Fox 351W power depending on build question


Active Member
Jun 17, 2016
Can someone educate me? Say you have a 95 Lightning roller engine with TF heads, F cam, TF upper/lower intakes. What would be required to rebuild this engine with these current parts (minus the cam maybe) to achieve 400 RWHP? How is higher compression achieved? Not sure where I'm at now compression ratio wise, and I only can get 91 octane here in my area. I guess boring to a larger displacement would gain more power? Why wouldn't engines be built to their maximum power potentials (while being safe/reliable) from the start?
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New Member
Jan 10, 2020
I am currently building a Lightning "Interceptor Bronco" based on 1995 intake and heads. This stock lightning combo with stock 8.8 compression ration made 240 hp.

Without a turbo or supercharger, I'm expecting 300 hp.

With only 91 octane fuel available, my target compression ration will need to stay below 10:1 compression.

Higher compression will require higher octane fuel. (or something inventive like water injection. Water has infinite octane.)

You will likely have too much compression with the Trickflow heads on 91 octane fuel.

You will need to carefully measure cylinder volume as well as cylinder head combustion chamber volume. You can get estimated intake manifold and cylinder head flow numbers by searching the net.

Once those are established, the remaining variables are: fuel management, ignition tuning, cam grind and compression.

You can lower compression by dishing pistons or boring. You can increase compression with domed pistons or shaved heads. Several gasket thicknesses are available.

400 hp is ambitious; but, you should consider a power adder: turbocharger, supercharger. It that case, you will want comparatively low compression to begin with.


New Member
Jan 10, 2020
You can also try plugging in the variables to software like VirtualEngine2000 and try to predict HP.


will be trying this sex one when I can find it
Mar 5, 2019
OP asked for 400 REAR WHEEL horsepower which is closer to 500 at crank right!?!


Active Member
Jun 17, 2016
My motor is already built and running. I haven’t had it dynoed. I’m just curious as to what this motor is capable of with my TF heads,TF upper and lower intake if it were to be rebuilt in the future.


5 Year Member
Jan 10, 2011
when you have it tuned, the maximum MAF flow is a very good indication of how much HP it makes. If you have a tuning means (QH, etc), you can log maf and get it from there too, or at least get real close.
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