Frame Rail Damage

[Nigel Mulvey]

I've been having a closer look at my project 260Z and not suprisingly there is a bit more rot than first noticed although that hasn't put me off. What is of concern though is that the frame rail on the passenger side has sustained some damage in the past. It looks like the rail has landed heavily on a kerb or similar and there are considerable indentations in the area although there does not appear to be any twisting in the adjacent areas.

Does anyone know if this might be symptomatic of further damage? Are such indentations fixable or has the strength of the car been compromised to the point where I should try another donor vehicle? It doesn't actually look that bad, but I just want to be sure.

Unfortunately I can't provide pics as I don't have a digital camera and my scanner has broken.

[2ManyZs]

I have not seen too many Z's that didn't have some kind of damage to the rails under the floor pan, either from road hazards or someone putting a jack under them (not wise) so yours isn't the only one.

If the floor pans are still straight and the thickness of the rails hasn't been compromised either from the damage or rust you should be OK. The rails aren't as important structurally as a good set of floor pans, but, if they are rusted to the point where you have a lot of holes they perhaps should be replaced. Since by your previous post are going to have the chassis media blasted after you strip it, you probably ought to go ahead and replace them now. I believe you can still get them separately without buying a set of floor pans. They usually are included with a floor pan set, but if your floors are in good condition just replace the rails themselves.

These rails usually rust out from the inside, water and garbage usually enters somewhere in the front of the frame rails, usually in the engine compartment or around the T/C rod mount, and a lot of times the drain holes don't drain out the moisture the way they should.

If you are going to strip the car down to a bare shell and blast it, you might as well replace them now, no sense in having them detract from the rest of the job. Worse yet would be having to replce them in a year or so, if a hole were to develop and have to do the whole underside of the floors again.

[Alfadog]

Where should you put the jack then?

Say a Z has a frame rail which was rusted out from the inside and then someone put a jack undeneath it and the frame rail crumpled right through and put a crack in the floorpan. The rail and floorpan need replacing but not on the other side. How expensive would that job be?