: Fueling Heads and "rolling slide valves" articles by Ray Bohacz
Jul 29th, 00, 05:52 PM
Has anybody been following Mr. Bohacz's "high power" tech articles on the "fueling heads" and the "rolling slide valves"??
Just curious. I wrote him a letter and lo and behold I got a call to call him back to discuss this.
I called him back and asked him about the "fueling head " article and if using 409 chevy heads set flat to the deck of a Gen IV engine along with a modified intake to fit the angle of (I think) 16 or 18 degrees difference between the two along with flat topped dished pistons to give the C.R. that fueling was using would work.
Whats anybody think of all this??? Just something to talk about for the fun of it. pdq67
Jul 29th, 00, 07:56 PM
Jul 30th, 00, 06:50 AM
As far as I know, the Fueling heads are the "Centefire" series of head, with almost centered spark plug location and figure 8 shaped combustion chambers. I did a conversion on a friend's 454 '93 pickup to the centerfire heads, and it was well worth it. The truck gained over 6 mpg, and made 453 ft/lbs torque at 1,600 rpms. All done by 4,500 rpms, but that is just where the heads and engine were designed to go. The Fueling head isn't flat on the combustion chamber side, has a figure 8 chamber, does raise the comp ratio to just over 11.00:1 on a stock late model 454 truck engine, without piston change.
I would think the Fueling heads would not bolt to a 409, nor give acceptable comp ratio on one, and a 409 design head on a 454 would have to have one strange BB piston with the depression it would need for a useable comp ratio.
Last I heard, Jim Fueling was in the process of developing a performance version of the Centerfire heads for BB engines. Klein Engines, in Phoenix, is the authorized vendor for Fueling Centerfire heads.
If the rotating valve system is what I think it is, then it is a system developed in the 1930's by Mercedes and Auto-Union, and now made by a company named Coates. The full name is the Coates Sperical Valve Head. This head has intake and exhaust ports closed and opened by semi-round barrel shaped "valves" with ports through them, that align the head ports with the sphere ports for opening and flow, then close for compression and firing strokes. RPM potential is unlimited, there is virtually no oil in the top end as the "valves" and their drive shafts run on permanently sealed and lubed ball bearings, and the heat of the combustion chamber is now easily accesed by the water jackets. These heads use no cam, lifters, pushrods, rockers, conventional type poppet valves, springs or retainers, have virtually no rotating resistance, are belt driven from the crankshaft.
Coates has a web site, but I can't remember the address for it. They do mostly Ford Windsor 302 conversions, now, but have had heads prototyped for GM for a few years.
I figure that is what is meant by both Fueling and rolling side valves, two diferent approaces, two different companies.
Jul 30th, 00, 08:02 AM
I saw the engine displayed at SEMA around 1087 or 88.
They had several examples, ford, harley davidson. and I think a jag.
At that time he said they kept blowing up engines because they would rev to the moon!
Here's a pair of links: http://www.coatesengine.com/
The article says he's been working on this since the 60's
Lots of headaches in sealing, cooling, lubricating, I guess the equivalent of cam timing has to be machined into the rotary "valve" So if you want different cam timing, you'd have to move the port or change the rotary valve location.
Also the air flow goes into the rotary valve as it's turning and it's only lined up correctly for part of the revolution.
Maybe someday It'll be perfected...
I heard Mercedes infringed on Fueling's patent on the three valve concept, and he was suing them. Any news on that?
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[This message has been edited by davidpozzi (edited 07-30-2000).]
Jul 30th, 00, 09:19 AM
The first article from Mr Bahacz's on the fueling system was in the April 1997 issue of Popular Hot Rodding on page 34.
I didn't buy the mag with the "Coates" rotary valve article, but that was it.
Mr Bahacz wrote parts one and two of an article in "Engines" by the Hot Rod Performance Series (Display Until 4/24/2000 date on the shelves) where a bunch of "kids" (with great respect) at Nothwestern College, Lima, OH did a buildup on a 502 using the fueling sustem. The project was "kind of" snake bit (as aren't all projects) but the overall gist of the program was very promising, (like very low SBFC numbers on 87 octane gasoline with a C.R. of about 12 to 1, and unbelievable torque.
I think these articles came out originally in Car Craft.
These got me thinking about two articles in Pop Hot Rodding about building engines that run on low octane fuel but have high C.R.'s by using very small compression chambers, flat top pistons and long rods if you could fit them and afford them.
One article was on small and big block chevys and the other on a pair of "blue oval" engines.
It said to take the smallest combustion chamber head you can find and plane it .100" more to minimize chamber volume. This along with a flat top piston "supposeably" makes the engine more efficient in the combustion process and so it doesn't preignite or detonate. Has anybody done any engine building using these techniques???
The "Coates" valve setup sounds great but is it long term (like 150,000 miles worth) practical???? Again just somemore stuff to think about. pdq67
Jul 30th, 00, 02:44 PM
Fueling heads aren't three valve, but only two.
As far as I know, the first three valve engines were again, Auto-Union, in the very late thirites.
Honda made numerous three valve experiments and did build a couple of motorcycle models with three valve heads, all twin cylinder cruisers. Two intakes, one exhaust.
Haven't heard of any suits between Mercedes and Fueling, but who knows.
Spherical valve engines can have the overall position of each set of spheres changed for timing as any single overhead cam engine can (will move both opening and closing points per sphere), but changing both opening and closing points individually has to be done with different "holes", with different start/stop points in the sphere itself. Not such a hard thing to do if you have a few different sphere combos just laying around.
Jul 30th, 00, 05:36 PM
I meant use 409 heads mounted on a 454 and make an aluminum intake match the heads. The pistons would have to have a matching "reverse" or dished combustion chamber in them to make up for the lack of any combustion chamber in the 409 heads. I read an articleon 348/409/427's that said the old Z-11 427 heads flowed more air then about any heads that the General ever made but I don't have any experience with them.
I ask this because of the fueling heads being "flat" with very small combustion chambers. Any more thoughts???? pdq67
PS has anybody built any minimum combustion chamber/maximum compression ratio 87 octane engines??? If so how does they run???