Structual crack or minor damage?

[REBELUTION]

Fist time poster, but have been using this invaluable site for quite awhile on my build. Quick background…. I’ve done a few minor builds through the years, but nothing with a unibody design. Got a hold of my Buddies ‘76 280z and during the teardown, found way too much rust to deal with, (He had it tarped in his back yard for 8 years in Florida!) I then located a nicely priced ’74 260z shell. I started in the rear and have replaced every spec of rust with solid metal. As I just moved up to the front end, I found a horrible looking tear/rip/crack on the passenger side inner fender! The Engine frame rail on that side is in good shape, but front 8 inches of driver’s side engine rail is rusted out.

I’m building this as a Resto/Mod with a Ford 302/T5 power train.

My question is… can ya take a look at the pics and tell me if I’m dealing with some catastrophic structure failure, or would simply welding up the tear/rip/crack suffice? Any ideas as to the cause?

BTW- My ’76 was fully equipped, with newly rebuilt tranny and freshly rebuilt L28 engine…. Body parts are pretty much trashed, but trim/interior and such were in OK shape…. Get with me if you need some parts.

Thanks. KRIZ

(Tilt your head 180 to the left in order to properly view the first photos )

Edited July 20, 2010 by REBELUTION

[Geking]

Does it look like the suspension on that side has been replaced? Would you really want to spend the time and money on a car that was through something so major that it tore the unibody of the car? I am by no means an expert, but I think that if someone hit something on the passenger side wheel hard enough it might cause that damage. I would bet good money that the frame of that car is not straight and it would take more than it is worth for a full restro mod, esp with the added abuse of a V8 car.

[bobbyc]

if it were my car...and everything else was straight...i would pull the crack flush and weld it up...then put a plate over that and weld it up.

[johnc]

The front clip of the car is tearing off. My guess is that the car was in a bad wreck and someone did a crappy job of welding on a replacement front clip. Junk the chassis and start over.

[JMortensen]

Do you really think that is a write-off John? He said he had driver's side frame rail issues. If he was willing to cut out and replace both frame rails, then it seems to me that the fender well could be fairly easily cut and patched as well.

 

I had a crack in just about the same location but it was only about 1/2" long. I welded it. Not sure how long it takes a crack like that to propagate but I had autocrossed my car on slicks for years and done some track days with it so it was ridden hard and put away wet for a long time.

[REBELUTION]

Ouch! I thought I did a thorough walk around on the car prior to buying it. It was only after I put it up on jacks and took off the fender, did I notice the crack. It looked like just a ripple with the undercoating covering it. Only evidence I found of a prior collision, was semi-minor damage to the rear passenger side fender, as if the car had been backed into something. Since I'm positive the clip has not been replaced, there are no other signs of major damage, and I have serious sweat investment already, I'm gonna roll the dice and go with a new set of rails. I'll hammer and dolly the crack back into shape and weld with a brace. Afterwards, I'll take it to have the alignment checked prior to any other investment. Thank you all so much for the advice! We'll see how it goes.....

[johnc]

Do you really think that is a write-off John? He said he had driver's side frame rail issues. If he was willing to cut out and replace both frame rails, then it seems to me that the fender well could be fairly easily cut and patched as well.

 

I had a crack in just about the same location but it was only about 1/2" long. I welded it. Not sure how long it takes a crack like that to propagate but I had autocrossed my car on slicks for years and done some track days with it so it was ridden hard and put away wet for a long time.

 

How much longer then 1/2" is the crack in the picture above? Its probably 11 1/2" longer then the one in your car and is beyond the frame rail and making its way up to the upper front frame horns. And the crack is on the good side (non-rusted frame rail side) of the front clip. That means both side of the front clip are compromised.

 

If the car from the firewall back is good then replacing the front clip is an option but, IMHO, if I owned that car I would scrap it and if a customer brought it in for me to repair I would clip the front after trying to talk the customer into buying a new, good shell for $1,000 or less.

[REBELUTION]

Hmmm, Let me add one other thing that may or may not make a difference. When I purchased the car, the prior owner had just replaced the floorboards and cut out the floor rails, which are still missing. Without the floor rails present and the driver's side engine rail rusted, could I have possibly caused the crack while putting the car up on jacks (I lifted that side first)??? Reason why I ask is, although it was hidden under the coating, the crack appeared fresh when I looked at it from inside the engine bay.

[jbehuniak]

I work on blackhawk airframes for the army and the biggest thing I've noticed is when we get a crack, fix and strengthen it, a crack starts somewhere else. Notably the helicopter is subject to thousands of vibrations and has a brittle aluminum frame. The point I'm getting at is if you fix the crack and then put the new rails on and floors in, what are the chances of that part being too strong and weakening possible cracking, bending or twisting another part of the car especially with the added TQ of a V8.

Ya the helicopter has 2 1700ish hp engines and weigh around 18000lbs but it was once designed for that back in the 70's. Todays aircraft we are finding out the mod's they did 10 years ago are screwing different parts and the fixes we are doing today we are looking for the effect tomorrow. like everybody on here likes to say just my $.02

good luck with it and youve come this far already, make it good!

[hoov100]

I would at the very least put a new frame under it, front to back.

[REBELUTION]

AAAAARRGGG! I do thank ya all for the advice and input. I've put too much sweat into this car to trash it, coupled with the difficulty to find a good shell at an affordable price, here in Florida, I'm going to go head with the project.... I'll keep ya posted.... Thanks you again