dimsum

Success! The engine and transmission are out, and the car is ready to go in for frame work. Thanks for all the help.

I went around to get some quotes today. A good number of shops aren't even interested in touching a job like this. The quotes I received were for cutting out the old floor pans and frame rails and welding in the new ones. The two quotes I was able to get were for $2500 and ~$2100. The ~$2100 quote includes sealing the seams and applying another sealant to the frames and floor pans. However, he wants to see the car next week before giving me a firm quote. I do not know if the $2500 quote includes sealant. However, this vendor did see the car and parts. Both shops will put the car on a frame rack to make sure the car stays straight. Does anybody know if these prices are outrageous or reasonable for this type of work?

Careless, If you have time, I wouldn't mind seeing what you have in mind. I think I can picture it in my head, but I just want to make sure. Can you also explain the "primitive methods?" That kind of work sounds right up my alley. Thanks.

The car will mostly be street driven with a little track time, so I don't think a full cage is practical. I have a roll bar in there right now bolted to the rear wheel wells. I have been reading up on strengthening the rockers, but so far everything seems beyond my abilities. It sounds like the additional steel would just be extra weight. I was thinking they would strengthen the frame rail walls. That way, if I jacked up the car by the rails, the rail walls wouldn't crush.

I spent last night examining my new BadDog rails (front and rear) and how they fit on the car. I wish the front and rear pieces came as one piece, instead of two, so they were a little more rigid. After looking at the rails, I tried to think of ways to make them stronger, like Pete's. I thought about adding a long, steel box, sandwiched between the BadDog rails and the floor pan. If this long box ran the entire length of the car, it would eliminate the seam between the front and rear sections. I drew up some crude pictures that are not to scale, but should hopefully clarify what I was thinking. Cross section of rail and additional box: Side view: This wouldn't make the rails as strong as Pete's design, but it would be an improvement. I'm not a metal worker, only have rudimentary statics knowledge, and am basically thinking out loud here. Please provide comments and thoughts.

Thanks to everybody for the information. Just to clarify, I can either put a bolt in the green hole, or use the bracket circled in orange, to lift the front of the engine?

Sweet. Thanks.

I don't think you can use that top bar to mount a racing harness because the harness belts would come down at too steep of an angle. While the harness would fit physically, it would not be safe. In this thread, Mikelly explains that the straps, "...should be at a 45 degree angle below your shoulders. They need to be anchered below those holes in the seat BIG TIME..." http://forums.hybridz.org/showthread.php?t=116804&highlight=racing+harness I have a roll bar without a bar running behind the seats to attach a racing harness to. I, too, thought about attaching the harness to the upper bar until I did a little research.

I have an L24 block. The picture shows the front (fan) end of the passenger side. Can anybody help me identify the two holes circled in green? They are the same size and thread pitch as the intake/exhaust manifold stud holes. When I bought the car, nothing was attached to these holes. Specifically, I want to know if I can put a screw in those holes and use it to hoist my engine out of my car. Any ideas? I am hoping to attach the chain to one of these holes and two manifold studs on the driver's side to lift the engine. Is that a good idea? Also, what is the plate circled in orange? Does the hoop serve any purpose? Thanks.

If you remove the bars you erased in the picture, it would compromise the effectiveness of the roll bar in an accident. The resulting bar would offer you some protection in the event of a roll over, but I wouldn't use it for extensive track time. Any strong lateral impact could bend/collapse the upper bar without the additional support.

Thanks, all, for the reassurance. I was hoping there wouldn't be any problems, since the clutch still looks and feels structurally sound. I'm planning on getting a lightened flywheel of some sort to go with this clutch. I'm still trying to research the pros and cons of aluminum vs. steel.

I just bought a "brand new" Centerforce Stage 1 clutch. Although the clutch has never been installed or used, it was originally purchased in 1994. The guy sold his Z years ago, but he just found the clutch in his garage. Can anybody tell me if this clutch is safe to install and use? Although there is some minor surface rust, it is easily removed with some steel wool. Can anybody think of any problems I might encounter with a clutch this old? Thanks.

Woo hoo! Baddog rails and Zeddfindings floor pans just came in yesterday. Very exciting. I'll post pictures soon. My friends have been recommending that I put the car on a frame rack when I get the frame rails welded in. Is that necessary, or can I get them welded in with the car on jack stands?

Wow. That site is a lot of information on wheels and tires. I just added it to my favorites.

Does anybody have the maximum dimensions for a seat that will fit in a 240Z? I think the main constraints are the width of the hip area and the shoulder area. I'm sure the maximum shoulder width depends on the height the seat is mounted as well.

That makes a lot of sense. The rear section of the rails aren't supported very well at all. I just put an order in for some BadDog frame rails and Zeddfindings floor pans. Thanks to everybody for the recommendations. I think they are my best option since I don't have experience with metal work. I'm excited to get them in. My bank account, however, is not looking forward to it.

Careless, thanks for the encouragement. I'm still very excited about this project, dispite the unexpected rust. I have to agree that even if the car was in better condition, I would want to improve the frame rails and floor pans. Right now, my restoration plan looks like this: 1. Remove everything from chassis. 2. Prep for welding. 3. Repair rust and weld on frame rails and floor boards. 4. Spot weld chassis. 5. Paint. 6. Re-install engine, drivetrain, and suspension. 7. Restore interior.

A few questions in reference to the original post: How do you improve or ensure good brake release? Is it as simple as keeping your calipers clean? I've read in multiple places on this forum, including this thread, that stock 240Z brakes are sufficient to stop the car in both street and track situations. Does this theory apply to the stock 240Z rear drum brakes? I always thought that a disc setup was a significant improvement over drum brakes based on the mechanics of disc vs. drums. Or, does this theory only apply to the front brakes?

I finally grabbed pictures of the main rust spots on my Z. Just a warning: they're not pretty. Please feel free to give me your opinions on this project. This is all on the passenger side. I'm not sure if the previous owner drove over something or not, but it looks like the bottom of the car hit something hard. And then there are these two rust spots that aren't on the floor pans or frame rails. Here's a closer look. This is what I get to look forward to for the next few months. Yay.

I agree with Mike. It looks like you're making progress. I'm jealous...every time I look at my car, I wish I knew how to weld so I can stichweld my frame to stiffen up the chassis. My friend was just explaining to me that you can drill through existing spot welds, re-weld it, and grind down the excess weld to also improve stiffness. Trying to do more research on that process.

With respect to numbers 4, 5, and 6: I think lighted pistons, crankshaft, and rods will be more beneficial in increasing engine RPM. The lighter these components are, the faster your engine can spin (higher redline). In my view, the benefits from lightening your engine internals differs from the benefits of lightening your flywheel and wheel/tires. But, I guess it all comes down to making your Z faster.

This is an interesting thread, so I thought I would add my two cents. As people have said before, the equation to calculate torque is: distance * force which nets you a unit of ft-lbs. If you are rotating something around a centerline, the amount of torque you need to move it is dependent on how heavy the item is and how far away it is from the centerline. Bringing this back to the discussion of flywheels, weight removed from the outside (closer to the outer edge where the teeth are) of the flywheel will make a bigger difference from weight removed from the center of the flywheel. Based on the equation, the distance from the center of the flywheel to the location of the mass affects the torque required for rotation. This same concept can be applied to the drive shaft. However, I think rotational speed also comes into play with the drive shaft, although I'm not sure how it fits into the equation. Time to do more research.

I'm working on removing my engine and transmission from my '73 240Z as well. I figure the drive shaft (propeller shaft) will slide right out from the transmission, but what is the best way to get it back in when it comes time to re-install everything? Is the best way to unbolt the drive shaft from the rear differential? The only way I can figure to do this is by removing the lower brace on the rear diff. Is this what I'm supposed to do?

Thanks for all the suggestions. I have been looking at the pictures of both the Zeddfindings rails and the Baddog rails, trying to figure out what the differences are between the two. I'll give Z Car Garage a call this week and see if they can do it. I've been talking to some auto body shops. Some are interested, some are reluctant, but most are expensive. Grrr.

Jon, now that you've completed this step of your project, would you still recommend using the cut-off wheel as the best solution? Also, would the wheel work for cutting the floor pan welds to remove the pan? Thanks.