BritishV8 Forum

General Category => MG Sports Cars => Topic started by: Jim Stabe on March 11, 2013, 04:59:35 PM

Title: Easier way to a wide MGB
Post by: Jim Stabe on March 11, 2013, 04:59:35 PM
Here is the thread I promised to stop hijacking the fender flare thread. I have been working for the past 12 years on my project to widen my MGB roadster and most who are reading this will probably have seen the journal at one time or another. The bottom line is my build has been an evolution away from the original thought of just widening the shell to cover the C4 suspension to what it is now with nearly the entire car being fabricated and well under 300 lbs of MGB metal remaining. The event that took the project off the rails was after I cut the car apart and spread the two halfs apart and I took the Corvette front suspension on the original Vette crossmember and raised it up in place where the MGB crossmember used to be. It was an almost perfect fit and I could have had it mounted easily within a weekend and retained all the MGB front structure. The problem was that the A arms and spindles were beautiful forged aluminum pieces but the crossmember was really UGLY. Rather than do the smart thing and build a crossmember that looked good and would mount the Corvette aluminum pieces, I decided to build an entire front structure that incorporated the Corvette suspension pickup points. That structure had to be tied into the monocoque somehow which led to the building of a Lotus Elan style backbone chassis and the eventual elimination os nearly all MG sheetmetal inside of the outer skin. Am I happy with the way the car turned out? Absolutely!  I love the proportions of the car now and I believe it will be a good platform for the 500 hp it will eventually have. Was it the easiest way to do it? Absolutely not!

A number of people have expressed a liking for the look of the car but don't want to take on that much work. I can't blame them one bit. The aim of this post is to show an easier way to create a wider MGB roadster that would be more practical than mine will be (no door glass or top) but could be completed in an amount of time not significantly longer than more conventional V8 swaps that have been done here on the board.

So what can be done differently to make it easier? Let's start with the mechanicals.

Try to choose a front suspension that is on a removable crossmember, it will make your life much easier by not having to make a custom crossmember and all the geometry and pickup points are already done for you and the steering is already mounted. I don't have much to offer for which one to get but just take your tape measure and spend some quality time at the junk yard. Look for something that requires at least a 6" track increase as that will give yoiu enough room in the tunnel to run the exhaust. What you select has everything to do with how wide you make the car so have the parts before you start cutting. Most removable crossmember suspensions I have seen would be very easy to adapt to the MGB front rails. For simplicity sake I would use a solid axle for the rear, they work well and are easy to mount with coilovers. When you are reinforcing that junction between the rockers and the rear of the car (see below), think about where you want suspension arms to attach and work it into the design.

Before you start cutting make sure you have all the mechanicals you are going to use. Remove everything right down to the bare shell. Fixture the car with something similar to what I used (see part 1 of my journal) so that you can slide the halves closer or further away from each other once they are separated. I would remove the battery boxes and mount the battery in the trunk. You will want the extra width all the way through the tunnel so you can run the exhaust up inside the tunnel for extra ground clearance. Just one more advantage to having a wider car. Remove the slam panel and vertical brace by cutting out the spot welds, you will be able to extend it on each side and reuse it with the stock latch. Cut out the top of the tunnel that contains the removable panel with the shifter opening. To bisect the car, start at the front with a 12" blade in your Sawsall and cut through the oil cooler panel on the centerline of the car and then through the cowl down to the opening on the top of the tunnel. Continue cutting along the top of the tunnel over the driveshaft and up to the top where the battery cover shelf begins. Cut 90* to the centerline 1" back from the edge along the front of the battery cover shelf to the front of the wheel well, the cut should go straight across. Next you want to make a cut just outside of the seam in the center of the rear wheel house separating each side into two pieces - an inner and outer half. The inner half has the interior panel attached and the outer half attaches to the outer fender skin at the wheel opening. Now it starts getting trickier because you want to leave everything intact in the center portion of the rear of the car between the two cuts you just made in the wheel wells. Don't cut the diaphram as shown in the picture though.



Next you want to make a straight, horizontal cut in the diaphram from the top of one wheel well to the top of the other. Then make a cut on centerline through the outer and inner body panels between the trunk and cockpit down to the horizontal cut in the diaphram. A good reference are the photos of the body being assembled here  http://www.chicagolandmgclub.com/techtips/mgb/pdf/mgb_ckd_assy.pdf

In the trunk, make a straight cut across the floor just to the rear of the rear reinforcing rib and cut through the very end of the "frame rail" . Then make two cuts, one on each side of the license plate, to intersect the cut you just made. These cuts will preserve the license plate holes and the latch bracket. Drill out the spot welds holding the outer trunk floor to the outer portion of the wheel well.  You will also need to cut out the welded in crossmember and the loop under the driveshaft at the rear of the passenger compartment.

Now the only thing holding the two halves together is the frame rail area just ahead of the wheel well. Study the pictures in the link above to see where you need to cut - too difficult to try and explain.

Now that the shell is in two pieces you need to decide how wide to make the car. A lot of that decision depends on what suspension and drivetrain  you plan to use and what it's track width is (see the section on mechanicals above). What I did was to set up the suspension at ride height with the wheels and tires I was going to use on a platform and then pull the body halves apart until  it looked right. I left a little tire sticking out because I wanted a slightly bulging fender but you can have everything inside the stock body lines if you want. You then need to fill in all the gaps with sheetmetal. If you separated the body halves by 7" you will need to weld in 7" strips to fill the gaps and 3 1/2" strips of metal to join the wheel well halves back together and on either side of the license plate section in the rear. For the outer body panels at the cowl, rear of the cockpit and around the license plate you need to contour the metal slightly to blend with the body shape. Find someone with an English wheel or get one of the harbor Freight planishing hammers to create the contour. The less you widen the car, the less the compound curvature is an issue.

Make sure you reinforce the area where the rocker boxes join the rear frame structure. How you do this will vary depending on how much wider you make the car but there is plenty of room in the wheel wells and on the inside of the rail area. This is a critical strength area so use doublers and extra bracing. This is not how I did mine so I can't offer much first hand detail.

Some of the details:

Instead of putting bumpers on the car (trust me they are a pain to cut and weld into the right curvature and very expensive to chrome) just do rolled pans and nerf bars similar to what many have done here on the forum. They give the car a good look.

I would use a steel hood even though it weighs more, it is much easier to work with. Cut the outer skin down the middle on centerline. If you want to retain the badge bump on the front, cut it out first. On the inner structure, cut out the center section that has the latch and then cut the remainder of the inner structure on centerline. Like the rest of the car you will have to fabricate the filler pieces and weld them in. For the outer skin, pay another visit to your friend with the English wheel. The inner reinforcement fillers will require some metal forming so they match but nothing too difficult. When welding the filler pieces in, do it with a series of tacks skipping around so you don't add significant heat to the panel distorting it. Keep adding tacks in between until the entire seam is welded - it takes a long time but you don't warp the metal. Don't get too agressive grinding the welds for the same reason. Repeat the process for the trunk lid. The less the car is widened, the less you need to worry about contouring the outer skin pieces.The stock hood and trunk hinges and latches will still work as they did on the original car.  

Run a fishmouth style grille (no frame) that is easy to fabricate with either vertical bars or a wire mesh

For the dash you can get creative sectioning a stock one or make one from scratch. Again, many folks on the forum have made custom dashes, this one is just a little wider.

Get another cowl air grille and cut the two to make one. You can weld it with some of the potmetal welding rods available and get it rechromed.

I saved the worst for last - the windshield. If you want to have a top you should probably modify a stock MGB frame. You need to find a windshield glass that has the proper contours and enough width that can be cut down to fit in a modified frame. Take a stock MGB windshield glass and cut it down the middle vertically. If you live close to San Diego,I'll give you one. Take that to the junk yard and start laying it on different windshields until you find one that has a similar curvature and the extra width you need. You will find that the MGB windshield has a lot more curvature than most. The top and bottom rails of the frame will need to be cut, bent and welded to match the curvature of the glass and extended to the right width. You will need two sets of rails. This will be the most challenging part of the build. If you run a top you may have to reshape the forward edge of the latching bar to match the new curvature of the windshield. The top bows can be extended by welding in sections of tubing and a good upholstery shop can make a new cover.

So what will you have when you get done? A better proportioned and better handling car with stock body lines. An engine compartment that will accept almost any engine you want to put in it (my vote would be an LS). Exhaust that runs inside the frame instead of out through the wheel wells. Exhaust that does not hang below the bottom of the car for good ground clearance. Wheel wells that will accept any size tire you want to run without flares. Enough room (width) for a decent size radiator and fan. A really high COOL FACTOR.

I hope this might encourage at least one of the more adventurous among you to take on the project.
Title: Re: Easier way to a wide MGB
Post by: MGBV8 on March 11, 2013, 05:39:09 PM
Thanks, Jim!

If I ever get that garage built, I'm ready.
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 11, 2013, 06:00:03 PM
Get busy Carl, I want somebody to park next to in Colorado Springs.
Title: Re: Easier way to a wide MGB
Post by: BlownMGB-V8 on March 11, 2013, 07:15:10 PM
Great writeup Jim. So I just have to ask though, how far are we willing to go to reduce the labor and cost? It seems to me that we are looking at a range and at the wider end we have cars like yours while at the narrower end we have flares. So far we've seen primarily the Rabbit flares which add maybe 3 inches to the width. Then there are cars like the MG-Roadmaster, my car and a few others which have been widened up to about 6" by various means usually involving either Sebring flares or hand formed sheet metal or both. Many think these cars look like deformed cartoon cars but others like them. I'll pose the question though, how wide can we go with this approach before it becomes unmanageable?

Along with that question, how far can we go with altered bodywork before altering the tub becomes the only practical solution?

If we take what has been done as the starting point it would seem that somewhere around 6-7" is going to be pretty close to the practical limit on widened bodywork, and while this does give you clearance for wider tires (up to a 315 is possible before tire diameter starts to create a limit) it does nothing for exhaust clearance. (and now I know why you made the tunnel wider) So it begins to look like the 6 to 12" range is where the sectioned tub really applies the most. Less than that could be said to be too little gain for the effort. And then of course there's the windshield. Nice solution on that btw, but I don't expect to see many follow ups. What can be done to retain the stock windshield? I have no idea, since the windshield is pretty much tied to the doors and wing glass.

So here is a thought. Considering that the width at the doors is the biggest limiting factor in widening just the fenders, what about widening the doors themselves? The sills of course will have to be made wider as well but that could give room for the exhaust to be tucked up inside if done right. I haven't tried this so it's just a jumping off place for another approach. There would be issues with the front and rear fenders of course. What I have done is section the front fenders beside the top flange and add a wedge of sheet metal tapered from a point at the rear to 3" wide at the front but this creates a "wasp waist". Because the fender is double layer at the rear and there is a curve to deal with keeping the straight lines would be more involved. The same issue with the curve would apply at the rear where the fender approaches the welt, and then the rear treatment is tricky as well. But it's something to think about.

Jim
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 11, 2013, 09:30:25 PM
Jim

I don't quite understand what you mean by widening the doors
Title: Re: Easier way to a wide MGB
Post by: BlownMGB-V8 on March 11, 2013, 11:56:11 PM
Make the door itself a few inches thicker to eliminate the "wasp waist you get when you widen the fenders.

Jim
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 12, 2013, 10:40:15 AM
Not a bad idea but you would be pretty much limited to glass packs and pipes exiting in front of the rear wheels. You would also  lose the extra width in the engine compartment
Title: Re: Easier way to a wide MGB
Post by: BlownMGB-V8 on March 12, 2013, 11:51:03 AM
True. And as it stands I believe with a 17" wheel and the right offset you can fit pretty close to a 255 under the front fender without widening it any, possibly even wider. That's plenty of tire on the front of an MGB, and I am even toying with the idea of going back to a stock width front end on my car at some future time. (I think that would be number 6) Just kicking ideas around here, since any widening of the bodywork that way would involve changing the curvature of the upper 1/3 of the panels to match. Still it could be done. The front fenders only have an issue around the windshield but that cut could be just outside of the mounting points and I think it could be carried off pretty easily. The doorskins could be cut close to the weatherstrip flange. The rear fenders could be cut near the top welt. But at the rear the tail lights would be an issue. Perhaps the cut could be carried down the inside of the welt and follow the crease to the bumper, leaving the tail light mount intact.

Since rear tire width is really THE issue, I think it might not be that hard to taper the width of the car, keeping it at stock width at the front and going something like 6 or 7 inches wider at the rear with this method. In that way the stock beltline could be retained along with the smooth uninterrupted plane of the car's side. The angularity would be almost unnoticeable and in fact would very likely go overlooked except for the wide rear tires. At the doors the extra width per side would be about 2" give or take, and I don't think that much added to the door and sill would be any inconvenience. As for the exhaust, I've run it through the rockers for over 2 decades now and have a few new ideas. Two specifically, which I'll be adopting before long. First is a chambered pipe which should be better than the glass packs. This is an insert than can be slipped inside any size pipe. There is room for 4 chambers and the diameter could be anything up to about 3" while still leaving adequate clearance. On my car I use perforated stainless panels to form the rockers for cooling and that works reasonably well. At the rear, instead of turning the pipe out in front of the tire as it is now, I expect to go through the inner panel, coming out underneath the car just ahead of the wheelwell to the inside. You can look and see where this spot is. It'll be a little tight and will require a smaller diameter tail pipe but 2" will certainly work and it might be possible to go a little larger. From that point rearward I plan to follow the contours of the system on the MG-Roadmaster, as Dave VanWyck has done a masterful job of routing past the Jag IRS, adding a pair of resonators along the fuel tank in similar fashion.

Granted, that probably makes for a warmer package than tucking it up in the tunnel where there is more airflow, and if you consider all the work involved in modifying a car in this manner, is it really any easier than sectioning it down the middle? Perhaps not. The single biggest advantage I can think of would be leaving the windshield intact.

Incidentally I developed a way to splice two front bumpers that leaves a small discolored weld zone 1/4" wide behind the bumper overriders and that could be done on the rear as well. It basically involves a jig to position the pieces and hold a shaped chunk of dry ice against the chrome to narrow the discolored zone. (I may even still have the original jig around here somewhere) Then the bumper is mig welded from the bottom. A small amount of chrome infiltrates the weld bead and prevents oxidation, (10 years now and no rust) but running stainless wire in the mig would be even better as I think you would then be able to grind, polish and buff the very small exposed weld bead to an acceptable finish, as long as you could do it without going through the chrome.

Any way you look at it this is going to be a big job, but given the amount of panel replacement we've seen in conversions in the past is it really any more than what guys are already doing? Maybe not. By the time you're doing floors, sills and doglegs it isn't really much of a leap and a good bit of the work is either on top or on the bench.

Jim
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 12, 2013, 01:06:18 PM
The idea of tapering the width is interesting but I'm not sure how to pull it off. If you widen the car 7" at the rear axle centerline that is 3 1/2" per side. The distance from the front point of the beltline to the front of the door is 45% of the distance from the front of the beltline to the rear axle centerline so the front of the door would have to come out 1.57" to keep the beltline straight. The rear of the door is 81% so it would have to come out 2.83". You would almost have to keep the vertical contour of the body side stock all the way back to keep it from looking goofy. If you just added width to the body panels and kept the door top and the rear welt in their stock locations, the bulge would get progressively rounder as you went back or you would have to make it square like the old racing Porsches. To keep the vertical contour stock, you would have to move the hinge pillar out 1.57" and the latch pillar out 2.83" and the body would have to be cut inside of the welt, probably at the crease between the welt and the trunk, and the metal massaged so the lines flowed. You are starting to get into some major surgery and you still don't get the advantage of a wider engine/radiator compartment or tunnel.

I had considered cutting the bumper using your method and over riders but I wanted a really clean look on the front without over riders or bumper mounting bolts. I had to add 11 1/2" of width and I could not get the curve to flow smoothly with just two cuts. The outer 1/4 was OK as is but the center 1/2 required a lot of pie cuts and welding to get the contour so it looked right.

Another project that might be interesting would be widening a GT. The windshield would be less of an issue because the glass has less curvature and you could find an existing car that had a glue-in glass that was close and cut the entire frame out of the doner and weld it into the GT. The rear glass would not be much of a problem since it has very little contour and you could find a doner glass fairy easily. With the extra width, the too-tall top would look more in proportion with the car.
Title: Re: Easier way to a wide MGB
Post by: BlownMGB-V8 on March 12, 2013, 04:10:36 PM
Yes, I think the GT would benefit greatly.

Don't think moving the door posts and latch posts would have to be done if the doors are just made thicker. Yes, this is more or less wasting the extra space but the cut could be just outside of the windshield mount, the idea being to move the skin out while leaving the frame in place.   An inch or two at the front would ease the angle as well, and it may be that the taper idea does not help any. The car is remarkably easy to widen at the front with this method anyway, as the grille area is not affected. I see the inside crease or valley at the rear being usable in the same way.

`Clearly you gain a lot more in many ways with a split down the middle but I think both are viable for different goals.

Jim
Title: Re: Easier way to a wide MGB
Post by: MGBV8 on March 12, 2013, 04:27:41 PM
I think I would try to compromise and allocate part of the extra room for the tunnel (two inches, maybe) & most for the cockpit. A bit more elbow room would be nice. Plus, a couple more inches in width would greatly open up the seat choices.
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 12, 2013, 04:31:02 PM
What is the width of a stock MGB well where the seats are located? I'm curious how much wider mine came out.
Title: Re: Easier way to a wide MGB
Post by: BlownMGB-V8 on March 12, 2013, 05:01:04 PM
20"
Title: Re: Easier way to a wide MGB
Post by: roverman on March 12, 2013, 07:37:20 PM
I thought I posted this-but..use 2 MGB windshields, L/R. bonded in the middle, or a verticle center bar. Are aerodynamics important ? The wider the car= more drag. It's a compromise between ultimate handling , speed and aestetics. If your using irs., perhaps exhaust pipes may be routed inside the widened door cowl areas, and then routed under  the irs, to central/rear mufflers, like Corvette ?  Onward, roverman.
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 13, 2013, 10:37:06 AM
Carl

I did allocate extra room for the seats - between 2" and 2 1/2" because the tunnel tapers slightly. I built the whole tunnel so it wasn't a big deal but I think it would be fairly easy to widen the passenger wells on a simple split car as well.

Art

You can't just cut the windshields and join them as you proposed because the glass starts to curve back once you go past the centerline and you end up with something like this and it gets worse the more the car is widened. Same problem with the bumpers

Windshield.jpg
Title: Re: Easier way to a wide MGB
Post by: roverman on March 13, 2013, 11:23:53 AM
Ok, so with your car, there would be 5 5/8" of curved/central area, per side ? Could the center ends be pushed forward, to compensate ?  Cheers, roverman.
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 13, 2013, 11:34:41 AM
The height of the glass also peaks in the center. If you pushed the center forward enough to make a consistent curve you would have to allow more than the 5 5/8" and the front of the glass would probably extend into the hood, there is a lot more curvature to an MGB windshield than you realize. It's difficult to visualize until you actually try to do it.
Title: Re: Easier way to a wide MGB
Post by: roverman on March 13, 2013, 06:02:45 PM
I see some street rods, with aftermarket peeked/curved windshields,(named after the designer). Seems like they might lend a retro look, to the right LBC.  Unfortunately, I think there is ample scope creep, with Hemi Healey, already.  Cheers, roverman.
Title: Re: Easier way to a wide MGB
Post by: flitner on March 13, 2013, 10:38:58 PM
Hmm, wasp waist, I can relate to that. While I was halfway through my build, the guy you see in some of the pictures said in his punch drunk manner,, It looks like it was tee boned.
Title: Re: Easier way to a wide MGB
Post by: BlownMGB-V8 on March 14, 2013, 05:33:28 PM
So could we summarize by saying that with the center section method the biggest issues are the windshield, grille and bumpers, while with the outer panels method the biggest issues seems to be matching curvature at the top of the panels, and difficulty in adding seat width?

Jim
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 14, 2013, 05:53:05 PM
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Title: Re: Easier way to a wide MGB
Post by: classic conversions on March 14, 2013, 11:25:07 PM
I have seen Jim's car, is not only the wide body but also the well engineered sub frame and back bone in the center that stiffens the car.
Jim also put the correct angle of the upper A arms to control anti dive which is the same as the C4 Vette.

There is much more than just wide body, impressive work. I can't wit until the day is done, I get to drink  Jack Daniels upon completion of Jim's car, if the offer still on the table.

We could ride together to Colorado Jim if I finish my wide track GT. It would be hard to see what is ahead if  I follow
GTBodyWork018.jpg
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on March 15, 2013, 10:18:16 AM
The offer still stands. A friend of mine is going along in his Cobra coupe and the wives are going in comfort in a 993 Porsche.
Title: Re: Easier way to a wide MGB
Post by: mworthan on November 19, 2021, 08:28:34 PM
Hello Gents...
I know I am resurrecting a pretty old thread but wanted to see if anyone who may understand MGB's better than I, and the nuances of the instructions, could help me clear up the trunk area.
Jim did a great job, I just think I'm a little too unfamiliar with the structural components to have a clear understanding of the last few steps in the trunk.
I thought the easiest way to communicate was to snap a few pictures and mark them up best I can.  I am still tearing it down and haven't stripped the body of paint, rust and seam sealer yet.
Where I struggle is at the back of the trunk (boot) area.  I get the benefit of separating at the mid point of the wheel wells that would allow wider rear wheels and tires.
I have questions in the content of the pictures themselves and should probably just let them speak for me.
Thanks for any guidance. - Mike
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Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on November 22, 2021, 05:34:21 PM
First, what is your overall plan? What engine/trans are you planning to use. What front suspension? How much do you plan on widening the car? What rear suspension are you going to use and how are you going to transmit the forces into the structure of the car? How are you going to reinforce the structure?
I have been on vacation in Cancun so I apologize for the delay answering.

I'm not sure I understand what you are asking. What you should end up with is the monocoque in 3 pieces - the trunk floor and bulkhead with the inner halves of the rear wheel wells attached and two body sides with the outer halves of the rear wheel wells attached. Actually, there is a 4th piece which is the trunk latch and license plate section. At that point you should be able to slide the body sides laterally to create the desired width with the trunk floor section remaining in place on centerline. You might find it easier to remove the trunk floor outboard of the frame rail and behind the wheel well and fabricate new pieces once the body is put back together. By removing that portion of the floor the cut in the wheel well will go all the way to the opening you just made and the rear cut in the center of the trunk area will end after you cut through the frame rail into the opening.

Before you raise a Sawzall in anger you really need to have the car in a fixture. If the parts are not held in proper relationship with one another, it will be almost impossible to put them back together in proper alignment. When I made my final cut to separate the two halves the pieces did not move at all relative to each other. Once you have slid the outer pieces outward to the desired width, the gaps you need to fill with new sheetmetal will become obvious.

Good luck.
Title: Re: Easier way to a wide MGB
Post by: mworthan on November 22, 2021, 11:02:11 PM
Vacation in Cancun.  Nice...I appreciate the interest.  I'm committed but, yes, too little information in my original post.

Scope (in order of your great questions):
1. Overall plan...A cruiser, a hot rod MGB, something different, maybe even willing to incorporate very non-conventional solution ("Duvall-esque" winshield, Bop-top, etc..
2. I have a 4.8LS ready to be refreshed in February (builder is busy).  Boost it, turbo.  LS platform responds well.so a single GT45 or twin GT35's.  Torque cam (BT Torque cam), street able, AC, nice interior, etc...  I want my wife to ride with me (support the habit). I want to drive it in local SE USA trips.
3. 4L80 (turbos will smoke the 4L60's) although I'm not overly aggressive.  This is mostly street (a little track)
4. Here's where I'm not sure a pure split wouldn't make more sense.  I'm good with a traditional M2 IFS.  60" track with a matching Foxbody 8.8 on a parallel 4 - link.  Mini tub the rear wells.  So, maybe I need to think a full frame welded in, maybe delete the front frame and tube it ( with fender mount points) and teh full frame.  I can jig and build it.
5.  Reinforcement... tube.

So, I am generally thinking a welded in frame to transmit forces.  I know at this point the shell is over built.  Sills are typical.  I would leave them as is.  A full chassis would include sill support.  
 
I now struggle with the thought of channeling a frame (problematic) or creating a full perimeter frame (2x4) with tube support under the floorpans.

Tell me I'm crazy.  That 10" to 12" width would help plumbing the hot and cold side of those turbos.

Thanks for listening!
Mike.
Title: Re: Easier way to a wide MGB
Post by: mworthan on November 22, 2021, 11:18:03 PM
Completely agree on having the car in a fixture on a dead flat and planar reference table. Fixtures and skids on each half so that can slide perfectly apart with no fore and aft misalignment or Z axis change.
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on November 23, 2021, 01:49:55 AM
You should check with Chuck Royer, Slightly Modified over on the Experience. He has a full frame incorporated in a standard width car with a high HP engine so could provide you with some guidance. The 11" width increase does certainly help with the plumbing and worked out just right with the Corvette 60" track. Also allowed easily fitting a 31" wide radiator for better cooling. Like you said, the MGB has a pretty rigid monocoque structure especially through the sills so I chose to add the extra rigidity with a backbone tunnel Lotus Elan style - the car is very rigid. I am also fairly tall so I wanted the floors as low as possible in the car so I could sit as low as possible. The floors are attached to the lowest point of the pinch weld giving the car a very flat bottom with the exhaust tucked up inside the tunnel so it doesn't drag. Probably one of the  reasons it doesn't feel light at 130 mph ( the fastest I have gone not the top speed of the car).

Be sure to start journal on this site to document your build.

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Title: Re: Easier way to a wide MGB
Post by: mworthan on November 23, 2021, 09:16:01 AM
Will do.  Thanks for the advice and guidance.  I just have to say what an inspiration and how clean your build is.  I keep going back to it.  I will reach out to Mr Royer.  I completely agree with you about keeping the seats low.  I'm 6'0" but most of that in torso, not legs, think mountain gorilla.

I'll also document on the forum and not just lock up the photos in my phone.

My thoughts on the frame would be to basically build something similar to what Scott's builds (see attached).  The perimeter frame would structurally replace the sills.  When I bought this the owner put it on his lift.  I poked and it looked great.  i thought, "what a little peach I've found!".  I pulled the fenders and the outer rocker at least on the passenger side has been replaced and I don't think it was perfect (door gap looks fine but fender alignment looks wrong). They also only tied the A pillar back to the sill inside the door jamb.  Horrible tie back and I'll document booger welds and all found. Driver side has rot hidden under the fender and the outer sill and diaphragm at least are shot.  Inner sills look great.  My hope would be to fully frame it with the perimeter frame replacing the diaphragm and castle rail and tubing frame with a chassis X member under the pans which are perfect. I haven't measured the top of inner sill to floor pan to see if there is an inch hanging down of a 2"x4" frame (tucked in the inner sill) for  the1"x2"(or 3") rectangular tubing cross member frame to tie under the car like a basket.  Anyway, just thinking out loud.

I really like how you tucked the exhaust up into the transmission tunnel.  Dumb question... Any issues with heat soak on the transmission? I'm with you in that I don't want to drag my exhaust.

Thanks again.  The car is nearly stripped (no sense documenting that) so I'll start a project journal to expose all my inadequacies :)
ScottsPerimeterFrame.jpg
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on November 23, 2021, 11:34:27 AM
I don't have any temp sensors in the trans but I don't seem to have any issues with heat soak. If you look at how I built the tunnel/backbone structure I built the framework out of 1" tubing and sheeted it on both sides with 18 ga steel and sandwiched some 1" urethane foam insulation in the middle. Before I had the carpeting in I could drive the car barefoot and the tunnel was just slightly warm and the exhaust was right on the other side. You will need to make the tunnel wider than mine if you want to fit the exhaust along side of a 4L80 trans but you will still have plenty of room inside. I have considered an automatic in mine but not sure I have the appetite for major surgery on the car at this point. The third pedal is my theft deterrent because nobody knows how to drive a stick anymore.

I was fortunate with my car that I have owned it since it was a 5 year old California car and there has never been any rust in the car at all. It was a shame that I had to throw all that pristine MGB metal away when I was building the car this time.
Title: Re: Easier way to a wide MGB
Post by: theonlyiceman53 on November 27, 2021, 06:43:50 AM
Hey Jim,
I just saw this post!  In a way, I wish I would have seen it before I cut it but it all worked out.  I had thought about following a method similar to what you laid out but ended up cutting it right down the middle.
Cheers,
Bill
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on November 27, 2021, 10:55:45 AM
This just reappeared after 8 years and I had forgotten about it or I would have pointed you to it when I heard you were cutting up yours.
Title: Re: Easier way to a wide MGB
Post by: Airwreckc on September 09, 2022, 10:12:09 AM
Hello Jim and Jim,

I was thinking about a a couple of different approaches and I'd like your opinions.

1) I am thinking of sectioning the front fenders.  First I'd section between the hood and the  fender curve about an inch.  Then I'd section on the other side of the fender curve another inch, similar to the two Volkswagen pictures I've attached.  I would then increase the thickness of the door about two inches--I'm thinking of welding another door panel over the original one to make for a bit more side impact strength.  I'd also add rocker panel extensions, using rocker panel patch panels.  I am thinking this *might* give me some more space for a side exit exhaust in front of the rear wheel well.  Finally, I would cut the rear fender panel and bring it out to line up with the wider door, tapering back toward the existing taillights and valance.

2) A similar approach to the front fenders (still with a 1" section between the hood and the fender  curve), except instead of sectioning the fender on the outside of the fender curve, I'd slice the fender in line with the headlight  (or just outside the headlight) and grow the width of the opening from nothing at the headlight to about an inch at the end of the fender.  Then, instead of making the door two inches thicker, I'd taper the door thickness, from nothing at the front to two inches at the back of the door--and do the same with the rocker extensions.  The idea here it to have a rear opening to the front fenders, similar to the 928 pictures I've attached.

What are your thoughts on either of these ideas?

Thanks much!

Eric


VolksWider1.jpg
VolksWider2.jpg
928Wider1.jpg
928Wider2.jpg
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on September 09, 2022, 11:56:50 AM
I think I would cut the fender along the edge of the hood like the top picture and leave the back portion open like on the 928. That way you preserve the arched top of the fender and the fill piece is just flat stock. You also don't have to mess with the doors and sills as much. If you have extra fenders I would leave a few inches of the rear portion in the stock location so the front edge of the door fits under the fender and the step down is covered.
Title: Re: Easier way to a wide MGB
Post by: Spitfire 350 on September 09, 2022, 11:58:25 AM
Reminds me of IMSA style fenders, a look I really like 👍
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on September 09, 2022, 12:24:28 PM
I agree Phil. The rear fenders would require some widening as well if he does the fronts. An open-ended box might look appropriate and would be relatively easy to pull off. Maybe a more subtle version of this

th.jpg
Title: Re: Easier way to a wide MGB
Post by: Airwreckc on September 09, 2022, 12:48:57 PM
Great input Jim.  Thanks. How much of an opening at the back of the front fender do you think would be needed to look correct?

And Phil, yes.  Apparently the 928 was also inspired by the IMSA fender idea.  I just seems to me that this is a much easier way to widen the fenders than a bunch of compound flaring--or worse, having to use fiberglass, which I'm trying to avoid.
Title: Re: Easier way to a wide MGB
Post by: Airwreckc on September 09, 2022, 12:52:28 PM
Also Jim,

Can you explain what you mean by "If you have extra fenders I would leave a few inches of the rear portion in the stock location so the front edge of the door fits under the fender and the step down is covered."
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on September 09, 2022, 02:14:40 PM
Get some chip board and tape it on the car until you are happy with what it looks like. If you are adding 1" of width at the hood line then your fender will be sticking out 1" at the door.

"If you have extra fenders I would leave a few inches of the rear portion in the stock location so the front edge of the door fits under the fender and the step down is covered."

I mis-stated, sorry. The rear edge of the fender has a step down that the front edge of the door covers when it is closed. By having a few inches of the original fender still in place, the opening created by the outer fender will have a finished look on the inside with the section of fender in place instead of seeing the kick panel of the cockpit. The outer fender will have the step down that will need to be addressed to create a finished look.
Title: Re: Easier way to a wide MGB
Post by: Airwreckc on September 09, 2022, 02:36:09 PM
Jim,

Thanks, yes makes sense.  I have a couple extra fenders that will be useful for that.  And yes, have to figure out how to fill that step down on the exposed fender edge, but I did notice that.
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on September 09, 2022, 02:52:23 PM
One way to fill the step down edge would be to get some 3/16"x1/2" steel and bend it to shape to fill in the step. The flange above the beltline is about but it is narrower below. You could tack it in place and grind down the extra width at the bottom to line up with the fender edge. If it tacked securely you could either lead in the gaps or use All Metal body filler. The steel will greatly increase the strength of the edge.
Title: Re: Easier way to a wide MGB
Post by: Airwreckc on September 10, 2022, 02:54:31 PM
Jim,

Thanks for the suggestion.  Sounds like a good opportunity to practice my welding.
Title: Re: Easier way to a wide MGB
Post by: johnsfolly on September 13, 2022, 09:30:23 AM
The skill you guys demonstrate leaves me in awe! I guess the kids would say "Awesome, dudes!"
Title: Re: Easier way to a wide MGB
Post by: Jim Stabe on September 13, 2022, 11:36:12 AM
I guess the kids would say "Awesome, dudes!"

If you could get them to look up from their phones.