Topic: Kenny Harmon F cam, Ride report.

[Don R]

I'm using megacycles specs at .040 since I haven't found .050 numbers anywhere. I was zeroing in on it but the duration changed as I moved the cam closer to CL. I assume that means my wheel of dial indicator moved so, back to square 1. I can do this but it's resisting by best effort. I'm checking TDC again and marking the dyno end too.

[Don R]

OK. The auctual intake lift is .370 on all lobes Exh. 330.  Adv. 385/330 but that's OK.
 
The intake duration is advertised at .040 on the megacycle card.   28*/62* @ 270* with a lobe cl of 107*.

I can get 106.5cl at 25*/58* with 263* dur. or  107*cl at 24.5*/59*  with 263.5* dur.  or at 28*/55* I get 103.5cl with 263* dur.

Should I stay with the 107  cam card lobe cl even though the opening event is 3.5*  later?  I can't seem to get closer to the 62* closing number.  22/61 makes a 109.5cl.

Does this make any sense at all? If not, I'm hauling it to a drag bike shop an hour from here.

[Don R]

Kenny Harmon had the D cam, the F cam and the super F. This one must be the weenie F. I've never heard of one with 370 int.  lift. it's clearly marked KH/F might be a one off or something. That said, 370 is great with me. Might still be too big LOL.

[johno]

Hi Don,
at 040 you quoted inlet specs  28/62 at 270 duration, just curious mate  did you do the exhaust open , close & duration numbers as well ?
johno

[Don R]

Those were the numbers from the megacycle cam card. To answer the question,
Not yet, I logged 6 different opening intake numbers to check intake lobe angle last night and thought I'd see if I was on the right track before doing the exhaust.

I've rolled the motor over so many times it's pumping oil.

[johno]

Thanks Don,
Mate I think your falling into the trap of trying to reproduce the cam card specs, 99% just wont happen.

 The reason for dialling in the cam is to make sure its installed in the correct position indicated on the card , so advanced or retarded etc  caused by manufacturing tolerances, different chains, worn sprockets, maching in head and changing the cam to crank centrelines , that kind of stuff.

My advice is stop stressing about the card. work on seeing where the cam is positioned in relation to the crank  and see how it compares to the card in terms of advanced or retarded prefered by the cam grinder.

TRY this method see if its easier for you Don , if not go back to the centreline method that most people use.

Forget .40 try the industry standard or .050  ( further from open / close ramps the better the indicator is.)
Next, at .050 lift what are the inlet open degrees and then what are the exhaust close degrees ?

Subtract one from the other and divide by 2 .............................gives you how many degrees the cam is advanced or rettarded.     if inlet no is highest then it will be advanced , if exh was highest then it is retarded .

SO DON , now its time to look at the card.  the only numbers to look at is the in open and exh close of course and what does the card say where it want s the cam set ?  eg their are 3 scenarios for you to choose from.

Advanced eg   in open 30 deg exh close 28 deg         ( so inlet higher number most common is advanced 1 deg  by  30 - 28 =2 divide by 2 = 1 deg advanced   

Straight up and Down ( now their is an old term)  eg 30 in 30 exh

Retarded ( rarely required)  eg inlet 28 deg exhaust 30 deg

That should simplify it a bit Don, also I would make the point that the card is a good indicator only to position the card and often it can be improved by looking at the style of riding  and use , other mods etc by advancing slightly mostly but occaisonly retard  so dont panic if its  a degree or so fron the card reccomendation. eg if using on the street I always set my cams  a couple of degrees advanced to smooth things out mid range and torque lower down etc    eg in open 33 ex close 29

Any keep Don keep posting, this cam business is a real head spinner for everyone when the first start, your not the only one .       

[Don R]

I knew with the duration difference I couldn't match it. I'm just not sure what a SOHC 4 likes.  All the videos I can find show a perfect match to the card and they stop there.

I logged the .050 numbers too.  I have them in the shop. My concern is intake valve to piston clearance and my goal is to advance it slightly to lower the torque curve a bit.
 I have a frame kit on the bike so I can take it apart on a whim.  I really expect this cam to be a little too peaky for my intended use but, I have it, how can I not try it?

Thanks for simplifying it for me.

[johno]

Donny go go 
Sounds like your getting a handle on it Don.
If your thinking the cam might be a bit on the big side certainly advance it. I agree.
yes check the the clearance valve to Piston, its all assembled so use the old RC method of dial gauge on spring retainer using spanner on adjuster , or screwdriver under rocker cam pad and push down to feel the piston, try TDC then 5 deg then 10 deg  then 15 degrees, if your close it will show in that range , if worried and want to be exact just fine tune the degree wheel until you fine the minimum gap ?

Then smoke  it up in a big donut to celebrate.
ciao johno

[Don R]

I did the exhaust and re-read what was posted and the little light bulb lit up inside my head.
  Thanks Everyone for all the patience and input.  I hope I didn't wear out the cam flange threads.
 The motor auctually pumped oil it was rotated so many times. LOL.

[PeWe]

This reminds me about when I timed my CX-7 cam. First time I did it by myself from the beginning. I turned the crank around a lot. Maybe the new pistons got their brake in...
Rocker arms softness/clearance mad a huge difference. I got closer to specs after a while.

http://forums.sohc4.net/index.php?topic=120425.0
I think I finally got it in the end of the thread.

[Don R]

I didn't find that thread when I searched, that would have been very helpful in thinking the process through. It's still good information to read and pick a few tips as I finish my project. Thanks.

[Don R]

I put the mystery header on it today and went for a ride. I'd like to say it's everything I wanted and more. It has a slight lope at idle, the large muffler quiets it nicely, if feels like it did with the Honda F cam until the rpm's come up a bit then it pulls until you wonder if you are holding on tight enough and are the grips going to pull apart.
 I definitely need more brakes. Holy crap. Anyone have a right hand caliper bracket for a K0?

[scottly]

Anyone have a right hand caliper bracket for a K0?

I do, but I'm pretty proud of it. It's a rare CFC magnesium part. I also have the right side caliper and arm, as well as rotors; I have some already drilled, and maybe one or two un-drilled on hand. I can drill your existing rotor to match one of my pre-drilled rotors.

[Don R]

 Thanks, I surprised with all the cnc equipment around no one has re-popped a bracket yet.  It's a pretty limited market though. I drilled the rotors on my F1, they came out nice. It's a fun afternoon doing that job. It seemed to me the cutting oil makes a lot of difference.

[Jerry Rxman Griffin aka MuthaF'er]

Yeah, and R E T I R E M E N T helps too. Let's see, what will I do today after I run out of computer stuff? Finished the old car project yesterday. Maybe I'll take the cat to the vet but I do need to work on my bike too. Yard work done for the week. Ahhhh............

[Don R]

Both bikes are running, the race car is ready to go for next weekend. I had time to work on the house and trim trees. Ooh, I can restart body work on the wrinkle tank.

[scottly]

I've read where some guys have modified a left side bracket to work on the right side. IIRC, one of the mounting bosses has to be machined down, and spacers made for the other two.

[754]

I think that is how most were done..
 Heyvi know of a guy that understands Honda fours.. that has a CNC mill..

[Don R]

I thought some high tech mill guy would digitize one and then flip the program left to right so he could spit out a few billet copies of both sides. (sounds easy right?) 

[754]

We should mention this to scottly.
A cnc cut one would not look quite the same, but pretty good if you texture it with sandblast.. It will work well.

[scottly]

Simon (Lordmoonpie) had one CNC'd, but it cost him dearly:
http://forums.sohc4.net/index.php?topic=71535.0

[Don R]

That link was quite informative, looks like I'm doing a bit of tig welding if I'm going that route, in the meantime it seems my existing caliper is hanging up a bit, that's the reason for the hard lever and lack of braking. It barely drags when off but somethings amiss for sure. Not so long in miles since it was gone through but it's been apart for powder coating and an engine top end. I guess it sat inside the shop long enough to have an issue.

[scottly]

Tig welding??? None required to fit a second brake!

[johno]

Donny gogo.
Fitting a second disc, best article I seen is in SOHC four ( here) CB 750 K dual disc conversion.
check it out , no welding  just spacer here and there, bit of trouble shooting .
Like my boy says , got a problem dad..... google it.
ciao johno

[Don R]

I've seen the spacers welded on. Not required but it looks good.