Wild Thing Cams

[T300]

Totally agree NW guy4 fun the larger throttle body tuned correctly performs quit well
all the way through the RPM range even the smaller sticks on stock valves
have benefited with a couple Ft of tq and 5+ hp at WOT with the right air filter.
Be hard for one to detect the difference riding the 50 to 58mm tuned accordingly without looking.
Will pay particular attention to the Lower to mid Valve lift velocity in the Head build.
Once again the good advise and opinions much appreciated.

[compressor#v]

I find it amusing that it's posted a good head porter, ports/flows heads tailored to a specific cam, when the question was asked a few years ago on another forum, the current crop of porters on both sites laughed it off and essentially said good luck tailoring a cam to how a head flows. So which is it?

Note: This is not a slam on any head workers out there, just asking for clarification.

[nw_guy4_fun]

I think that was my same point. Good functioning heads work plain and simple. They flow enough to feed the motor and exhaust without injecting any issues and at mid to higher engine speeds offer much higher VE number potential. The tailoring are the very fine hairs in that equation. I will never buy into a scarcity theory, many know how to get there including the porters mentioned.

[CowboyTutt]

Hi Compressor. I was referring to what size valve to use, what port size, what rpm is the engine desired to make power, what is the rider's riding style, what is the proper chamber size to yield the proper static compression with pistons being used, and what is the lift and duration of the cams. If the cam is designed to work from 3000-6000 rpm with 585 lift then the heads have to also work for that, or they will choke the top end.

I agree that there are heads with somewhat generic design that work for many applications, mine included with the 1.9 intake, 1.625 ex, 1.75 port on a 103 with 84cc chamber. Makes for an easy 10.5 static compression with little to no dome and makes broad power. My heads are similar to Don's in the sense that the CFM plateaus at about 600 lift and the gains from 600-700 lift are small. If I were going to run a cam with over 650 lift then perhaps the heads would be set up differently. Maybe Don can answer that. The S&S B2 heads flow poorly at low lift (worse than Don's heads featured here or even my own) but have huge gains at higher lifts but they are essentially a race head.

But as the OP mentioned, he wants the stock valve sizes for his riding style and application.

If Don says it will work, then I suspect it will.

Don, please correct me if I'm off base here. There's probably something I have misunderstood on some level.

I hope I explained myself a little better this time.

-Tutt

[nw_guy4_fun]

Even with stock sized valves I can get them to flow decent. You have to supply the motor with what it demands to hit the mark. Based on the rpm and displacement there are calculations to approximate that. So a short cam torque oriented lower compression 95-103 can work well there but it is so much easier for me to use new performance valves 1.9" and 1.575" plus the flow is better with no downside, the materials are more durable than stock as well.

The heads are port limited which is why they are loosing flow gain at the higher lifts between lift points. The valve is out of the area of influence or let's say it diminishes rapidly at the higher lifts and it's the port that is influencing flow. Below .25-.27 L/D Ratio the valve mainly controls Flow CFM. When going oversized (overkill) on ports and valves shunting by cam is possible but really the best approach is to match all the parts.
Very overly simplistic explanation of a complex topic, others will have their spin on it too for sure.

Here is a typical example of a 114" at 11.3cr with an andrews 64 and CVO110 heads that flow 346 and average 247 from .1-.7@.1 intervals. Notice the VEs even still strong at 2,500, 95%. This is software and I would not trust this data 100% nonetheless it is a useful guideline.

[compressor#v]

Thanks Don & Cowboy.

[CowboyTutt]

Interesting information about the ports Don. Didn't know that. Thanks!

-Tutt