Driving our old cars at high speeds

[Scruffy49]

You guys can hit 55? Lucky... my truck ith a 218, 3 speed top loader and 4.78:1 rear end tops out at 50, gas pedal alsmost through the floor, engine trying to jump out of the frame. My dad used to drive it in high school, said the only time it hit 60 it ended up breaking the crank in half and holing the stock block.

 

I'm hoping the 230, 5 speed and more modern rear end (Ranger 4 banger) will let it do better than that. Might go ahead and upgrade the rear again before I bother swapping the Ranger axle in (afraid it won't hold up). I'd really like to run an IFS/IRS but I'm so far beyond broke it isn't remotely amusing... I can't even swing free parts right now (ran out of welding wire).

Edited February 4, 2013 by Scruffy49

[55 Fargo]

You guys can hit 55? Lucky... my truck ith a 218, 3 speed top loader and 4.78:1 rear end tops out at 50, gas pedal alsmost through the floor, engine trying to jump out of the frame. My dad used to drive it in high school, said the only time it hit 60 it ended up breaking the crank in half and holing the stock block.

 

I'm hoping the 230, 5 speed and more modern rear end (Ranger 4 banger) will let it do better than that. Might go ahead and upgrade the rear again before I bother swapping the Ranger axle in (afraid it won't hold up). I'd really like to run an IFS/IRS but I'm so far beyond broke it isn't remotely amusing... I can't even swing free parts right now (ran out of welding wire).

Scruffy, had a 4.30 diff in my 47 Chrysler at 1st, no idea how it got there, someone was a bit crazy to install it. Even if you swap in a set of 3.73 gears, would make a world of difference, or install late model mopar 8 1/4 diff, like mine, and sail along not bad, at 50 mph she isn't revving all too high at all, 60-65 mph would probably not hurt it much either, but you better have brakes, steering, and suspension in preemo condition at higher speeds....

[Uncle-Pekka]

Yes shipping would be pricey,but maybe not a huge amount of choice, the side gears can be swapped if 1 unit has the newer 16 spline and the older has 10 spline. The newer came out in 1954, according to info,but who knows.

A lot of the europe guys ship entire cars and bigger parts, so if needed not much choice...

Fellows,

Shipping can be arranged. There are private business forwarders who haul cars in sea containers from US to EU all the time. They take heavy mid-size parts such these hogheads at reasonable cost and ship them in the corner of a container for us.

 

What I am worried, is just this spline thing & other non-interchangeable features. I have a stock 1948 D24, thus the spline count will be different to late model parts - right?

 

Just happen to come across this web-site: Vintage Auto Parts. http://www.vapinc.com/

 

What does this line mean: "Ring gear only - for use with 11T pinion" - is my D24 stock pinion 11 teeth - can I change ring gear only and thus get 3.55:1 ratio?

 

 

 

Dodge                    Part #                                                                             Tooth Count   Ratio          Price        

1937-1956 Dodge  WX2138D (Ring gear only. For use with 11T pinion)   39                    3.55 to 1    $95.00

Edited February 4, 2013 by Uncle-Pekka

[55 Fargo]

That would be a heck of a deal, if that's all what is involved, there should be no problem with a direct swap with 3.73 hoghead from Mopars till 1953 or 54, just ensure what you buy is a 10 spline set-up, direct swap, nice and good to go....

[Plymouthy Adams]

Pekka....answer..no...ring and pinion gear are sold in sets...would not suggest you mix and match...I cannot believe a company would even entertain such a thought..on initial install the gears also have a timing mark so to speak..

 

You can can have this 3.9 I have ..I do not have a need for it whatsoever..your call...not sure if we can get a forum transport here...to Lamar SC..but I can get it to Charlotte to anyone coming that way from Lamar SC..will be happy to hand it off to them if we have a volunteer..

[DJ194950]

Fellows,

Shipping can be arranged. There are private business forwarders who haul cars in sea containers from US to EU all the time. They take heavy mid-size parts such these hogheads at reasonable cost and ship them in the corner of a container for us.

 

What I am worried, is just this spline thing & other non-interchangeable features. I have a stock 1948 D24, thus the spline count will be different to late model parts - right?

 

Just happen to come across this web-site: Vintage Auto Parts. http://www.vapinc.com/

 

What does this line mean: "Ring gear only - for use with 11T pinion" - is my D24 stock pinion 11 teeth - can I change ring gear only and thus get 3.55:1 ratio?

 

 

 

Dodge                    Part #                                                                             Tooth Count   Ratio          Price        

1937-1956 Dodge  WX2138D (Ring gear only. For use with 11T pinion)   39                    3.55 to 1    $95.00

I'm running 3.9 rear ratio with 2.15 x 70 x r15 with an OD trans in my 50 4 dr. 65mph is easy cruzin.

70mph no problem either. About 80 starts to sound to wound up for any great lenght of time, but the fan noise is probably the curprit. The only real holdback is my brakeing avail. With the others on the road on cells, kids, etc. i do prefer the slow lane at 60+ and drive behind the trucks when in commute traffic here on the 99 hwy. in towns.

Uncle pekka search on ebay for OD solenoids: overdrive solenoids and r-10 transmissions.

6 volt solenoid look for 1955 and back, 12 volt 1956 up, do NOT have to be for MOPAR, just r-10 trans with 1" stroke on plunger, most are, ask!!

Have not found a loose rear gear set yet of these years, they were built!!

 

Best to ya,

 

Doug

[55 Fargo]

3.9 gears would work well with an OD trans, on your car Doug what you hear at 80 mph in OD, is what you would hear at 65 mph just in 3rd with the 3.9 gears. I am not sure uncle pekka, even has an overdrive trans waiting to go in, but if he did, then the 4.1 gears would be fine, that is why I think He is looking for a 3.73 set of gears...

[DJ194950]

3.9 gears would work well with an OD trans, on your car Doug what you hear at 80 mph in OD, is what you would hear at 65 mph just in 3rd with the 3.9 gears. I am not sure uncle pekka, even has an overdrive trans waiting to go in, but if he did, then the 4.1 gears would be fine, that is why I think He is looking for a 3.73 set of gears...

 

Way back on post 12 Uncle-Pekka stated that he had a OD from a 54 savoy, just missing solenoid etc.

 

At 80 in my 50 it just sounds too busy to me, but probably just fine. My 8 cyl. tach is way off and i haven't taken time to figure out a conversion that it could mark correct #'s for the six. Heck it was free just needed cleaning and rewire.

I don't like the 'busy' sound at 65 either when in 3rd. no OD. Sounds better at 57-60mph.

Just me, like the quiet and feel that i'm taking it easy on the motor.

Actually i plan to put in 3:73 gears when my friend gives them up from his 49 bus. cpe. A project waiting to get started.

Then i could go out on the freeways and try to kill myself by cruizin at 85+!!

best to ya all,

Doug

[Uncle-Pekka]

Doug, 

Yes, you're right - I have a R10 unit on my garage floor, which I planned to install in my D24. (As I also wrote in this thread, I am still missing 6V relay and only have a defect solenoid).

 

However, currently having 4.1:1 rear ratio the engine is noisy already at 50 mph, thus I anticipate installing R10 will only help some. My aim is to also improve the rear ratio.

 

Now my concern is the interchangeability of the 3rd member. What is the drive shaft spline count in my 1948 and what are the available parts to 3.73:1 or 3.9:1.

 

According to D24 work shop manual the business coupe models were delivered with 3.73 rear ends and 3.9 was available to all but 7-passenger limousine.

 

Pekka

[Plymouthy Adams]

IF your car had come from the factory with OD the default rear gearing would be 4.1...when the R10 was introduced in later part of 52 it was also offered to the dealerships as a retro kit for earlier cars..primary this was done to move the 51's off the sales lot left from previous model.  A 51 with OD does not recieve points loss with OD due to this known fact..  There is no record I have found on searching stated if the rear gears of the 51 models were changed to 4.1 from stock 3.9...I am saying not, as that would have led to a a greater dealer cost...but I just don't know that answer.  the 4.1 with OD is  2.87 final drive..theorthically,  this will increase your cruising speed 48 MPH at same rpm if paper racing..actual speed may vary due to enigne condition, car weight, atmospherical conditions, road conditions and nerve of the driver with old stock brakes..

[Robert Horne]

You guys can hit 55? Lucky... my truck ith a 218, 3 speed top loader and 4.78:1 rear end tops out at 50, gas pedal alsmost through the floor, engine trying to jump out of the frame. My dad used to drive it in high school, said the only time it hit 60 it ended up breaking the crank in half and holing the stock block.

 

I'm hoping the 230, 5 speed and more modern rear end (Ranger 4 banger) will let it do better than that. Might go ahead and upgrade the rear again before I bother swapping the Ranger axle in (afraid it won't hold up). I'd really like to run an IFS/IRS but I'm so far beyond broke it isn't remotely amusing... I can't even swing free parts right now (ran out of welding wire).

Your truck sounds similar to my friend's 52 Studerbaker truck, barely get 50MPH, with the original setup.

 

My 38 Coupe has a 218, a 1987,5 speed Ranger trans, and a 95 Ranger 3.73 rearend. 

I am very happy with this set up.      1st gear is a little lower than stock normal, and the 5th gear overdrive is excellent..

I have a 86 Ranger 4 banger rearend, 3.25 ratio, I feel would be to high for my setup.

[Young Ed]

Uncle all the OD cars Dad has have 3.9 rear ends. Its a great combination. You still get some good off the line acceleration and low RPM cruising speed. You don't want to go too low or you'll be shifting out in and out of OD too much. My ply has a 3.73 and if I ever get around to putting an OD in it I plan to swap diffs between my truck which has a 3.9 and the car.

[Dodgeb4ya]

All the 1952-54 OD plymouths I have seen and parted here in the NW have had 4.3 rear ends. Too many hills and mountains here. My 1952 Belvedere has the stock factory installed 4.3 rear end. Works good as to plenty of power and highway speeds. Later 1953 and 54 were 4.1's as mentioned.

Edited February 8, 2013 by Dodgeb4ya

[Chuck51631]

Thank You all for your responses! I had the car on I-95 today it had no problems at 65-70mph. The posted speed limit. What amazed me is she could have and wanted to go faster. The point Todd made about points, condensor, and rotor made sence. I am going to pick up an extra set just to have them in the car in case of emergency.

I had my brakes updated years ago. a dual master cylinder all new brake lines and silicone brake fluid. I also have radial tires on the car and the front end has new king pins and tie rod ends. A wheel alignment was done after the front end work. I am planning on attending a car show next month with my car.

Thanks again,

Chuck 

[DJ194950]

IF your car had come from the factory with OD the default rear gearing would be 4.1...when the R10 was introduced in later part of 52 it was also offered to the dealerships as a retro kit for earlier cars..primary this was done to move the 51's off the sales lot left from previous model.  A 51 with OD does not recieve points loss with OD due to this known fact..  There is no record I have found on searching stated if the rear gears of the 51 models were changed to 4.1 from stock 3.9...I am saying not, as that would have led to a a greater dealer cost...but I just don't know that answer.  the 4.1 with OD is  2.87 final drive..theorthically,  this will increase your cruising speed 48 MPH at same rpm if paper racing..actual speed may vary due to enigne condition, car weight, atmospherical conditions, road conditions and nerve of the driver with old stock brakes..

Tim how did you come up with the 48 mph increase with a OD?

ONly off the top of my head, that does not seem right, please explain.  

 

Uncle-Pekka,

The 4.10 rear end does Not allow changes to lower # gear ratios only Higher ie. 4.30, 4.56 etc.

The carriers are different, at least per my old Hollander interchange manuel.

You will need a lower ratio gear carrier, 3.9 and lower and then that can be changed to a 3.7 or 3.54  ring and pinion set.

The axles # of teeth(spline) = 10.

Again per Hollander interchange.

Stock, 3.9 many mopar 6's ' 37-early 50's

3.7 Mostly Bus. cpe.'s

3.54 Mostly Chrysler 6's.

Most could  be Ordered, from factory or later installed.

 

Hope you get your changes done soon, more fun to drive if you can comfortly keep up with the traffic!

 

Best to ya,

 

Doug

[Dodgeb4ya]

It's true that the side gears IE-16 spline side gears changed to 10 spline sometimes cannot be done because of carrier case differences. I tried to swap a 1953 4.1 16 spline to a 10 spline. Could not do it as the carrier would not let me swap R&P and differential gears yet I have done it before on other rear ends in the past. Could be design changes as to Formate type and generated type gear sets. It's also extremely critical to get the ring and pinion set back in exactly as it was or know and have the tools and paint to set them up correctly with proper preload and backlash.

Bob

[Plymouthy Adams]

MAJOR EDIT TO INFORM THAT THE VALUES BELOW ARE WRONG ...Please read further on the thread for the proper speed...

I APOLOGIZE FOR THE ERROR...

 

 

Pekka, lets paper race that dog of yours...it is by factual equation and mathematics that for every .2 higher in ratio you get approx 8 MPH increase at same RPM..so wtih the OD being effectivel;y a 2.87 (ROUND TO 2.9) We have the following:

 

4.1

3.9 +8

3.7 +8

3.5 +8

3.3 +8

3.1 +8

2.9 +8

 

6 x 8 is 48

 

now effectively to get to that you have to again..run your engine to the same RPM that you so much are complaining about now...and your torque must be of enough ft lb to do the work..now we know that the flathead makes its torque at the low RPM and at that same RP your efective horsepower is considerly less than the rated..you get the peak HP at 3600 RP and you are now back up to the high RPM ban you are not wanting to run but hrsepower is now availalbe to do the work where torque tends to either slightly fall off or go flat...

 

so now you have the best of both worlds with the OD..the 4.1 ratio to kick that pig off the line and yet in OD have the ability to run at a higher speed at less RPM...

Edited February 7, 2013 by Plymouthy Adams

[DJ194950]

Pekka..lets paper race that dog of yours...it is by factual equation and mathematics that for every .2 higher in ratio you get approx 8 MPH increase at same RPM..so wtih the OD being effectivel;y a 2.87 (ROUND TO 2.9) We have the following:

 

4.1

3.9 +8

3.7 +8

3.5 +8

3.3 +8

3.1 +8

2.9 +8

 

6 x 8 is 48

 

now effectively to get to that you have to again..run your engine to the same RPM that you so much are complaining about now...and your torque must be of enough ft lb to do the work..now we know that the flathead makes its torque at the low RPM and at that same RP your efective horsepower is considerly less than the rated..you get the peak HP at 3600 RP and you are now back up to the high RPM ban you are not wanting to run but hrsepower is now availalbe to do the work where torque tends to either slightly fall off or go flat...

 

so now you have the best of both worlds with the OD..the 4.1 ratio to kick that pig off the line and yet in OD have the ability to run at a higher speed at less RPM...

Tim, so if he ran 2.9 rear gears in OD then he would be to go +48mph at the same rpms? With an OD that had a 2.9 increase??

 

I thought a r-10 OD had 1.7 increase in final out ratio to rear not 2.9??

 

Not that i can currently confirm r-10 ratio but where did you find these ratios??

 

Just askin'  

[55 Fargo]

Uncle-Pekka,

The 4.10 rear end does Not allow changes to lower # gear ratios only Higher ie. 4.30, 4.56 etc.

The carriers are different, at least per my old Hollander interchange manuel.

You will need a lower ratio gear carrier, 3.9 and lower and then that can be changed to a 3.7 or 3.54  ring and pinion set.

The axles # of teeth(spline) = 10.

Again per Hollander interchange.

Stock, 3.9 many mopar 6's ' 37-early 50's

3.7 Mostly Bus. cpe.'s

3.54 Mostly Chrysler 6's.

Most could  be Ordered, from factory or later installed.

 

Hope you get your changes done soon, more fun to drive if you can comfortly keep up with the traffic!

 

Best to ya,

 

Doug

Doug, can tell you this, not sure if this is the same in your books. I had a 4.30 diff 10 spline pumpkin in the diff on my 47 Chrysler, I then acquired a 3.73 10 spline pumpkin, it was a direct bolt in swap, no problem whatsoever....

[Plymouthy Adams]

final ratio...OD is .70 times the final gear of 4.1 for 2.87 total reduction...his gear is still 4.1 it is effectivley lowered by the 30% reduction.

 

if he had a 2.9 and OD the final drive would be 2.3..he does not have the torque to run that high a gear

[DJ194950]

Doug, can tell you this, not sure if this is the same in your books. I had a 4.30 diff 10 spline pumpkin in the diff on my 47 Chrysler, I then acquired a 3.73 10 spline pumpkin, it was a direct bolt in swap, no problem whatsoever....

Yes per my old Hollander interchange:

The entire 3rd. member(pumpkin) fits as long as axles are 10 spline. Most had 2 spider gears some had 4, more chances to fit or not without more changes!

Just can't change the ring an pinions between the 4.10 and up and lower ratios.

Again from an old interchange.

Maybe i should learn or get someone more computer  literate than myself to post the Hollader Interchange pages then maybe  Get them put on the Resorse pages-???

[DJ194950]

final ratio...OD is .70 times the final gear of 4.1 for 2.87 total reduction...his gear is still 4.1 it is effectivley lowered by the 30% reduction.

 

if he had a 2.9 and OD the final drive would be 2.3..he does not have the torque to run that high a gear

 

OK, i see what your thinkin' is. I totalally agree to not going overboard with rear ratios, especially with OD.

While i do want to try a 3.73 with a OD, i'm not planning to get rid of the 3.9's until i'm sure that's want i'm satisfied with. May be too much!

I had some 3.54 gears (pumpkin) that i decideced to sell to someone that that did not have a OD. i thought too  way much for a OD trans. 

 

   Doug 

[55 Fargo]

Yes per my old Hollander interchange:

The entire 3rd. member(pumpkin) fits as long as axles are 10 spline. Most had 2 spider gears some had 4, more chances to fit or not without more changes!

Just can't change the ring an pinions between the 4.10 and up and lower ratios.

Again from an old interchange.

Maybe i should learn or get someone more computer  literate than myself to post the Hollader Interchange pages then maybe  Get them put on the Resorse pages-???

Thanx Doug, it dawned on m,e after my post that perhaps you meant just the innards. I like you idea of the 3.73 with the od, why not, if I could afford it my 47 Chrys would have this combo like yesterday. nice lookin car you have there BTW

[Uncle-Pekka]

Fellows,

You got me convinced that I will first install the OD and test drive it to find out the acceleration vs. cruising.

It may be enough even with the current 4.1 rear end.

 

However, Tim's math adding +8mph for every 0.2 change adds up to 48 mph difference goes wrong.

The R10 ratio being 0.7:1 multiplies simply as follows:

 

If I ran 50 mph at 2500rpm without OD, a 0.7 OD will run me 50/0.7 = 71mph at same 2500 rpm engine speed

 

You can play with the simple division formula in MS excel, but here is simple web page with formulas programmed behind input cells:

http://wahiduddin.net/calc/calc_speed_rpm.htm

 

(Just NOTICE, that the formula input for tire size is tire RADIUS, not diameter. I used 13.5" for 205/75R15 tires)

 

Other way round:

Today I need to rev 2550rpm to reach 50 mph with my 4.1 rear end.

Same setup, but 0.7 OD encaged I only need 1785rpm for the same 50 mph - Sounds very good to me!

 

Finally, In case I should want to change the rear end ratio to, say, 3.9, as per Doug, I need to find a complete 3rd member, since 4.1 pumpkin does not allow smaller ratio pinion.

The spline count should be 10 to match original D24 drive shafts, right?

[Plymouthy Adams]

Pekka..I used a formula long ago from a British car website when I was crunching for the MG100 and going to '86 Metro with 3.44 gears..it came out to that value and I remembered it as such..but you are right ...on another set of formulas this evening after reading your post I confirm your findings..sorry so much for the error..now I can only think I either had a bad formula of the number 3 looked to be an eight...either way my post is in error and thanks for setting it right...hope this did not lead folks astray in any manner