Kevin69Mach1

I currently run a 351c 2v. I want to get this car to pull all the way through the 1/4 mile. Right now it has great low end, and peters out half way down the track. I have a best run of 14.27 at 95 mph. I know it has more to give.
Currently I am running a 69 Mach1, c-4 with a 2700 stall converter, 3.50 trac loc 9".
The engine specs are
351C 2v open chamber heads. SS valves with bronze guides, machined for studs.
The block is .030 with Kieth Black Hypereutectic flat tops.
Cam is a comp cams 270H.
Crane energizer roller rockers.
Weiand exellerator intake
Carter 625 cfm carb
Msd Pro-billet dist with a 6A box.
Timimg as at 14 with 34 total.

I think the cam is my problem along with the carb being too small. I am getting a 750 holley vac. secondaries ready to try out.

What should I do for a cam?
The car is mostly street driven on nice days, and sees an occasional trip to the track.

Thanks for your help....Kevin

STROKEXD

Agreed carb, cam and possibly heads are you current limiting factors. Sounds like you've got a nice short motor there. Timing, ignition, gearing, inlet manifold etc all sound spot on.

I would upgrade to a 750DP Holley and look for a mechanical cam in the range of 240-260 degrees duration (@ 50") and .550 - .600 lift - depending on your degree of head work. ie no porting go for the lower end of that range, more porting go for the upper end of that range.

Here's a nice link for clevo cams:
http://www.geocities.com/MotorCity/F.../camchart.html

Also suggest you download Sig Erson's Cam catalogue, that's got heaps of info in it, and some good ideas of what cam specs give a particular result.

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Kevin69Mach1

Thanks, Looks like I need a bit more lift and duration. Do You think an off the shelf cam is OK or should I opt for the custom grind?
I have a really nice holley 3310 750 vac secondary carb I am going to try out. I don't need to spend any money to try it, which is nice.
How good will a .550 lift, 240 @050 duration cam idle? I don't want to go over the top here.
Thanks....Kevin

davis

Try the carb and see what you think. Check your plugs to be sure that it doesn't lean out at the top end, and jet it up in the front a bit just in case.

I would probably recommend a F238 Crane solid cam, but since the car is mostly street driven, they've got a very similar cam in a hydraulic part. The main difference is in the ramp rates.

I've had good luck with the 3310 carbs, but I do a good bit of work to them. The biggest thing that I feel is necessary is switching the secondary metering plate (fixed jetting) to a metering block so that you can tune the secondary jetting. However, in an open plenum inlet world, it won't be such a factor. You may just be fine with it. A 650 DP is a good choice to test if you can find someone who can loan one to you.

The more effort you spend in making the car go straight quicker, the less streetable it is going to become. You need to decide where over the top is fairly early on. This is one of the reasons why the low-cost plate nitrous systems are such a strong seller. It gives weekend racers a chance to go very fast (relatively speaking) on the weekends without much modification to their streetability.

:davis:

STROKEXD

Kevin I would expect a cam of those specs would still have a reasonable idle quality, and unless it's a full on race car most people go for an off the shelf grind these days.

The Crane F238 Davis recommended would be close to what you need.

Personally I haven't had a lot of success with the 3310 750, I got more performance from a 650DP and later 750DP when I had a 351 cuber, but it's likely to be an improvement over what your currently running.

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