MGB Roadmaster

[Citron]

Jim,
I am planning to come up the end of April not March.  My mistake.

Steve

[BlownMGB-V8]

That will probably make it much more likely that we can get the engine ready for transport by by then. In the meantime I'll fit up the front unit, determine track for the rear and get some steel for the lower control arms on the rear. Then in my spare time (yeah, like I'm going to have any of that scarce commodity) I'll straighten and fit sheet metal panels. Somewhere along the line I think I'm going to have to get a mig welder. Maybe Harbour freight will come up with a good sale.

Jim

[accobraman50]

Hi Jim,  Here is a list of items I'm donating towards the Roadmaster project:

1: Rebuilt, complete MGB front suspension with 11" vented brakes. one grease cap removal tool.
2: New rack & pinion steering with new ball joints.
3: 2- Rebuilt steering u-joints. Misc. hardware, thrust washers, spacers.
4: 12" long 48 spline intermediate steering shaft.
5: New MSD Programmable timing computer #8981.  This was fitted to my Cobra then removed after fitting.
6: New MSD Soft-Touch Rev Control #8738.  Was fitted to cobra then removed.
7: Two Aldan AS-656-G adjustable shocks.  Fitted to cobra then removed.
8: One quart catch-can/overflow tank.

As you may not have use for everything, you mentioned that Ebay may be a source of revenue when you sell what you don't need.  I've listed the items here so other members may get first pick.

See you Friday,

Arthur

[Bill Young]

Jim, I've looked at the HF units and I'm not impressed. I have been looking for another MIG machine for myself and have found several units at good prices on Craigslist. I suggest that when you're ready take a look there. Here's an example that's priced hundreds less than when new. http://kansascity.craigslist.org/tls/561859433.html

[BlownMGB-V8]

Thanks Arthur, see you tomorrow. My wife and son will be coming as well, so we're looking forward to the tour and may get there just a little early depending on traffic.

Bill, thanks for the tip. I guess as a rule cheaper is generally cheaper, but I really don't expect to be able to spend more than a couple hundred on one. Always looking for a bargain though., and there's no tremendous rush. I've got the gas torch and the stick welder and can get by quite well with those until a deal comes along, but I certainly appreciate any leads.

Jim

[BlownMGB-V8]

Bill, please call me at (859) 816-2187. The guy is willing to deal on that welder and one of us should get the benefit of it.

Jim

[rficalora]

Check this one out good guys.  I may be wrong, but could swear I saw the same pics on one of the TX (Hou, Dallas, Austin. San Anton) craigslist sites sometime in the last 6 months.

[BlownMGB-V8]

Thanks Rob. Bill is going to make arrangements with him to go get it, I'm sure he'll be able to find an outlet to plug into and fire it up if he feels it's necessary. No money will change hands beforehand so we should be OK.

Jim

[BlownMGB-V8]

Had a touch of insomnia last night so I spent some quality time on the IRS design. It was all in my head so I'll have to look at the actual parts to see what will work but I got a lot of the details of the LCA fleshed out including inner pivots and mounting cushions, and I've pretty much decided on 1-1/4" x .125" wall tubing which will be substantially stronger than the 1-1/8 I'd been considering. Well, off to Indy with us..

Jim

[BlownMGB-V8]

What a day it's been. Sorry to say Arthur got stuck on I-65 an hour or so from Indy and had to spend over 2 hours sitting and waiting for a wreck to be cleared from the freeway and we all know what a frustrating ordeal something like that is likely to be. Luckily we were in touch by cell phone and an hour in had everyone at the desk of the museum trying to find out what had happened, but information was slow in getting out. By the time I was able to call and pass on what little information we could get, traffic had started moving again. I sure hope he had better luck getting back home. For our part, we got to sit in the Indy rush hour traffic coming back so nobody completely escaped the mess. What was I thinking setting this up for a Friday? Fortunately there was plenty to distract us at the museum while we waited there, I only wish Arthur had it so easy. But in due course he made it in. Turned out we weren't quite as close to the midpoint as I had expected, I think he traveled about 180 miles, maybe a bit more, while we went about 130 one way and 140 the other, but it certainly was a good place to meet and I think we all enjoyed looking at the cars that were on display there. The parking lot was quiet, uncrowded and a perfect place for taking the parts from his van and loading them into the back of my truck.

So the transfer was made and we're now back home. Beautiful parts too, I must say. In the morning I'll do a proper inventory, for now I'm content to let them rest in my trunk while I rest from the day's activities.

Arthur once again I must thank you for this most generous contribution and you may rest assured that in doing so I am expressing the gratitude and appreciation of each and every one of us who have embarked on this quest. We welcome you to our ranks with open arms, and look very much forward to meeting again at the summer meet.

psst: Guys, he should have his Cobra running by then. Now that's a car I want a ride in for sure!

Jim

[accobraman50]

The trip home was a breeze.  When I reached the site of the accident on my way back, traffic South bound was still backed up for a mile or more and the debris clean-up was still in progress.  Bad day for a couple of truck drivers.  

Jim, When I got back to the shop I found that I did not pack the 12" splined shaft.  It will stay in my steel rod supply unless someone has use for it.

Regards,

Arthur

[accobraman50]

Jim, have you seen these IRS suspension mods?

Arthur

http://www.streetrodgarage.com/index.asp?PageAction=VIEWPROD&ProdID=584

http://www.cp-performance.com/photo5.html

[BlownMGB-V8]

Thanks Arthur, quite interesting to be sure. The MG is probably Kevin Jackson's car, he posted a photo on page 3 above and has been a lot of help in sorting out the IRS. The other link is something I hadn't seen before but it has some nice touches. The inboard coil-overs have the wow factor, but unless we were building an open wheel car where wind resistance was a factor I don't see much point in them and would rather have the inboard brakes for unsprung weight reduction. I do like the easy toe-in adjustment link though and a top link is an advantage. I'd like to see more spread on the LCA pickup points or a triangulated UCA for better thrust control but it looks like a decent design. Might not fit under an MG without major modifications. At the very least the battery boxes would have to go. Also the way the toe in adjustment link is made reduces the rigidity of the LCA in torsion to a significant degree. With a triangulated UCA it wouldn't matter because there'd be no torsion but the two point link gives no resistance to acceleration forces.

I do have a question or two about the IFS. This is an Arntz/Butler unit right? Is there a page where I can look at the specs for it? I'd like to know what calipers and rotors it uses, others on this board may be interested in going to a chevy lug pattern. I noticed on the Cobra board that they use Camaro, Jag, Nissan and Mustang  brakes and I'm just wondering how much interchange there may be between them and in what ways. This is an area where I think we have much to learn from the Cobra people and it could give us a lot of wheel and brake options that we don't now have. I recall you mentioned that these are the 12" Camaro brakes and I see where there is also a 10.75" chevy option which would require a different caliper of course but could be useful for someone who wants to stay with the 14" rim size. Believe it or not, there are a few out there, and I also run 14" wheels on my car currently, though that is likely to change within the next year or two.

I must confess I tend to hibernate through this part of the year so I still haven't unloaded the truck. I did open the box with the sparky parts and had a quick look, but I'll no doubt have more questions as we go along if you don't mind.

Jim

[accobraman50]

Hi Jim,  

I've just gone through my records to refresh and reboot my brain on what was involved in doing the Cobra brakes.  The brake rotors are 11" diameter 1968 Camaro.  I have notes that also show that these may be the same as: 1968 to 1988 Nova. 1969-1972 Oldsmobile Cutlass and F85.  A GM parts supplier should be able to make sense of it.  I knew a guy at NAPA  that gave me some of this info.  I also noted that I found that these rotor-hubs were available from from a performance supplier as a two piece hub-rotor combination.  I did not keep part numbers, as I saw something (Fast Cars) in the future, although I did'nt know of Ted at the time.  The two piece combo would be ideal for anyone wanting to do this mod today, as the hubs require some machining.

There are no places to read the specs about the Butler brakes.  The inner and outer bearings on the Camaro have the same inner diameter dimension as the MGB stub axle/bearings.  So the Camaro bearings would fit right on to the MGB.  However the the distance between the inside and outside of the Camaro bearing as installed in the rotor are about roughly *3/16" wider then the MGB. (* will find out and confirm this exact dimension.)  Butler's cure was to machine the rotor hub inner bearing recess deeper by the roughly *3/16". to align the plane for proper bearing/seal fit.

The rotors on mine (yours) are different.  I did not machine the inner recess of the Camaro hub.  I worked  a couple of doors down from Berry Bearing (now known as Motion Industries) and found a bearing set that was thinner.  However, I ended up having to machine the outer bearing recess roughly 1/8" deeper so that the castelled nut would be deep enough for the cotter pin to fit the hole in the axle.  Thinking about this now it may have been easier to change the outer bearing to a thinner one too and eliminate the machining.  I don't know why I did'nt take this approach.  It may be worth looking into now, as there are so many bearing combinations available from bearing suppliers.

The caliper/bracket is not a modification I would consider doing today even though the caliper is still available for about $75.00 from NAPA. Have other MGB guys created brackets to fit multi-piston calipers to the Bee?  The bracket for the caliper was modified by Butler Racing. Caliper and bracket were 1974 Dodge Dart 400.  

Let me know if you need more info.

Arthur

[accobraman50]

Hi Jim,

While combing through my records on the suspension today, I took the opportunity to put together the the costs of the items that I donated to the project.  

Front suspension parts & labor $ 3,110.00
MSD 8981 $220.00
MSD 8738 $  69.00
Aldan shocks $100.00
Catch tank $19.00      

Total $3,518.00

I've not included anything for the delivery service to Indi.

Please review and let me have your comments.

Regards,

Arthur

[MGBV8]

Arthur,

Awesome contribution!


"...the same as: 1968 to 1988 Nova"

I believe you meant 1968-1972 Nova. That is what I scrounged disk brakes from for my '68 Camaro.


More interchange info:

http://www.chevy-camaro.com/faq/chevy-camaro-faq-first-gen-disc-brakes.shtm

[BlownMGB-V8]

Arthur, that sounds like it is probably accurate. We should get with Steve DeGroat (sec/treas) for any followup paperwork you need. Interesting how close that comes to the Fast Cars IFS, but then Cobra parts have never been known for being inexpensive. These parts will serve our purpose quite well. As I mentioned on the thread before, we are not building the ultimate BBB/MGB, merely pointing the way. It will likely remain for others to build the 2200 lb car.

I imagine we'll exceed the $5000 reporting minimum this year which means the IRS paperwork will have to be filed, including about a $400 fee. So we need to plan for that. The paperwork and fee won't have to be submitted until closer to the end of the year but I'd think we'll all feel more comfortable sending it in sooner. Any contributions earmarked for that purpose will be set aside until we have enough to cover it and a regular report made as we approach that goal. Currently we have $449.46 in the treasury.

At the next Roadmaster Weekend where we have visiting participants (always the last full weekend of the month unless announced otherwise) we will inventory our parts and select surplus for auction, decide on how to distribute those parts and do whatever packaging is deemed necessary. Everyone's input here is welcomed. My own thoughts lean towards offering the parts to participants and visitors to this site first at a fair market price, and then taking them to ebay. In that way some of the enthusiasts here can support the project indirectly, bearing in mind that even if they could get the item elsewhere for less, in buying it here they are supporting the Roadmaster Project.

Looking forward to a good summer.

Jim

[Citron]

Arthur,
Thanks for the great donation.  As trs. I will have figure out how to get you a receipt for you records and what else to do.
I will seeing my tax person this month and will discuss it with her.

Steve

[BlownMGB-V8]

More good news. There will soon be a mig welder here that we can use on the Roadmaster project. Bill Young sent me information from Craigs list and I made a deal with the seller, then Bill made the exchange and will ship it to me here while at the same time I will send him a check to cover cost and expenses. This will not come out of the  BADASS treasury, but I will make it available for use on the project. The unit is a Snap-on 120v with variable wire and heat, spot and stitch weld adjustments. I have a bottle of gas to use with it already and Bill has  checked it out for arc and feed so we should be good to go as soon as it arrives. Looks like the sill and floor work just got a whole lot easier.

Jim

edit: Incidentally, in case anybody was wondering why I own this mig instead of BADASS, I left it up to Bill to decide since he found it, whether he wanted to keep it, donate it, or let me buy it. He chose the latter and I think that choice satisfies all parties although I know Bill is still looking for a welder for himself. The reason I say this is because it furthers the project, which was Bill's intention. It doesn't cost the treasury anything which also helps keep us on track, and it gives me personal control of the asset which I like in the event our construction site should ever change. Just wanted to be sure that made sense to everyone.
J

[BlownMGB-V8]

Bill Spohn: "People tend to underestimate the forces involved in the suspension and I can't count the number of bent Panhards and lower links I've seen. "

To add to that sentiment, from my own knowledge and experience in dealing with loads and stresses, I can't believe the number of poorly designed rear suspension links I've seen. With the amount of development work that's been done you would think that some of it would have been carried over from F1 and Indy cars to street IRS setups but somehow most builders just keep overlooking the monstrous forces applied to the rear suspension components. My theory is that they look at the slender and lightweight links used in F1 and want them, but not understanding the forces involved neglect to account for the weight difference and other factors like durability and differences in material choices, then make design changes without understanding how different loadings affect the part. LCA's are a perfect example. Any LCA on a car that uses the half shaft as the UCA is going to see some pretty large torque forces. Jaguar accounted for this with a very heavy LCA and beefy pivots. So what does the aftermarket do? Replace the rigid hardened steel bearings with plastic and make up a light weight LCA that cannot possibly handle the same torque load because they do not recognize that there even is a torque load on that part. And if they do add a UCA they don't triangulate it but attach it at two points only and expect it to compensate for a spindly LCA without accounting for the fact that a two point attachment cannot control torque in the least. Sorry for the rant. I've been trying to understand it and it just doesn't make sense to me.

On a lighter note, we have the new front suspension unloaded and sitting on the front of the car.
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Obviously things are getting a little cluttered but we'll get that all sorted out soon enough. There are so many things in the photo that you almost can't see the suspension but I'll get to those other items shortly. It's a pretty decent suspension, just heavy, difficult to make adjustments to, and not possessed of modern geometry but quite capable of doing the job we ask of it. Much of the weight is in the brakes, and as Arthur noted, the '74 Dart 400 calipers are a heavy choice (and becoming hard to find). But, consider this. In 1980 I went from wire wheels  and stock brakes to Mustang brakes (roughly equivalent to what we have for the Roadmaster), 265/50-14 tires and 11 lb wheels and the overall weight of the package was virtually unchanged. Those wire wheels are HEAVY! So our wheel choice can definitely offset the extra weight of the big brakes, and with a little extra sprung weight the ride should be about the same.
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Here is our current choice of springs. The pair in the center are the old ones out of my roadster, Huffaker -1 with a little sag. The yellow springs are Cobra. I haven't checked wire size but they look very similar to the first ones, and could very well be identical (when new). The next set is stock GT and the outside set is probably TR-6 front springs. At least we have choices.
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Here we see our ignition system shaping up nicely. In addition to the MSD-6 donated by Mike Domanowski we now have a soft touch rev limiter module and an electronic timing control module, all msd so it should all be compatible.
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Here is the thermostatic fan switch, Jaz catch tank and there are various other parts lying about as well.
So have fun looking at the photos and trying to see what you can identify. Something to do whilst being snowed in.

Jim

[Bill Young]

Jim, I would have been more than happy to donate the welder, but after I thought about it for a while I realized that the assets of the organization will eventually have to be disbursed when the project is complete and any physical assets other than the car could be a problem. Better to let you purchase it and continue my cash donations which can be applied to the car for parts or services. I think I've already found another small MIG machine, so no problems there.

[BlownMGB-V8]

Thanks Bill.

We're now officially cutting metal on the IRS!
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Here you see the original half shaft alongside one that is rough turned. The diameter is 1.215" and will be turned to finished size after the tubing is purchased for making up the finished part. These stock half-shafts are not balanced, are in the rough forged condition and as such are not round and not especially straight either. The turning was done on a small 7" bench lathe with a cemented carbide tool at 850 rpm and there was a fair bit of bouncing going on which eased up noticeably as the shafts were turned round and straight. There are still variations in the ends but the balance overall should be much better when we are done
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Here we have both shafts rough turned. The dark streak is all that remains of the original forged surface. Since the original width was 66" we need to remove 7" from each shaft to reach the MGB's 52" track width and could consider taking another 1/2" or so to fit wider tires. This would be the marks on the unturned shaft above, showing how much shaft will be left to insert into the tube as a pilot. Simple mild steel tubing should suffice, but with a wall thickness of around 1/4".  I have on hand some 2" x 1" hollowbar but that would be overkill and add more weight than we need, as well as requiring a good bit more turning. These shafts need to be able to stand up to about 2200 ft/lbs of torque so a thinwall tube just won't do. CWI uses a 2-1/2" .156" wall tube for their driveshaft style half-shafts, our OD will be about 1-5/8 to 1-3/4" so a thicker wall is needed.

Jim

[Phillip G]

Guys,

Great project !

I see a lot of brake/hub/ work.

Has anyone got a good supplier for upgraded MG B lite weight O/E disc rotors - ones vented, slotted and much drilled for SCCA road racing ?

Phillip G

[accobraman50]

Jim,

Great job on the turning of the half-shafts.  Will these be a press fit into the tubes?

After reading about the vibration you encountered while turning them, I'm concerned that I never once considered having the half-shafts on my Jag rear end balanced.  I don't know why the thought never crossed my mind, Duh! Had the engine balanced, and flywheel, clutch, driveshaft too.  Never considered the half-shafts.

I'll be dismantling the Cobra to get it ready for paint in about three weeks.  At that time, should I consider pulling the shafts & U-joints to have them balanced?

Would appreciate all comments  .

Arthur

[BlownMGB-V8]

Arthur, I don't think I'd tear a car down to balance the shafts, but if I was in there anyway I'd plan on having the balance checked. Chances are good you'd never notice it, but if everything else is running nice and smooth you might. At highway speeds depending on tire size you would be in about that range. Your machinist should be able to balance one without drilling holes in it I would think, grind a little off the high spots. I'm guessing you have XKE half shafts. Being shorter they should be a little better balanced to start with. The probable reason most people don't bother with them is that the half shaft rotates 1/3 to 1/4 as fast as the driveshaft. I could have run these up to over 3000 rpm but wasn't comfortable with doing that. I'm sure they would have shaken rather badly at that speed. As far as the brakes go, the rotors should be pretty well balanced to begin with. I can't say I know but I'd think the manufacturer takes care of that for you. Still it would be interesting to check just to see how close they are out of the box. Should be really close. The half shafts have a center hole drilled in each end so they are mounted up between centers for machining. A driveshaft shop should have fixtures for attaching them by either the flange or u-joint to their balancing machine. Sometimes U-joints come center drilled also.

Once I have the tubing the shafts will be turned for a light to medium press fit in the tubing ID. Although a heavy press fit might sound better, in practice it requires an absolutely straight setup in the press to avoid deforming the tube and with the rounded ends of the yokes that is difficult to achieve. I'll probably use a .002" interference fit, leaning towards the tight side and then weld the ends with the shaft between centers on an old scrap lathe bed, then pop it back in the lathe for final cleanup and to make sure it runs smooth. I've had lots of practice on driveshafts and have no doubt that this will give us the right part for the job.

A tubular driveshaft such as those sold by CWI would be a lot lighter, something worth looking into if there is clearance. In our case I'm not sure if it would be an option, but this is a low bucks project so we're going the low bucks route.

Something else worth thinking about if you build an IRS with a top link (UCA), Spicer sells various sizes and lengths of splined couplers. By proper selection it may be possible to combine a male and female spline with the proper u-joints and flanges to get the needed half-shaft length. Since these are fully machined parts no balancing is needed and this gives a viable alternative to CV shafts. In fact it is probably the simplest route to converting a Jag IRS to full control arms and floating half shafts.

Jim