Thread: How much do I Stroke

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Currently
3.562 offset 350 crank (cast) 47 pound weight
6' alloy rods
12:4 to 1 comp SRP 30' over
Comp cam Mech Roller 12-904-9
Brodix track 1 flow ( In 277 @ 700lift, Ex 218 @ 700lift
Super victor manifold
Barry grant carb 975cfm

Result 10.18 @ 131mph 1/4 track
glyde 5k stall
9' 4.11 gears
26 x 8.5 x 15 slicks

Engine apart.

Question;

Do I stick to what is working and replace crank with a forge crank and 6' alloy rods again?
Do I chase a bigger stroke?
Can a bigger cam work?
THE MAIN QUESTION IS FORGED STEEL CRANK + H - BEAM RODS V'S FORGED STEEL CRANK + ALLOY RODS?

IS THERE A DIFFERENCE IN THE WAY THE POWER GETS THROUGH THE MOTOR???????????

I did a search on your cam, the 12-940-9 you listed the 1st post is a circle track cam. The cam you list here now does not show up on comp cams database, you probably typed it wrong this time. You are drag racing and I would get a cam made for drag racing to start with along with a better crank. A 10.18 in a 2500 pound car is nothing to be ashamed of.

I would update to a better crank and the proper cam for your application. Then I would change the tires to a taller size, and probably the stall converter, a little less stall. This cam you have now is rated at 3000 to 7000 Rpm, and if you are at 7600 at the big end, you are out of power at about the 1100 foot mark, and just free rolling at that point. You got some good parts and You could probably get in the high 9'S if you get your motor and driveline combo to work well together.

here is a link to the cam you list.

http://www.compcams.com/Cam_Specs/Ca...?csid=341&sb=2

Also I would go with a good set of forged steel rods, an alloy rod is overkill for what you have.

Also I assume you are leaving on a tranny brake, what RPM are you leaving at ? And are these tires slicks , drag radials, or what ? Is this car backhalved coil over or whats it got ?. And remember you can have all the power in the world, but if you do not transfer it to the groung just right, its just going to have you chasing more power for nothing.

Tires are definately slicks
tranny dont require trans brake.
Can stall to 4200rpm no creep.
I launch at 3500 on a 2 step module re; 60 footer 1.45
at 4000rpm 60 footer 1.62
Sorry cam is mech roller says large engine long track on specs.
Cam card specs located http://www.compcams.com/Products/54-89.pdf
page 76
In regards to susp it is still factory stock which is not a coil over it has the springs sitting on the diff, shocks mounted behind the diff and two top and two bottom arms holding diff in place mounted towords the front of the car factory stock.
My wheel arches do not allow me to put a bigger or taller tyre on. I would like to retain this feature BUT GO FASTER is this possible or am I pissing in the wind?

Yes I see the cam specs on page 76 and it is also stated as an OVAL TRACK LATE MODEL 1/4 TO 3/8 MILE CIRCLE TRACK CAM FOR STOCK CAR RACING. If you were to put in a drag race cam and If you were to drop down on the stall size and run a tranny brake, that car could be in the 9's, even with the smaller tires you have now. With the stall you have now you are sky high on the RPM'S right from the start, you have to figure if the car will not move until 4200 to 4600 rpm and the cam bottoms out at 7000. Youve only got a 2400 to 2800 rpm operating range of power available to run the car under full power.

There is nothing wrong with a leaf set up, but The leaf set up you have is about at its limit and sounds like you have it set up really good to run a 10.18. I personally think your weak links are the cam and stall you have. and a trans brake added to a smaller stall speed would equate into a broader range of low end power that you are wasting just to get the car rolling off the line with the current high stall speed, and into some better 60 foot times also, and that would mean better times on the big end.

Thanks moony that does make sense.
I'll see if some of the boys round here can grind me up a cam with a wider rev range and we'll change the stall hope that drops me in the 9's.
Talk soon