X-Ray view of internal body cavities 240Z

[Mikes Z car]

Hi,

Does anyone know if there is a set of X-Ray type views of various parts of a 240Z or pictures that show these areas with the outer metal surface removed? I am particularly interested in the lower part of the dogleg just in front of the rear wheel and other rust prone areas as I am thinking of packing those areas with chassis grease (poor man's POR-15) to stop it from rusting. I lost my last 240 to rust don't want to lose my current car that way.

Thanks!

Mike

[Seppi72]

Here are two pix of the structural steel on the inside of the rocker panels. One of the front end and one of the rear. I hope they help you.

However, you must know that there is undoubtedly at least surface rust on all these bits. If I were you, I'd figure out a way to bathe these parts in Ospho to convert the rust and then apply a two-part epoxy or polyurethane coating to them. You'll have to remove the seats, dogleg finisher panels, sill plates, and pull up the vinyl covering to expose all those lovely access portholes. It's a bit of work, but surely worth the effort in the end.

[beandip]

First off I wouldn't pack the area with grease. Moisture will still find its way under it and rust the metal. There is a design flaw , in my estimation, on these cars. It is the cowl drains. They drain water and dust/dirt and all sorts of stuff inside the front fender just forward of the doors. It just pours down and lands in the cavity and is supposed to find its way out the drain at the bottom. The major part of the water does, but the dust/dirt and leaf particles lay down at the bottom and rust out the lower part of the fenders. Also this is the front end of the rocker and this is exactly where the crud lands and eventually rust a hole in top of the end of the rocker. Now water pours in the rocker and travels back and attacks the dog leg as well as the whole rocker. This is a EASY remedy. Buy a 45* 1''PVC elbow at the hardware store and a length of clear vinyl hose of the size that will tightly slip into the elbow. I used silicone to seal and hold the parts in place. The PVC elbow will just fit inside the drain at the top where it enters the space inside the fender cavity. Cut the hose so it reaches the drain provided at the bottom. Now with the parts secured with the silicone your done. From now on when water drains out of the cowl it will just go out the bottom along with all the crud. Thanks to escanlon for coming up with this fix.

Gary

Edited June 9, 2009 by beandip

[Mikes Z car]

Here are two pix of the structural steel on the inside of the rocker panels. One of the front end and one of the rear. I hope they help you.

However, you must know that there is undoubtedly at least surface rust on all these bits. If I were you, I'd figure out a way to bathe these parts in Ospho to convert the rust and then apply a two-part epoxy or polyurethane coating to them. You'll have to remove the seats, dogleg finisher panels, sill plates, and pull up the vinyl covering to expose all those lovely access portholes. It's a bit of work, but surely worth the effort in the end.

Thanks for the dogleg pictures, they are very good. I may have to make a new hole inside the car to gain fuller access to the dogleg; the porthole there may not provide enough. I pulled the inside finisher back a little and looked with a flashlight through the porthole; no surprise, I can see rust in there. I bought some long skinny brushes at bed and bath that are on steel twisted wire that can be bent into different angles. Good idea on ospho; it would be a good thing for this area. I'd love to get a camera in there with a light on it.

[Mikes Z car]

Hi Gary,

I just noticed the quick reply option.

I have seen an old VW rabbit that dumps the cowl water into the engine compartment on both sides in front of the floor pans. The z has enough trouble with floor pan rust already though. I will follow your advice on the cowl drains. I plan on using grease on top of some other treatment, ospho and/or rust bullet/ POR-15. Not sure what is best approach for difficult to access areas like air vent in cowl area, hoping long skinny brushes can reach where my fingers can't.

Mike

[=Enigma=]

Forget the grease. Just drill small access holes and use a long spray wand to treat the area with metal ready and then coat it with POR 15. If the area has any oil or grease on it it's probably best to use Marine Clean as well but this is really optional for hidden away areas like the interior of rocker panels or the inside of frame rails, etc. There's no need to put anything on top of this coating unless it will be exposed to UV light. Even then it's not absolutely necessary unless you care about it changing color.

Edited June 13, 2009 by =Enigma=

[Mikes Z car]

Hi Adam,

Two people I know have backed you up on the idea of forget the grease, both have worked with aircraft and have noted grease turns milky white when it absorbs moisture. Getting the POR-15 in the dogleg cavity will require a dauber of some kind and an inspection mirror. I may try home made wax oil afterwards to protect what I can't get with the POR-15.

Thanks for the info,

Mike

[=Enigma=]

Why not just spray the POR 15 after properly thining it according to the directions? This is actually what I was suggesting. I've not tried this but perhaps someone has and can comment.

[Seppi72]

There's a good article in the August 2009 issue of Grassroots Motorsports (page 101) regarding how best to treat rust. This is the issue with Pete Brock and Datzilla on the cover and a great article on 240Zs from stock to wild on page 40.

[Seppi72]

When I treated the nooks and crannies (like the frame reinforcing channels that run under the rear half of the chassis) of my other '72 with Ospho last year, this is what I used.

I took the aluminum spray head from a device that is intended to shoot undercoating in a sideways pattern (it's just an aluminum end cap with 1/4" internal pipe threads that a narrow slot cut into it about halfway up perpendicular to the axis) and mounted it on a brass fitting that was 1/4" outer NPT on one end and a hose barb on the other. I hooked this up to a flexible PVC tubing of an appropriate length and the other end of the tubing was hose clamped onto the pressure pot outlet (straight metal tubing). I also hose clamped a length of flexible, stiff wire (like metal coat hanger wire) to the PVC tubing at the hose barb end and taped the tubing to the wire every few inches so the geometry was locked in.

I could use the stiff wire to push the spray head to the desired location. I then had a friend trigger the pressure pot (determine beforehand the pressure that gives a decent spray) while I twisted the assembly clockwise and then counterclockwise and slowly withdrew it from the cavity. I did this a couple of times to ensure complete coverage.

I don't believe that PVC would be compatible with the solvents in POR-15 so you might have to use polyethylene (PE) tubing. This could be even better as PE tubing is stiff to start with and the metal wire might be unnecessary.

[Mikes Z car]

Bob,

If Ospho is thin like water I wonder if an ordinary windshield washer and reservoir off of a car from a salvage yard could be used as a sprayer with your setup? Maybe a windshield spray jet from that same car could work for the sprayer if bent properly. I looked up pressure pots, I will need to figure out something cheaper. I also have wondered if I could use an ordinary drill with a long stiff wire in the chuck with a skinny brush on the end that could be dipped in Ospho or POR-15, inserted in the frame rail or other cavity and then spun as it is withdrawn? I don't know if that is workable for POR-15 if it is too thick but it is cheap.

Thanks for the pointer on the magazine article I plan on getting that issue.

Thanks,

Mike

[Mikes Z car]

Gary,

The cowl drain mod sounds like a great idea. I will do that mod when I take the front fenders off to put some rust preventative on the inside of them. To prevent leaves from clogging things up on the cowl drains I plan on laying a screen (painted black to hide it) right under the cowl so I can pull the leaves off of the top of the screen and keep them from falling further in and clogging up the drains. Hardware cloth might be better than window screen. May as well do that as I finish up doing the the windshield wiper motor replacement (from a Honda Accord) that is ready to be installed and sitting on the workbench.

I wish I had known all of you when I had my first Z, I would have kept it and stopped the rust.

Thanks,

Mike