Road Speed and Modding MVs

[maple_leaf_eh]

Originally Posted by David Dunlop

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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"