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MG MGB Technical - Need floorpans and trunk floor.

I am helping a friend restore a 71 MGB and it needs new floor pans and trunk floor. I have access to a donor car with good parts. I would like to know if Moss or VB panels are worth the money or should I use the ones on the donor car. After restoring 2 MGA's, a mgtf and an Austin Healey 3000, I have come to appreciate how important correct fitting panels are. Thank you for your help.

John
John Progess

John,

I've welded in several aftermarket floor panels and one boot floor. They all fit well - with little or no fussing. Also, I've used parts of floor panels on a couple of occasions and found the alignment with original panels to be excellent. I've seen the same consistency with sills, rear quarters, etc.

I've had problems with aftermarket bonnets. Ultimately, I used them on drivers, knowing that they wouldn't pass concours judging. But hey, at car shows the bonnets are up! The usual problem is that they are a little too short - leaving a wider gap than I'd like at the cowl.

Otherwise, I've had only one problem - with a Heritage front wing. But rather late in the process, a bodyman-friend of mine took some measurements and discovered the problem was the car, not the wing!

FWIW,
Allen

Allen Bachelder

John, a lot depends on if the new panels are Heritage or other. I did the floors on a friends B last year and the panels didn't have the drain hole fittings or any of the studs installed for the fuel/wiring clamps. Other than that the fit was fine, although the flanges were larger than necessary and had to be trimmed. I suppose that if the edges of the sills or trans tunnel were worse I'd have appreciated the wider flanges. I still can't image the work involved to remove panels intact from a donor car and install them. Makes replacement panels look good even with the higher cost.
Bill Young

I can't imagine rescuing floors from a donor car, period. In most cases, it seems to me that if the donor car has good floors, it ought to be the "donee" car.

FWIW,
Allen
Allen Bachelder

If you are sure the donor vehicle has really good panels, IMHO, it depends on how much work you want to go to. Cutting the spot welds is not difficult but is time consuming.

I am a cheapscape, so for me, If I had the donor and the floors and trunk were in very good condition, I would do the work to pull them.
BEC Cunha

Whadya think - would it be easier to rough cut outside the floor panel edges and then grind the spot welds out on the bench?

FWIW,
Allen
Allen Bachelder

Allen,
That is what I was planning on doing. The donor car is a 79 so the trunk floor is not an exact fit but the floor pans are the same, as I understand it, and all are in good condition. I am not sure but I think the only difference in the trunk floor is that the rubber bumper floor is more rounded at the rear to accomodate the rubber bumpers. Where can we buy Heritage panels? I have had to save old panels before and I know that it is labor intensive. I will let the person with the money make the final descision. Thanks for the responses and have a good day!

John
John Progess

I have a trunk floor that is heritage made. Willing to sell it--contact me offline.
James Johanski

John There are 235 spot welds in the floor pan of a 67 MK1. Probably the same give or take for the 79. For the front floors, you will still have to drill the spots out to get it off the subframe of the 79. That would also leave you with all the holes to plug weld it back in to the 71.
BEC Cunha

On the donor car I would just drill out spotweld with a 3/16"drill. I would then use this hole to weld the panel back on our car. To remove the panel on our car I grind out the spotweld or use a spotweld cutter to keep the subframe flange intact for welding of the donor panel. You are correct in that it is a pain! So you still have about half the labor even using new panels, no way around it. Have a good day!

John
John Progess

Crikey, you are brave! That's a load of spot welds to drill out. Rather you than me!

I would go for the non-Heritage floors. If you are handy enough to drill out the 235 spot welds, I'm sure you'll be able to make up small strengthening plates to hold the nuts for the seat runners. As far as I know, the drain holes were intended to let the paint run out at the factory and are not strictly necessary.

Good luck! Mike
Mike Standring

Mike,
It is easy for me to talk about replacement as I am going to supply the tools and shop and some verbal support not the one doing the work. The owner and money man, Clayton, is going to do the work. He reads this BBS so he knows the effort involved and he will be the one who makes the final decision. Have a good day!

John
John Progess

Keep in mind that, particularly way down in the foot wells, it's not that easy to see exactly where the spotwelds are, or to keep the drill centered well enough to get the entire spotweld drilled out. Any way you do it, prepare for a long tedious job. You'll have to drill the spotwelds out of the crossmembers with the floor in place - either that or cut the old crossmembers out of the doner car. I'd cut the pieces out next, rough cutting outside the perimeter, but as close as possible. Drill the remaining old spotwelds out on the bench. Have several sharp bits handy!
That still won't compleely free the floorboards from the old inner sill, heal board and transmission tunnel flanges; it will take a combination of angle grinder and air chisel to clean the remaining flange material away.

New aftermarket floor panels can be had for $85 a pop at LBC. Heritage ones go for $140. They both fit fine, but the Heritage ones are more complete regarding fixings. In either case, to save $170, or even $280, you're going to end up paying yourself (or whoever does it) about $2 an hour, I'd guess. You'd be time and money ahead to get a part-time job in fast-food to pay for new panels. I just can't imagine trying to rescue old floors. Repairing a rusty body shell is so time-consuming at the outset, I just can't see why one would wnat to aggravate the process this much. You have my unflaging respect and support, but I just wouldn't do this.

Out of curiousity: if you're donor car has good floors, what is wrong with it to make it a donor?

Good luck!

Allen
Allen Bachelder

Allen & all:
The donor car has been given to us for whatever resources we can salvage from it........(read: free! always a good thing)
That is the reason that we were even considering taking the floors from it.It does have some major issues of it's own, not the least of which is that it is a RB car, a '79 and we are doing a '71 that is solid otherwise.
Based on the info that you all are providing, I have decided to go with new pans. My question is as John mentioned before, are the heritage pans available from the usual sources and based on what Allen has said, it appears that LBC has them. Next question, is it cost effective to spend the extra $50 to $60 each to get the pans with the seat strengthening nuts, etc.

Thanks for your help guys,
Clayton
C. Merchant

Clayton,

Yes Moss lists the "Heritage" floor panels as well as the aftermarket ones. LBC is a Moss dealer, except they discount. For example, the Moss price on the Heritage panels is $165 each; LBC has them for $140. Definitely a worthwhile discount.

I've always used the aftermarket panels as I believe the Heritage floor panels are a relatively recent offering. At any rate, while I've generally bought Heritage panels whenever I could, I was not aware of Heritage floor panels being available when I did these. The main challenge is locating the captive nuts for the seat rails - which is not that difficult; it just requires care. Make sure you measure the locations of the holes/captive-nuts in the old floor before you tear it out. From side-to-side, try to set it up so you err away from the transmission tunnel. You also can drill the holes a bit oversized to give yourself some leeway. Bolt the outboard seatrail to the floor on the bench and install the seat on the rails. This will allow you to double-check your location of the holes for the inner rail. On the bottom, reinforce the floor panel with a piece of at least 18 gauge metal and/or one or two heavy gauge fender washers. Snug the bolts up tight such that the seat slides easily for the full adjustment range, then weld the reinforcements/washers and nuts to eacy other and to the floor. Of course, make sure your reinforcement patches on the front holes will still fit inside the crossmember.

The reinforcements are important; otherwise in the event of a collision the seat rail nuts could tear themselves out of the floor.

' Hope this helps a bit. I used a pneumatic punch to put holes about an inch apart all round the perimeter. When you're test-fitting the floor, go underneath and trace the outlines of the frame members on the bottom of the floor. You'll have to drill these holes, but drilling them on the bench with the panel upside down, the traced lines will show you where to drill the holes.

I think there are some archives dealing with the old argument: whether or not to leave the side flanges on the new panels. It is more correct to cut them off but I prefer the added strength of leaving them on. More holes to drill, as the punch won't go around the 90-degree bend of the flange. But then you'll have two rows of plug weld holding all the seams and fewer water traps. I leave them on, but others do not.

I use lots of drill-screws to pull the floor up tight to all mating surfaces. Then once the plug welds are done, take out the screws and weld up those holes. Don't get carried away and let your drill run very fast when putting in the drill screws or you'll strip them. Experiment with a few in scrap pieces to get a sense of the best speed, and if your power drill has a break-away clutch, adjust it so the drill will slip before the screw striips.

' Hope some of this is helpful. Oh! One more thing. Remove the fuel line(!!!), wiring harness, etc from your old right side floor panel before you cut it out. Well "Duh!" I hear you say but it happens. And if that fuel line has any fuel in it, the results could be spectacular.

FWIW,
Allen
Allen Bachelder

One more thing. If you haven't done this before, you'll be positively AMAZED at how many wrong ways there are to install seat rails. If the stop blocks are still on them, that helps a bit (so often they're missing), but none of the four are interchangeable. If you haven't removed them from the car yet, mark each of them for location and orientation - front and back, etc.

Allen
Allen Bachelder

This thread was discussed between 17/01/2007 and 22/01/2007

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