Notching frame rails
 

I need to notch the frame on my '62 Catalina where it kicks up over the rear axle. Trying to make room for my 275-60x15 Yokahama's. They hit the frame from about half way up on the tire but look like they'll clear at the lower half. Can I slice an inch or two out of the farme and box it with steel plate? Will this weaken the frame at that point? What gauge steel should I use? I really don't want to narrow the frame and rear if I can help it. Thanks, Doug.

I've done alot of that type of frame notching....my rule was never go more than halfway thru....I always used 1/8" mild steel plate to fill back in and weld everything, will still be plenty strong.

Thanks. I think I will be removing less the half the thickness but I will double check to be sure.

its never advisable to drill ,,cut the frame radius

So you're saying I should do a conventional narrow job, i.e. cut the frame in front of the kick-up, or go back to the narrower wheel and tire setup?

I'm just going off my own experience, I built drag cars for 15 plus years, did a ton of minitubs and such. Never had any problems notching the frame, yes if you butcher it up and don't properly replace what you took out you could have problems, if you put it back right you will not have any problems.

if the sides are being notched then thats different,,but the radius isnt from my teaching supposed to be altered
its tensile steel and even heating it up tends to harden it .
of course if the repair is done well enough it will last but it will be more rigid there than designed to be

That makes sense...my understanding is he's just notching into the side of the rail, and if that's so there really shouldn't be any problem at all. I wouldn't be afraid at all to do it. If you're just trying to gain an inch or so, that is the ONLY way to do it, cutting and moving the entire frame rail in is an extremely time consuming process, plus it seems like you always get into a body mount or have to modify a crossmember or two to do it. Those old cars are built with frames from hell, many of them are 4-5" wide (overkill) Cutting and boxing back in PROPERLY will be just fine. I recently did a 87 Monte Carlo where I cut the entire outer half of the frame rail in the wheel well off and moved it in 1 1/2" (reused the factory piece) it was still plenty strong and looked good when done.

It will be fine,use the 1/8 inch plate like suggested. I work part time as a fabricator at a chasis shop and we notch frames often for mini tubs and have not ever had a single problem even with cars running sub 1.3 60 fts.

has anyone seen the frame rails on a new isuzu truck?
so many holes drilled in it you can hardly place a dime in between holes
in one 3 ft. section i counted nearly 30 holes

I've seen some pretty swiss cheese frames before, old super stockers and such

Well, if it doesn't work maybe I'll go nuts and back-half it...naw! I think I'm gonna give 'er a whirl. Thanks for the input guys.

You could also add addition plates over the sides of the rails after notching to give wall thickness & strength.
Doug

heres how i did my minitub . i was going to notch the frame but decided to make new rails , weld them in then cut out the old.

here's a pic of mine, sorry it's fuzzy and upside down, but you can see how the frame's been sliced out and the original outer piece bent in and re-welded. a shop did this.