Howzit. I'm helping a friend get his '32 frame ready. After placing all the cross members in for mock-up, we're 1/8" out of square on the full length. What is considered acceptable? After considerable monkeying around, I am of the opinion that 1/8" out is close enough for Henry Ford. He thinks it's his rails and wants to replace them. Considering all the components he'll be mounting to the frame, won't he have more than enough opportunity to compensate for what he considers the Grand Canyon gap? Would appreciate any back-up or schoolin'
If that frame is within 1/8 measured diagonally, I'd sure call it square, but then, I'm from Arkansas and lots of things from here are crooked.
!/8" out of square would be too much for me..... It may of been fine for Henry Ford, But what was the original horse power of the 32 to what its going to be when you are done.
Plus or minus 1/8" is probably OK. The closer you can get it to absolute square the better, but sometimes you just can't get therel Plus or minus 1/16" is what I shoot for. It would seem that you could get the cross measurement dimensions little closer. Are both rails exactly the same length? Try to determine where it is off and make what corrections you can. 1/8" is not a lot and probably won't be noticeable. Good Luck!
1/8" difference on the diagonal measure is not as bad as it sounds...having one rail less than 1/16" ahead of the other will cause this.
1/8" is nothing and nobody, nobody would ever notice. I'd bet 1/4" out was an acceptable tolerance for old cars from the production line. Don't sweat the small stuff like this. It won't affect anything in the short or long run.
if you only have the crossmembers in and mocked up...why not weld it in an order so the heat pulls it back into square when you get to that point? theres gotta be something off causing it to be out of square if its all said and done and 1/8" out diagonally i think i would leave it...but if your just mocking it up...why not find the problem and fix it you can try pulling the long side with a ratchet strap to put tension when welding or push the short side with a port-a-power good luck Zach
might spend some time measuring the diagonals on each part of the frame, ie front, center, rear, see if that shows where it's out of whack.
You guys are right, I think we'll hit it tonight one more time and if we can't figure it out, maybe he'll let it go. Thanks again.
Well only you will know its out of wack when the car is finished. Like they say A good carpenter can hide his mistakes.
I'd like to hear from our Pros with jigs/tables (Hotroddrummer,Dirtys,Clark...)as to what they consider acceptable?
GM's new cars have a tolerance of 3/16"....Our tolerance is 1/16" which is actually 1/32" diagnolly, over the 12 foot span, but we try our damnedist to get them to zero.
and what are you actually measuring to (or with) that you think you are going to get an accurate measurement of less than 1/8th?? the variables of the parts you are measuring to are going to be more than that. if you measure to the radiator mounting holes or the front spring pin hole in the front crossmember, what is to say they aren't drilled out of center by a 1/16?? just get it close and make everything else to fit. It's not a big deal. I've raced cars bent like a banana that still handled extremely well as long as you accounted for the bend.
Wouldn't worry about it. My new Ford van was 1/4" out ( on our frame machine at the shop) Just wanted to check it.
I try for 1/16" or so diagonally - this is on a Deuce frame in my jig. A lot of times the holes are not stamped exactly the same in each rail, so be careful what you are using as a reference point in your measurements.
As long as it drives straight and some ***hole isn't crawling all over it with a tape measure, you should be O.K..
I guess I'm in good company with a crooked car, my frame's off by an 1/8th...who cares? as long as your suspension and drivetrain are square, it'll all still roll down the road...
You set 1/2 of one frame rail out in the sun and the rest of the frame in the shade for an hour at noon in August and see where those measurements go... A ladder frame is going to expand and contract and twist more than that 1/8" just from heat differences.
I agree, Shoot, 1/8th on a frame is great. is it on a jig? Perfectly flat? Is it all welded? If you can end up with a frame 1/8th out when its welded, you are doin great. Especially if you are doin it w/out a jig.
i was told my jeep from the factory had 8mm tolerance and they had gotten it to 4mm at the frame shop after the wreck. didn't even have to re-aligned it and that was 120,000 miles ago
I built a Tee ucket in the 70's, the frame was 3/16 out. I worked at a Ford ***embly plant. I asked one of the honchos I knew was a rodder to check a print for a new car. At the time, the frame for a Galxie had to be + or - 3/8. To me, that means it can be 3/4 inch off and still be oK. My car handled great. The adjustability of the raduis rods takes up any problems.
Modern cars are built on a 3mm tolerance, 5mm on frame. 1/8 is a 1/16th out of square. You are as good or better than a modern full frame truck built on a jig by the factory, and yes, that includes those toyota trucks all you jap drivers rave about.
I agree that 1/8 is acceptable. I use my suspension mounting points as a good reference, front leaf pack bolt on the transverse leaf, center of the tierods on the split wishbones, kingpin centers etc. I'm not too sure on the porta power or ratchet strapping the frame till its square especially for 1/8". To me it would "preload" tension into the ch***is. Like if you were to jack up the car near the front tire eventually the rear tire would lift off of the ground. If the ch***is is preloaded the other side may lift sooner or later than the other side. Kinda like oil canning only with the whole structure. Besides what if your buddy spends big $$$ on new rails just to have everything tacked together and have it out by 1/8" or worse?
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