quote:Originally posted by Rapier:
...How to build a 351C for reliable street driving with modest power and good fuel economy. Target is at least 300bhp and at least 15 miles to a US gallon....
Derek, it CAN be done!
I have had Pantera owners tell me they get 20 mpg on the open road! Even my 8.0:1 '74 Cobra Jet motor gets 15 mpg on the open road with a carb & distributor that need rebuilding.
Here’s your shopping list:
1) Clevite 77 crank & rod bearings
2) New flat top FORDGED pistons
3) File to fit iron rings
4) Zero deck the block
5) Rollmaster timing chain
6) SPS, Milodon or ARP rod bolts
7) New or rebuilt balancer
8) Steel or aluminum flywheel, your choice
9) Dynamically balance the reciprocating assembly
10) Use your open chamber heads, resulting in a 9.0:1 compression ratio
11) Install new one piece stainless steel valves, 2.19” intakes, 1.71” exhausts
12) Ford Motorsport bolt down roller rocker arms #M-6564-C351
13) Head work (multi angle valve job, pocket clean up, exhaust port grinding)
14) Electronic ignition
15) Comp Cams XE 274 camshaft, springs, retainers, keepers, lifters
16) Custom length 3/8” pushrods
17) Holley 750 cfm, vacuum secondary carb on your existing intake manifold
18) Aviaid or Armando oil pan
19) Standard oil pump
20) Hi pressure relief spring, chrome moly oil pump shaft, Fram HP1 oil filter
21) Dyno tuning for carb & ignition
I don’t have any dyno time with this cam, it is a modern grind that hit the market long after I stopped building motors, but I can guarantee you this motor shall go north of 350 bhp if assembled caefully. The feedback on this cam is all good, it provides plenty of throttle response when you nail the gas pedal, yet it is docile around town with good drivability. The limiting factor to power production will be that damn GTS exhaust system. If in the future you wanted to explore making more power, the exhaust system will be the next item on the agenda. If the budget has a little more room, a good addition to this motor would be a Blue Thunder intake manifold. It would give you a bit more bhp above 5000 rpm, and extend the rpm range of the motor.
No stroker crank, no fancy rods, no expensive heads, no new intake manifold, no roller cam. Just a good rebuild, a little head work & a nice flat tappet hydraulic cam. This motor will probably run on lower than premium octane fuel too.
Your friend on the DTBB