Time for you to fess up George

Time for you to fess up George

Joined: May 10th, 2008, 1:04 pm

May 20th, 2012, 11:01 pm #1

What did you do to your motor to turn it into a charging rhino? I was around when those cars first came out and they were anything but a rhino. They didn't turn anywhere near 7000rpm. More like 5500. I know you got a BT intake and 4500 carb but what about exhaust and cam? Come on George give us some goods. You and Dan are the gurus of cleveland engines and everybody on this forum believes
in what you have to say. So cut loose with what you did to your motor to make it so impressive.
Thanks Greg

Joined: October 1st, 2004, 8:05 pm

May 21st, 2012, 1:01 am #2

I don't claim to be a guru. I just have my stories to tell like everyone else here.

The M code motors were built with 5000 rpm parts: 4300A carburetor, single point distributors, light valve springs, lightweight crank damper, mild camshaft lobes. But the Q codes & R codes were better at revving.

To answer your question: The short block has been prepped to endure high rpm: ROMAC damper, forged slugs, ARP rod bolts, tuftrided & polished crank, Clevite bearings, oil mods and dynamic balancing. Nothing exotic, trick or controversial from my point of view.

Heads: quench chamber, lightly ported, lightweight valves, good springs with steel seats & Ti retainers. "8 inch stiffy " push rods

Ignition: Duraspark I box (dynamic dwell) with MSD distributor & coil

Exhaust: DeTomaso GTS exhaust (mini tri-y shorty headers with 2" OD primaries, short 2-3/8" mid pipes, ANSA mufflers).

Cam: something very similar to the cobra jet spec I've been sharing on the internet lately. I like the new lobes I've been recommending better than the lobes used for my motor's current cam. I have a hotter "boss spec" too, but I'm old and prefer the milder camshaft.

Nothing super secret or high tech. No short cuts either. Just the old stuff I've always shared with you guys.

Old school cam grinds with wide lobe centers and low overlap give motors flatter and wider torque curves, and a different type of idle characteristic. The flatter torque curve means the car won't burn rubber quite as easily, but that is also tantamount to making it easier to control traction and accelerate. Instead of a lopey idle the motor will have an old school burbling idle. And most importantly the exhaust valve opens early enough to allow the motor to rev! You'll find the old factory grinds for the 351C opened the exhaust valve in the range of 80° to 86° BBDC. The Pantera's ANSA mufflers are very restrictive, with this exhaust system its imperative for the exhaust valve to open early in order for the motor to rev.


Pantera Photos | 351C Historic Information | 351C Technical Information

If you use a 351C 4V powered vehicle for a grocery getter ... the eggs aren't going to make it home!
Last edited by gpence on May 21st, 2012, 1:26 am, edited 1 time in total.