My dad has recently started racing a vintage stock car in a local vintage group. I have been going to help him and I want to join in on the fun. I started putting together a car out of parts I have left over from other projects. I have a 65 f100 frame that I have swapped the front I-beams from a 77 f100 onto in order to get disc brakes and power steering. I am going to run a 300 and already have it mounted. I currently have an aussie speed 2v intake, 500 cfm 2v holley, pertronix ignition, and headers on the motor. mated to a stock style 3 speed with an old hurst floor conversion. For a body i am going to drop an old nash statesman body over the frame and cage. The class does not allow trucks. Rear is a stock 9in.

I know that running twin i beam for a circle track car is unconventional, but I want to spend as little money as possible and just run for fun. I don't mind running at the back of the pack as long as i can get it to work halfway decent.

Any one have any suggestions on how to go about getting the truck chassis to handle halfway? i can copy the suspension set up from my dads 57 Ford that he is racing but the front geometry is a complete different animal.

And sorry, use something else is not an option. Part of this whole scheme is to find out what twin i beams can do. If its a complete failure down the line i can crown vic subframe it, but i really want to make the twin i beam work. I like different.

I could also use suggestions for a good, but affordable cam that will wake the 300 up beyond the stock grind.

thanks in advance.

 

The problem you face with the "I" beam front suspension is a tremendous amount of un-sprung weight and constantly changing camber that's going to be different between the left and right wheels. Adding a front stabilizer bar will help with the camber issue while helping to keep both wheels kinda pointed the same direction. The only problem with that is a front sway bar will increase the tendency to under steer to counter that you also need a rear sway bar to add some over steer and balance things out. Front sway bars were available from Ford 75-79 rear sway bars were available on the big Broncos.
Here is a thread to look at Stock 2WD front sway bar dimensions - Ford Truck Enthusiasts Forums
I have a front sway bar on my 65 from a 78 F350 and it greatly improved the stability and ride quality for a street driven truck.
As far as a cam lots of companies grind cams for a 300 I6. Just try to figure out what RPM you will be at coming out of the corners and find a cam that will produce a lot of torque at that point.
Good Luck

 

You could also add dropped spindles or “I” beams. As mentioned sway bars also.

 

For circle track, the I beams might not be that bad of geometry. I would stagger the ride height left to right to take advantage of the camber gain curve i-beams have- lowering the outside will gain negative camber like you'd want, and raise the inside to gain positive camber.

 

I dont think the camber being different will matter a whole lot. but i could be wrong. My dads 57 has different caster and camber settings on each side. I think if i can add weight jacks to both front springs i can control the amount of body roll and preload going into the turns. I think i will have to run the front end lowered to the point that both tires are cambered in at the top. none of the vintage cars run sway bars, Im not sure why other than maybe they dont work well with having a different spring rate on each side. The rears usually run several more leaf springs on the right side and they all run a much heavier spring jacked down on the front right. my biggest concern though is getting it to oversteer and not understeer.

 

You can help the oversteer to the left by running a smaller tire on the left than on the right. Very common for circle track racing in some sectors, at least.

 

I am thinking they might work ok too. the drivers side camber is almost going to have to be negative unless the beam can be bent and/or modified.

 

You are correct, my dads car is running a much larger series size tire on the right side as compared to the left. helps with turn in for the front as well as with a locked rear end it makes the car naturally want to push to the left under acceleration to make it corner better. I will be doing the same on my car.

 

Are you running dirt or pavement?

 

I would definitely try a sway bar on the rear to help keep it planted then play with different springs on the front L and R. Where are you located? Sounds like it'd be a blast to watch! Growing up in rural Missouri, we played with the street stock boys, had a $400 engine claim rule to keep honest folk honest, our first car was a beat up hand me down Javelin IIRC, I always wanted to run a truck, but they never would allow it or start a truck class.

 

The way I would think about this twin I beam front end is that it is sort of like a ladder bar vs a 4 link where the instant center point is a fixed height and distance away from the wheel where with the A arm front end they produce an instant center at just about any distance and at any height. This has a big effect on the roll center height and location. On the twin I beam figuring the roll center would be easy, a line from the pivot point to the center point of the tire at the ground and where those two lines cross it the roll center. I think that I would make it so that you can change the height of your pivot point lower or higher to get the roll center where it needs to be. A lower roll center gives that end more grip(rolls more with the same rate spring) vs a higher roll center(rolls less with the same spring rate). The position of the roll center might not move around as much as it could with a A arm setup.

Once you get the ride height check the bump steer. That might take some doing to get decent.

 

Every track we run is on dirt.

 

I will try and find a rear sway bar. I am in southern illinois but the last two races we ran were at Farmington Mo, and Doe Run Mo. Our next race is in Peavly Mo.

 

1/8 or 1/4 ? Banked? Sure wish there were more places in Kalifornia that had good old fashioned fun tracks for the "Farm Leagues" as we used to call them back home. Madera Speedway is down the mtn about an hour or so away, they still have the fun punkin smashin event every year which is a blast for the kiddos!

 

Hate to say it but you lost me.