Box the frame or Not?

[Deleted User]

I am getting started on my 1930 hudson coach and am wondering. The frame seems to be Very beefy, and mine is straight and true with no rust. Do you need to box this frame for serious horsepower? To start out it will only be about 400 hp, but hopefully with some help from turbos it will become 800+.

RL Chilton

Not being real familiar with the earlier Hudsons, let me ask? Is the frame a C-Channel type of construction? If so, I don't care how thick it is, even if it's 1/4", my recommendation would be to box it. At 400hp, and I'm assuming 400 or so lbs/ft. of torque, which is more important when determining amount of "twist" in the frame, you could certainly put that much power in your frame and drive it . . . for a while. Eventually, and probably not long after, the torsional load on 70+ year old metal and joints are going to cause them to twist enough and weaken. There's so much more "twist" available in a "C"-channel frame than there is in a boxed frame. Keep in mind the orginal powerplant probably had 65 to 75 hp. You want to increase that by 5 or 6-fold with 400 ponies. That's a whole lot more muscle than a stock frame was ever designed for.

[Deleted User]

If you plan on putting 800 HP in that frame You NEED to at least box the frame and SHOULD consult a reputable chassis expert. You might get away for a little while without boxing but it will eventually fail. Maybe sitting in the driveway or at 10/15 mph, Maybe on the track or the interstate at higher speed with catastrophic results. The original frame was never meant to withstand the power you plan to put into it.
Bob

[Deleted User]

well I guess that answered my question! I have looked into custom frames and I just wont be able to afford it, maybe before the turbos go in I would switch it over. it is a C channel but it has a Curve on the bottom edge that was supposed to add 30% to the strenght, I was always expecting to put in additional cross tubing for support, should have mentioned that i guess, and now that I thought about it for safety and security boxing is the best I can do right now with the x type crossmeber system. I was going to do one like the attached picture. Plus all the cross members wil be replaced with rectangular and round tube ones. My dad had already put in tube engine mounts and tranny mount and a couple of others. when I get out to the garage to work on it I will take a pic of what he did so far!

Ol racer

Boxing will add strength. Suggest installing a roll cage with diagonals to add more ridgity

Unknown

Have you decided what type of car you want this to be when finished? Will it be a daily driver? Do you plan to keep it at local events, regional, or cross country. Or will it be a trailer queen? The reason I ask, is that if you're not sure you might be able to afford a custom frame, you might not be able to feed 800 horses on cross-country travel. I've got a hi-performance smallblock, with dual Holley's, and have re-tuned the car for economy, instead of performance, because mine will hopefully see Coast-to-Coast.The answer to these questions might help you design your car.

mrsbojigger

Just box it and get it over with. You won't regret it later.
Peace,
Chaz

MikeWA

Even if you don't INTEND to use those 800 horses, no hotrodder on earth can resist just "blipping" the throttle a bit once in awhile- and the "blips" get more frequent, and more intense, until you bend it. Lots easier to box it and reinforce it while it is still straight, and "you haven't broke nothin'" yet.

mrsbojigger

Amen brother Mike!
Boxing the frame is one of the most practical things he can do for his car since it's already torn down. Not that much sheet steel involved and just some cutting and welding. My '47 Ford convertible's frame is boxed. It is so strong that once I had only three wheels on the ground with the other wheel missing. (That's a story for another time though) That car sit there like a dog with it's hind leg raised taking a pee. Now thats strong.
Peace,
Chaz

Browniepetersen

This is the best advice... I am putting a Chevrolet 327-350 (last running engine in the car was a 283 and it was not boxed.) in my 39 Mertz "Hudson" roadster and consider that boxing the frame is a requirment. Even though this convertible has a reinforced and rather "beafy" frame, I would not consider going un-boxed.



mrsbojigger wrote:

Just box it and get it over with. You won't regret it later.

Peace,

Chaz

RL Chilton

I totally agree. Box it and don't worry about it ever again. Beef up the K-member while you're at it. Do it at home and don't fork out 10 or 15K for a "custom" frame. Even if you had none of the equipment you need, the cost of quality equipment is considerably less than buying a custom frame. The knowledge you need to do the job is readily available. You just need the desire, determination and perseverance.

essexcoupe3131

Hi all, definately box it and put in some x framing, check out the 31 frame, did this and it will just about handle most things, by putting the x framing in it will stop the chassis from twisting to bad, if you look at your chassis and jack up 1 corner a watch how far it will twist and thats without any weight into it



Mike

[Deleted User]

how thick steel should i use? was thinking 3 16ths, but most chassis places sell 10 guage for boxing the frame

mrsbojigger

10 Ga. is fine!

essexcoupe3131

I wouldn't you call it insanity, we down under call it fun and try to get as much as possible, cant wait to give mine a bit of curry,cant even help myself even in the company car, got to get that 6 litre screaming so its run in good and proper , Phew lucky Iam the boss

LOL

Mike