Jason33

I have a 351 windsor that I am building for a car to run on a dirt circle track racing. The rules say that it has to remain stock appearing. So the out side I am just using a aluminum intake and a 4 barrel. the 4 barrel is a 2240 series . Is that right? I will have to look again about carb anyway to my question. The way they check the engines is by pulling the vacume on the engine. It has to have 17 pounds of vacume at I think it was 900 rpms. What kind of cam can be used to build some horsepower and still keep sock vacume. Is it even possible. Thanks in advance for all of your help. Oh yea I am boring 30 over and we can not run headers. but we can port exhaust. Stock appearing. thanks

Jason33

I guess no one has a output on the cam question or maybe I ask something wrong. I know the cam affects the vacume. I understand that but surely there is a small duration towing cam or something that can be better than stock and still pull stock vacume. If this is the wrong place for the question please let me know.

Jason33

I called Crane Cams and this is the cam the recomended for me to use. I would like to know from yall if this is a good suggestion that was made to me or do I need to go less or bigger or any input would help me. Remember I have to pull stock vacume on the engine. That is one of the tec. rules on the engine at the track. this cam is sapposed to do that.


Part Number: 443942 Grind Number: H-272-2 (REPLACES HMV-272-2)
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1969 Up FORD-MERCURY 8 Good idle, daily usage, w/centrifugal or small Rootes supercharger, 2600-3000 cruise RPM, 8 lbs. maximum boost w/8.5 maximum compression ratio advised. (50 state legal, pre-computer, C.A.R.B. E.O. D-225-32). Basic RPM 2000-5501
Engine Size Configuration
351 C.I. V
Valve Setting: Intake .000 Exhaust .000 HOT
Lift: Intake @Cam 3027 @Valve 484 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3200 @Valve 512
Rocker Arm Ratio 1.60
Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 25 BTDC 67 ABDC 272 °
Exhaust 75 BBDC 29 ATDC 284 °
Spring Requirements: Triple Dual Outer Inner
Part Number 96803
Loads Closed 107 LBS @ 1.700 or 1 45/64
Open 268 LBS @ 1.210

Recommended RPM range with matching components
Minimum RPM 1800
Maximum RPM 5400
Valve Float 6000
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 1 BTDC 35 ABDC 107 216 °
Exhaust 51 BBDC (3) BTDC 117 228 °

Sand1

You would be way ahead of the game to find a circle track forum and see what those guys are running. Most are happy to talk about these things. I drag race and from what I know about classes...they vary a bunch. The aluminum intake may not be legal in the class you want to run in, if stock appearance means just that. One thing for sure, if you pull up to be inspected and they hear the engine loping, your going to have problems. This sounds like a stock class. Everyone pushes the envelope on whats legal in thier class, but if your just starting out they will all tell you nothing is more important at this point than seat time. Get it out there and get some time behind the wheel. Then build it as you learn more about what you can and cant do legally. If I had to suggest a cam I would say buy what they call an RV cam, or towing cam. It will give you some more power but is still considered a daily driver type cam and shouldnt get you in trouble at the track.

Jason33

Thanks Sandi, and you are right about the cam. That is what a lot of people have told me. Also as far as seet time I race go carts all over the country for about 15 years but I understand this is a lot different than a gokart. Have a good day and thanks again for your help.

C0V3R

Have a look at the horsepower db to see if theres something built close to your motor in it. Checkout the link below.

Usually when you increase the cam specs you will lose a bit of vacuum at idle.

__________________
http://www.302w.com