Hey guys. So I'm building a g***er style 57 chevy, and I'm planning on building a removable aluminum trans tunnel so as to make transmission and clutch work easier. My question is, will my floor be solid enough once the tunnel is cut out? And what would be the best way to reinforce it? I've been under this car countless times starring at the floor trying to come up with a good plan and can't seem to figure a good plan. Any help would be appreciated!!!
I'm using a cross member for the trans. I would like to make the trans tunnel out of aluminum and secure it with winged Zeus clips for quick easy removal. BUT with all of that, there won't be much structure. So I'm trying to come up with a good way to reinforce the floor without some overly complicated HEAVY structure
yeah, thats what I said. I did that to the Mustang gas tank serving as a floor for my 1950 Ford Crestliner trunk
I'd go with the 1 x 1/8 flatbar and fit it all up on top drill the holes in the flatbar and floor boards then pt the cage nuts on the bottom side of the flat bar and you should be able to bolt it in and spot weld i through some more holes between the bolt holes in the floor.
But what about the "humpy" part? With that cut put won't the floors tend to lean in towards the middle???
Why not use a second hump cut a little longer along with the 1/8" strap as a bolting down place. It would just need a step flange to lay over the floor pan lip. All you would be adding is the weight of the strapping and you would still have the strength of the steel floor. Aluminum would be lighter and easier to move around, but do you really see yourself pulling it off a lot? I would want the strength and protection of steel over the weight difference.
Mercs and other cars have this. Beads rolled near the edges and reinforcement along the edges, and you'll be fine.
I was checking out this car a few weeks ago and noticed the transmission hump cover(s)...didn't have a clutch bit on hand, but it seems to be a good visual for what you mentioned:
How about drive shaft loops. Aren’t you going to need those? Maybe two of them? Use those to secure your tunnel and save yourself from injury as well.
I did this using nutserts on my '39 Chev coupe, but my trans access isn't huge, so no extra reinforcing beyond stock supports. I have 1/4" nutserts every 3" and a self adhesive foam on the cover so it seals once bolted down. It was quick and easy, and is very strong. Unless your access is a huge piece I doubt it needs extra bracing; just use lots of nutserts and bolts.
Actually ya. I'll probably be removing and swaping cluches. Years ago I had a chevelle that I drag raced and was constantly changing things and breaking things. I told myself if I ever build a 4 speed car that I race again it WILL have a removable trans tunnel
The size of the hole makes a difference on the amount of reinforcing you need. If you intend for removable section of floor to be the entire tunnel from the seat to the firewall, I sure would want extra bracing. I would also want extra bracing if the hole went from the floor pan to the floor pan on the other side of the car, I would still want extra bracing. What your seat is attached to would also be involved when it comes to extra bracing.
My 27 has removable floor pans and tunnel,I used welded tabs drilled and tapped ,bent the tunnel out of 18 gauge around a flat steel frame, it replaced the wood floors and fibergl*** tunnel, as stated before I didnt really have to remove anything to service any parts but Im happy its all steel now, I say go for it , for me it was a great upgrade.
When I built my Austin g***er with SBC I screwed up and in an attempt to keep things tight and save interior space I got the trans tunnel too close. I had a flexplate failure and when I got under it to unbolt the bellhousing I couldn't get to the top two bolts! My car had been finished for a couple years, and interior was fully carpeted, so didn't want to do a bunch of drastic changes. So I measured a spare bellhousing for a pattern, and after rolling back the carpet I measured from points on the firewall where various devices were bolted through and laid out holes inside to mark and test drill using a 1/8" bit. Once I drilled the holes I planned to use a hole saw to open them large enough for a 9/16" socket, and luckily my layout was perfect and didn't need shifting to line up. I drill 3/4" conduit holes that are 1.125" diameter and removed the two bolts. Dropped the trans back a few inches and slipped the new flexplate in. Once it was done I used 3/4 KO seals that have a wing on them to tighten and plug the holes. If I ever need to pull the trans or engine again I can now just roll the carpet back and remove the seals. This avoided a lot of cutting, and possibly losing any strength in my trans tunnel or floor. Some old cars used small curved cover plates over bellhousing bolts as access doors. You might consider that as an option versus a complete removable trans tunnel. It would retain strength and accomplish the same thing.
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