Finally getting around to building my '30 AV8 with a 59AB and 39 trans . I'm having an issue with the engine hitting the firewall. I put the engine in bolted the trans to the torque tube and put the motor mounts where it landed. I have plenty of room up front. I'm trying to avoid cutting the firewall. The body is sitting correctly over the mounting holes, the body blocks seem to be in decent shape (although I have ordered new ones to see if that helps). I've searched the forum and read threads for hours and everyone is a little different. What am I missing?
shouldn't have to. they are really close even in the body the motor was intended for, like a 1/4", but yours is too close. sorry, i dont have the answer, but some one will shortly i assume. good luck
Are you able to lower the front of the motor? That would bring the manifold breather away from the firewall.
Move the body back a touch. To my knowledge, you will never get the clearance you need with a Model A rear axle/torque tube.
When I built my old av8 I almost got away with no firewall modification. It was like 1/8" clearance but when id drive the car hard the frame would flex a little and id snap the fuel pump off the intake. Happened twice at least. Finally I smashed a blister into the firewall with a ball peen hammer. Good luck
I agree with Aaron D in dropping the front of the Motor. Look at the fan angle to face of the rad. It's wide at the top and narrow at the bottom. It can stand to come down enough to clear the Firewall. Won't be much but enough.
If I remove the rubbers from the front mount I do have the clearance I need. So to use the rubbers I would have to move the brackets lower but looking at most other builds the mounts are on the bottom edge of the frame. I've tried raising and lowering the trans also without much difference.
I'm working through the exact same thing right now on my build with the same body, trans and engine. I've set the car up how I want it with the straightest line from crank to rear end while keeping the carb base level, I've come to the realization it will not fit or if it does it needs recessing in some areas. I'm more than likely going to reverse the firewall to ensure maximum room all the way around. Interested to see which way you go, have fun.
Fellas, circling back to my response about moving body back a bit. This will give an idea of what 3/4" looks like. No fenders, no problem. Sorry for the pic quality.
Definitely seems like a good route, wont work for me though, when I set the body tight to the engine the center line of the wheel well is noticeably on the aft side of the axle.
Got it. I'm sure over the years of scabbing bodies together, there are some variations. Something else I have done and works really well is to make up a ring spacer that goes between the trans mount and clamshell. The one I did was 1/2" thick if I remember correctly.
neither 51mach or 65stang have told us if they are trying to use the model A rear and tube. if trying to keep the mechanical brakes, well thats a different subject, but fact is a v8 rear with a custom length tube and drive shaft would solve all problems by moving the motor 1/2" forward as it seems to have room there
I tried and tried and tried, then tried again, but could not fit my 8BA without modifying the firewall. But...I also have fenders and the hood, so I didn’t move the body or radiator location. I ended up welding in a portion of a shovel in place, to make a deeper firewall recess just under the beading in the firewall. Looks factory, gives me the room I needed, and tires are in the correct center of fenders, and hood gaps are good. The floor needs modifying in the center a little because of the shovel relief, at first I just ground a v in the wood, but ended up making a metal floor, so I just V’d it when welding it up.
I was thinking of doing something like that but you lose some spline contact. I am trying to use a Model A rear and tube. I am planning on using a 40 rear end and tube in the future which would solve my problem now, but to make things more complicated I plan on using the A wishbone unsplit with Snyders wishbone mount on the trans, which lines up. I like the shovel repurpose!
I'm running the stock A rear end and tube with juice brakes, my trans sits lower in the rear to clear the stock A crossmember and to keep the driveline in a straight(est) line, which is where I think my clearance at the firewall is becoming more of an issue. If you could move the rear of the trans up or the front of the motor down it might fit but the geometry would be off.
yeah, i like the shovel idea, ingenuity at its finest. but still, this has been done for decades, and in all the old photos it sure looks like there is no mods to the firewall.
Are you sure that the rear end isn't towards the rear a little bit? I would think with no trans mount, the rear spring and axle could be back just a touch. Without the trans bolted down to a mount it could move. Maybe just pull the engine and trans forward a little? Dave
I'm running an 8BA in my Model A and had to make a small notch at the bottom of the firewall to clear the fuel pump riser. Mocked it together without notching and was too close so did a small notch. I set the engine where the base of the carburetor is level
I notched out the firewall and used an electric fuel pump , worked great. You can also use a torch and heat massage and shrink to fit. IMO modify the filler tube then use a electric fuel pump, you will be glad you gained a few extra horses by not using the mech fuel pump and saved a bunch of grief from firewall issues.
No one wants to hear this but if one has a minor interference I have always found that a 32 ounce ball peen hammer is an essential part of my tool collection. granted I have never considered that anyone was ever going top put anything back stock after it had once been hot rodded.
That's why I'm hear. To seek the wisdom of The Hamb. Going to fab a crossmember. I'm sticking with the mechanical brakes.
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