Opinion wanted on flathead cam.

Looking for some opionions on the cam profile I am thinking about for my flathead.

51 Ford flathead, 3 5/16 bore, 4" crank, stainless valves, Thickston PM7 with dual 97's. Not sure about ignition yet. The profile I was thinking about is a grind from Nielson Racing Cams. Grind #FH-365, lift .365", adv duration 280, .050" duration 244. It is listed as an old style full race. Engine will be in a 28 roadster on deuce rails and street driven.

Any opinions on this?? Too much cam? Could use a little more cam?

Any opinions appreciated.

Jim

 

Oh yeah, forgot to add the heads will be either Edelbrock or Navarro. Leaning pretty heavy toward the Navarro's

Jim

 

I'd lean toward the Navarro. Had them on my flathead rail in the early '60's. Had a Winfield cam but modern tech is probably better. And, no I'm keeping Hallibrand.

 

I'd guess it would be pretty good - not too far off a Howard M-12 or Littero L-100 specs

 

I think the most I would go with your setup is the Isky 400jr.

 

Isky 400 Jr .400" lift, 258* duration (adv)
Howard M-12 .360" lift, 275* duration (adv)
Littero L-100 .375" lift, 270*(I)/260*(E) duration (adv)

I think the Isky is a higher RPM powerband than either of the other two - which are mid-high range...but I'm definitely no cam expert!

 

Specs sound about right to me, but thats not the whole story.Do you have a cam card? Think it will run fine with your combo.

 

I know nothing about flatties,but you might give this guy a call.
Ive been trying to get him to become an Alliance Vendor & I'll keep trying.
He does this as a side buisiness,& I work with him at our 'regular' jobs.
He makes nice stuff.

http://www.baronracingequipment.com/

 

Hi Mate,

I always though that it was lobe separation and duration (and therfore overlap) that determined the rpm band the cam produced the most power in? In this instance I would ***ume that it would be the M-12 that would be the high winder?

Educate me!

Danny

 

You're absolutely right re: lobe separation & overlap - all else being equal, I think higher lift is required for higher rpm due to the valve being open for a shorter time - obviously some of this can be altered to a point with duration, but all else being equal, as rpms go up, actual time open goes down.

Like I said, I'm not a cam guy - more of a cave man.

 

Hi Ernie,

I'm more of a Philistine then a Cave Man!

I'm bored at work and thinking about the cam dynamics; what you say is true, if duration and lobe separation is the same, then higher lift would result in better breathing. But would it result in a higher rpm power band?

I have no idea lol.

Danny

 

Higher lift doesn't necessarily mean a higher RPM powerband, but it does facilitate one. Lobe seperation and duration play a big part in the powerband location.