My 1950 2R10 PU has the small Champion engine, a non-OD T9 transmission, a 5.57 Timken axle, and 215R85-16 LT tires, which limit cruise to 45-50 mph (2700-3000 rpm). Would like to cruise 60. Champion engine recently rebuilt, along with carburetor and distributor. Looking at higher speed axles, say 4.86 or 4.10 Timkens. From an engine rpm point of view, a 4.86 would increase cruise from 50 to 55, and a 4.10 would increase cruise from 50 to 60, which would be nice for freeways. The question is power. Would a 4.10 axle unreasonably bog down the engine? Thanks, Phil B.
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I wouldn't think so. In fact, I would think the 4.10, even coupled with an OD transmission would improve your driving pleasure; assuming the truck is now used for driving and not hauling. That 5.57 would be hard to live with in anything but the back forty.Brad Johnson,
SDC since 1975, ASC since 1990
Pine Grove Mills, Pa.
'33 Rockne 10, '51 Commander Starlight. '53 Commander Starlight
'56 Sky Hawk in process -
Yes, a 4.86 or 4.10 is a much better axle ratio for highway driving.My 1950 2R10 PU has the small Champion engine, a non-OD T9 transmission, a 5.57 Timken axle, and 215R85-16 LT tires, which limit cruise to 45-50 mph (2700-3000 rpm). Would like to cruise 60. Champion engine recently rebuilt, along with carburetor and distributor. Looking at higher speed axles, say 4.86 or 4.10 Timkens. From an engine rpm point of view, a 4.86 would increase cruise from 50 to 55, and a 4.10 would increase cruise from 50 to 60, which would be nice for freeways. The question is power. Would a 4.10 axle unreasonably bog down the engine? Thanks, Phil B.
Yes, it will require much more frequent downshifts on hills and in the 20-40 MPH range.
No, the T9 is a stone-age transmission and a terrible choice for a light truck. You've been looking for a T98 here and on other fora. The T98 is an infinitely better driving experience.
Maybe, since a transmission swap is in your future anyway, you should consider the Borg-Warner 3-speed overdrive option. Most restored 2R10s no longer need the granny first gear of the 4-speed for starting a heavy load on rough ground. Thus, the is the real answer for a restored truck driven unloaded most of the time. It is much more flexible and economical than the 4-speed. The .70 overdrive with your 5.57 would give a 3.89 top gear for cruising. All the OEM parts are readily available, it bolts in just like the photos in the Shop Manual show. If it were mine, I'd install a floor shift conversion.
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Thanks to both Rockne10 and Jack Vines -
I go Friday to pick up a T98A transmission from a Big 6 engined truck. It seems that T98(A)'s from Champion engined trucks are unobtainium. Fortunately, SI has the 3 different main drive pinions needed to convert Big 6 and V8 T98 and T98A's to fit a Champion engine.
The reason for the non-OD 4-speed with granny low is my personal foible - the OD 3-speed option is more practical, but even with a modified Hurst floor shifter isn't quite truckish enough for me, which is why I bought a 3/4 ton rather than a 1/2 ton in the first place.
So, my problem is whether to get the 4.86 axle offered to me, or to keep looking for a 4.10. If I settle for a 4.86, that's likely not enough change to cause serious bogging down, but then again only gives me a 55 mph cruise. If I wait for the 4.10 and find it bogs down too much, I can always swallow my prejudice and fall back to the OD 3-speed option, and all I am out is the cost of the T98A and its conversion to a Champion main drive pinion. I'm inclined to wait for the 4.10, unless someone's experience says the 4.10 is certain to really bog down. I need to make up my mind this week if I am to accept the current offer of a 4.86.
Again, thanks for all the advice and for tolerating my retired engineer's mania for detail. Best, Phil.Comment
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HI, Phil.
All we old car/truck enthusiasts are masters of rationalization. However, for some of us, Champion and truckish does not compute. ;>)the OD 3-speed option is more practical, but even with a modified Hurst floor shifter isn't quite truckish enough for me,
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Hey Jack - I have had to adapt after 40,000 miles of trailering with a 6.0L Chev 2500HD, which would tow 6,500 lb of flatbed and car up any Western freeway pass at the speed limit. So, the difference between a Champion and a Commander engine doesn't seem like much. Anyway, Studebaker must have thought a Champion engine was ok in a truck, because they put one as standard equipment in every pickup from 1/2 ton up to 1 ton. Had I known more about low-powered 50's trucks, I likely would have gone with a 2R11. But, I didn't, and I am now stuck with $3.5K in overhauling my Champ engine, and am trying to squeeze every bit of performance out of it I can. Which is fun, too. After asking around, I find a 2R5 (Champ engine) with OD will barely pull 60, whereas a 2R6 (Commander engine) does fine. With a 4.10 axle and the 215R85-16 tires, my 2R10 is geared about the same as that 2R5, so I conclude a 4.10 is just too low. I am now looking for a 4.86, which will give me another 5 mph cruise. It has been suggested I do a couple of cheap things to up the high-speed torque a bit - swap my 7.0:1 compression head for an 8.0:1 one (59-60 Lark), switch to a Commander carburetor, and make sure the centrifugal advance in my distributor is per spec. BTW, can anbody tell me what the advance curve is supposed to be? My service manual is silent. Anyway, thanks, Jack, for all your good advice and comment. Cheers, Phil.Comment
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Yer talking to the wrong folk. I have personally had a Champion-engined C-cab w/overdrive up to 80 MPH with no problems. It was working hard, but it got there.After asking around, I find a 2R5 (Champ engine) with OD will barely pull 60, whereas a 2R6 (Commander engine) does fine.
The suggestions you have received are great starting points. IIRC, you are an engineer by trade. The Champion engine is just like any other internal combustion engine. It responds to the same techniques. If one really wanted to maximize the performance, completely rebuild the distributor, convert to a Pertronix system, completely rebuild the carburetor, then instrument it with a Innovate A/F system. With the wide-band O2 sensor, one can determine what is happening with the combustion. Then the carburetor can be jetted to provide the optimum A/F ratio.
Question - are you running radial tires? They are worth quite a bit of performance and economy on their own. Have you set the toe-in. Nine of ten Stude trucks I've worked on over the years have worn steering parts and toe-in all over the place.
jack vinesPackardV8Comment
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"and I am now stuck with $3.5K in overhauling my Champ engine'
So have you already done the overhaul? If not, then you should consider redirecting your efforts toward a later 185 engine. Slightly more HP, but more importantly (as with Commander 6's) more torque.Comment
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I had a '53 2r5 with the 4:86 rear end, and I added an overdrive, then it cruised nicely at 60 MPH. I get your point about the 4 speed, tho; they're nice and truck like!Comment
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Thanks for all your replies. Finally I seem to have acquired the Studebaker experience needed to speak the language all you people with more experience. Your experience with 2R5's (Champion engines) is very useful. I still haven't bought an axle, so can still change my mind (yet again). Jack's suggestions were fun to read. The A/F ratio meter and the wide-range O2 sensor are just the thing for the anal retentive (like me). An accelerometer that reads g's in pounds per ton would also be interesting to measure small changes in performance. I do have radials, I did rebuild the carburetor, the steering gearbox is rebushed, all the reach rod and tierod ends are new, and I have set toe-in (though not caster or camber, as the kingpin bushings are loose). A visit to an all-make car show yesterday triggered an even better thought for increasing hp and torque a bit - remove the mechanical fan and insert an electrical one inside the existing HD radiator shroud where it wouldn't show. This would add likely 3-5 hp to the net at the wheels especially at the 2800-3000 rpm the engine would be running at cruise. With the ram air available at cruising speed, the electrical fan would not be needed anyway and would not be running, especially with the huge HD radiator core. The 12V 65A alternator can handle the drain from the fan. Speculation is fun, isn't it? Cheers, Phil.Comment
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Yes, Phil, the electric fan idea is a good one. I've found OEM fans to be more durable than the hot rod aftermarket. Since I'm cooling a higher performance V8, I'm using the Dodge Viper electric fan and it is perfect size and fit for the C-cab radiator. It also has two speeds, so it is relatively quiet until you need the max flow. A wonderful side benefit to removing the engine-driven fan from a C-cab is half the engine noise goes with it. Running without the fan at highway speeds is almost like having an overdrive as far as the noise reduction.
If you are interested in the Viper fan, I've got a new one on the shelf. Very easy installation, once you figure out where to plumb in the two-speed sensor switch.
jack vinesPackardV8Comment
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Hi Jack- Yes I am interested. Would the Viper fan fit inside the HD fan shroud I already have, leaving the appearanc of the engine compartment the same? Or is it integral with its own shroud so I would have to discard my existing HD shroud? Single or dual fan? Price? Pix?? Phil.Comment
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Hi, Phil,
Yes, the Viper is a large single fan with two speeds. It bolts perfectly inside the Stude shroud and is hard to notice once it is in place.
Here's a link to a guy who sells the fan, controller and harness for $410 http://moesperformance.com/index.php...1feea3626354d7
Mine is fan only, without controller and harness. I'll have to check, but you can have it for what I paid for it.
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