Project EFI Stroker
An Article by Ken Mattice
May, 2001
Page 3
Topside, the valve train runs under the control of T&D Machine shaft mounted rocker arms taking their cues from a Competition Cams split duration hydraulic roller cam. It all fits under Sunbeam Specialties LAT Tiger valve covers once they had gone on a "Bridgeport" diet. The right valve cover was converted to the left side "breather cap" system, and both were heavily baffled. I thought about glass windows in the valve covers. Just kidding! There is no PCV valve and vacuum for the brake booster is supplied by an electric pump from a Ford deisel.
The rest of the engine is fairly conventional (see Parts Tables at end) except for the distributor which is a prototype MSD unit Duttweiler helped develop, which turned into the Pro series. This unit is smaller in diameter and a little shorter, which is required to clear the front throttle body. The distributor advance is locked out at zero degrees, and oddly timed by setting number 1 cylinder at 45 degrees BFTDC. Utilities are powered by a double belt drive system, with custom aluminum pulleys built by Dale Akuzewski.
So how did it run? Much like the conventional 347 ci stroker motor currently in my Tiger, torque was the order of the day. (See Data Comparison) The 347 puts out 350 ft. lbs. of torque @ 3,000 RPM, while the larger 364 starts @ 380 ft. lbs., both solidly in the "fun zone". They peak at 400 and 430 ft. lbs of torque respectively. Both engines are pretty similar, although the larger motor produced notably more horsepower at 460 hp compared to 385 hp for the 347, both at 6,000 RPM.
Take a look at this Horsepower and Torque Graph . What a great looking torque and horsepower curve the smaller carburated 347 engine has . The EFI 364 has a "sag" in both torque and horsepower around 3400–3800 RPM’s. This is a graphical representation of dyno pull #15. It was rather fascinating to watch Duttweiler "fix’ or tune this problem away. After each dyno pull, the data collected by the dyno is displayed and analyzed by a Toshiba laptop, which is also connected to the Speed Pro. Based on what he sees, the experienced tuner then goes into each cell of the fuel and ignition curve (by 25 RPM increment) and adds or subtracts fuel and timing as appropriate. These new values are downloaded to the Speed Pro as new modified instructions. The engine is run again, and if the tuner got it right, the sag is gone. The programmable engine management unit enables unbelievably finite control. The sag did go away, so I can expect really super throttle response, although it is hard to imagine it getting much better than the carburated 347. The 347 by way of reference, has a very highly tweaked Holley 650 double pumper, built by a company called Fuel Curve Engineering.
So, when all is said and done, is the significant expense of this type of EFI and the controlling electronics worth it? From a pragmatic engineering perspective, probably not, but you could apply the same "no" answer to a GT-40. From a confirmed motorhead/dreamer perspective..absolutely.. yes!! The EFI suffers some of the same fit problems as do Weber carburetors in a Tiger, which no doubt rules it out for most.
Stay tuned for real world driving impressions once this engine is installed in my 1965 Mark I Tiger, which has some pretty serious suspension mods to handle these beasts! Dale Akuzewski's t-5, 5-speed has managed to live behind the 347 for a few years and should be up to the task of the new motor. I am happy to take your comments, or to provide further details or sourcing information. Just "click" on my name in the title, and an E-mail is pre-addressed.
Take a look at our Regional Clubs section for more information and tips.
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