73 Rust Issues

[kyletilley.com]

Morning all, I've tried searching but can't see the answers I'm after. Maybe Americans word it differently!

 

My 73 240Z has some fairly major (in my opinion) rust issues. Putting a new floor and a pair of the Bad Dog frame rails on doesn't phase me. I am however a little concerned about the corners of the transmission tunnel and that the front chassis leg has a few little holes in where the subframe bolts on has a few rust holes.

 

I've attached some pictures, from what I can tell it needs new floor pans, frame rails front and rear, both sides, and the work doing on the front. If I've missed anything please say! Be good to know your thoughts on how to progress.

[lazlo]

You have some pretty serious repairs ahead of you if you are going to make the car safe. My guess is that you probably have some other rust hiding that you can't see right now.

 

You are going to need to pull the lower interior to get at the floor pans, you should remove the doors first to get them out of the way, and then you are going to need to drop the front assembly to do the work on that section....which means that the motor and tranny have to come out.  Make sure and get good measurements on everything because the bolt holes are going to have to line up when you put it all back together.

 

Others will have differing opinions, but I think that you want to treat this as a single project and not split it into pieces.  The work will be cleaner and easier if you have everything out of the way.  I would also tack in some temporary braces in addition to getting good measurements, as things will start to move as you cut out the rust.

 

At the end of the day, it is just steel.  Try searching youtube for some videos of how others have repaired similar issues.  The general principles are the same and you can get some good tips, even if the subject isn't specific to Z's.  The key difference between a Z and a lot of the muscle cars that people restore is that the Z is a unibody design, and you need to keep this in mind.  With an old hunk of detroit steel, you can typically just separate the body from the frame, here they are integral to one another.

 

Take your time, make a plan, and don't get discouraged.

[kyletilley.com]

Thanks for taking the time to reply. It's a little daunting, but I've got a welder and I'm not afraid to get stuck in!

As I said, my primary concerns are the corners of the transmission tunnel, (any one have an idea of the best way to tackle that?) and the subframe mounts. I've seen a lot worse in Datsuns so I'm hopeful I can save it! I've had it up on ramps and poked around, it doesn't APPEAR to have any hidden rust.

[rturbo 930]

What does the rest of the car look like? With rust that severe, I'd check over the rest of the car before doing anything.

[kyletilley.com]

I've gone over the car extensively. The exterior of the car is in good shape. I've ripped everything out of the inside and there are is no rust or holes. Strut tops are in good condition, no rust on the boot floor etc. Just the areas mentioned. Thoughts?

[LowCarbZ]

In my opinion that thing is going to have to be torn right down to just the chassis and you won't find out just how much rust there REALLY is until you start cutting stuff out and seeing where it ends.  

 

A total ground up is the only way to justify putting that much work into that car.

[kyletilley.com]

That's what the plan was. It's an ex race car, that I bought knowing it needed a truck load of work. It ended up getting stored outside for a year and I think that took it's toll.

 

I've undertaken partial rebuilds before on a mk2 escort and a sunbeam lotus. But this is a little more severe. Any tips, advice, constructive criticism always appreciated!

[lazlo]

Considering you already have the tools and experience and a plan to do a ground up, I'll go out on a limb and say that a lot of the questions will answer themselves once you are going.  I have seen several examples of people cutting out the front frame and starting with fresh steel, and the trans tunnel looks like it will probably be sheet metal work for the most part.

[johnc]

Here on the west coast we would strip that car and scrap it.  If you've done rust repair on an old Escort and an old Lotus then the S30 should be a piece of cake.

[kyletilley.com]

Hey John,

Yeah, I appreciate that. However EVERY shell I viewed had rust problems most that the owners didn't even know about. Admittedly I could have made life easier for myself by purchasing one with a little (a lot) less rust. But if I was going to have to cut bits out and weld new in, it makes sense to do it all and do it all properly rather than having to do just patches. This is what I keep telling myself anyway! We'll see how it goes....

[motomanmike]

How much do you have in this thing? Not trying to be rude  and if you don't want to answer I totally understand.

Edited August 15, 2014 by motomanmike

[rturbo 930]

Yeah, I think everyone has their limit with what 'too much rust' is. When the engine bay frame rails are rusted out like that (not just the TC mount reinforcements), for me, that's too much rust. If you want to tackle it, go for it, but otherwise, scrap it and start over. I'm from NJ so I know getting a solid car isn't exactly easy, but I still think you can do better than that.

[mtnickel]

Yeah, I think everyone has their limit with what 'too much rust' is. When the engine bay frame rails are rusted out like that (not just the TC mount reinforcements), for me, that's too much rust. If you want to tackle it, go for it, but otherwise, scrap it and start over. I'm from NJ so I know getting a solid car isn't exactly easy, but I still think you can do better than that.

 

I had very minimal rust restoration experience starting my Z, but I can certainly say i'd agree with the above. Unless you have a great passion for metal work and the space and time. I bought my 74 Z for roughly $2000cdn and it needed the typical areas (pans, doglegs, battery area/firewall, etc). The more I dug into it, the more I figured I should have stripped the shell and done had it blasted, but I dont' have the means or time or space to do such a thing.

 

If I was to do it all over again, I would troll the desert area craigslists (phoenix, palm springs, nevada, etc) and spend 5-10k on a much much better starting subject. Sure its a lot of money, but you gotta factor all your time and parts in.

 

But all the power to you in whatever you decide!

[kyletilley.com]

Thanks for the replies guys.

I've got $1000 in the car.

I have to admit that the car is far more rusty than I realised. However whether through either stupidity, bravery and misplaced faith in my own abilities I'm going to keep at it with the car. A fabricator friend of mine recommended cutting the entire front end off and tubbing it. It already has a weld in cage so I could triangulate the front section into the cage. This is my favorite option right now.

[rturbo 930]

A tube frame? Check this out then, post 12.

 

http://forums.hybridz.org/topic/54629-front-tube-chassis/

 

More pictures in his album here

 

That said, I think that's a bit overkill, unless there's a lot more rust that you're not showing us. Replace the frame rails with some square tubing and call it good.