vanscottbuilders

Found this picture of a 1923. Would be great to restore mine to look like this.

That would be a very cool truck/trailer combo. Good luck with your project!

Paul Van Scott

TandemB,

There is a stamping on the rear end carrier housings that should indicate the rear end ratio.

I am not certain as to the exact location, depending on the model of rear end.

Someone will chime in here with the exact location. But, being an impatient person, I have

found that if I look for a flat machined surface on the carrier and clean it off good, the ratio numbers

have always shown up. Usually with initials showing the carrier type, such as "CRD".

Be a little careful though, the numbers you want will be stamped, not cast, in the housing - made that mistake once already.

The subject of changing the ratio for more speed is pretty controversial around these forums.

If you are using the 673, 711 or 673T diesel engines, there isn't an overbundance of horsepower or torque

to allow a high road speed along with good pulling power. If you are using the truck as a dump truck, that might be a real

consideration.

As it was recently explained to me, Mack used the heavy duty rear end differential assembly, with all of it's big gears, to deliver the bulk of the torque multiplication, rather than using the relatively weaker transmission assembly like other manufacturers may have done. Consequently, the old Macks were extremely durable, albeit slow. The Macks could also use slower turning, lower horsepower engines. Again, for dependability, and also for fuel efficiency. Monkeying with the Mack formula now, fifty years later, probably has some consequences that we haven't planned on.

There isn't any one answer - but, I think that using a different transmission with an overdrive (or two) for better cruise speed is a logical solution, especially if you are going to work the truck with the original diesel engine.

Paul Van Scott

Doug,

That sure looks like a really nice R model.

What are you going to do with it?

Paul Van Scott

Well, we're at $3.699 for diesel in Upstate NY. And it is going to get a lot worse.

This isn't going to go away.

Just like most low tech industries today, we are working for a lot less money today in the building industry than we were twenty years ago. Seems ridiculous.

The only fix is for each and every one of us to reduce our our dependency on imported oil.

And, at the same time, we need to stop buying imported junk! The fact that the WalMarts and K-Marts and Kohls and on and on can exist in this country by pushing Chinese inferior products on us is just plain criminal. And it's our own fault - we keep buying useless stuff, and lots of it. Just to feed our arrogant greed. It's very sad to look at what we are doing to ourselves.

Let's stop buying imported junk, and go back to making our own goods. That fixes a multitude of problems in our society. American pride goes way up, welfare goes down, and we can work on becoming a strong country again. Seems like a worthwhile goal.

To fix the oil problem permanently, we need a suitable alternative for about 50% of our current consumption.

Bio-diesel has some promise, as does hydrogen as an auto fuel, and ethanol as a general use fuel. Obviously as the price of crude oil rises, the alternative fuels become more feasable.

We probably will never be able to make public transportation a reasonable alternative in the US. We just plain like to drive too much. So public transportation is not a realistic part of the picture, at least not yet.

Less expensive and renewable electric power sources will also be a big part of the "oil hostage" solution in the future.

But the biggest and most powerful piece of the whole puzzle is you and I. All of us, every single one, has to make an effort to change. Period.

I believe very strongly that we have the best country in the world. A little crazy at times, perhaps, but the best country in the world. If we can't work to keep it great, then who will?

Sorry for the rambling, but I've had enough of hearing everyone try to blame someone else for these problems. These problems are our own fault, and we are the only ones who can fix them. Let's get busy.

Paul Van Scott

gvam,

Check the web for AllMacks in Harpersfield, NY. (allmacks.com)

Kevin All has a lot of restorable trucks on site, and he has been a great guy to deal with.

It's worth a trip for you (maybe 4 hrs.) to his facility to see the inventory.

My B-67 was originally a Beck Motor Freight tractor from Philadelphia. It will be finished as a

composite of about three trucks, as a result of the cab rust and changing the rear end & transmissions.

I may be going a little farther with the restoration work than I needed to, but the end result is a truck that I know I can depend on

for regular use. I absolutely hate things breaking when I'm using them, so I am willing to do what's necessary while their in the shop.

A truck like this could have been roadable without taking the cab off, and without ever removing the engine or transmission, if someone

were just going to ride around on Sunday afternoons and go to the shows once in a while. Still a great toy, just not as useful as a

completely renovated example.

That's what is nice about the old trucks - anything goes! And everybody likes them. And - they can be finished over time, at your convenience.

If I can be of any help with your project, please feel free to contact me through BMT.

Thanks,

Paul Van Scott

I won't be alone in telling you to contact the Mack Museum.

The curators there do a great job of providing you with information on your truck.

Don't forget to send them a donation. (protocol)

You will find their contact info elsewhere on this site.

Welcome aboard!

Paul Van Scott

this is a nice looking B-67 that was on the F.L.Moore and Sons calendar this year-best looking truck on the calendar.Didn't say who owned it or where it was from.

That's a real nice B-67. It's a little unusual with the black frame and blue fuel tanks and fenders.

The common two tone seems to be the frame, fenders and the fuel tanks are the same.

Good colors on the old girl.

Thanks,

Paul VS

Hey Morgan,

Do you know the original spec for the springs?

And, if you were to guess, how much stiffer would they want to be before there was a potential for excess valve train and camshaft wear from trying to overcome the added spring strength?

Thanks,

Paul VS

Paul,

I built a system similar to what you are after for my B67. There are pictures somewhere around the house. Works great, simple to build and sure saves to old neck and guts. I'll start looking for pics but keep after me - I got old timers disease!! 740-742-2203

Tom

Thanks guys.

Tom you told me about this when I first called you to register the truck two years ago! And I'm the one who forgot.

I am reassembling the truck now, so I'll keep after you like flies on s--t!

Thanks,

Paul VS

I was hoping you would chime in here.

That's what I wanted to hear Glenn, Thanks.

The exhaust brake manufacturers tell me that, because of the low RPM on the Mack, more back pressure is better for braking.

But everything I know about pressurizing the exhaust system with no cylinder compression says that the valves will float, or close slower than normal.

I don't think I am going to go further with this idea, unless someone can really convince me that there won't be valve problems.

I do own a new TEC engine brake. As I have said, it doesn't look like there is clearance under the firewall for it. But I should really measure it to be sure.

And I was hoping to keep the TEC brake for a future 285hp project I have up my sleeve.

Probably the best research I could do right now is to find the best performance brake lining to get the most effective braking from the service brakes. The old truck won't be used for revenue anymore, and I'll never wear the brakes out. So a softer material might work out well. Do you know anything about what might be available?

All I remember about driving the B models thirty five years ago was how many times I thought I was not going to stop! I'm way too old for that now.

Thanks,

Paul Van Scott

Nice to know there is someone moving at about my pace - AND has photo trouble too !!

Best of Luck with your project.

Paul Van Scott

this is the closest thing to a shop i've got-a shed packed so full of crap I can barely get in it!

Don't let those pictures of my B-67 fool you.

Shortly after they were taken my uncle Jimmy (also my shop partner - we each have one half of the space and the center area is up for grabs) moved in his old Kenworth W900A and took the front end apart. Then he brought home Morgan's 351 Peterbilt project - now that's in there. Along the way I brought in my Willys pickup (recently sold it) and my Ford Jubilee tractor. Then my spare Mack motors and three transmissions, along with a derelict rear end unit with an air ride system I thought I might make use of. (Another failed brain fart)

So the real truth is that you can't walk around in my shop either! In fact we spend more time moving stuff around than we do actually working on anything.

Years ago I built a shop for one of my uncles, a retired master mechanic. At the time I couldn't understand why he would not let me build him a bench.

All he said was "if I have the space, I will fill it with junk".

Truer words were never spoken.

Seriously, we have been pretty fortunate in the equipping of our shop. My uncle has semi-retired from his heavy haul trucking operation, and I have been in the building business for a long time, and both of us have been involved in automotive and racing projects all of our lives.

So we have gathered up stuff along the way.

The shop space itself is rented from a good friend in his large excavating business facility. The building was originally used for the manufacture of pre-cast concrete beams, and it is huge with 22' ceilings. So the electric service is three phase and heavy duty. It is well heated and well lit, clean and comfortable.

We have a new 24 x 40 x 20' high Gorbel bridge crane that is powered in all directions and has a 6000# electric hoist. It's a neat toy! (Gorbel is a local company, literally adjacent to my back yard). Got a large air compressor set up. And between us we have a good selection of heavy 3/4" and 1" drive air wrenches for the big stuff. Came up with a good used 5000# propane fork lift. And we have an older large Lincoln wire feed welder and plasma cutter, and a couple of sets of torches.

We are also lucky enough to have a large quarry yard very close by that we park all of the trailers and "future projects" in. (Jimmy still owns around sixteen trailers of all shapes & sizes, mostly lowboys and variants of lowboys like beam trailers, step decks, jeeps and stingers) All out of sight and fenced & locked.

This is something that we have planned on for a long time, and I think it is coming together better than we had envisioned. We are feeling pretty blessed, and both of us are looking forward to retirement and working on our trucks.

Paul VS

Does anyone have any experience with American Carrier Equipment's Superide air suspension cross member?

The system uses the existing leaf springs and replaces the rear frame cross member in the single Mack B model.

Looks pretty interesting. So I am looking for feedback.

Thanks,

Paul Van Scott

I have received a reply by phone from US Gear, manufacturer of the D-Celerator exhaust brake. They say there is no undue or added stress on the engine with a properly sized and properly operating exhaust brake. quote:"An exhaust brake is basically a throttle plate, similar to any gasoline engine, albeit with the throttle on the exhaust side of the engine rather than on the intake side. The exhaust brake causes positive pressure in the engine, which slows the piston in the diesel, rather than a vacuum which slows the piston in a gas engine when the throttle is closed."

The comment was that the valve failure, which indeed does happen, is caused by the pressure overcoming the valve spring strength and slowing the exhaust valve closing, which in turn affects the rocker arm and the followers', or lifters' ability to follow the cam. After a short while, valve, or as Morgan pointed out, camshaft damage occurs. Over pressure is most commonly caused by the butterfly valve sticking closed, or by orfices in the butterfly becoming "coked up" from exhaust deposits. Both scenarios can cause severe over pressurization. (The Williams brake unit used small orfices in the butterfly to limit the amount of back pressure a brake would allow)

The US Gear unit, which appears to have better control over the back pressure by using a second smaller "waste gate" valve for active pressure control, is designed for a maximum of 33 psi back pressure. In a 40 psi rated engine like the 673 or 711 Mack with healthy, stock valve springs there should be ample braking assistance and no pre-mature valve failure.

At about $1,295.00, it is a bit less than a new TEC engine brake, but more important, the exhaust brake does not require a shimming plate beneath the valve cover. In my B-67 there does not appear to any room for the raised valve cover where the engine comes thru the firewall.

Interesting Stuff!

Paul VS

Cool!

I second that -- Cool!

Happy Thanksgiving everyone.

Paul Van Scott

I need to correct myself - I said that the exhaust brake back pressure for the newer "pickup" diesels was low at 14 psi.

It is not - actually it is around 40 psi.

And, apparently, the Mack diesels of the fifties and sixties (not including the newer Maxidynes) were rated at a maximum back pressure of 40 psi also. And Garth is correct in that the original Williams exhaust brake did supply 30 psi max pressure for the Mack engines.

My idea of 10 psi for less engine stress is okay for the engine, but not enough pressure to do any braking. Apparently much less than 25 psi is not very effective.

Morgan's comment about heavier valve springs has been brought to my attention by a local Caterpillar wizard. And Cat even offers a retro-fit kit that allows 70 psi back pressure in the 3406 and 3408 engines! Must stand the truck right on its nose when you lift the throttle.

I have contacted three manufacturers of these units, and I am waiting for a reply. I will keep you all posted. My general initial feeling is that putting the old engine at risk is probably not worth it. And I don't know if stiffer valve springs are even available. It's just my nature to be curious and always looking for better efficiency and better performance.

For those who might be interested in an exhaust brake - I have learned that a little maintenance is pretty critical. Lubrication and cleaning of the moving parts needs to be done frequently and with the correct high temp lube. I have been cautioned by one of the manufacturers to be sure that all operating parts are located within easy reach for service.

If the butterfly valve sticks and remains closed, which can happen, it is either time for an immediate shut-down or good-bye motor. And it could be spectacular!

Paul VS

Not too bad Barry!

It will be interesting to see if you can notice any increased business with the ad running.

Sometimes advertising is a little tough to justify, but putting your name out in front of everybody ultimately will pay off.

Paul Van Scott

Thanks Garth,

I don't have any idea how much back pressure would be tolerated by one of these fifty year old engines and their tired valve trains. Probably not as much as when they were new.

My understanding from PAC is that many of the early exhaust brakes did not calibrate the back pressure very accurately, and as a result many engines had trouble. An over pressure condition could conceivably cause a multitude of problems.

I think the pressure used today on the Dodge/Cummins, Ford/International and GM Duramax pick-up truck diesels is down around 14 psi. I assume that it is a low enough pressure to keep from driving the exhaust valves back against the springs from an open position.

It would seem to me that almost any added back pressure in the exhaust system would have a braking effect on deceleration. It should fill the cylinder with exhaust air on deceleration, making the piston work harder to come back up.

This could be way off the mark - but I'm thinking that a 10# wastegate would do the trick.

Thanks for the input.

We are hoping to load shortly for Portland Or., and load home with Morgan's Peterbilt and a GMC project. I'm not sure if I'm getting stiffed out of my B-61 cab delivery or not. There may not be room on the trailer for it. I'll keep you posted.

Thanks,

Paul VS

I've been talking with PAC about building an exhaust brake for my B-67 with a 673P diesel.

They have told me that, although they do not offer a brake for that particular engine, they could easily build me one, if I knew the amount of back pressure the engine would handle.

Does anyone have any idea?

Or, does anyone have any ideas where I might go to find out?

Exhaust brakes were, at one time, a fairly popular accesssory. So I am certain that information is out there someplace.

Along the same line - PAC says that Jacobs always built the exhaust brakes for Mack products. I have learned that Jacobs still makes exhaust brakes for motorhomes and the "big three" pickup diesels, but nothing for Class 8 trucks.

Does anyone know of another manufacturer that might offer a stock product for the 673? Williams or TEC? or?

I am interested in this exhaust brake idea. An engine brake for a 2 valve Mack head does not fit under the firewall on a B-67 easily.

I would have to shim the cab and fenders up about 1" to make it work. That puts the steering wheel pretty close to the top of the dashboard - looks like a knuckle buster to me.

Thanks,

Paul Van Scott

Photos added to original post!

Thanks Barry. Sorry to be such a meat head - but I guess I just don't get it!

And Glenn - I love that "hunting wagon".

Paul VS

Now - I think I've got it.

Unfortunately these photos are of a poor quality.

I'll do better next time.

Paul VS

Doesn't look like this is any better either. I quit.

No pictures from me.

I'll keep the descriptions coming, and show the trucks for everyone to see.

Sorry,

Paul VS

Now - I think I've got it.

Unfortunately these photos are of a poor quality.

I'll do better next time.

Paul VS

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Thanks for the info Guys! I hate being a lab rat for aftermarket parts, but the price is right and I dont see many/ any alternatives. Sounds like a reputable company and a quality product. I will post my results once installed on the 285 and in the truck, hopefully before Christmas.

Speaking of being a lab rat - has anyone tried a PAC exhaust brake with their old diesel?

It sure looks like a simple and effective way to help the service brakes.

I know Williams was a big exhaust brake manufacturer, but I haven't found any information about their current products.

We just had a rented straight truck for moving some work stuff - an Isuzu with a six cylinder diesel, and a factory exhaust brake - really nice, smooth and quiet braking. The brake would automatically shut off at about 15 mph. It was plenty strong enough to hold a steady speed down a pretty steep grade, and to slow the truck before a curve, rather than using the service brakes.

And - it looks like about half the cost of a Jacobs or equivalent TEC engine brake.

Thanks,

Paul Van Scott

Thanks, I'm going into the office tomorrow, and I will try my new found knowledge on the truck photos.

Just might work !!

PVS

I think that the problem has to be the Google Picasa photo holding system.

I will take some current pictures and try my old Kodak Easy Share system. Never had any trouble with it. And it's a local company for me.

Paul VS

If there is a nice picture here of my dogs, I think I am making progress!!

No Mack photos on the home computer.

PVS