Thread: Gasser susp question

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I'm going the gasser route with my 51 Dodge and building my own subframe. I was going to order some sheet steal and box tubing this week but have a question first. I was planning on 2x4, 1/8 inch wall for the front frame rails. They will be mounted toward the top and I was going to gusset from the bottom of the frame up with the same box tubing. Will this be stout enough to stand up to a few wheel stands? The rear spring shackle will be close to the rear, so I think it should be ok. I'll be running a 8 pt cage, if it was going to be a full cage I'd could run strut bars. I guess I could still do it. I could weld them to a plate and bolt them to the firewall with another plate inside. Something lik,e the early chevy II front clips they sell now. This will have a iron head BBC, so there will be some wt hanging out there. Any ideas or suggestions? This is my 1st gasser build.

Best advice you can take is to make sure you have that front end plumb, square and true. You didn't say what type front axle you are using. Is it going to be a straight tube axle? if so make sure you get the steering correct. The thing needed most is the engineering of this and to make sure all the welds are right.
I have been friends with a local fabricator for 50 years, he's done it all from building street rods to all out race cars and that includes gassers. He's very fussy and measures everything for being plumb and true. And after watching him and just sitting and talking about cars for all these years, it take lots of hands on experience and years of doing this kind of work to truly produce a car that is right.
I just hope if you get stuck at any point you get hold of someone who can point you in the right direction. Remember it's you being behind that wheel, make sure you dot the i's and cross all the t's.

Originally Posted by vht

I was planning on 2x4, 1/8 inch wall for the front frame rails. They will be mounted toward the top and I was going to gusset from the bottom of the frame up with the same box tubing. Will this be stout enough to stand up to a few wheel stands? The rear spring shackle will be close to the rear, so I think it should be ok.

VHT, while your description is undoubtedly crystal clear to you "...toward the top..." and "...going to gusset from the bottom..." leaves a lot to the imagination. Now I'm not a chassis designer, but for me to offer any suggestion on the strength of a fabricated joint requires surety that we're talking apples & apples on the approach, nothing left to imagination. I'd suggest that at a minimum you post pictures of the existing chassis, marked or taped to show cut lines, and maybe cardboard mock-ups of your proposed joints; or maybe dimensioned sketches with a detailed description of how you plan to proceed. No disrespect intended, but like Chopt50wgn says, your life, and the lives of others that you're racing, depend on your design and execution being spot on.

Check out these;
My '56 Gasser
60's style Gasser Willys build | MIG Welding Forum
1960s Straight-Axle Gassers - Giving It To You Straight Up - Hot Rod Magazine
TECH: start to finish custom / gasser budget build. | The H.A.M.B.
Gasser Straight Axle
Woody's Hot Rodz Gasser Chassis - Street Rodder Magazine
GasserPlans.com - Build your own Gasser - the right way!

Originally Posted by 36 sedan

Check out these......

An excellent post, with a ton of relevant info!

So you are wanting to do wheelies with an iron headed big block???????what kinda crash landings/bounces are you looking for????????

You might want to talk with these guys about bending up a frame for you....
Custom Front Frame & Rear Frame Rails | Auto Weld Chassis

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If you look at the 56 chevy in the link posted, that is what I got in mind, only mine will be a little stronger done the way I'm thinking. Don't have pics right now. I was wondering if 1/8 inch wall will be stout enough. You got to keep in mind that the eng will be set back and the rear mount for the spring will be at or behind the welded sub. I will use 1/4 to do the boxing. If I do this, I don't want the sky high stance, so I want to keep the front rails at the top of the stk frame, that'll leave a little over a inch gap at the bottom. I was going to plate it with 1/4, and then gusset it at the bottom if that makes sense.

Originally Posted by vht

If you look at the 56 chevy in the link posted, that is what I got in mind, only mine will be a little stronger done the way I'm thinking. Don't have pics right now. I was wondering if 1/8 inch wall will be stout enough.

Yes.

Originally Posted by vht

You got to keep in mind that the eng will be set back

If you've never moved an engine back, you have no idea what a nightmare it can be. New firewall, move the seat back, move the steering back, move the pedals back, re-engineer the rollcage, yada, yada, yada, but if you're gonna do it anyway, I might consider using front and mid motor plates tied to the frame.
http://s914.photobucket.com/user/bil...t0011.jpg.html
Order specs from SFI for frame and cage building instructions, $38.00....
SFI Spec 25.5C Full Bodied Car Stock or Modified/OEM Floorpan and Firewall with OEM Frame or Uni-Body Construction – 7.50 to 8.49 Seconds; 3,600 lbs. Maximum
http://sfifoundation.com/drag-racing-chassis/

Originally Posted by vht

I will use 1/4 to do the boxing.

Overkill..... 0.188" (3/16") will be plenty.

Originally Posted by vht

If I do this, I don't want the sky high stance, so I want to keep the front rails at the top of the stk frame, that'll leave a little over a inch gap at the bottom. I was going to plate it with 1/4, and then gusset it at the bottom if that makes sense.

Again, 1/4" is overkill. This thing will be heavy as an Army tank.

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There won't be that much 1/4 used, just the pieces around the 2x4 box. Should have been clearer on the engine set back, I can put the #1 plug a inch or better behind the spindle centerline without rebuilding the firewall. With the nova clip I had on there, the engine mounts set a little behind the crossmember. I could do the major set back deal, I just don't really like them back that far. Engine heat, screwed up dash and all the things mentioned above don't appeal to me. I don't like them a mile in the air either, at a rod run Sat there was a 55 chev that set perfect, a Henry J that was 4 ft in the air. I looked at the 55 about 10 times. I should have took pics but I was feeling like crap and didn't think. These damn doctors don't find out something soon, I won't be building anything.

Your 4" x 2" will be just fine, if your concerned about the joints weld on 1/8" fishplates on the joints. If your using a straight axle it wants to be minimum 2" OD x.250" wall seamless tube.

Ok, finally found a axle, suppose to be a 57 chevy, 1/2 ton truck, complete. Going to ck it out this coming Sat. Width will be perfect for this old dodge. Hubs are on it, so that'll be a plus, the spindles won't be all rusted up. Disc brake change over is available. I wanted the truck axle, I think it'll be stouter than Speedway's and it is dropped some instead of strait. Also bought a 8.8 out of a explorer, disc brakes, 3.73 limited slip. I'm going to cut the long side 3 inches, that'll center the pinion and give me a 56 1/2 rear end.