Quote: <TABLE border=0 cellSpacing=0 cellPadding=6 width="100%"><TBODY><TR><TD style="BORDER-BOTTOM: 1px inset; BORDER-LEFT: 1px inset; BORDER-TOP: 1px inset; BORDER-RIGHT: 1px inset" class=alt2>Originally Posted by benno Ok first if I were you find out the carbon content of the chassis or someone might know, then use the appropriate welding rods , you might need to pre- heat the chassis , weld then slowly let it cool down. You have to get it right or it will crack again. is there any truck chassis manufactures nearby? Take it to them .Ben. </TD></TR></TBODY></TABLE> Shit. Do we now need to be scientists instead of Hot Rodders? <!-- / message --><!-- sig -->__________________ Nope, and carbon content and preheating is a waste of bandwidth on a mild steel tube frame. BUT you do need to know thay you've created a perfect stress concentration. Especially if the cutout only goes partly down into the frame tube.
WTF where are you coming from!!! This is a car frame not a NASA product. Look under your own daily driver and see some of the welds.They all work. Look at the welding on race cars at the track.
I would probably plate the inside of the frame in that whole area with a C shaped piece that was made to fit internally. Could be done in three 1/4" thick pieces to build it, and then fit inside and both plug welded and edge welded. Then the notch for the fuel pump wont have to support a thin frame area.
Ever notice that the stiffness of an empty soda can drops significantly, when you put a dent in it ? Same idea here. The notch weakens the frame, and the flexing is concentrated at the weakest point.
I agree with 1971. It should have boxed on the inside first then a cosmetic piece can be formed to cover it and those welds could be ground. The square tubing flexes, that 1/4 or 3/8th wall pipe standing on end won't.
Letts see Welded without a "v" or ihe's fficient "v" then ground flush removing all the weld instead of leaving it in the "v". Welded too cold . Poor design lacking internal stiffening measures ???? ( can't see that now) Too much flex in that area requiring redesign. I'd put my money on first or second , maybe both. Mig welds love to crack when ground flush, extra care needs to be taken to prevent it. Holding a gap , proper joint prep, proper machine settings, they all play a part. Going to an electric pump would eliminate that problem. But fixing it with a internal patch and good weld of the pipe section should do it. I'd give you a hand , but its about 8 hrs drive.
I'm with going electric, and reboxing to the original rectangle shape......... Be sure to stop drill the ends of the cracks to prevent further crack progression. 4TTRUK
I would be surprised if the frame was made from anything other than ordinary low carbon steel. On the other hand, this discussion pushed one of my buttons. An I'm not a scientist so I don't need to knew that shit attitude can get a person in trouble. I think that if the time ever comes when we aren't allowed to build or modify our cars it will be because some just run er knucklehead mows down a bunch of kids in a school crossing and ends up on the national news. In some countries it's already illegal to do much to a car, and in a few states there are already lots of restrictions. When I hear someone say "f that shit" when someone tells them the the right ways to do something it tells me they are either too stupid to understand or too lazy to do it right. Examples of what one person or another has gotten away with doesn't mean some is a good idea. Whether or not one is a physicist or scientist, the laws of physics apply to everyone. While it's possible to get by with some things some of the time, asking for trouble is the easiest way to get some.
Use a 1/16" drill at the very end of the crack to prevent it from spreading...grind off the paint...weld. And lose that mechanical pump and fill the hole with a custom made filler piece.....make sure that the welds are hot enough and that you have good penetration...grind them smooth when finished....BTW, that's a nice little T you have...I'm a big T fan from 40 years ago....sure do hope you can get her fixed.
Should be lots of rod shops and welder/fab shops in PA. Find one, and get it fixed. And have them check out the rest of the welding on this thing.
You asked for comments. Are you just being sarcastic, or are you actually upset that some posted things you didn't want to hear?
Sorry, didn't mean to sound sarcastic at all. I see how it could read that way. Hard to put emotion in print. Just a lot of choices. I wanted to hear them all. I REALLY meant the THANKS!! Looks like get rid of the manual pump, put in electric, repairing the area and some boxing of the frame rails is the most popular. At least short of a new frame. Bill
I wass just thinking, if you were going to get rid of that POS I wouldn't charge much to haul it away.
Well you may be right but I think you "over reacted" to a "tongue in cheek" comment. Regulations to car mods are very tough here in New Zealand so I doubt very much that I am going to do some half assed welding just to get it knocked back by the Authorities. But come on, Carbon content testing and truck chassis specialists??? And I never said "f that shit" .. I said Shit. Huge difference in meaning. Right, I've said my peace.
The problem is that with the C-notch not leaving much metal width on the top and bottom of the rail that section becomes unstable and subject to severe twisting under load. I would get rid of that C-notch and put an electric fuel pump on it for piece of mind.
I need to add a thing or two here. I know the car fairly well and have a pretty good working knowlegdge of frame fabrication. I think a bunch of guys here are missing some things which are posted in the pics. The "notch" does not go all the way through the frame. It is a kind of cone shaped affair that cuts through the top rail and stops a bit before the bottom of the rail. The frame is constructed of 2x3 rectangular tubing, most of these are 3/16 wall. This is plenty stoudt for a car that most likely weighs in at under 2000 lbs. Because the bottom of the frame is in compression and the top is tension the cone should be pretty close to the same strenght as a straight rail, if not stronger, if of the proper ga. and correctly welded. The obvious failure here is overzealous grinding of an improperly prepared weld with inadequete penetration. If the weld is v cut and properly welded it will be good as new. The mechanical pump works a lot nicer than the electric so why lose it? In theory, most T's shouldn't be running hairpins with a tube axle or the same in the rear but because of the limited loads on them you can get away with a lot more than on say a deuce, which is much heavier. My 2 cents.
^^^^^^^^^^ That is 100% accurate. All it needs is someone who knows how to prepare metal and how to properly weld. It held up 6 years the way it was, so it will last a lifetime if someone does it right. Don
The bottom of the frame is actually in TENSION, because all the static load is from the top. While the ultimate strength of the frame may be sufficient, the stiffness is not the same as a straight rail, because the Section Modulus is reduced.
Sorry if you or anyone else thought what I posted was aimed someone in particular, it wasn't. It was just general comment and observation. Every time I go to a decent sized car show I see at least a few things that shouldn't be on the road and it bothers me. I am definitely for people doing as they chose, but not when it might injure someone who was just minding their own business.
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