351C power output

Can anyone confirm what sort of power output a 4v 351c could be expected to produce at the wheels?

The spec and miles of my engine is currently unknown, other than a Holley carb and intake and possibly a mild cam. It is running factory cast exhaust manifolds and driving through a toploader and 9" rear end. No PAS or air con, just the water pump and alternator as external power drains.

RWHP was dyno'd at 225 (after a lengthy session setting it up properly), which I felt was a bit disappointing. Comments?

Thanks, Mark

Reply to
Mark Allen
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225 hp @ the wheels would be 265 at the flywheel. Also keep in mind that the hp ratings in the early 70s are not compairable to todays numbers. For example one article I read claimed that the 271hp 289 and the 225hp 5.0L were almost identical when it comes to real world power output. Thats a 20% differance in ratings. So if you add 20% to that 265 number thats around a 315hp old school number. That still seems on the low side, but I'm not sure what a 351 4v would be rated at. Also is it a closed chamberd or open chambered head? Even a fresh 351 cobra jet 4v is going to look weak compaired to the numbers of a '70 Boss 351 4v.

MadDAWG

Reply to
MadDAWG

FYI: The following are SAE GROSS (aka Brake) horsepower ratings. Gross HP figures are calculated without many of the accessories (such as alternator, water pump, etc.) attached to the engine. After the 1972 model year most manufacturers switched to SAE NET horsepower ratings.

351C 4V 300 BHP @ 5400 RPM 380 lb-ft @ 3400 RPM

Yet another $.02 worth from a proud owner of a 1970 Mach 1 351C featuring

Reply to
Grover C. McCoury III

alternator,

Also the Gross ratings where done with blueprinted engines where the "newer" ratings are suppose to be pulled right off the production line.

So its probably not that far off then. 300 hp would be aprox. 255 at the wheels. I'm not sure if the accessories and exhaust would be worth another

30hp, but I'd bet its pretty close.

MadDAWG

Reply to
MadDAWG

Thanks guys, those numbers / conversions are pretty much in line with what I was thinking.

The reason I was disappointed is that the motor had a $5-6k rebuild back in the early 90's when the car was rebuilt as a clubman's circuit racer, so I was hoping for more.

The motor doesn't appear to have been swapped since then as the parts shown on the invoices relating to that build that would be externally visible are still in place.

Don't know how much power it's worth, but the previous owner stuck "BOSS

351" on the air-cleaner in adhesive letters ;-)

Mark

Reply to
Mark Allen

You have to be missing at least 50 hp then :)

If you have details of what actualy in the motor I can run it thru my software to give you a little better idea. All our info was based on a stock

351 4v. You can email me at snipped-for-privacy@NOSPAMhotmail.com by deleting the spam trap.

MadDAWG

Reply to
MadDAWG

Actually, that's a spam shield, not a spam trap. :-D

Reply to
WindsorFox[SS]

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