Hot Cams? - Kawasaki KLR 650 Forum
1987 to 2007 Wrenching & Mods For maintaining, repair or modifications of Generation 1 KLR's. 2007 and earlier.

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post #1 of 13 Old 02-08-2016, 07:26 AM Thread Starter
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Hot Cams?

Anyone try the "Hot Cams" listed on the Happy Trails website?

Camshaft KLR650 Hotcams (1996-2015)

Do they make opening up the intake and exhaust worthwhile?
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post #2 of 13 Old 02-08-2016, 10:20 AM
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Good question!

No direct experience with "Hot Cams," but some general comments, and a vague, nebulous answer to your question follow.

Valve lift, duration, and overlap (parameters controlled by the camshaft grind), ideally, work with the SYSTEM of the engine's fundamental design (displacement, compression ratio, aspiration, exhaust, etc.).

Thus, a "performance" camshaft is dependent upon the total system in which it presumes to play a role.

Now, for the (unsatisfactory) answer to your question:

ONLY if your engine "system" can take advantage of the valve lift/duration/overlap offered by an aftermarket camshaft can you realize its potential value. Implanting a "performance" cam in an otherwise stock engine is a step on a path of diminishing returns, IMHO; YMMV.

Someone may drop a Hot Cam into a stock KLR650 and set the World Land Speed Record at Bonneville, but unlikely in my view. A coordinated system approach, on the other hand, can profit from "performance" camshafts.

My opinion only; others respected.
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post #3 of 13 Old 02-08-2016, 07:10 PM
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Wow; thought I edited my post above; reckon I didn't, through operator error.

Anyhow, I added a comment to the effect; you may freely ignore the discouraging words I provided! If you do, and should advance toward an aftermarket camshaft anyway, I suggest you check out Web Cam products Web Cam Inc. - Performance and Racing Camshafts, a company with which I am familiar, since BEFORE they became Web Cam (nee "Webco," the camshaft segment of Weber carburetors, back in the day, I've been told).

Check cam specifications and prices; again, my suggestion.
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post #4 of 13 Old 02-09-2016, 11:48 AM Thread Starter
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Yes, Damocles, what you say matches what I've read about engine tuning in general. I've also read that the basic engine mods like opening up the intake and exhaust breathing have little effect on otherwise stock KLR engines.

And so, I wonder if a hotter cam along with appropriate intake and exhaust mods would create that "balanced system" that would show a gain power through better volume-metric efficiency.

Before I commit time and money, I wondered if someone had already gone down that path with "Hot Cams" or any other cam swap.

I wonder if the stock ports can flow well enough to work with the cam, intake and exhaust mods.
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post #5 of 13 Old 02-09-2016, 08:41 PM
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twinjet,
From what "I know" and what I have read, there are "very few" people in the 'porting' business that actually "know" how to port a KLR650!
The wide 'valve angle' with the 4 valve design has apparently "confused" many!

With-out "proper porting", performance cams are 'basically useless'!
With "proper porting", performance cams can 'gain a little'.
With "improper porting", one can lose "a lot"! Permanently.

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 85,000+ miles & counting
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post #6 of 13 Old 02-10-2016, 01:13 AM
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Hot Cam went in And came out shortly after ...... tho the chart provided shows a better power peak it does shorten the rpm range by a wack...1500rpm at the top end ....

you get better bottom end power and mid range but you loose the top of it ....i have smooth bored my intake and exhaust and run a freeflow V&H XCR muffler and to be honest Stock Rocks when it comes to cams with this breed of bike ....

they did actually put a little thought in it .... if your going to be belting it around off road 90% of the time then go the Cam upgrade cos it will help in the dirt ... but on the road it will go like stink then nothing once you get into top gear it will feel lost ...... save you money and play around with the cogs stock is 15/43 ive gone 16/42 and it hammers nicely on road and still have good off road gearing ..

and my hot cams btw went in the scrap bin not long ago ...
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post #7 of 13 Old 02-10-2016, 06:43 AM
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Thanks for sharing your experience, Tengai91!

I think cam grinders have the capability to move the power peak across the rpm spectrum to some extent. When the peak rpm point is moved, as in the words of a song, "Some gotta win, some gotta lose!"

Seems like perhaps for your own Hot Cam grind, the lower end was emphasized, at the expense of high rpm operation. Don't know whether other engine modifications might have comprised a "system" compensating for the low-end concentration, to some extent.

Back to my premise: Implanting a "trick" camshaft must be integrated with the engine system to take full advantage of the valve timing (lift/duration/overlap) variations offered.

Regrets your Hot Cam didn't work out for your application; further regrets for what must have been a rather expensive experiment.

Again, much obliged for your sharing your experience.
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post #8 of 13 Old 02-10-2016, 07:19 AM Thread Starter
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Quote:
Originally Posted by pdwestman View Post
twinjet,
From what "I know" and what I have read, there are "very few" people in the 'porting' business that actually "know" how to port a KLR650!
The wide 'valve angle' with the 4 valve design has apparently "confused" many!

With-out "proper porting", performance cams are 'basically useless'!
With "proper porting", performance cams can 'gain a little'.
With "improper porting", one can lose "a lot"! Permanently.
I hear what you're saying. I saw a Sportster head that was ported by Branch or Axtel (can't remember which) and the port shape was anything but intuitive. Just getting the seat angles right is a black art.
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post #9 of 13 Old 02-10-2016, 07:27 AM Thread Starter
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Quote:
Originally Posted by Tengai91 View Post
Hot Cam went in And came out shortly after ...... tho the chart provided shows a better power peak it does shorten the rpm range by a wack...1500rpm at the top end ....

you get better bottom end power and mid range but you loose the top of it ....i have smooth bored my intake and exhaust and run a freeflow V&H XCR muffler and to be honest Stock Rocks when it comes to cams with this breed of bike ....

they did actually put a little thought in it .... if your going to be belting it around off road 90% of the time then go the Cam upgrade cos it will help in the dirt ... but on the road it will go like stink then nothing once you get into top gear it will feel lost ...... save you money and play around with the cogs stock is 15/43 ive gone 16/42 and it hammers nicely on road and still have good off road gearing ..

and my hot cams btw went in the scrap bin not long ago ...
Thanks for sharing your experience with Hot Cams. Sorry they didn't work out for you. And since in my case, I'm looking to build more of a road bike (these old bones are getting brittle) I'm looking to boost the mid to high range so they wouldn't be a good fit for me either.

The consensus seems to be that it's hard to out engineer the Kawasaki engineers.
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post #10 of 13 Old 02-10-2016, 08:56 AM
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I had the cams in for about a month .... something i tried and yes it was a bit of a hit on the wallet ..... honestly Kawasaki have done a good enough job with the head and the valves , and to be honest the cams werent much different to the stock ones just a bit more on the lobes to open it up ... which does have a counter effect with the carb settings ....IE: you need more air to move through it for full proper effect .... best bet is to play with the gearing and its less expensive ....

KLR 91 Tengai
GTR 86 1000
zuki 83 GR650
zuki 83 GN250
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