P-51 / cam

Thinking of upgrading to P-51 heads and new flat top pistons for my 545. Would be close to 13.8 - 14 compression. Wondering if my current flat tappet cam .648 lift 262* duration @ .050 would work ok.

Are you estimating C/R?

14.03 based on Wallace Racing calculator with 3cc piston (probe), zero deck, 72cc chamber. I had figured it a week ago, so knew it was right in that range, based on their program.

Whats the B/S?

It will work, but its definetly not right.

Cams a little small for a race car and you need to make sure the probe's have the correct valve relief.

glenevans wrote:14.03 based on Wallace Racing calculator with 3cc piston (probe), zero deck, 72cc chamber. I had figured it a week ago, so knew it was right in that range, based on their program.

You are right.I just seen where you had a 545.

4.39" bore, 4.50" stroke. I just have never had a roller cam......

Now would be a good time to get one IMO.

probably right ......

dfree383 wrote:It will work, but its definetly not right.

Cams a little small for a race car and you need to make sure the probe's have the correct valve relief.

x2

Yeah, with that cam you're leaving about 100 thou's valve lift on the table. You'd be much happier to step it up.

Sweet car 4th Horse, but I'm biased to '69 fastbacks w/boss 9 scoops ( Mine is Wimbledon white ) what size cam do you run ?

It's a comp cams solid roller stick with specs by Kaase suited to my car's heavy weight and high altitude where I'm at. It has a 109 cl and lift in the .760 area with 280 duration at .050. I have the cam card someplace in my shop but I'm at work now.

Is this a drag race deal? What is your conv. stall?

I do mostly bracket racing with the car, but occasionally drive on street. I have an 8" continental converter, 4900 stall. 4.11 gears, wide ratio c6, full weight 1969 mach 1. Currently crosses finish line @ 6400 rpm w/ dove-c heads , 2" crites headers. Footbrake start. Also high elevation here in SLC, Utah about 4400 ft.

crank is scat cast 9000 series, so probably need to limit rpm's

glenevans wrote:I do mostly bracket racing with the car, but occasionally drive on street. I have an 8" continental converter, 4900 stall. 4.11 gears, wide ratio c6, full weight 1969 mach 1. Currently crosses finish line @ 6400 rpm w/ dove-c heads , 2" crites headers. Footbrake start. Also high elevation here in SLC, Utah about 4400 ft.

Vacuum brakes?

I converted to manual brakes ('74 maverick disc / drum master cylinder), manual steering and no A/C.

I apologize for asking so many questions but, many times it aint about caming the engine. It's about caming a guys combination.

1] 4900 Vs 5600 stall.

2] Foot brake Vs transbrake.

3] 4400 Elv. Vs 400 Elv.

4] 3400 lbs Vs 2400 lbs

There is not one answer given the variables.

I do appreciate the time and info that has been given here. Yes, I do agree with you Lem that the combo needs consideration to properly cam and build the engine. I sort of started out thinking I would drive this car more on the street, but it has been leaning toward racing only. I guess the overall goal with this particular car would be low to mid 10 sec. quarter mile times after getting the good heads, mafia intake etc.