Anyone know anything about these? They don't look like the W/C heads RevMaster was working on, which were the only other W/C heads I had heard of...
- David
//edit: They say they have an option for dual spark plugs... I'd bet money they were designed to be aircraft heads. (Not that that's a problem, just an observation). It also says they have "Fuel Injection / Nitrous Bosses". I'm curious about that- perhaps it's the flat spots right on the head casting where the intake manifold bolts on?
Last edited by WD-40 on Sat Oct 08, 2005 9:39 pm, edited 1 time in total.
They look great, but I am not sure about their application on a car engine. The horsepower specs are decent, but only rated to 4200. I wonder what they would do with a car cam and some RPMs, and I wonder what the porting and valve options would be like with them. Any head builders got any opinions?
Look at the combustion chambers...either somebody got jiggy with a die-grinder, or poor quality control (or both...I wouldn't let pictures like that exist if that was my work...).
Stripped66 wrote:Look at the combustion chambers...either somebody got jiggy with a die-grinder, or poor quality control (or both...I wouldn't let pictures like that exist if that was my work...).
Do you mean the fact that they aren't symmetrical? I'm pretty sure that's because of the dual spark plug option.
If you look at the other head photo, you can see the bumps into the rocker area to clear the secondary plugs. The secondary plugs sneak in between the pushrod tubes, and come in at an angle. The plugs both angle the same direction, either frontwards or backwards, not radially out from the center of the head (if that makes sense...). So the combustion chamber on the right side of the pic needs that little ledge to give the plug a flat spot to enter the chamber. The left side is more suited for it as-is.
They could have used identical chamber layouts if the plugs exited in different directions, but that must not have been possible. It looks like the rest of the chamber has been reshaped to accomodate this, to keep the chamber volume the same.
I don't know any of this for sure- its just a guess. But I'd bet money on it.
You're exactly right. From a performance standpoint, both lower plugs should face toward the exhaust valve. Yet, the angles must be different for access to the plugs. While one side is simple, it took a dozen heads for me to arrive at the precise angle for the other side.
Hmm... In looking at it again, I'm not sure what they're thinking on the left (#2/"3) side. They got the other side correct.
could you run an engine on the street with no cooling over the cylinders? or is that a drag car?
obviously in an airplane, you'd et all sorts of flow for cooling the cylinders.
Pablo wrote:You're exactly right. From a performance standpoint, both lower plugs should face toward the exhaust valve. Yet, the angles must be different for access to the plugs. While one side is simple, it took a dozen heads for me to arrive at the precise angle for the other side.
Hmm... In looking at it again, I'm not sure what they're thinking on the left (#2/"3) side. They got the other side correct.
What they were thinking is: I am going to use this on an airplane engine that will max at 4200 RPM, and run constant low RPM speed.
They would convection cool a little bit. Most of the heat is (was) in the heads... Removing ALL the engine tin (including the back plate) would give a lot more room for turbulent air to just float around.
What the kit from the ad suggests is to make some scoops under the car, so that while driving a little bit of air blows through the engine bay. It basically says that while driving it is fine, and it warms up (but slowly) while just sitting...
Good enough? Dunno. You could always use some of those drag race blowers though, or run an old fan shroud with the skinny fan.
I have a set at my shop now, they were sent to me by Aircooled.net, for evaluation, port work on so on. I not alot of time on them, but I will say, this head has very nice ports and airspeed out of the box.
I will know more in a few months.
I have no doubt they have potential, and Darren, you're the man to find out what they have in them. What's your opinion on the geometry of them, in terms of valve and plug positions and angles? What is your gut feeling on what heads they could compare to with the right work?
DRD wrote:I have a set at my shop now, they were sent to me by Aircooled.net, for evaluation, port work on so on.
One of the things I liked about the heads was the dual-plug option. Are you evaluating this configuration, or are you just re-shaping the chambers for "normal" use?
Also- I know you're still working on them, but "full potential" aside, do you feel they're decent heads "out of the box" with NO work on them? Or do they have problems that need to be addressed first?
DRD wrote:I have a set at my shop now, they were sent to me by Aircooled.net, for evaluation, port work on so on. I not alot of time on them, but I will say, this head has very nice ports and airspeed out of the box.
I will know more in a few months.
Convince John to send them to me
I am ready for them.
I would also bet money that the dual-plug arrangement is for airplanes. Airplanes generally use redundant electrical systems, so that should one system fail, the other one can still fire all of the cylinders.
David, I'll loan you my neat Ground School manuals sometime.
- Scott
P.S. And the whole water-cooled heads thing is heresy. We shouldn't even be talking about this.
