Engine: 1949 2R5 Drive Notes

[Robert Crandall]

I am now 5 years into the revival of my 1949 2R5 truck. It has been driveable for 2 years. My suburban development is large enough that I can put around 6 miles on it without repeating any streets, so I have been driving it around the neighborhood as a novelty. I took care of some administrative requirements, so I am now venturing outside of the neighborhood. I can go far enough to suit me on 35 mph roads, which is good, because 35 mph is all I can tolerate on my date code 1977 tires.

I have noticed a few things that I am not sure what, if anything, to do about.

1. In second gear the truck will not go faster than 20 mph. It makes no noises; it just will not go faster regardless of accelerator position. Is this normal? I count around 4.5:1 for the differential ratio.
2. Our area is completely flat; the only inclines are on overpasses. For the one on the 35 mph road near my house the engine pings on that incline until I drop speed to around 25 mph. I made one trip over and back at 20 – 25 mph. On the next trip over I bought 10 gallons of premium fuel, and the engine did not ping on the return trip. It seems odd that I would need premium fuel for this truck with this differential ratio. The cylinder compression readings, 1 thru 6, are: 140, 145, 145, 145, 145, 110. This photo is of the timing mark setting. Is there something else I can look for, or is this condition normal?
3. I must slow to around 5 mph before I can shift from 3rd to 2nd without grinding 2nd. Also, 2nd falls out as soon as I let off the accelerator. Are these conditions normal?

Thanks.

I cleaned up the gages and painted the gage cluster cover. The remainder of the interior trim had been painted a brown before I bought the truck. I found that off the shelf Rustoleum item 249032 Gloss Khaki looks like the color that I see in photos of other trucks. I painted the glove compartment door to match the gage cluster. Both pieces look nice now.



I have had a lot of help from this forum. Thank you all.

[Ross]

The good news is that none of the conditions you describe are normal--pity an original owner who bought a truck that could barely pull an overpass and which jumped out 2nd when descending a grade. I think the salesman would have a hard time closing the sale. The bad news is that none of your conditions are normal meaning they all need attention--except your compression readings which are quite good. In fact, they are so good I am wondering if the head has been milled too much at some point. Flatheads get very irritable with too high a compression and loose breathing capacity.

First, your timing is too far advanced--at a slow idle with the vacuum line disconnected to the distributor you should land on the right hand mark in your photo. While there you can make a quick check of the advance mechanism--as you rev up the engine, the mark should move further to the right. Repeat this with the vac line hooked up. At idle, the initial position should be the same, but as you rev up, the mark should jump somewhat farther to the right, and snap back immediately when you snap the throttle shut. This tells if the vac advance is working. In "normal" condition, that engine should be able to run on the cheapest low test gas imaginable.

As for your very leisurely performance in second gear, have someone push the throttle to the floor while you observe--make sure the carb is opening all the way.

Your transmission is probably misaligned to the engine, or is simply worn out. A decent one should not be hard to find.

[Mrs K Corbin]

And while you're at it find an overdrive tranny and driveshaft for when you get the engine up to par...

I Very Good tune-up is in order and testing of throttle linkages, and of course the procedure that Ross described above.

my 2R5 with the original worn out 6 would at one time top at 90. Now tops at 70 last I tested. That was without OD.
the OD just drops the engine RPM a bit, but doesn't help the speed.

The thing won't pull itself out of a wet paper bag, but is ok for weekend stuff.

There are 2 cautions. Brakes need to be as good as you can get them, and leave room between you and the other idiots. I rebuilt mine with a Turner Dual MC conversion, new wheel cyls, new lines and hoses, when I finally did it all. Plus used Silicone Fluid at that time to keep it from sticking, which it used to do often.

The second Caution: Use Non-Ethanol Gas if you can get it. No matter the cost. It will save you much headache later. Been there and done that.
I now run it in my weed-eater, airplane, Studebaker, Lawnmowers, etc..... Anything that is not used every day.
Ethanol is hydroscopic, meaning it will absorb moisture from the atmosphere and basically "rain" inside your tank. Plus it is rumored to eat old fuel systems.

Oh and for the transmission.... Check the little rubber donuts that go in the shift linkage. I'll be they're worn out and need replacing and that you need some adjustment.
Been there done that.

[Robert Crandall]

Thank you for your advice. I will try the timing adjustment. Both advances are working. I learned how to work on them from earlier questions. The centrifugal was working, and the vacuum was not. Mr. Vern Ediger provided a working vacuum advance from Kansas, and I cleaned and graphited the centrifugal advance parts.

I also learned from earlier postings that my engine is older than the truck. The serial number is for an M series truck, so it has been changed. I have not had either the engine or transmission out or apart since I bought the truck. I have seen other advice about the possibility of misalignment or wear, but I do not want to look. I can drive it now, which I like doing a lot more than I like working on it. I worry about what I will involve myself in with the 'while I'm at its'. Also, I hold out for finding all of the parts that I would need to change to an overdrive transmission. The transmissions themselves occasionally turn up (but nowhere near SE VA), but I will not change until I find all of the parts. If I ever do scrounge the parts, then I will take the whole drive train out and refurbish it all while I make the change.

Thanks.

[52-fan]

The one cylinder being down on compression suggests a burnt exhaust valve. My 52 Champion was down on power, but would drive okay on the highway. When I finally pulled the head I found a chunk of the exhaust valve gone in cylinder #6. Replacing the valve made quite a difference.

[52-fan]

My 2R5 with the original worn out 6 would at one time top at 90. Now tops at 70 last I tested. That was without OD.
the OD just drops the engine RPM a bit, but doesn't help the speed.

The thing won't pull itself out of a wet paper bag, but is ok for weekend stuff.

Your truck must not have the stock rear end. There is no way that a stock 2R without overdrive would do more than half of 90 MPH for long. I wouldn't want Mr. Crandall to think his truck is that far off.

[jackb]

Lots of tales in this thread.... If you don't have a burnt valve, you might have rust a small rust point firing erratically. I'll bet that cylinder valve(s) were open at the time of inactivity. If not a valve problem, re-adjust the timing back (retard) by loosening the screw on the distributor hold down. My 245 has a stamping on the block for advance/retard (mixed fuels in the day)... but hard to see...I know people are different , with different driving habits, but... why not use the brakes to stop or slow down your vehicle, rather than the clutch disc ? There really is no need to engage the clutch/tranny to slow the truck down... a pure waste of energy unless on a descending grade....

[Robert Crandall]

Thank you all for your further advice. The first part of my now 5 year revival was cleaning and painting the body undersides. The next part was replacing every brake component and converting to silicon brake fluid, dual master cylinder, and Chevrolet rear drums. The 'while I'm at it' for that included repacking wheel bearings and replacing the seals. I did replace the shifter grommets.

This truck was honored with inside back cover placement in the January 2016 TW.

I recently had a braking scare with an off topic 1950 truck, also with up to date maintenance on the brakes. A routine interstate on ramp where people like to race to the front of the line then jump in. The people already in the line had to quickly stop. I never follow closely, so I had room to stop, but it was difficult to balance stopping quickly with releasing enough to keep rear wheels from locking. I pulled it off with only minor chirping, but it was unnerving how much of my following room distance I used up to get the truck stopped.

[Skip Lackie]

WRT popping out of 2nd: It might be worthwhile disconnecting the shift rods from the trans levers and checking their adjustment as described in the shop manual. It's possible that the trans is not being fully engaged into 2nd gear. If that doesn't fix it, it's probably a worn-out gear.

[Robert Crandall]

Thanks for your further advice. It may take a couple of months, but I will look into all of the possibilities. Thanks.

[Old Radio Tech]

I have a 1949 2R5 but with a 4spd. I was told the only difference was the addition of the granny gear. Your 1,2,3 equals my 2,3,4. Based on that-my rear ratio is 4.8.2. 20mph in 3rd(your 2nd) is about right. You sure your engine isn't floating after 20mph? 5mph downshift from 4th to 3rd (your 3rd to 2nd) is also about right. I always use premium fuel. Are you using a lead additive? My compressions are running 110-115. 45mph in high gear I'm winding near 3000rpm. I've found if I regularly run past 3000rpm in any gear I start blowing oil out the filler and the aspirator, which makes it drip and requires a lot of wiping. If I hold it to 3000rpm, no blow by no drips no wiping.

[Old Radio Tech]

as per JackB, the only time I downshift is when I'm rounding a full 90 degree corner or have to slow considerably for someone in front of me and then if I have time, I come to a complete stop and start over. Whenever I come to a light or stop sign I immediately go into neutral and use the brakes. With the gear ratios involved I can start out in 3rd fairly easily and keep it in 3rd to almost a stop and get going again without lugging it.

[Mrs K Corbin]

I've had mine on I24 pegged out at 70. Don't have a clue as to the engine RPM. As for the Diff, it's studebaker. but don't remember the ratio off hand.
almost 30 years ago I had it to 90. but that was a healthier engine with no OD.

[Robert Crandall]

Thanks for the further advice. It could be that the engine is floating at 20 mph in 2nd. It just seemed odd to me, but I am not bothered about it; I just go to third. I drive exactly as is described in post #12. My words seem to have described that I use the clutch as a brake. I do not. What I meant was that when I am in 2nd, when I let off the accelerator, decelerating the engine, not the truck, the shifter drops to neutral.

It seems like taking the transmission out then making a check of the alignment of the bell housing to the engine would be interesting and not difficult. It may not be until July, but I plan to do that. I will change the timing before then.

I use a fuel stabilizer, but not a lead additive. The nearest fuel without ethanol is 50 miles away, so I do not use that either.

Thanks.

[Old Radio Tech]

My understanding is that the newer engines that were designed to run on unleaded have hardened valves and seats. The older engines that were designed to run on leaded gas don't have hardened valves and seats and the lead was a lubricant. If you don't use a lead additive you'll burn out your valves especially the exhaust valves.