JoeTR6
Reader
12/20/15 3:20 p.m.
Getting the Triumph 2.5 to rev over 6200 RPM is a challenge. You can buy a forged crank for $$$, and I've heard of adding an extra 4 bolts to keep the flywheel attached. The problem is harmonics, and a decent crankshaft damper (e.g., ATI) might also fix the problem. The 2 liter motor doesn't suffer as much from this. Thrust washers either need to be replaced often or (if rules allow) modified to take higher loads.
The Triumph 2.5 has gobs of torque, and with the right cam and header, the torque curve is pretty flat. I have no direct experience with a 1600 Kent motor, but suspect it's power is more at higher revs.
I should do some dyno runs on our autocross TR6 to see what it really puts out.
One thing to consider, how available is each option...
Formula fords are converting to the Honda fit engine, so you might find more of the Kent engines available.
Burton power has rocker shaft mounts and a few other parts to take care of the simple weak points in the Kent engine and even though it is a simple push rod design it will rev to 9,000 RPM. That just seems like a better race motor.
If you go with the Kent engine and happen to find any Fiesta heads, you don't want those, those you will want to sell or give away. I have room to store any that you find....
You don't want to use the fiesta head or crankshaft, the head won't flow as well and the crank is shorter.
Ford now sells "NEW" Kent blocks and someone was authorized by Ford to cast up aluminum versions of the FF head. It's not cheap but better then an old used cast iron one. These engines are tough. I used to rev my ITC Fiesta to 7K at times to save an upshift and a down shift. The only engine problems I ever had was a blown head gasket due to overheating. Fixed with a bigger then stock radiator.
