Road Speed and Modding MVs

[chris vickery]

Guys
I have recently entered into an online debate elsewhere regarding newbies whose first questions regarding MV purchase is "how can I make it go faster?"
For whatever reasons, this irritates me like crazy.
I am of the opinion that our heritage vehicles were engineered in such a manner that they were intended for certain roles. For the most part, HMVs are cumbersome, slow moving, torque driven monsters with a sole purpose to transport man, machine and cargo over rough terrain. As such, they were purposely built with low range gearing and with engines of limited horsepower for the era in which they were created.
Any of you who know me will understand that I am a purist at heart but not without reason.
I understand the addition of extra lighting, signage etc for safety reasons, to be seen. I can also see minor changes to get a little more out of our vehs without being extreme. Unfortunately I am troubled when I hear those words uttered as I know in the back of my mind that the new guy wants his old army truck to be a hotrod and this, my friends, is an accident waiting to happen and would certainly be detrimental to our hobby. Afterall, not every shade tree mechanic is an automotive engineer...
Am I over-reacting? Thoughts?

[maple_leaf_eh]

I am undoing a PO's mods - 1/4" holes on the fender lips for some sort of rubber flares, evenly spaced holes on the front bumper, two discrete holes on the bottom of the grill for the wires, mounted mud and snow tires, foam insulation residue in the strangest of places, 4" dia car radio speaker plates welded to the rollcage, a hole where the car radio used to be in the dash, a panel across the rear body (actually a smart way to keep stuff inside the body), and a modified civilian swing-out tire rack. Lots of 4x4 Jeep off-roading details which are all wrong for a stock M151A2. Not slagging the PO, just saying I own it now and this is what I want to drive.

[rob love]

For some, a bit more speed is no different than the added lighting and reflectors. Driving a Chev at 40mph on the highway can be dangerous if someone travelling the same direction ends up smackin your rear. (OK let the puns begin). I'm not saying the military vehicle has to go 60mph, but if perhaps slightly larger tires gives it a few more MPH, and still retains reasonable historical accuracy, then OK.

I drive my Jeep to and from work on any day that it's not raining. The highway I travel is posted at 90kmh, which means most are travelling 105. I only take the Jeep to 50-55mph (a bit under 90) so while I consider it reasonable, I am pretty sure the dozen vehicles behind me would rather I found a different route or a different ride.

[The Bedford Boys]

We put a Bedford K crownwheel amd pinion into a friends Bedford MW. The truck will now hit 60mph. Made it into a much nicer truck to drive, not that we go everywhere at 60mph, we really just wanted to be able to cruise at 45mph comfortably.. (35mph original top speed is a bit tedious in modern traffic). Im a bit of a purist myself, but I also think that as long as the vehicle is on the road, then history is still being kept alive

[Lynn Eades]

Rob, there is nothing wrong with being slow on the road. If I'm driving something slow, I regularly pull over to let others go by. If I'm in the car, I like to go as quick as I'm allowed.(sometimes plus a little.... Did I write that?) I then hate the inconsiderate B with 10 cars up his A with no intention of letting anyone through.
It's all about keeping left (or right) and exercising a little respect for the guy your holding up.

As far as modification goes, aside from handling issues, one of the issues with old M.V's. is braking. If you're going to increase the h.p, what are you intending to do about stopping the thing?
Some of these old vehicles were under braked at 30mph. It takes a lot more brakes to haul them up from 60mph. and they don't usually lend them selves to serious upgrading.

When I was in the army I remember seeing The brakes from an RL Bedford wrecker cooked like you wouldn't believe. It had another Bedford RL on a suspend tow. We have some steep hill ranges here. He was on a long descent and although the driver was supposedly trained to do the job he had not followed the rules. He'd let the rig go too fast, and if I remember correctly was lucky not to have been in a major accident.
Many of these old vehicles are fine to drive, empty, but load them up and they require a bit more skill and lots more patience.

[Keith Webb]

When I was regularly driving both the F60L or the C15A sigvan I used to think of the many cars behind as my "followers". I'd always let them pass when I could though.

[Ganmain Tony]

To put it simply - I agree with you. I am a bit of a purist at heart as well.

I have frequently been given advice with my truck on how to make it go faster by completely modifying it.... in my opinion, modification destroys the soul of the vehicle.

That said... it is on 12 volt, has bigger profile tyres, has an after market oil pressure and temp guage and has indicators.

It even has one working headlight which I guess would have been blanked off during convoy work in WW2.

I like to think I did these to improve the vehicle to keep me safer on the road..... in a world of fellow modern motorists with which I have the delight of sharing the bitumen.

My thoughts... as a contribution to the discussion.

[Luke R]

A little bit off topic but as a driver, I get annoyed being stuck behind old dears caravan which is a little to big for the falcon/commodore that's towing it but I don't have a problem sitting behind a classic/vintage truck, car, etc.
But that's just me being an enthusiast I think.

[David Dunlop]

Chris. It probably boils down to the degree of modification and why for me. I tend to look at it from a respect and understanding perspective. Some people simply do not understand what they come into possession of (and don't care even if politely pointed out to them), they are fixated on a personal goal with the vehicle they have and off they go like a bull in a china shop, with complete destruction of the vehicle the ultimate end point. In this area over the years I have seen a very original slat grilled Canadian Contract MB totally trashed by an owner that insisted on dropping a Chev V8 into it along with a power steering setup and adjustable highback modern front seats. A very complete Cab 13 Gun Tractor out in the Shilo area many years ago had the full body ripped off of it and tossed, along with the engine and the frame turned into a giant mud truck with an old pick up body put on it. Similar fate with a COE FWD Tractor here in Winnipeg that had full canvas and all the fiddly bits when found. In fact, right now, just three streets away from where we live, some young kid brought home an absolutely mint Early 30's Chev coupe this spring he bought from the neighbour of his Granddad in the country somewhere. It was a barn find he says he paid $1,200.00 for and it has been sitting outside, at the side of their driveway for three months now getting rained on and covered with bird poop. He plans to 'hot rod it'.

From a personal perspective, I have always thought it would be great to own a Cdn Grizzly or Sexton and also be able to restore the proper RCASC Tractor and trailer rig to move it about with. But I always had it in my mind to find two Tractors: one for full on restoration, the second to carefully repower to get acceptable highway speeds out of. But that is just me.


David

[maple_leaf_eh]

Originally Posted by David Dunlop

...

From a personal perspective, I have always thought it would be great to own a Cdn Grizzly or Sexton and also be able to restore the proper RCASC Tractor and trailer rig to move it about with. But I always had it in my mind to find two Tractors: one for full on restoration, the second to carefully repower to get acceptable highway speeds out of. But that is just me.

David

Where do you draw the line at modern engines in old vehicles, in particular V6 diesels and automatic transmissions in Shermans? There is a shop in France that ditches the WW2 powerplants for much more fuel efficient and reliable engine and transmission combos. Out of highway buses I think. The exterior is the same, but not the sound or the innards.

[David Dunlop]

Terry. If they are doing it to extend the service life of the Sherman, why not? Brazil and Isreal have done amazing things to Shermans and Centurions over the years to keep them active, and in the end another interesting MV variant is on the record books.


David

[Phil Waterman]

Hi All

Interesting topic with many variations to the reasons to change and engine.

Of my three CMPs only the HUP is what I would call stock, in that I made a very conscious effort to keep it as original as possible. I was lucky in that it as my first CMP was the most complete with virtually every part installed on the truck when it was built still there when I got the truck.

The C60S and C60L were not what you would call complete both have what you would call "locally supplied bodies" both now have bigger and more powerful versions of the Stovebolt Six Chevy engines a 261 and 235. Neither of these engines have really change the inherent top speed of the truck. The more power just changes how fast you get up to speed and how much of it you can keep on anything other than flat ground.

Drove the Pattern 13 C60S with the orginal 216 engine for many years and it was perfectly happy and stable at registered 50 MPH which with the 11:00x20 is closer to 60 MPH. But any grade was pulling the truck down in speed. This is where the necessity to me of up engineing to the 261. It is the difference of taking the mountain road near me 9% grade in third gear at 30 MPH with hazards flashing vs 20 MPH or less in second gear with the 216 engine.

In the years that I have been driving these trucks the road traffic in out area has increased very markedly as has the number of heavy over the road trucks that now take the mountain grades at 50 MPH with out slowing down. The younger drivers on the road today also don't have any under standing of what to do or not do around trucks.

I will echo the concern about not over running the brakes more power even if you don't really drive faster than original top speed. Keeping your safe following space for you brakes in heavy traffic can be hard. On the topic of brakes while my C60S doesn't notice the generator trailer when I'm towing in terms of power or speed. The brakes surely know that there is something back there.

More speed for some MVs it a futile effort, they just are not happy above a certain speed and they do everything to let you know it. Of my three CMPs only one is happy above 40 MPH and I don't thing that there is much that could be done short of balancing every part in the drive train basically re-engineering everything. As I say one is happy at speed and has always been so.

One last comment re-engining an old vehicle to keep it moving when an appropriate vintage engine is not available is of course preferable to letting the scrapies catching it is of course preferable.

Cheers Phil

[David Dunlop]

Phil. Good point about limited vintage engines and parts. For CMP's, I suspect the Chev fans will hit the wall sooner than the Ford fans as far as the supply of the vintage 216's and parts running out. It completely lacks the 'hot rod capability' the Ford V8 gained which has kept modern blocks and parts in good supply for it, though not without modification challenges in their own right.

I read this weekend of a Spanish Buschon 109 restoration in the USA somewhere that have encountered a similar dilemma. The original Daimler engines for the Me 109 are so hard to find and rebuild costs so steep, they are working on an Allison conversion for their project. It is apparently a smaller block than either the Daimler or Rolls engines with a good supply still around and they discovered, with some skilled engineering, it will fit within the original Me 109 G9 cowl work. If it all comes together as planned, they end up with a plane that can be easily converted to the Daimler in the future, but can still fly now without having to be concerned about nursing as much time as possible out of required engine hour time between overhauls.

Now as long as the powers that be don't continue to mess with gasoline octane ratings...


David

[Harry Moon]

While my mods are limited, the 10.50 X 16 tires gave me more speed over the 900 X 16. The Fenton Dual exhaust manifolds gets me a lot further up a hill before gearing down and inching up the side.
I choose my routes carefully before hand, taking into consideration turns with limited vision, hills, up and down.
But to me it's all about "Momentum Management".
Looking way ahead on lights, stops, merges etc.
Worst thing is that I'm going to make that light followed by a yellow.
Annual brake inspection and adjustments a must.

[David Dunlop]

Interesting read so far in that one's location seems to play a noticeable part in the engine decision making process. Not really much of a factor at all here in the Winnipeg area. Dead flat as far as the eye can see north and south for hundreds of miles. However, west of here in the Brandon and Shilo area one starts to climb a series of steps up the old Assiniboine River Delta formed at the bottom of the old glacial Lake Agassiz. And if you go an hour East, you get into Pre Cambrian Shield country of Northwest zones real quick with lots of hills and twisty roads. Neither areas are very original CMP friendly, and if you are frequently on the road, a well thought out engine upgrade is a logical option. I suppose if you are in an area of expensive gasoline (compared to diesel), if there are any such places still left on the planet, another good reason for a well thought out engine conversion.

Also interesting how the common factor of more power/speed needing to be offset by braking ability plays into it. Wonder how many conversions have ended badly because that was not thought through properly.

I often wonder how that mud truck conversion of the FWD ended up, primarilybecause of the chain drive configuration of the original power train being exposed to what I recall wax going to be a 5.7 litre Hemi.

David

[universalgrl]

Convoy speed "25 miles an hour"

[Bob McNeill]

Every day we run into speed bumps of one sort or another, maybe your grand dad doesn,t get out of his car as quick as you, the old lady has trouble finding her change at the checkout and your in a hurry, IF someone is a bit slower than you OR does something different to the way you do it, sorry that's life, learn to have consideration for others [ walk a mile in their shoes ] If I,m doing 35MPH going to an event enjoy the drive you will get past, hopefully safely. And since we travel in convoy watch out for the next pothole in lifes road.