|
|
Elite Veteran
  
Location: Victoria, BC. Canada | Howdy,
Well I spoke to the fellow today that bought the 440' & trans out of my coach; he's mostly got it ready to run already and shared with me what he discovered during the partial tear-down.
Before I say dick, I need to say that I always thought #846 was running pretty good and had pretty fair power output during the paltry 5000 or so miles I've put on it since I've owned her; moreover, considering the job this old rat-motor was tasked with, I thought it was getting comparable fuel economy to what I'd calculated on the trip home in #509 when I brought her up here from Santa Cruz a few yrs back (ie. 6 - 7 US mpg, or, 8 - 9 Imp. mpg).
Today I learned that I really don't know much about the venerable ole' 440' Chrysler.
The buyer, Paul, is reasonably confident that this was the original engine in #846. He told me that this engine, in the condition it was in when he got it home, was down 100 to 150 HP over what it should have been making.
This really blew my mind! (what's left of it after the 60's & 70's)
Here's Paul's autopsy results:
- camshaft lobes on a few cylinders severely worn down about 1/8".
- TQ carb over-fueling so badly that there was nearly '0' ignition spark and causing a huge carbon build up.
- timing chain worn out & very loose.
- engine did not have the big-rods but did sport a steel-crank.
- cylinder walls and rings (after 85,000 miles) were still in serviceable condition.
Epilogue: Terry has yet to realize what the true potential of the 440' is in the FMC application.
Almost regretting pulling it for the Cummins swap vs rebuilding it.
Almost...
Terry
#846
|
|
| |
|
Elite Veteran
Location: Oceanside, CA |
Flat tappet hydraulic lifter cams are really tough to keep healthy nowadays, even many of the modern synthetic oils don't provide the protection that the old high zinc(ZDDP) oils used to have. Amsoil has a good one, but, not everyone has access to that. Modern engines with all roller valvetrains don't need near as much lube film(much less friction) and can run much lower viscosity lube.. |
|
| |
|
Extreme Veteran
Location: Ignacio Colorado | We can start by saying it was not the original engine or it would have had the big rods. The very late coaches didn’t have the big rods but up to at least #902 did. If it was 100-150 hp down it wouldn’t have run like it did. Your guy must only think race crap.
The stock RV 440 camshaft had .430” valve lift. I’m running a camshaft with .366” valve lift. Also smaller valves. Nobody would think this a smart change. They would say, “I thought you wanted more power! Well I got more useable power that is right where it counts now that I have the 0.69 overdrive.
With the stock 440 pulling the steep grades at high elevation I would have to go to first gear and back out of the throttle. I could run through first and catch second gear but it could not hold second. I would have to drop back into first. Now with the torque down where it is needed I can run second gear at 2,500 rpm up the steep grades. If it was to drop rpms it is only coming down into its peak torque curve and more power is waiting. Not like the more, more, more attitude that winds up running worse where you need it.
Better breathing intakes and exhaust would seem smart but they only gain power on the top end. Smaller port (runner) intakes and single exhaust make more low rpm torque! Yes the broken record speaks again. Less is more!
Bill |
|
| |
|
Elite Veteran
Location: Oceanside, CA | Well it's been 4 months since you removed the bumper...(insert finger tapping here) |
|
| |
|
Elite Veteran
Location: Victoria, BC. Canada | I've been polishing it...
You should see it!
Way too busy of late and a couple'a health issues tossed in for good measure didn't help much either.
Will get back at er' soon but don't even think about me getting it done like you did Lenny; 'Joe the Fabricator' I ain't.
If I fall somewhere in the middle of the completion time-span of yours and Stephen's - I'll be dancing!
Terry
#846 |
|
| |
|
Elite Veteran
Location: Victoria, BC. Canada | Well I finally completed the parts deal with my friend Jay in Arlington, WA.. Jay previously owned #614 and parted that out before buying an MCC (Barth) with Cat/Allison running gear.
After not being able to sell the MCC in a timely fashion, he contacted me to ask if I was interested in any of the parts.
I said, "YES" unequivocally.
It took two trips down to Jay's place to get it done, one in early March and then again last month, but thanks to Jay's generosity and hospitality (and some much needed help and direction from Stephen) I now own a converted 3.73:1 differential, a full set of disc-brakes and six 22.5" (6-lug) Alcoa's.
FWIW: I've also scored a 47RH transmission here on the Island and have posted some measurement comparisons between the (4x4) 47RE vs 47RH overall lengths.
Bottom line: if you plan to use a 'Stubby' (4x4) version of either of these units to get yourself an overdrive, the RH brings another 5" in length to the table.
http://www.fmcowners.com/mbbs22/photos/photo-thumbnails.asp?albumid...
Hope to get back at this soon as time and resources permit.
Cheers,
Terry
#846 |
|
| |
|
Elite Veteran
Location: Oceanside, CA | Detailed pics and descriptions of the brake parts would be of interest to many. Also pictures of the stamped on part numbers of the 6 lug alcoas. Sounds like a good score of parts. |
|
| |
|
Elite Veteran
Location: Victoria, BC. Canada | Yeah, figured the diff stuff might get some people interested, too. Not.
Need to get going on the diff swap then try to figure out how I can build and configure the trans so I get some miles out of it.
Wheels and brakes will be last and I may wait a while before I do them, but I will try to get a pic of the stamping on the wheel for you.
Cheers,
Terry
#846
|
|
| |
|
Elite Veteran
Location: Oceanside, CA | If you install both those taller tires and those higher gears then you are going to have to some pretty significant power mods to the 12v to keep it from being a total dog off the line...you will also need that (extra power) to keep your overdrive from being all but useless on anything but flats.
A stock Dodge 3500 pickup with that same engine/trans combo that came with 3.73 gears would have also come with 28" tall tires, if you were towing 9000lbs with that truck(to match your FMC weight) you would have just shifted out of overdrive for the duration (maybe used it on some downhill flats) of your trip. That's with 28" tall tires. The smallest you can get for those 22.5's is going to be in the 35" range, if you put 35" tires on the truck I mention above you would definitely need to regear to 4.56-ish just to get back to where you were.
Of course you can build tremendous power with the 12v, if you are going that direction (fuel pump mod, bigger turbo, etc.) then what I said above is OBE. If you think you can run this set up with stock-ish power then you are going to find that you are lugging it a lot, the lugging leads to overheating and torque converter failures(if you haven't spec'd a heavy duty billet Torque converter for your 47rh you are going to be sorry).
I really encourage you to find a step van that came with a 12v 5.9/allison, those typically have a 2000 series allison with a stand alone controller. You will get the low first gearing you need, better control, and something that is actually designed for full time heavy duty use. If you are set on a mechanical trans and are not going to build engine power much (but still run 3.73/35"tire) then you'd be much better suited with an Allison 545, you would have absolutely no need for overdrive.
Edited by LCAC_Man 2019-05-07 7:08 AM
|
|
| |
|
Elite Veteran
Location: Victoria, BC. Canada | Morning,
Okay, what's "OBE"?
Thanks for the response, Len. I think what you're saying has great validity. I am a carpenter who, while being pretty good with wrenches sometimes, is still a carpenter and it takes me a lot longer than you to sort stuff out. Patients is encouraged and yes, that could include a lot more 'finger-tapping'.
I discovered those 'rpm calculators' on the internet and fiddled with them a lot lately. And I agree, seems any way you slice it, 37" wheels with 3.73 gears and a .69 OD puts you in the Auto Bon' stratosphere with questionable low-end grunt. And while I do tend to run my coach with a heavy foot and at the least try to blow the doors off the odd Winnebago for posterity, I am doing this swap for two primary reasons: to dramatically improve the hill climbing ability and fuel economy.
With the stock diff, 37" wheels and the .69 OD, at 65 mph I'll still be under 1900 rpm. That's workable, I think.
So, on further consideration (including your additional input) I will hold off on the diff until the engine/trans work is done, then run it for a while to see how it goes. The tall lower gears on the 47RH are of a concern to me also. I'll keep the diff till the day arrives I want to take her to Bonneville and try to screw them guys with the GM mo-ho rocketship, or, I burn up the rotors and have to go back to smaller wheels and drums again.
My plan (subject to change, as it has a dozen times already :-o) is as follows:
- Engine: do KDP; 60 lb exhaust valve springs (for exhaust brake/to save my rotors); front/rear oil seals; install Badgerland propane system; 4" exhaust. My guess (hope) is this should put me closer to 300 hp and over 500 lbs/ft to the ground with modest fuel economy gains, lower EGT's and a considerably 'cleaner-burning' engine.
- Trans: rebuild with upgraded TC and increased line pressure in the valve body.
Will try to post more pics of the brake-parts and wheel stampings over the weekend.
It's Solo's (my dog) birthday today; he's 3 yrs old and officially not a teenager any more. Going to pick him up a big farkin' steak on the way home tonight.
Cheers,
Terry
#846
|
|
| |
|
Veteran
Location: Houston, Texas | Hey Andy, on ours we have the original rear end & 19.5 tires and if we want to use 6th gear, we have to cruise around 70 mph (where legal) in order for the 6th gear to be any good. (1800-1900 rpms) that's where we feel the best torque and no slow downs on small Texas hills, excellent torque and very little smoke, I just wish we had our new GPS cruse control already installed because if I don't keep an eye on the speedometer we can hit 80 mph (bragging) very easy...=
Rico & Carmen
397
12 V Cummins & 6 Speed Allison |
|
| |
|
Elite Veteran
Location: Oceanside, CA | OBE = Overcome by Events or obsolete
Rico's experience is much the same as mine, I set my trans in manual shift mode and set it to 5th, only occasionally do I tap up to 6th. I find that 1900-2000rpms puts me in the best inlet air/cooling water temps and is the right mix of being between torque/hp bands. Anytime I run lower in the rpm range all my temps run just a bit higher and the trans is more likely to shift around more often. If I'm in the hills I use the manual shift mode to stay at 2000-2100rpms and tap down for trans/engine braking as needed.
Edited by LCAC_Man 2019-05-08 10:13 AM
|
|
| |
|
Expert
Location: Cottage Grove, OR | ricogomez - 2019-05-08 6:19 AM ... if I don't keep an eye on the speedometer we can hit 80 mph (bragging ) very easy...= Rico & Carmen 397 12 V Cummins & 6 Speed Allison LOL! I hear you Rico, coming back from my last trip East, I was anxious to get home and in sixth gear it was an easy cruise across Idaho at 80 mph (which is the speed limit on I-84) in sixth gear. Standard differential and 19.5 wheels. |
|
| |
|
Extreme Veteran
Location: Scottsdale, Aridzona | What ? WHAT ? You mean if I change to a Diesel engine in my FMC . . . I won't get 50 MPG . . . or be able to cross the Grapevine in 10th Gear at 75 MPH ?
Acronyms ?
Here is another that comes from my days (daze?) in Unlimited Airplane Racing - BER = Beyond Economic Recovery or Beyond Economic Repair.
Never forget . . . we are all Charter Members of the TURD Polishers Club . . . The harder you rub . . . the duller it gets !
Press ON ! Lou #120
ps: www.crawlpedia.com/rpm_gear_calculator.htm
It is TIRE DIAMETER that applies , not rim diameter.
Edited by hemi354az 2019-05-08 11:32 AM
|
|
| |
|
Veteran
Location: Houston, Texas | Mr Stephen, hopefully the paint stripping didn't fall off while breaking the sound barrier.
one of the most important things we notice with our conversion is the difference when taking
off from a stop, I don't know if its because of the 6 speed or the diesel engine, either way we
like it, that's why we keep the rear skid wheels on just in case.
Rico & Carmen
397
12 V Cummins & 6 Speed Allison |
|
| |
|
Expert
Location: Cottage Grove, OR | Rico, the difference leaving a stop is because of both the transmission’s deeper first gear versus the 727 and the higher torque of a Diesel engine at low rpm. I always keep a light throttle starting out as I don’t want to to twist one of the stub axels inside the rear hubs or the splines in the hub caps. Yes, I like it also! |
|
| |
|
Elite Veteran
Location: Oceanside, CA | BigRabbitMan - 2019-05-08 12:39 PM
I always keep a light throttle starting out as I don’t want to to twist one of the stub axels inside the rear hubs or the splines in the hub caps.
Yep, if you get into it too deep from a start you'll get some chassis shudder!
|
|
| |
|
Elite Veteran
Location: Victoria, BC. Canada | Well all I can say at this juncture is that I'm envious of youse' guys and your grunty 1st gears. (reverse too!)
If it were not for my commitment to adhere to my 'economy-build' mantra - which suits my 'not-so-fat' wallet just fine - I would absolutely be more focused on an Ally, or, the 68RFE.
Sounds like your coach is working out fine, Rico. Go easy on the D-max guys pls.
Cheers,
Terry
#846 |
|
| |
|
Elite Veteran
Location: Victoria, BC. Canada | Hey,
Len, you asked for a pic of the Alcoa wheel stamp. Here it is: http://www.fmcowners.com/mbbs22/photos/photo-thumbnails.asp?albumid...
Been mulling over this diff and final drive ratio BS and I'm finding myself still vacillating on using this diff or not. Would be easier to put it in before the engine goes in.
With 37" wheels and the 3.73-diff I can stay out of overdrive (4th) till about 55-60 mph (1863 - 2032 rpm). To my carpenter's mind, that's a good head of steam for climbing hills after you drop out of, or, into 4th. What am I missing here? The 6BT makes peak torque @ 1500 - 1600 rpm depending on the source of the reference.
The other thing that's rather intriguing to me is this: with the .69:1 47RH overdrive gear I could, with rest of the house in order, bust 100-mph at just over 2300 rpms, or, in a moment of greater lucidity - cruise at 80 mph at 1870 rpms.
Doable perhaps.
Terry
#846 |
|
| |
|
Elite Veteran
Location: Oceanside, CA | I don't understand your fascination with very low rpms at high highway speed, it's not at all realistic, you will lug that motor, you will overheat, you will have transmission failures.. You need to quit focusing on "peak torque @ 1500 - 1600 rpm" those are engine dyno numbers that have to be balanced with the peak HP numbers and biased with vehicle weight.
Even on a standard 12v pickup if you installed 37" tires you'd be under geared, how do you think that doubling the weight of that same vehicle wouldn't absolutely kill the performance?
Rico is giving you priceless info on this, he is running the factory diff gears with 33" tires and spends a lot of his time in 5th gear like I do, 5th gear is .71 so damn near a match to your .69 (with you having a bit of an advantage there), just going from the 33 to the 37 inch tires at that point takes you beyond the 6th gear ratio of the allison (which is only occasionally in use with the Duramax that makes more power)...why would you want to do a gear swap that would make your .69 OD all but useless??
Thanks for the wheel pics, I'll be interested in all details of the brake parts as well. |
|
| |
|
Elite Veteran
Location: Victoria, BC. Canada | Morning,
Thanks Len. More sage-advice apparently falling on deaf ears. My Pa always said I had a thick head. I do appreciated the feedback.
Yes, obviously I'm having trouble getting my head around this.
I've got an old 95' Ram 12V with a 47RH (2wdr) that is my work truck; read, beater. That old bag of steel, along with other considerations, is responsible for convincing me to run with the Cummins for my coach. I tow a 6 x 10 box trailer with all my tools in it, so truck & trailer GVW around 8 - 9/K. The work it will have to do in my coach would be like adding the weight of another truck to the circus (6000/lbs).
Been running this truck for over a year now and it's apparent to me that the stock 12V just ain't happy running above 2000 rpm. This jives with what the trucker - I bought my coach engine from - explained to me. He said the 12V is most efficient cruising around 1800 rpm, give or take 100. He knew these engines.
If I run 37" wheels with the stock F-140/4.625:1 diff - it puts me well above 2000 rpm at 70 mph and slightly higher again if I have to find 36" tires (255/70 R22.5) in order to leave clearance to run a set of chains on the rears if need be. I'd then be pretty much limited to 60 - 65 mph highway speeds.
I'm likely not alone when I say that it's hard to keep my foot out of it when I drive my coach. In a nutshell (my head) I routinely find myself cruising well above 70 when conditions permit. I simply love driving my coach fast.
So, what to do?
I can't run taller wheels, that's a given. If I put the 3.73 diff in and end up not happy, the gears can be swapped out with say 3.91:1 or such.
Calculator says with the 3.73 diff I could drop a gear on the hills, climb them at 55 - 60 at 1800 - 2000 rpm. That's a good head of steam, no?
Or I could just slow down. I am getting older...
Terry
#846
|
|
| |
|
Elite Veteran
Location: Oceanside, CA | I'd leave the diff as is and run it...it's not any easier to change with the engine out (IMHO) and I think after driving it, you'll find that you won't want to. At 16000-ish lbs (which is where you'll be after the swap) you will be boosting all the time, the engine will be loaded all the time and will need to move more water and air to stay cool, the extra rpm makes that happen. I've got a buddy with a COE Cat 3126 project that fought this idea as well, they make peak torque at less than 1500rpms...it took forever for him to accept that the only way to keep it from overheating on grades was to run at 2000rpm...
There are dozens of threads like this: https://www.cumminsforum.com/forum/94-98-powertrain/322955-cruising-...
Quite a few caution the low rpm and the effect of lower line pressure in the trans allowing slippage and excessive wear..
Edited by LCAC_Man 2019-05-12 12:51 PM
|
|
| |
|
Elite Veteran
Location: Victoria, BC. Canada | I hear what you're saying.
What am I missing here?
https://www.crawlpedia.com/rpm_gear_calculator.htm
3.73 diff + 37" tires + 1:1 (3rd gear) + 60 mph = 2032 rpm! (or, 1863 rpm @ 55 mph... or, 1965 rpm in 2nd gear @ 40mph)
Again, what part of this do I have wrong?
Thanks again for your patience while trying to edg-jima-cate me. Don't give up on me just yet...
Terry
#846 |
|
| |
|
Elite Veteran
Location: Oceanside, CA | My point is you keep talking about 2000-2200 rpms like it's too high to run, and what I (and many others) are saying is that is exactly where you should be running, with that transmission, at that weight, and those hwy speeds. In short I guess I'm rejecting your assertion that the Cummins "doesn't like" to run at those rpms, there's just too many testimonials that contradict that.
What you seem to want is the optimal rpm regardless of constraints; and if you were running an 8 or 10spd eaton/fuller trans you could have your cake and eat it too, but, you have boxed yourself in a corner with your transmission selection. |
|
| |
|
Veteran
Location: Houston, Texas | MY experience with our setup is that ours feels just right cruising around 1900 rpms, we get 11 - 12.5 mpg with our diesel generator running and with our original rear end gears and standard 19.5 tires/wheels...we changed the 60# springs on the intake & exhaust, changed the fuel pin, governor spring and turn the fuel pin down all the way on the VE44 pump, we also add 2 gal., of premium
gasoline most of the time when we fill up, planning on installing on the very near future a water/methanol injection systems to cool off the EGT's when climbing those long hills...
Terry, I wish you could inspect our installation to help you save money on the installation, is not a professional mechanic grade installation of course, because we did a lot of trail and error things with ours,
but we kept it as low tech as possible to save some money, after we finish it' looked like it had been in there since day one from the factory.
Rico & Carmen
397
12 V & 6 Speed Allison |
|
| |
#846 Cummins Swap.
