reground hotrod cam

[marcinstl]

remember back in the day when hotrodders would send the camshaft off to get it reground (more lift, longer duration)? has anybody tried to play around with the 2 lobe camshaft found in a Kahr pistol? how about a custom trigger bar?

[kerby9mm]

As long as the trigger pull is smooth the left side is good. The right side cam depresses the striker block. If you hold the trigger all the way back & you can rack the slide the striker block cam is going up far enough. If you cannot rack the slide or the slide drags the cam is going up farther than it has to and is pushing up against the bottom of the slide. Kahr ground down the striker block cam on my mk9 3 years ago so the slide could be racked with the trigger all the way back. I am not suggesting this is a problem when firing the gun.

[CJB]

Grinding a cam to get greater lift and duration..... seems counter intuitive unless you put in some sort of lifter block, or longer lifters, or longer pushrods, or have fully adjustable rocker arms, etc.

At any rate - I ended up "grinding" the cam on two of my three Kahr's. The one that went back to the mother ship is perfect. The two I got used both had cams that would lift the striker block higher than it could go, effectively trying to lock the slide to the frame. I will admit - this is an issue you will not encounter while shooting - since the unlocking likely occurs before the trigger has reached its full rearward movement. However, it pained me - between my ears. Both cams are carefully shortened and reprofiled - in situ - with very judicious use of Mr. Dremel, and his associates Mr. Fine Sanding Drum and Ms. Very Fine Craytex wheel. After washing, both pistols reassembled, and working like the one that returned to the mother ship. Thats about it for my cam experience, except to say that any cam that closes the intake valve at about 30 degrees will result in increased effective compression, less reversion effets, and loads of low end torque, but what the hell do I know.....

[muggsy]

Unless you are a highly skilled certified gunsmith don't mess with the cam. You're begging for an ND and a lawsuit.

[marcinstl]

Kahr cams by Isky? hehehehehe.
my knowledge of cam profile design wouldn't even make me dangerous, let alone competent. that's why I come over here and ask. what I should have asked is, is it possible to come up with a cam that would make the trigger feel like there was a more definite "wall" before the shot breaks? maybe instead of a smooth ramp the cam lobe would have just a slight step at just the right place? and how about different trigger bars? shorten the travel and move the break forward?
seems like tons of hotrod parts for Glocks, XD's, M&P's, nothing for Kahrs.
(any of this would be for a range gun only. always carry stock, out of the box guns.)

[CJB]

Kahr has a short stroke model with safety, dont they?

[TheTman]

I know what you are saying, my M&P trigger has little resistence, until it hits the point after which any further travel releases the striker and fires the pistol. I've tried to find this spot on my Kahrs, and can hit it maybe 50% or the time, when I'm lucky. I gave up and just apply smooth steady pressure throughout the trigger travel, and it works out ok. They are never going to be target pistols, nor were they intended to be. They do very good job as a self defense pistol, and the trigger is just about right for that purpose, for me anyway.

[muggsy]

What makes you think that hitting the wall or stacking is a good thing? A trigger should be smooth and break clean with little over-travel.

[marcinstl]

it's so easy on a 1911, or a Glock, just buy the parts and install, make it shoot anyway you want. short trigger travel, break about 1/2 to 2/3 back, a little wall(extra squint on the front sight) and bang. then again, why would anybody put a 350 chevy in a 29 Ford? (because you can.)

[muggsy]

My advice would be to buy a Glock or 1911 and leave the Kahr alone.

[marcinstl]

if I was younger and stronger I could manage to tote a full size gun around everyday/all day. that's not the way it is, so the big guns are only range toys for me. I've gotten used to the Kahr trigger and that made it possible to shoot other DA pistols and revolvers with some proficiency. I'm now shooting a Kel-Tec (weird double click reset) and doing good with that. with the DA trigger, it just took me a couple of thousand rounds to get with the program. (old dog can learn a new trick).

[skiflydive]

Grinding a cam to get greater lift and duration..... seems counter intuitive unless you put in some sort of lifter block, or longer lifters, or longer pushrods, or have fully adjustable rocker arms, etc..

To get more lift you grind the "bottom" of the lobe and take up the difference - usually only several thousandths - with the adjustment on the rocker unless you have hydraulic lifters which don't need adjusting but might need longer pushrods. Longer pushrods are usually available or can be easily made if the adjustment changes the rocker geometry too much. To change the duration - the amount of time the valve stays open, you grind the "point" of the lobe to change it's profile and adjust as above. On overhead cam engines the cam followers can be shimmed. Man it's been a long time since I thought about this stuff. Used to do it all the time.

[CJB]

Oh hell, the engines I work on, all have push rods that are converted to adjustable, and keep the hydraulic lifters. Its just a matter of getting the push rod about .1 inch into the lifter travel, which is usually about .2 inches. Its not too critical. Then again on a race engine... it is. Anything I put together has to be streetable. Just my own way of doing it. I still like the 30 degree intake cam closure, its about optimal. I'll take higher lift to a point to a point, maybe only .010 or so. The problem is, all the new engines are fuel injected, and you really cant time the injector pulse to correspond with the new intake timing..... so tradeoffs ya know?