Revised power to weight ratio

I incorrectly calculated the power to weight by using the gross vehicle weight.  The curb weight of the fiesta is quite a bit less than that.  I found this spec online for a 1981 UK spec XR2 at an online site  http://www.carinf.com/en/55b046200.html .

So while these numbers are not wrong, the don't reflect the curb weight ratio.

Power to Weight Ratio

GVW
Stock - 63 HP/2690 lbs GVW= 1 HP per 42.7 LBS of Car
Rebuilt - 105 HP/2690 lb GVW  = 1 HP per 25.6 LB of car

Curb Weight Ratios
Stock 63 HP/1766 CW = 1 HP / 28.0 lbs
Rebuilt 105 HP/1766 CW = 1 HP / 16.8 lbs

Fiesta 1.6L Kent Engine Rebuild on the Dyno

The Stock US Fiesta specs out at 63HP @5300 RPM.   With a Formula Ford Intake & Carb, we achieved 110BHP.  Sweet!  lets see what she makes with the carb/manifold that will live in the car.

When we put the Weber 32/34 DFT 9A on with an XR2 intake manifold, we achieved 101 BHP.   However, the dyno numbers showed rich fuel usage numbers.  We drilled out the air intakes on the primary and secondary jets to .170, the Air/Fuel mixture was still running rich...Hmmm.

This run on the dyno had a couple issues.  One, the fuel return line was not hooked up to a meter to subtract the fuel going back to the tank, so we are going back to the stock 155/160 air jet dimensions, and trying it again.  Also we did not have the cold air box hooked up in the dyno room, so we loose power there.  We should get a few HP back with the air box attached...I was told it could get back close to the 110HP mark, but I will assume 1/2 that gain for this power increase calculation.

Now when I took the engine in, and Curtis got it disassembled, he noticed their was a bushing issue that stopped the rotor from fully advancing the timing.  That made perfect sense since it felt like it had about 40 BHP and gave up pretty early.

When we started to examine everything, we discovered .040 of taper in the cylinder walls...so as long as it is apart, lets make it right, ohhh, and add some high compression pistons...and balance everything....and lighten the flywheel... screw it, lets just rebuild it. And so we did.

I cannot wait to get this bolted back into the car and give it a proper thrashing.

105BHP/63BHP = 66% power increase.

Power to Weight Ratio
Stock 63 HP/1766 CW = 1 HP / 28.0 lbs
Rebuilt 105 HP/1766 CW = 1 HP / 16.8 lbs

Engine on the Dyno

What started off as a valve job on a recently aquired ported and pollished formula ford head, turned into a full rebuild with high compression pistons, a GT cam, a new fuel pump, NOS Weber 32/34 DFT 9A (wrong bolt pattern), and a great engine builder in Platte City, Mo.

Farley engines has specialized in building Formula Ford Race engines for years, and was only a stones throw up the road.  What a great resource to have so close.  The Fiesta engine -- 1.6L Kent -- is basically the same engine as a Formula Ford engine and is highly tunable. Farley Engine was able to do every thing I needed done.

So here is where we are at on the dyno

Set up 1: Loaner formula ford intake manifold and carb.  I'll post the readouts when I get them. The Kent was fed a diet of 100+ octane Aviation gas during these tests...they do not have that at the Quick Trip.

110 BHP @ 6800 RPM....

Set up 2: XR2 Intake Manifold, 32/34 DFT 9A ;170 Air Jets

101 BHP @ 6800 RPM, no cold air intake