A-V8 Roadster

Deuce Man

Deuce Man

Well-known member
I am building an A-V8 roadster, late 40's, Dry Lakes look (isn't everyone?) I am going to box the frame and am leaving the original center crossmember. Will boxing stiffen the frame enough or should I use some sort of X-member? How about some pictures of similar projects?

I have a '39 rear I want to make open drive. I am told Tractor Supply has a bush hog yolk that will fit the Ford pinion spline. Has anyone ever cut off an outer torque tube, bushed it, and installed one or two lip seals?

This is a real budget project. I'm trying to buy as little 1-800 stuff as possible. Any fresh ideas will be greatly appreciated.
 
You should head over to the HAMB where you will find a MUCH bigger pool of rodders to help you along. Good luck...sound like a cool car.
 
Get the "bible", "How to Build a Traditional Ford Hot Rod" by Mike Bishop & Vern Tardel.
I built 2 Av8's using the book.

Speedway sells an open drive conversion for the banjo rear. Or, sell that rear and get a truck rear that is already open drive.

Boxing the frame depends on the condition of the frame and what engine you are using.
If you are using a flathead and the frame is nice, you probably don't need to box it.
I used Vern Tardel's '32 K member repro shortened to fit a Model A frame with the Model A crossmember. I boxed my frame because it wasn't that nice to start with.

Yes you could also use the X member out of a '33 to '36 Ford but that will require a lot of cutting and fitting & welding and you'll have to use a '39 trans.

My roadster is my avatar picture, I have other pics in my profile also.
 
I didn't box my frame-big mistake! Even a good running Flathead can twist the frame on a model A. I would box it from the front x-member to the center one, and run some radius arms as far forward as you can to control the rear.
 
Check out The Hotrod Works site. They have a radius rod and torque arm set up for the rear axle. They have an open drive conversion too. All good ideas to look at even if you build it your self. The open drive commercial set up can be used on the passenger car rear axle but it helps to have the drive shaft rear yoke for it too.
www.hotrodworks.com

Model A frames flex a lot. I'm sure more than one old time hot rodder had a door pop open when they turn a corner or hit a big bump. The 32 K-member helps a lot but it will still flex a fair amount. On an open drive set up, it would be a good idea to add to the K-member to make an X-member or just make an X-member from the start. Boxing helps a lot but the frame will still twist a little unless its X'd.
Kerby
 
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I used a 39 rear end and torque tube,I did cut the tube and the drive shaft,(did not want to go with open drive shaft),also cut the rear wishbones.I'm not done with the build yet(5 years)so I can't tell you how well it will work. Like hotrodvideo said the bishop / tardel book is an excellent investment.As you will read in the book,I did not box the frame.I guess I'll see how that works out this spring when I have it finished.
Menno
 
flatheadA: The torque tube actually changes the way things flex a good bit. The rear axle pushes against the transmission then the rear transmission mount and engine mounts carry the forward load to the frame along with some of the torquing action. Thats why all those old V8s had the steady rods or anti-chatter rods as many call them. That kept the rearend from pushing the clutch arm out of whack and also kept the fan out of the radiator. The K-member or a well built cross member with a little bit of K or X framing will work with a torque tube OK as long as you don't punch too much horsepower to it. The Bishop/Tardel book doesn't mention much about boxing since that's the way they built there little AV8 roadster. They didn't go too high on the horsepower scale and the K-member along with the original model A crossmember holds the flex & bend pretty well. Even that little kick up in the back of the frame helps solidify a fair amount in the narrowest part of the frame back there.

Kerby
 
All great information guys - most of my ideas were pretty close to what most of you suggested. Just makes me more secure knowing my ideas are not too off the wall!

Thanks.
 
There was an article in one of the magazines a while back of some European Rally driver who built an A with a hot late model four cylinder overhead cam engine. He incorporated an "X" member between the center and rear cross members. I have to see if I can find the article. This is something that would keep the frame from twisting. The way I see it, boxing the rails wouldn't. My opinion.
 
rotorwrench:I did kick up the rear about 3" and I modified the center cross member to except the top load trany ,uncut wishbones and the 39 brake and clutch pedals.It's a stock flatty(8Ba) so not a lot of horse power,even after I rebuild the engine I don't think the horse power will increase that much.
Menno
 
next question I am using a 49 50 ford f1 steering box looks like it protrudes inward a little too much what is the simplest way around this ?
 
The Bishop/Tardel book addressed this by cutting off the F1 frame mount flange and welding on a model A flange after adjusting for a workable length on the sector shaft part of the housing. Vern Tardel also has a little book published that gives good info on both the F1 and F100 box modification for the early Ford conversions and it's available from his web-site.

On the frame boxing, there is a lot of variables about whether to box or not. I have seen some frames that are so rusty at the old 4-banger rear motor mounts that they either have to be patched there or boxed or both. This was an area that got fatigued from years of service and corroded to boot. If the frame breaks there, which has been known to happen, it will kill your ability to steer the car due to the location of the side steer box. If it happens at high speed a person would be lucky to survive it. A fella just has to look it over real well, scratch his head, and decide for himself if he wants to box that area. Its a must if you use a heavier 200+ HP overhead valve engine in there.

Kerby
 
Here's mine. Solid as a rock.
DSCN0369.jpg
 
I also used the Tardel F1 box to model A flange,make sure you mock it up and mark it before you weld.Then it will fit into the existing holes in the frame.As an extra support I cut off another model A flange and put that on the outside of the frame(if I get a chance I will post a pic).Unfortunately that box location doesn't leave you much choice for an exhaust.
Menno
PS nice frame Bassman
 
rotorwrench said:
flatheadA: The torque tube actually changes the way things flex a good bit. The rear axle pushes against the transmission then the rear transmission mount and engine mounts carry the forward load to the frame along with some of the torquing action. Thats why all those old V8s had the steady rods or anti-chatter rods as many call them. That kept the rearend from pushing the clutch arm out of whack and also kept the fan out of the radiator. The K-member or a well built cross member with a little bit of K or X framing will work with a torque tube OK as long as you don't punch too much horsepower to it. The Bishop/Tardel book doesn't mention much about boxing since that's the way they built there little AV8 roadster. They didn't go too high on the horsepower scale and the K-member along with the original model A crossmember holds the flex & bend pretty well. Even that little kick up in the back of the frame helps solidify a fair amount in the narrowest part of the frame back there.

Kerby
Click to expand...
i went by the book all the way so far so good
 
keep it coming guys when I was a kid I would have had to spend a years lawn mowing money on those little hot rod magazines to get this much information then again they did fit into our school books! next question I have a 10 leaf rear spring books say roadsters,coupes had 7 or 8 leaves which leaves do you remove to make a 10 leaf spring equivelent to a 7 leaf?
 
Hotrodvideo said:
Get the "bible", "How to Build a Traditional
Ford Hot Rod" by Mike Bishop & Vern Tardel.
Click to expand...

You really should get this book... It's got a wealth of information in it by those who have done it before and will pay for itself many times over in avoided mistakes...
 
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