Welcome to our Site for MG, Triumph and Austin-Healey Car Information.
|
MG MGB GT V8 Factory Originals Technical - T5 Tunnel Bashing
I have just completed my umpteenth read through of the V8 Newsletters (if you don't have these you need them). Throughout, I didn't see any comments on whether the "bump" at the firewall end of the transmission tunnel needs to be flattened upward. It is clear that with the Rover tranny the transmission tunnel needs to be flattened so a straightend is flush from the hole for the stick all the way to the firewall. Is this also true for the T5? I would like to minimize the number of times I will have to test fit the engine and if it needs bashing I'm ready to go now. Any T5 users want to comment? If it needs it I am going to use an air chisel with a mushroom head rather than a big hammer. Sound good? |
erich.hovley@ti.com |
Erich, I am not sure if you need tunnel bashing for the T5 trans. I installed a Rover 5-speed box and even in the case of the Rubber Bumper models you have to cut away about 2 inches from the top of the tunnel. I do not see how pounding with a sledgehammer can accomplish that because there is a lateral reinforcement bar in the middle of the tunnel on the place where the radio is located. The best way is to cut away the entire section on the top and make a new roof for the tunnel. For once, the book "give your MGB V8 power is right on that. It shows the template to make this mod and it worked OK for me. I read that you have air power so it should not be that difficult.Good luck with the conversion! It is well worth it if you like all the power it will give you while driving. Werner |
Werner Van Clapdurp Lynchburg |
I think the main factor would be what engine mounts you use. I test fitted the engine and T-5 using motor mounts from Towery. The T-5 needed about .5 - .75" more, so I cut the top of the tunnel. After doing some more thinking, i'm going to design my own motor mounts. These will not use the standard mounting position on the frame, but will mount on the back side of the susp crossmember. This will allow me to set the oil pan about 1/2" above the crossmember. I also have enough room for a 14" X 3" K&N Low Rider filter, which I didn't with Towery's mounts. Since I already have the tunnel cut, I can't quite tell if the T-5 would fit with no mods. I do agree with Werner. You would really have to bash on that bump to get it to move. There are about 3 pieces of sheetmetal joining there. I might be able to take a pic of my cutout, so you can see what's behind it. Just e-mail me if you want it Mike |
Michael Hartwig |
I'm not sure about the T5 -I have seen several installlations of the T5 done by Malcolm Beer over here in the UK on racers and I under stand that the height needed is a lot less than that for the Rover 5 speed. BTW I don't believe that it is neccessary to put a large box into the roof of the tunnel as per the aforementioned book-(which is so full of errors that I wouldn't trust it any way)-if you use the factory mounting position -ie factory block mounts and engine mounts.Most of the conversion mounts that I have seen place the block higher in the engine bay which in turn puts the gearbox higher in the tunnel.You can see my solution on the V8 conversions web site-essentially it involves cutting out the the downstand seam with two parallel cuts of an airbody saw and then dressing the tunnel roof up so that the height at the gear lever end runs thro' to that at the bulkhead end-the cut is then seam welded up and the 5 speed box will just fit with about 6mm vertical clearance.( I would think that if you can get the 5 speed box in this way that the T5 would fit also) Regards JB |
johnbourke@panther.netmania.co.uk |
Don't reinvent the wheel for this installation just yet. Unless you have strong convictions for doing otherwise, Dan Lagrue at D&D Fab, Glenn Townrey, and Mike Callihan here in Colorado all advise using Glenn Townrey's (or similar) A.C. motor mounts (those designed for use with air conditioning). They allow the use of the standard MGB engine mounting postions and the T5 will fit in without any bashing or cutting with the exception of elongating the shifter hole 1 1/2 inches to the rear. These mounts will also provide clearance for the oil pump/front stablizer bar and an adequate air filter. Call Glenn and talk with him. Dan at D&D Fab. sells a bracket for the rear T5 tranny mount that allows the use of the stock cross member when used with these motor mounts. (Also can be home fabed withsome 3/4 inch angle iron). Larry |
Larry Diede |
Do you have the T5 already? I am a great fan of the Toyota Supra box. It is hugely strong(even used behind big blocks), nicely compact, has good ratios, the gear lever comes out in the right spot and it is cheap to buy and to rebuild. The Supra box will fit in a MkII MGB tunnel with out any bashing, even on chrome bumper without a rubber bumper cross member! |
Aussie Dave |
Per Larry's comments, I have a T-5 in a rubber bumper car, Glenn's A/c mounts, & D & D's angle tranny mount. It did require the use of a BFH for installation, but did not require cutting. Depending upon your skills & equiment, cutting & re-welding may be easier, but a big box added on is definitely not required. Remember that all of these cars are at least slightly different, & some will require less bashing than others. At the V-8 Meets, I have seen cars converted with the same parts where engine height varied as much as 2", so remember the old cavet, YMMV (your milage may vary). Jim |
Jim from G'berg jimbb88@erols.com |
After having converted 2 bees to V8 spec I'm definitely of the opinion of having a box extension on top of the gearbox tunnel. Otherwise the clearances are so tight, you may find that all your bashing with a sledgehammer wasn't enough. Then engine and gearbox will have to come out again. Fabricating the box, cutting the tunnel, then welding takes 2-3 hours and well worth it. No more will it won't it go. Also it give the scope of lifting the rear end of the gearbox higher. This will level out the oil in the G/box and help to ensure better lubrication. |
antonio.skky@freeserve.com |
This thread was discussed between 10/08/1999 and 10/09/1999
MG MGB GT V8 Factory Originals Technical index
This thread is from the archives. Join the live MG MGB GT V8 Factory Originals Technical BBS now