KH with KR heads

Postby EKHKHK56 » Sun Feb 17, 2019 7:39 pm

I use the deepest reaching hottest plugs for vehicles in Fairbanks. Nothing else works at -50F. Fine here year round, it usually only gets in 70s. For example. All Chevys, Fords, etc get Autolight Single Platinum AP-26 fits most V8s. Night and Day difference in performance between a 23 and a 26 but both screw in and the parts guy wants to dump them. All should be tossed except the 26 for this climate. I have restored carbs since 74. SMOG legal passing Check every year when we had that. It was California based regulations. Anyway I know how to make anything run the best it can. Usually old pickups, out of gas, with 3 flats and a junk carburetor to start. :shock: Great to hear them run like new again after carb and fine tuning, and all the little things no one knows about. #CarburetorMan Erik
User avatar
EKHKHK56
 
Posts: 920
Joined: Fri Apr 18, 2014 5:20 am
Location: Fairbanks, Alaska USA

Re: KH with KR heads

Postby LDB » Sun Feb 17, 2019 9:58 pm

Rest assured; if the Harley engineers back in the day thought moving the spark plug closer to the exhaust side was going to eke out a few extra ponies, they would have done it! Spark plugs have been moved all over on Ford flatheads by various manufacturers back in the day at one time or another and it never made a whole lot of difference. However, most ended up with the plug closer to the exhaust side, even Ford. A lot of that is/was just theory and not a night and day gain in power. I think many thought that the location helped to control detonation by firing the hot side first and some of the burn would travel to the cooler side rather than fire on the cooler side and then be even hotter when some of the burn would travel to the hot side.

In my opinion, the Harley design on the intake side of the combustion chamber channels a good amount of the combustion toward the shelf over the piston top and the point of ignition needs to be over the intake valve for it to happen as they intended. And last but not least, I bet if the truth were known Harley experimented with moving the plugs all over.
LDB
 

Re: KH with KR heads

Postby Coolbreeze » Sun Feb 17, 2019 10:20 pm

My Indian 841 has dual plug heads: one over the piston and one over the valves. I cannot tell any difference in starting or power output when I use one or the other. Of course this is not exactly a powerhouse; so, it might be hard to tell if there is any change in output.

BTW, I am trying to devise a way to fire both plugs with a ~10 degree advance of the plug over the valves with respect to the spark plug over the piston. That way both flame fronts should converge nicely and the engine should reach its optimum in terms of power and efficiency. I wonder if Harley ever considered doing that?
'56 KHK
'60 XLCH
'48 Chief
'42 Indian 841
'64 BMW R69S
'84 Moto Guzzi V65Sp
User avatar
Coolbreeze
 
Posts: 42
Joined: Tue May 01, 2018 12:44 am

Re: KH with KR heads

Postby thefrenchowl » Mon Feb 18, 2019 7:00 am

Official factory issued timing chart for all sorts of K models.......

Image

It's nice to see that irony is completely lost on some members here....

Patrick
Last edited by thefrenchowl on Mon Feb 18, 2019 9:24 am, edited 1 time in total.
Flat Head Forever
https://web.archive.org/web/20071011184353/http://www.harleykrxlrtt.com/index.htm
I'm the one who has to die when it's time for me to die so let me live my life the way I want to...
thefrenchowl
 
Posts: 611
Joined: Sun Jun 28, 2015 4:33 pm

Re: KH with KR heads

Postby thefrenchowl » Mon Feb 18, 2019 7:10 am

I am trying to devise a way to fire both plugs with a ~10 degree advance of the plug over the valves with respect to the spark plug over the piston.


Harry Arminius Miller tried that on one of his early 4 banger twin sparks, circa 1916...

Engine kept braking rods so they put an end to that silly experiment...

Patrick
Flat Head Forever
https://web.archive.org/web/20071011184353/http://www.harleykrxlrtt.com/index.htm
I'm the one who has to die when it's time for me to die so let me live my life the way I want to...
thefrenchowl
 
Posts: 611
Joined: Sun Jun 28, 2015 4:33 pm

Re: KH with KR heads

Postby EKHKHK56 » Mon Feb 18, 2019 11:10 pm

BOTTOM LINE...I believe Patrick is trying to sweetly whisper in our ears " hey dummies, you think you know more than the H-D Factory??? " Patrick, you are Korrect. All the playing around is just that, just fun and some foolish.. FACTS: Harley Davidson built the K with perfect 45" cams to match the heads, valves AND ports. AND the KH, great 56" match...on Cams, Ports, Valves. The KK and KHK. Beautiful state of art Side Valve Hot Rodding Science setting industry standards high. Thing is, out of the box these are proven systems ready to perform as is. Truthfully, a KH would whip a KHK easily in a drag race with novice racers because it pulls much harder, much sooner than the KHK. Same note. K 45s can be bumped up in cam area, say KH profile, but they run sadly on low end, catching up and performing later. Harley Davidson knew exactly what they were doing with their 1929 blue print by 1952...trust me. So all this Mutt Motor stuff is is for fun only. Rot de Hey, right? Peace. SideValves. Rumpity Rump.. :P Erik
User avatar
EKHKHK56
 
Posts: 920
Joined: Fri Apr 18, 2014 5:20 am
Location: Fairbanks, Alaska USA

PreviousNext

Return to K, KK, KH, KHK

Who is online

Users browsing this forum: No registered users and 17 guests