For now this is all I have time for..............

 

Mario,

I will try. I don't think anyone with a mostly stock engine should interpret this as typical results. I do think that most would benefit from these cams with a ported head, carb and high compression. I think our results were because we have sooooo much flow, our cams were a real bottle neck that was not allowing the rest of our componentry to work at peak performance.

I think if there is a lesson to be learned it is how much more potential horsepower can be had with the HP4's if you get a great enough quantity of flow. We were obviously at the limitation of the 109's but our porting, carb and exhaust were obviously capable of more.

Another thing I think is going on is this. Air does not blow into the motor. It is sucked in by piston displacement. That means the source of the vacuum is the combustion chamber. I think of it like the powerjets on a Lectron carb. If you install a larger powerjet (larger orifice) when you rev the throttle, it will suck more fuel earlier. If you put a smaller jet in it will take much more vacuum going through the carb to create enough suction in the tube to draw fuel off the float bowl. The size of the opening near the vacuum source leverages much more fuel than its size increase would indicate. The same thing happens I think with valves on a motor. If you have a certain amount of vacuum from the cylinder. If you increase the valve opening just slightly it will leverage much more air entering the filter. Not only that but it will need much less vacuum to pull more air so that means you have more air/fuel moving through the motor at lower rpm and way more at upper rpms. More power accross the board. This is over simplified but the basic concept I think is good. If you don't have larger valves, cams are another way to create a larger orifice for the vacuum to leverage air through.

We simply used this aggressive cam's high lift and long duration to leverage much more air and fuel than we were able to with the 109's.

Also, the NM burn rate is a factor that I will let someone else get into.

The test was legitimate. The dyno runs did not happen on the same day but conditions were similar and cams were the only change.

 

What was the temps on the 109 run and what were was the temp on the hpr4s?? The dyno sheets I have usually have temps. If the temps dropp below 70 the nitro wont burn good. That could make up most of the difference as far as astronomical gains. Dont get me wrong, I know hpr can make a cam that makes great power and they have good product. BUT if temps/bpressure/ wernt equal that says alot with the NM.

 

The temps were both in the mid to lower 60's and air moisture content is kind of hard to determine because it is done in a closed garage. The conditions were similar for all the dyno runs.

Mario, I won't have my feelings hurt if you simply choose not to believe the results. I am sincere about that. The gains were ginormous and there will be a lot of skeptisizm. If I was trying to pull a fast one on you guys, don't you think I would have picked a more reasonable increase to make the sale?

I am running with this because it is accurate for our bike.

 

Well if you are BSing everyone with this, you best let me in on it...J/K, I know you were looking forward to seeing the difference you were feeling when you rode. 17 hp, I am pretty sure you could feel by the seat of your pants [img]i/expressions/face-icon-small-smile.gif[/img] We are going to be doing some talking on the next ride man...

 

Way to go NUT. Just so long as this is not like the carb test, where the TM-45 was not set up properly and cited as 8hp less than Lectron instead of simply stating how long it takes to correctly set up each carb.

Mario will figure it out sooner or later and report his findings. Muliple resources adds validity.


Good job NUT! I'm impressed.

 

If ALL thing being equal. As a simple cam change I call Bs.. Sorry, Dont get all hurt about it BUT it just dont make sence in reality to ME someone is getting pencil whpped here.. Thats just my opinion.

No credit taken from HPR, I was just talking to Randall the other day about temps and nitro/alky... Randall and Eric no doubt know their stuff and have done much R&D on cams etc. I do run some of their stuff. Yes I have dyno tested their stuff with great results. I know seat of the pants and true testing on the hill and dyno differences you can feel and see different gains.

I have a decent flowing motor. Your tellin me that if I swap my cams out for the hr4s I would see about a 10 hp difference at the least? Id have to see it to believe it, But I guess im just hard headed.[img]i/expressions/face-icon-small-smile.gif[/img]

 

I just got a phone call from a friend and it was confirmed by Dave moore himself that did this test on the cams and found the gain. I hear he now has a newfound respect for hpr.


I guess I owe ya one Ron.. I take the BS call back. I know for a fact you did not mis-inform anyone here on the forum. But I just dont understand the baseline 109 HP # of 60 hp as you said. Your tellin me a BUILT race 650 motor on alky and 30% nitro pulled 60 hp ONLY. Ya see, this is just what I dont get.


Sandbomber gave me some info and I see him as one of the most trustworthy folks in the bussiness.

 

I call BS until it's confirmed on another Dyno. No way cam change only makes 20 HP!!!!!!Bring it to me I will dyno for free!! I know my Dyno is correct.

 

" I call BS until it's confirmed on another Dyno. No way cam change only makes 20 HP!!!!!!Bring it to me I will dyno for free!! I know my Dyno is correct. "


Right on, let's get some confirmation backup on this. Trusting because he said, she said, talking heads on web don't indicate anything. Only one or a few posters account for most posts anyway under multi id's. Suckering a dyno can't be that difficult, and a sample of one is not even a statistical sample (3 minimum). Of course its a drag race cam versus a standard performance cam on a flow-groomed bike using alkyhol, so its feasible but not prooven yet.