Hitch performance cam

sam2019

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13. June 2021, 1:57

I was following the discussion about the H. "performance" cam on the forbidden forum and wanted to chime in here.
As mentioned I have recently changed a worn cam for a new one. New stock cams have a mate black color on the contact surfaces - after some 30k km usage this becomes mate silvery with tiny irregularities a fingertip can just feel, a certain roughness that is not there on the new ones.
we changed the cam not because the performance was lacking but the excenter mechanism was faulty leading to irregular idle with cutouts - the cam would sometimes kick in the "depression mode" where the compression is reduced to 50% of its nominal value - in idle this leads to a cutout.
thankfully the picture on the H. site allows for some detailed study - albeit only from one perspective. But some conclusion may be drawn nonetheless.
The H. cam has a shiny silver contact surface. I looks like chrome. The rest of the cam looks 100% identical to the stock version. Form follows function so this may be accidental - but it also allows for the possibility that only a chrome patch was added to the OEM surface. I am assuming here, without being an expert, that a "sharper" cam would need additional material and not the removal of such.
Now if I was in charge of producing a "performance cam" it seems to me way more economical to base this on the OEM version which costs around 25 pounds for the end user (less for a dealer) - I could even spoil 10 of them and by experimentation find out the optimal performance - and then "lock that in" for an additional chrome surface. Additionally some surfaces seem to have been polished by H.
Chrome plating is no miracle work and can be done cheaply in India (and better but not so cheaply in England) and I would guess the price difference between the "elevated" H. version of exactly 10 times the stock is in line with H. usual profit margin.
Following are the H. cam and below a picture of an old used cam for comparison:
(The color difference is likely only a matter of photoshoping the picture which I did not but H. probably did for better effect - as can be seen in some reflective surfaces that probably where modified)
 

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sam2019

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13. June 2021, 15:05

Some comments to stuff said on the "other" forum:
I doubt these are just reground and will be rightly pissed off if they are. The price gives me some reassurance
Well, I would almost bet they are - and in a world where e.g. a set of piston rings costs 25 cents when bought in bulk and is sold for 25 US$ retail a 1000% price hike is not just common, it is to be expected, especially with a well known apothecary like H.
More to a cam than the physical shape, things like lobe centers, lift , overlap and advance come in to it too. As does precision.
I give you precision - but the rest is a function of the physical shape of the cam I would think.

So nothing radical or new needed , just a little more precision and the same technology as the 60 year old S cam would probably do, and that could probably be accomplished with an expert rework of the existing cam.
An adjustable cam wheel usually makes getting precise timing easier, and if the cam was completely new this would probably have been done, like the S & S cam for the 650 twins.


The H. cam looks almost identical to the OEM cam so precision is the only thing I can see going for it with maybe microscopic changes in lift and the other variables.
I would almost bet it is the OEM reworked in some fashion - not a new design or any revolutionary engineering getting 20% more power out of this engine. But who knows. I have been wrong before.
As my old now defunct footer on the forbidden forum used to say: if you want more real power then nothing can replace displacement except more displacement!
I also would want to argue that whatever this miracle cam can do (fill the cylinder better in some way) can similarly be done with the Powertronic - ultimately it does not matter much how the "right" fuel mix gets in as long as it gets in.
 

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sam2019

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15. June 2021, 4:41

Hitchcock just posted the dyno results.
Whow. I am a bit suspicious I have to say - but then again Dool will enlighten us soon enough.

I would like to elaborate on my doubtful position (sorry guys):
A "hot" camshaft shifts the torque a little further up, i.e. to a higher rpm range. The "hotter" the further. Since power is only rpm times torque, and consequently there is a higher torque at a higher rpm, the engine has more power. However, the existing torque is only shifted, where it was before, it is now no longer. A "hot" camshaft reduces the torque in the lower rpm range where we Hima lovers want it.
If the engine is kept on high rpm you have fun, in the lower speed range you have nothing. The hotter the camshaft, the stronger this effect, often even the idle rpm must be raised, because at the "normal" idle rpm there is not even enough power for keeping the engine running.
It is also a fact that due to the change in the hardware, the software, the engine control must of course also be adapted to this. After all, the map is designed for different hardware. So the PT is needed.
So if one has both - the cam and the 477, then OK - but if one has to choose between them the 477 is the more natural choice in that it gives more power but keeps the overall engine character intact.
 

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sam2019

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15. June 2021, 12:34

Quote from Dool on 15. June 2021, 10:41
Regarding the Cam, when I get mine I can sit it in a spare head, rotate it and take measurements, unfortunately without degrees I dont think it will show us much.
I am extremely doubtful about that chart. A plus of 20% will be discernible, even without dyno. I would venture that there is no perceivable additional power after installing that "none"performance thing.
I mean realistically IF IT DOES SOMETHING that something will change the entire engine characteristic - at the same time H. claims that no changes in the EFI configuration is needed. IMO either its below perception or it needs the PT.
OK, the formula for calculating horsepower vs. torque is as follows:
Horsepower = (Torque x RPM)/5252
This has been figured out a long time ago by Mr. Watt (of steam engine fame) so the relationship between the 2 is easily discernible.
So called engine dynos that are attached to the crank directly measure torque, and require an RPM input in order to calculate horsepower which then is called BRAKE HORSE POWER or BHP.
Chassis dynos (the one Dool uses) directly read HP, and run the math in the other direction to calculate torque based on engine RPM. Because they give you real life results (where the rubber meets the road) they are to be preferred when comparing real life vehicles (a bike with shaft drive can have more BHP than a chain driven one and still be slower with otherwise identical parameters).
If we compare tomatoes with tomatoes all is well. It only becomes a problem if someone wants to compare a torque chart with a HP chart and does not do the conversion math.
Sorry, but a "dyno" run without torque is fiction!@#.
And torque is power, HP is the work that torque can do in a given time!
This quote from the forbidden forum is wrong or at least misleading, while the second part is true the first is nonsense as can be seen above.
Instead of whinging on the internet, why not ask Hitchcock's for the torque data?
why not figure it out yourself with the above formula?
 

sam2019

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Also: (quoted from the Internet):


There are tricks a dyno operator can employ to bump up numbers, should that be desired. It’s been said that the man with two clocks never knows what time it is, and that same concept applies to dyno results. Unless they’re on the same machine, with the same operator and the same correction factors for temperature, humidity, air density, and load cell calibration and/or inertia factor, it’s impossible to make a direct comparison. Where dyno testing really shines is when tuning or checking the improvement (or lack thereof) from modifications, when it’s possible to get meaningful, consistent results.

One guy seems to have beat Dool on the cam test inasmuch a seat of the pants dyno counts as such. That being very subjective I will not discuss it but he ends his posting with:

Would I recommend it? On first impressions, yes, its made the bike what it should have been for a price thats a fraction of the big bore kits on offer.

That is like saying I can get half a KG apples for half the price a full KG costs LOL

If you are happy with 4hp over 8hp thats OK, but do not compare them price wise.

I am assuming here in both cases the work is done by the bike owner so we can compare only the goods plus the shipping - and amazingly the cam is exactly 50% of the full set (cylinder and piston etc.)

Yeah, math is a bitch. reasoning as well. Lucky for him I can't comment on it myself but maybe someone here can mention it over there ....
 
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