46RH (A518) Conversion project

Froggy1936 · March 10, 2018, 11:06 PM

Congratulations This learning as you go is a lot of extra work eh ? Mine runs a lot hotter than i would like but stays below the danger point .But is is not a steady temp ,it goes up and down depending on load, I only got about a 900 RPM drom with my OD ? But i also have a lock up TQ . I also use a refrigerator condenser they hold quite a bit of fluid I did not mount it in frt of the rad but off to the side .And my temp gauge pickup is in the rear of the oil pan . Frank

Rickf1985 · March 11, 2018, 10:22 AM

The most efficient cooler is a stacked plate cooler, that is one step up from the one you got which is one step up from the basic cooler. Now what I would do, and you can do it with the cooler you have, is add a thermostatically controlled fan to the cooler and mount it remotely.

Something like this.

http://www.jegs.com/i/JEGS/555/60345/10002/-1?CAWELAID=1710522205&CAGPSPN=pla&CAAGID=39714413703&CATCI=pla-484224304472&CATARGETID=230006180039220951&cadevice=c&gclid=CjwKCAiAxJPVBRB4EiwAsCA4aQUm-cUOZgOVF3XKR0E3Nrw-usEprnwD8iS_V1NX8zf-VOl20nv_oxoC5O0QAvD_BwE

Sasquatch · March 11, 2018, 03:35 PM

I did some digging in the Dodge manual and found that the 46RE, the lockup version of my transmission has an internal thermocouple that sets the danger point at 260 degrees and will kick it out of overdrive. So that tells me where the threshold is. But I still want to be well below that.

Rick, you and I are thinking alike. I thought about getting a motorcycle fan assembly because they are reliable and designed to be in the weather (and I can get them cheap) and do what you suggest. I ended up ordering the stacked plate style cooler and what I thought about last night was to mount it right up against the radiator so that the radiator fan will suck air through it quite often when going slow, or pulling a hill, etc. If that is still not enough, I will move it out away from the radiator and put its own fan on it. I just want to avoid adding another electrical circuit if I can.

Rickf1985 · March 12, 2018, 12:38 PM

On my 89 I have an interesting cooler from the factory. The right side is the AC condensor and the left side is the engine oil cooler. My transmission cooler is in front of that on the right and my power steering cooler in in front on the left. That is a lot blocking the radiator for engine cooling but since I went to the aluminum radiator I have had no troubles. I was thinking that oil/AC cooler would be good for your application. Just sort of throwing that out here for those who are following this since you already have the stacked [plate cooler which is the best out there. I think maybe the cooler you were using in front of the rad with the stacked plate and fan as a backup underneath somewhere on a thermostat for the fan. The overdrive without lockup is going to create a lot of heat. Once you lock that convertor it drops the temps drastically.

tmsnyder · March 12, 2018, 01:36 PM

I put in a very similar cooler. One thing to notice is that there is correct way to mount it so it fills without air in it and works properly. I'm sure you did but just something to double check. B&M has a tranny temp gauge that shows it in the green until 220F, and that's in the tranny itself. The oil exiting the tranny would be even hotter. You're good. You're looking at the hottest oil and it's only 220, it's fine. The pan temp will be cooler.

Sasquatch · March 12, 2018, 11:30 PM

I should have the new cooler on Thursday for an install. According to B&M, the temps exiting the cooler (cold side) should be below 200. If I am 220 on the hot side, I may be ok already, but I might as well get a better cooler on there.

Went to start the genny tonight and I have a fuel leak on the suction side fuel hose at the top of the fuel tank. Just great, now I need to drop the tank and fix it.

Sasquatch · March 12, 2018, 11:33 PM

Ok, Lets make some bets. As long as I can pull off the trip to AZ on the 23rd, what are your bets on fuel economy with the overdrive? As a long term average, I got about 7.5 before. That is twisting 3100 rpm at 65mph. Now I will be at about 2200-2300 rpm at the same speed.

So, what are your guesses? I am hoping for 8.5-9.5, with ocasional tanks hitting 10 on great days and 7 on bad days (wind, hills, etc.)

legomybago · March 13, 2018, 09:58 AM

If you were averaging 7.5 with the screaming 3-speed, I think you are going to get close to 10 like you say....

Rickf1985 · March 13, 2018, 10:59 AM

Quote from: Sasquatch on March 12, 2018, 11:33 PM
Ok, Lets make some bets. As long as I can pull off the trip to AZ on the 23rd, what are your bets on fuel economy with the overdrive? As a long term average, I got about 7.5 before. That is twisting 3100 rpm at 65mph. Now I will be at about 2200-2300 rpm at the same speed.

So, what are your guesses? I am hoping for 8.5-9.5, with ocasional tanks hitting 10 on great days and 7 on bad days (wind, hills, etc.)

What kind of terrain? there are some pretty steep hills out there. Flat running you could see 10 but if running OD on the hills it could drop to 5. Remember, you are still pushing a barn door down the road and every MPH over 60 increases the horsepower requirement exponentially. So once you drop out of that power band below about 2600 RPM you are going to hit a point of diminishing returns, and once you get the speed up to a point that you are back in the power band in OD you now need double the horsepower so basically you could be damned if you do and damned if you don't. There is no free ride here. I am really curious to see what you get though. I have long since forgotten what the mods were on the engine. did you go with the long tube headers?

Froggy1936 · March 13, 2018, 12:09 PM

I would not put a no on it As i was dissapointed in my results , I do believe that lower RPM,s Do not always result in better MPG . Frank neither does TBI . over a good Quadrajet ! i??

Sasquatch · March 13, 2018, 06:10 PM

I have had long tube headers for a while now along with a good TBI system that continually self learns and a proper cam for low end torque. On my test run I was wondering if she would have sufficient torque to pull the lower RPM's at speed. She did it wonderfully getting over 10" vacuum at cruise, so she should be good. Pulling hills, OD off, she will be no different than before.

Terrain between here and Phoenix is mostly flat, some rolling hills and two ranges to cross. So a mix of everything. But, there are many many miles of flat wide open terrain to cross (Nevada).

Rickf1985 · March 13, 2018, 08:53 PM

Then depending on winds you should see an increase. I am going to venture 8.5 average. What does the closest person win?

Wantawinnie · March 14, 2018, 11:43 PM

The A518 non lock up behind the Cummins in my Winnebago has temp senders at the transmission hot side exit and one in the pan. Typically there is a large difference in the two. Hot side will fluctuate a lot and spike easily. I've seen occasional spikes to about 220-230 pulling hills and that was in double overdrive(gear vendor also). Pan temps were way less in the 180 range and did not follow the spikes. This tells me the fluid is being sufficiently cooled before returning to the pan. Typically, hot side is closer to 200 on level stretches with pan temps in the 150 range. I've got a stacked plate cooler in front and a fan cooled underbelly cooler near the transmission. With the lockup converter I would expect you to do at least that good or better.

As far as mileage....honestly, if you get over 8-9 mpg at highway speed I'd be surprised. Last trip in the fall I ran 65mph with a bad headwind and got about 9mpg with the Cummins on a 300 mile trip. If I could get myself to slow down it would be better but 65 is effortless and feels about right for my combo on the highway.

I have yet to get on a decent stretch of road and run 55mph in straight overdrive for an extended period. Best tankful for me has been about 12mpg and that was mixed driving prior to having the injectors rebuilt. I had two dribbling and the pop pressures were way off on two others. I'm hoping to get up to the 13mpg range this coming summer. Although, I turned up the fuel screw on the pump 3/4 of a turn at the same time and am getting 35psi of boost instead of the low 20's. Power has increased substantially with that change as well.

Thanks for sharing the transmission modifications and swap. BTW: I have one of the JVX adapters to put a A518 behind the big block in my Charger some day.

Froggy1936 · March 15, 2018, 02:11 PM

Yes, This veh is another MAJOR PROJECT (look it up in the projects section) And save yourself a ton of time and money , Looking for increased MPG . But as you see if you cannot slow down , All modifications are just extra work. THere is an unwritten law that says Pushing a 4x8 sheet of plywood down the road at 65MPH will NEVER GET GOOD MPG . Frank W% It,s got something to do with why sail boats work ! :)rotflmao

Sasquatch · March 15, 2018, 10:45 PM

I am not hoping for good mileage. Just better, an improvement. I can not see why it would not improve at the same given speed when the engine slows down by almost 800 rpm. That is a lot of pumping air and fuel. Not to mention wear and tear on the motor. And engine noise.

Froggy1936 · March 16, 2018, 02:04 PM

My therory ,In overdrive ,is that you increase throttle opening Thereby passing more fuel . Under load the RPM Does not increase . Even though there is more fuel being used To create the HP Needed at the same RPM (each explosion has more force But not more speed . )My RPM went down approx 900 RPM for every speed recorded . RE: at the lower RPM,s More fuel is required to do the same work ! Frank

Sasquatch · March 16, 2018, 04:25 PM

Froggy, you are right and something I was concerned about until I drove it. At 65 in 3rd I was pulling 16" of vacuum, in OD at the same speed I was 13-15", so that tells me that the throttle is not that much farther open. Hoping that the reduced RPM will outweigh the slight increase in throttle load. I will hook my computer up to the injection on the trip and it has a readout of GPH (Gallons per Hour) and on a flat stretch of road I am going to toggle the OD on and off and watch the fuel flow rate through the injection.

Sasquatch · March 17, 2018, 05:39 PM

The new 30,000 GVW transmission cooler is installed. Getting ready to take her for a nice run to prove everything out.

The old cooler looks like something that came out of a heater box or AC box back in the 70's. I am sure it did. While it did have 3/8 tubing, I measured it and there was 34 FEET! of tubing in that cooler. With all the bends it had to reduce flow a bit.

Rickf1985 · March 17, 2018, 07:22 PM

Have you gone over that radiator as it heats up with a temp gun to see if all the tubes are flowing? It is looking a bit, uh,.............. old? I notice that you put the cooler to one side, did you know there was more airflow from the fan there than in the middle? Most people put it there so they don't block the radiator not even knowing there is more air moving there at slow speeds.

Sasquatch · March 17, 2018, 11:43 PM

The radiator is only discolored because of spillage when I fill it. I had it cored and checked a few years ago and the guy said it did not even need it, it was perfect inside. I have trouble getting my 440 to run warm enough. Cooling with this coach has never been an issue, ever.

I placed it to the side because my electric radiator fan is slightly off center. It also will allow me to install another cooler on the right side if needed.

Test run report. I was not liking that I was seeing 230 degrees on my gauge for the transmission on the freeway. Never got above 240, but still too high. When I pulled back up to the shop I pulled out my laser temp gun and started checking temps. Gauge was reading 230 with the engine running in park. Inlet to the cooler 180, outlet 117, oil filter housing (mounted on the hot side) 189, oil pan 190, overdrive section 175, main body 180. So, my temp gauge is not reading correctly. I bet the fact that I have liquid thread sealant on the T fitting I used to install it on the inlet of the filter assembly is adding some resistance to the ground side. This would increase the temp readings. I am going to dig out my Fluke and test this theory tomorrow. I may ad another ground, or just replace the gauge and sender before the trip.

Just ran and checked. I have zero resistance between the sender body and ground. I also checked the sender, as it was cooling. The higher the resistance, the cooler it reads, so my theory would have the opposite effect. I am going to go look at some gauges tomorrow or Monday. May swap it with a new one (with the sender) or just know it is reading high.

Did about 50 miles. Ran like a champ. Sorry for the blurry photo, but at 70 I was turning 2300 rpms. So much quieter in the coach. I can hear myself think (and heard a few new rattles).

Sasquatch · March 17, 2018, 11:45 PM

Why does it make some of my photos so small?

Rickf1985 · March 18, 2018, 09:57 AM

That is a decent RPM considering the modifications you have made. I am curious to see how this works out. For those watching that RPM would be a little on the low side on a stock engine.

What are you using for pictures? If postimage use the tab that says "hotlink for forums". Second choice from the bottom.

Sasquatch · March 18, 2018, 11:13 AM

It has been so long since this motor was stock, I have no idea what it would be like. Funny story. When my dad first got this coach from my grandfather when he passed away, he had the heads rebuilt and installed a Crane "RV" cam. It says RV, right? So it should be for low end torque, right? Good lord no.... When I got the coach it would cackle and sound like a top fuel dragster at idle. Probably less power than stock below 3k, and when you had your foot in it the thing became insane at 4k. The sound she made was unreal, and slightly orgasmic. That big block idle loping..... I could just sit and listen to it.

When I finally had enough and pulled the cam and installed a proper low RPM torque producing cam it lost all it's audible character, but boy did it wake up below 3k. The power really starts to come on at 1500 and pulls really well to 4k. The package along with the headers/exhaust, intake, FI system, and ignition work really woke up the motor down low. And, it still has the original low compression pistons in the holes.

If you have a coach with a 440, and you plan on keeping it and using it for some years, I highly suggest you make a couple very impressive mods. Yes, one of them is some $$, but worth every penny.

1. You must get a proper cam in there. I am using a Comp cams, but Hughes also makes a cam specifically for motorhomes that on paper, looks even a tad bit better. I also advanced mine via the timing gear set another 4 degrees to bring the power down even lower.

2. With the cam change you must address the intake and exhaust side. A relatively inexpensive Edelbrock manifold and one of the current throttle body 4bbl fuel injection kits. Over a properly tuned carb, you may not see any real power gains, but your mileage will go up some, especially as you travel at different altitudes and temperatures. But the real benefit is it just works. Everywhere, any temp, any altitude, any fuel. Hit the key and she fires, idles, and runs like a much newer car. Worth every penny spent.

3. Exhaust. Right now on eBay are $99 shorty headers for 440's. Dump these into a properly sized exhaust system and let that big motor breathe properly.

I also did ignition work, but I am not sure I saw any real gains there. Swapped from mechanical fan clutch to electric and the motor seemed to rev more freely, but the real benefit was how much quieter she ran.

I am going to stop at a couple of auto parts stores after church and look for a new transmission temp gauge kit. I hate paying retail but I do not have the time now to order anything.

Froggy1936 · March 18, 2018, 02:47 PM

I dug up some old No,s From 11/2/13 Driveing from North Wales to Pittsburgh all Turnpike Best with the Quadrajet was 9.2 @ 58 mph AVG. With the TBI & OD it went to 10.6 RPM DRopped from 2900 down to 2200 in 4th gear with lock up . The RPM ,s for ea gear are 55 MPH= 1975, 60 MPH= 2100 , 65 MPH= 2200 & 70 MPH= 2400. If the best HP is acheived @ above 2500 I am running below optimum all the time . I think i have a problem with vacuume With the old engine and QJ carb, Turbo 400 . I had 16in @ 60 MPH Now with TBI & 4L80E Od & lock up i only get 11 in @ 60 mph ?? Frank

Sasquatch · March 18, 2018, 05:49 PM

Froggy, I think some loss of vacuum while cruising at a lower RPM is normal. You are, like you suggested earlier, running a bit more throttle to maintain the same speed. It is a win loose situation. Lower RPM = less fuel used but more throttle to maintain it which uses more fuel. The hopes is that you save more than you loose when it is all said and done. Time will tell for me, I am heading to Arizona Friday morning. 2000 mile trip, sure hope I built that tranny right.... I am sure there will be a learning curve of when to override it and kick off the OD and just let her twist.

I found a Bosch oil temp gauge at the FLAPS (friendly local auto parts store) that is all mechanical for $19. I will get it installed tomorrow. Going to test it in some boiling water to make sure it is close to accurate. I would rather have no gauge than one that is suspect.