Woods TW 999-6 / Tman 590ps2

[C-Cat]

Strong, it ignites the rear tire 1st gear roll-ons and revs quick. The Boarzilla is a lot of pipe for the 110, I'd say great midrange and pulls hard to 5800-6000

[mickblues]

Nice this might be an upgrade from my tts 150 cam. I will have to look at this seriously or the 999 but should get the Ccp for my bike.

[C-Cat]

The wider lsa will work better with my heads

Can you elaborate why that is? Do you  treat heads differently if using cams with a narrow LSA than with cams with a wide LSA,  or go to different castings to compliment?

[Don D]

Not exactly. Wider LSA works better with any heads that function well, up to a point and assuming compression is adjusted for the intake close. In other words heads that breath well in the lift range +, and have the proper CSA for the given build. Of course you can go the other way, too wide of a LSA, as some cam tuners do that. This can give the "on cam" feel latter to "come on". Other cams I have noticed are on wide and late LC and LSA plus an exhaust that opens too early and too long, another set of problems.
Back to the close LSA, it adds overlap and TDC lift and associated potential issues. This tool has been leveraged by Woods and others, nothing new, and results in a high early torque curve and usually an early to shut down build in the rpm range. Extreme examples of the same are the S&S 635, Woods 408 and 400. Example of the other scenario Feuling 574. Pick your poison but don't forget about the pipe, it is equally or more important. If I was looking for a cam in the same class as the 999 I would look further assuming the heads were functioning well as I described. Long before the trick was leveraged by Harley guys it was done by stock class racers on short tracks limited to stock lift and duration cams and stock (well in theory) heads.

From another forum..
As a guideline, if the rest of the numbers are comparable, a cam with a lobe that is less separate (for example, 98 to 103 degrees) will offer a broader spread of power and tend to produce power at the low end, while wide lobes make for a more "cammy" cam, coming on harder and later in the game. Lobe Separation Angles (LSA) of 100-103 degrees tend to produce power at the low end.

LSA and Lift affect the "sound" and idle quality. Generally, smaller lobe separation angles cause an engine to produce more midrange torque and high rpm power, and be more responsive, while larger lobe separation angles result in broader torque, improved idle characteristics, and more peak horsepower.

A "tight" lobe separation angle of 103 degrees or less creates more valve overlap, which helps create that lumpy idle characteristic of big camshafts. The tighter LSA's are, the more likely problematical exhaust reversion into the intake will occur. Put simply, we can say that a tight LSA cam produces a power curve that is, for want of a better description, more "punchy." At low rpm when off the cam, it runs rougher, and it comes on the cam with more of a "bang." Narrow LSA's tend to increase midrange torque and result in faster revving engines. Generally, smaller lobe separation angles cause an engine to produce more midrange torque and high rpm power, and be more responsive. Typically, however, small lobe center numbers (more overlap) equates to more midrange power at the expense of top-end power. Probably the most significant factor to the engine tuner though is a tight LSA's intolerance of exhaust system backpressure. Remember, during the overlap period both valves are open. If there's any exhaust backpressure or if the exhaust port velocities are too low it will encourage exhaust reversion. A cam with 102 degrees of lobe separation angle will have more overlap and a rougher idle than one with 108 degrees, but it'll usually make more midrange power. A tighter lobe has more overlap. A tighter centerline starts torque curve sooner, and doesn't give a wide power band. A wider lobe doesn't start the torque curve sooner, but it continues to make torque longer and has a broader power band.

Wide LSA's result in wider power bands and more peak torque at the price of somewhat lazier initial response. Larger lobe separation angles result in broader torque, improved idle characteristics, and more peak horsepower. A wider lobe doesn't start the torque curve sooner, but it continues to make torque longer and has a broader power band. A street engine with a wide LSA has higher vacuum and a smoother idle. Big numbers (less overlap) will give more top end, sacrificing midrange. A cam on wide centerlines produces a wider power band. It will idle smoother and produce better vacuum, but the price paid is a reduction in output throughout the working rpm range.

Narrow LSA (98-103)
Moves Torque to Lower RPM
Increase midrange Torque
Increases Maximum Torque
Faster revving engine and more responsive
Narrow Power band
Builds Higher Cylinder Pressure
Increase Chance of Engine Knock
Increase Cranking Compression
Increase Effective Compression
Idle Vacuum is Reduced
Idle Quality Suffers (lumpy idle characteristic)
Open Valve-Overlap Increases
Closed Valve-Overlap Increases
Decreases Piston-to-Valve Clearance

Wide LSA (104-108)
Raise Torque to Higher RPM
Reduces Maximum Torque
Broadens Power Band
Lazier initial response
More peak Horsepower
Reduce Maximum Cylinder Pressure
Decrease Chance of Engine Knock
Decrease Cranking Compression
Decrease Effective Compression
Idle Vacuum is Increased
Idle Quality Improves
Open Valve-Overlap Decreases
Closed Valve-Overlap Decreases
Increases Piston-to-Valve Clearance

[C-Cat]

Thank you, that's what I call a detailed answer!

[Ohio HD]

That's kind of the cams 101 info.


https://tmfcycles.com/blogs/tech-tips/cams-explained

[Hilly13]

All great info for those wanting to understand but I think the biggest thing to get right when picking a cam/build is, taking the weight of your ride into consideration, how do you ride, what is your fun factor and build it to that, won't be everyone's cup of tea, dyno graph might not win at the bar but your riding enjoyment will be steller and that's the bit that matters most, well to me anyway.

[C-Cat]

That's kind of the cams 101 info.
I understand that, although my question was pertaining to HD Performance's Head work, and he answered my question derived from his quote.

https://tmfcycles.com/blogs/tech-tips/cams-explained

"The wider LSA will work better with my heads"

[Ohio HD]

That's kind of the cams 101 info.
I understand that, although my question was pertaining to HD Performance's Head work, and he answered my question derived from his quote.

https://tmfcycles.com/blogs/tech-tips/cams-explained

"The wider LSA will work better with my heads"

I wasn't answering for anyone. I was directing to a source of camshaft basics. There are others besides yourself that are reading the post.

[C-Cat]

I apologise. Sometimes I interpret text wrong and misunderstood your post.

[Don D]

Something not mentioned in that great text about cams.
We now are building predominantly EFI bikes engines. The intake is dry and fuel (and spark) by program. Injector timing is being tweaked as well, especially important beginning of injection. The potential benefits of large amounts of overlap are no longer needed. We can have a much smoother running, easier to tune, high horsepower build come together and that ties into my comments about tight LSA and the potential associated PMS. It's evolution, we are building beast M8s now with 25 and less overlap. Same comment for the .660+ VS <.600 lift cams. In my opinion the potential gains VS costs, which include maintenance, are questionable for most riders. Good heads that flow well in the intended direction are the start. 

[shindig]

Something not mentioned in that great text about cams.
We now are building predominantly EFI bikes engines. The intake is dry and fuel (and spark) by program. Injector timing is being tweaked as well, especially important beginning of injection. The potential benefits of large amounts of overlap are no longer needed. We can have a much smoother running, easier to tune, high horsepower build come together and that ties into my comments about tight LSA and the potential associated PMS. It's evolution, we are building beast M8s now with 25 and less overlap. Same comment for the .660+ VS <.600 lift cams. In my opinion the potential gains VS costs, which include maintenance, are questionable for most riders. Good heads that flow well in the intended direction are the start. 

And this is why my package from Don with a little 590 cam in a 117 with no PMS, great street manners, beats up on a lot of those high lift packages....even some of those 124s...  Its all about the correct combination and build....  Thanks again Don!