54 Plymouth Donor car & overdrive pull example

[Plymouthy Adams]

which only helped you as the looney bin in not listed under  "L" 

[46Ply]

It's been about two years here since the last post.  What's the progress on the transmission?

[pflaming]

I sold it and four others. I like the OD's but don't want to put one on a vehicle for someone else. They are not problematic, if in good condition which includes the electrical solenoids which can be pricy. My motivation is a higher top speed and that is more easily achieved with a rear axle swap. If I lived in hilly country, then it would have one on my vehicle. Jmpp.

With a three speed and a 3:73 rear axle I cruse at 65 mph and can still speed up and pass if desired or needed. I now would prefer a 3:54 but not just yet.

Edited March 26, 2015 by pflaming

[46Ply]

I sold it and four others. I like the OD's but don't want to put one on a vehicle for someone else. They are not problematic, if in good condition which includes the electrical solenoids which can be pricy. My motivation is a higher top speed and that is more easily achieved with a rear axle swap. If I lived in hilly country, then it would have one on my vehicle. Jmpp.

With a three speed and a 3:73 rear axle I cruse at 65 mph and can still speed up and pass if desired or needed. I now would prefer a 3:54 but not just yet.

What car and engine?

[Plymouthy Adams]

it amazes me that these cars were raced and achieved some pretty good avg speeds for the day and yet now...folks are afraid to run them over 55 MPH for a short jaunt to the store....

[pflaming]

i have a '52 B3B with a 218 engine. As Tim states, current drivers are so accustomed to quiet engines that the hum of rpms concerns them.  If I wanted to run consistently at 70 mph with the current engine, 3sp tyranny, 3:73 rear axle and 235, 75, R15 tires, I would drive it there for some 50 miles then back off to 65 for 10  miles, then up to 75 mph for 15 +/- miles, then back to 70 mph and hold it there.  It's the old school method of "breaking in" an engine.

 

Engines like human bodies get lazy and they need the carbon burned out, remember an engine operates on air movement, if you drive the car at 30 mph for 10,000 miles, then the manifolds build up 'stuff' that restrains the air. So now if you go to 60 mph the manifolds are caked up and resist the extra air flow. So it has to be "'burned out " and higher speeds do that.  Now that explanation may be a bit simplistic but that is the machanics 101 explanation. Or said another way, more exhaust pipes, split manifolds, faster air movement better running engine.  It's all about air, fuel, and fire flow.

 

Then watch the temp gauge and the oil gauges. If they change then slow down for a little while,  let the buildup cool and release the speed up and blow out the carbon,  I'm getting noise conscious because of my hearing so a quiet cabin allows for better conversation. It's called personalizing a car, not scientific I know but it works, we did it all the time in the '50's. A bit of oil treatment helps but is not necessary.

 

When I rebuilt my engine, I was a "freshman's freshman". I took took the measurements of my cylindars, two sets of pistons and the rods to a long time engine machinist and asked his advice and asked what was meant by balancing an engine. A balanced engine, even just the pistons and rods runs smoother at higher rpms, so we chose the best six pistons and balanced them to the respective rod. A small investment for a smoother running engine. I forgot I had that done.

Edited March 26, 2015 by pflaming

[46Ply]

Thanks PF?  

That's some of the best description regarding engine capability I've read here.  But, again, this is all new territory to me.  And I've been wondering what modifications get you the most bang for your buck.  

You didn't mention RPMs.  ...   but for instance the P15 was rated at 3600 max if I remember correctly.  So, does modifications increase this limit?  And I've heard others here state that you should not exceed 80% of that.

 

Maybe what I'm trying to ask is,   How can you know what limits are safe without blowing or damaging an engine?

[TodFitch]

it amazes me that these cars were raced and achieved some pretty good avg speeds for the day and yet now...folks are afraid to run them over 55 MPH for a short jaunt to the store....

And when I was a little kid I remember the people modifying cars were looking for 4.1 rear ends to swap into their car to give it better acceleration than the stock 3.whatever rear axle.

[pflaming]

The 4:1 gives better low end / acceleration but also lower top end. Recent posts mention cruise rpms around 2800 / maybe 3000 rpm which leaves you some top rpm power. To most that will be a bit noisy but then these engines are noisy, so you have to realize that and get accustomed to it.  You will noice that if you bring the rpms to say 2800, it will HUM, but once the entire truck has settled into that, the engine will relax and quiet down yet the RPMs will not drop, that's because the engine now is maintaining not pulling and now is no longer under stress.

 

Take all these comments as from a novice, like Ronnie said, " trust but verify".

[Don Coatney]

i have a '52 B3B with a 218 engine. As Tim states, current drivers are so accustomed to quiet engines that the hum of rpms concerns them.  If I wanted to run consistently at 70 mph with the current engine, 3sp tyranny, 3:73 rear axle and 235, 75, R15 tires, I would drive it there for some 50 miles then back off to 65 for 10  miles, then up to 75 mph for 15 +/- miles, then back to 70 mph and hold it there.  It's the old school method of "breaking in" an engine.

 

Engines like human bodies get lazy and they need the carbon burned out, remember an engine operates on air movement, if you drive the car at 30 mph for 10,000 miles, then the manifolds build up 'stuff' that restrains the air. So now if you go to 60 mph the manifolds are caked up and resist the extra air flow. So it has to be "'burned out " and higher speeds do that.  Now that explanation may be a bit simplistic but that is the machanics 101 explanation. Or said another way, more exhaust pipes, split manifolds, faster air movement better running engine.  It's all about air, fuel, and fire flow.

 

Then watch the temp gauge and the oil gauges. If they change then slow down for a little while,  let the buildup cool and release the speed up and blow out the carbon,  I'm getting noise conscious because of my hearing so a quiet cabin allows for better conversation. It's called personalizing a car, not scientific I know but it works, we did it all the time in the '50's. A bit of oil treatment helps but is not necessary.

 

When I rebuilt my engine, I was a "freshman's freshman". I took took the measurements of my cylindars, two sets of pistons and the rods to a long time engine machinist and asked his advice and asked what was meant by balancing an engine. A balanced engine, even just the pistons and rods runs smoother at higher rpms, so we chose the best six pistons and balanced them to the respective rod. A small investment for a smoother running engine. I forgot I had that done.

PP I am pretty confused with your posting?? Can you expand on this caking up of the manifold thing? How does this happen and what causes it. If I drive my car ten thousand miles at 30 MPH in first gear will this happen? Is this RPM or speed related? Or is this air fuel ratio related? Or is this general engine health related? Also how many engines have you "broke in" using that old school thing you mentioned? Is it necessary to re-brake in an engine that burned up in a garage fire? What is fire flow? Why did you balance a single piston and rod without comparing them to all the other pistons and rods?

[pflaming]

I should probably edit more than comment, but will offer some explanations. First, one thing I learned when I started this hobby was that there is not much tolerance to generalizations and that includes definitions, yet if I had to get glossary wize before I could work on my truck or ask a question, I would have quit a long time ago! Questions and incorrect comments, which get corrected, precede learning. So 'live with it', once an idiot not always an idiot!.

PP I am pretty confused with your posting?? Can you expand on this caking up of the manifold thing? How does this happen and what causes it. If I drive my car ten thousand miles at 30 MPH in first gear will this happen? Is this RPM or speed related? Or is this air fuel ratio related? Or is this general engine health related? All the former. Drive a car slowly in any gear as a way of driving and the engine will build up carbon accordingly.

Also how many engines have you "broke in" using that old school thing you mentioned? Every '50's car I owned. Is it necessary to re-brake in an engine that burned up in a garage fire? NO. What is fire flow? Lava.

Why did you balance a single piston and rod without comparing them to all the other pistons and rods? Didn't! The machinist chose one and balanced the other five to match it.

Sorry if I spoke out of turn!

Edited March 27, 2015 by pflaming