 As this chart shows, the flow...  As this chart shows, the flow capability of the UPM D3 head is impressive. Peak figures of 434 and 283 for the intake and exhaust respectively are likely to set new standards for SB heads of any variety. Note the swirl curve which starts at about 0.450 lift. This may be a key factor toward faster burn rates. |
 Like the intake port, the...  Like the intake port, the whole area of the exhaust is highly active. The only way to show what relatively small differences existed was to exaggerate such differences with large color changes as seen here. The slowest area is on the bottom of the port which nonetheless is still flowing fast. |
 The search for intake flow...  The search for intake flow ends about 1/2 inch into the combustion chamber. In just the same way, the search for exhaust flow starts in the region around the exhaust valve. |
 Because more of the exiting...  Because more of the exiting exhaust gases come from the region nearer the center of the cylinder, the exhaust port is shaped with a small but discernable bias in that direction. |
We expected the 0.250 figures of this UPM D3 head to be good because of the time put in to both position and angle the valves to minimize the effect of intake shrouding, but the 195 cfm seen was truly impressive. This is the kind of flow normally seen with a valve of some 231/48 diameter (2.375). At this level of valve lift, flow is all about the seat and immediate area up and downstream of the seat. The UPM D3 head uses a 50-degree seat which favors high lift flow at the expense of some low lift flow. This makes the 195 cfm at 0.250 all the more impressive. However, the main reason for the 50-degree seat is not so much any possible flow advantage, but as a means to help suppress the valve bouncing off the seat at closure. The increased angle helps out here by acting as a damper.
The flow this port is capable of is not the sole contribution to the high output this head has shown. The port velocity is also a factor. This is in the required range because the port is highly efficient in that it does not have any significant redundant area. What that means is the whole area of the port is utilized to near maximum potential. As a result, the port looks a lot smaller than you would expect when compared to other high-performance heads.
This is part of the ingredients needed to generate horsepower through a boost in torque rather than being able to hold the same torque to higher rpm. Indeed, the small but highly efficient port is probably the primary reason why this head also produces more torque than its predecessor. The computer-generated velocity map of the intake shows how little velocity variation there is over the area of the port. These velocity test results put this head in a top-of-class category.
Exhaust Flow
If the cylinder has the potential to fill well, then it should also empty well if all the potential power is to be realized. Again, the UPM D3 did not disappoint. By a small margin, it proved to be the best-flowing 1.625-inch-equipped exhaust port ever to go across the test bench.
At the 0.750 reference point so often used by head porters, this head, without the flow-enhancing aid of a flow pipe, delivered a might over 274 cfm. That's good, but the flow curve had not by any means gone horizontal at this point. Taking the valve lift up to 1 inch, which is about where a really serious drag race engine would be, showed this port was capable of no less than 283 cfm. With a flow pipe (this simulates the exhaust pipe), the peak numbers went over the 300-cfm mark.
Like the intake, the exhaust port showed a uniform velocity map. Having a small, efficient port is good for improved high-speed chamber scavenging and widening of the torque curve. That's just what an oval track racer needs to get off the turn faster, especially on tracks that have tight turns and long straights.
Swirl
The value of swirl is always in debate with race engine builders. It's one of those things that interacts so much with other factors that it is hard to pin down exactly what is wanted. A few years back, the big deal was not to have any swirl for fear of centrifuging the fuel out of the intake charge in the cylinder. However, this proved to be a problem only if the effect of lower intake charge temperatures and fuel droplets a little too big for the job were not properly addressed. Cooler intake charges from thermal-barrier manifold coatings meant the fuel leaving the carb boosters needed to be more finely atomized. When that was done, swirl started to get back into favor.
But a lot of swirl at low lift might mean the opportunity for some of the intake charge to go out of the exhaust port during the overlap period is increased. Part of the reason why the UPM head works well could be that at the lower lifts (when both valves would be open) the swirl is nonexistent. As lift progresses, the swirl builds to an appreciable level and is retained throughout the compression stroke and into the ignition phase. This, in theory, promotes a faster burn, which at the 10,000-rpm mark is definitely a positive factor.
An indicator here that our theoretical faster burn actually takes place is that this head typically needs about 2 maybe 3 degrees less timing than its contemporaries. The ability to use less advance means less pressure rise while the piston is on the way up the bore, without any sacrifice of pressure rise when it is on the actual power stroke.
Supply
It's pretty evident from the forgoing that this UPM D3 Ford head is a hot commodity. Because it is available in a number of versions to suit a specific application, Losito deals only with professional engine builders. Now this may seem somewhat offhanded, but when you know why, it will all make sense. To stay on top of his game, Losito must spend just about all his time trying to improve on whatever is the best today, otherwise tomorrow any one of a number of smart guys out there may have found what it takes to snag the No. 1 spot. It is only by virtue of a huge amount of effort and time on the flow bench and dyno that remaining totally competitive is possible.
If you believe these heads are for you, then get them through an engine builder who is recognized as being successful and competent in the type of racing you are into. But before you call, be aware that big horsepower usually costs big money, and things are no different here as a set of these heads with external CNC lightening, less valves, springs, and so on will set you back about $6,400.
Sources
Engine Builder Only Contact:
Ultra Pro Machining
Dept. MMFF
6350 Brookshire Blvd
Charlotte, NC 28216
(704) 392-9955
www.ultrapromachining.com
Engine Builders To Contact:
Drag Racing
Bennett Racing Inc
Dept. MMFF
1640 11th Ave
Haleyville, AL 35565
(800) 240-7223
www.bennettracing.com
Bob Panella Motorsports
Dept. MMFF
5000 E. Fremont St.
Stockton, CA 95215
(209) 547-1778
www.panella.com
Dirt & Asphalt Late Model & Road Race
Custom Race
Dept. MMFF
W. 2010 Governor John Sevier Hwy
Knoxville, TN 37920
(865) 573-1449
Cornett Racing Engines
Dept. MMFF
1647 S. Hwy 27
Somerset, KY 42501
(606) 678-2226
www.cornettthunder.com
Truck and Off-Road
Rancho Performance Machine
Dept. MMFF
28073 Diaz Rd., Ste.
Temecula, CA 92590
(951) 676-9292