Go Back   Ford Truck Enthusiasts Forums > Ford Vans and other vehicles > 1968-2013 Full Size Vans
Sign in using an external account
Register Forgot Password?


1968-2013 Full Size Vans Econolines. E150, E250, E350, E450 and E550

Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!





 
Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 07-13-2011, 02:39 AM
FrankGRUN FrankGRUN is offline
New User
 
Join Date: Jun 2010
Posts: 18
FrankGRUN is starting off with a positive reputation.
Torque Curve for Carbureted 460 RV Engine

Last year I purchased a 1982 Ford E350 24' Born Free Motorhome with 45,000 miles. The previous owner had added a Gear Vendors Overdrive to the C6 automatic. At that point the rear had the stock 3.73:1 gears. Within a year, he re-geared to a Dana 70 with 4.56:1 gears. Frankly, with the stock Motorcraft carb and full smog system, it ran poorly and often stopped on hot days on busy inclines with vapor lock. The fuel economy ranged from 6-8 mpg.

For some time I searched the web as well as this site and the 460Ford site for any and all information about the horsepower and torque curves. I was also on a hunt for any info on how the increase the fuel efficiency of this powertrain. The Born Free specs indicate that the Motorhome weighs in at 14,000 fully loaded. But neither Ford or the RV manufacturer gives any info about the torque curve or even the engine torque rating.

After studying the forums for advice I made some choices and made a few modifications. I thought I'd post them here under the assumption that others are out there with similar frustrating experiences.

By way of modifications, I replaced the Motorcraft carb and stock cast iron intake with Edelbrock components including the 1411 carburetor (750 cfm as recommended by the Edelbrock engineers) and the 2166 intake manifold, thereby deleting the EGR system. I sent the distributor to Scott at Reclamation for recurving, added a Crane Hi-6S ignition to the Duraspark 2 system, switched to Iridium plugs, added Accel ignition wires, included a fuel pressure regulator and finally added a 3" exhaust from the exhaust manifolds through the muffler and on to the tailpipe. This included the y-pipe connector. I toyed with adding headers and full dual exhausts, but this motorhome holding tank configuration blocks any reasonable exhaust path on the driver's side of the vehicle. I used a Flo-Pro 4115 muffler with 3" inlet and outlet. I did not change the stock cam or the timing gear as access was just too intimidating with the van configuration.

I also added a Compucruise fuel economy gauge, a vacuum gauge and a tachometer. As a final step, I took the package to Superior Automotive in Placentia, CA to DynoTune the result. With the Dyno run (Dynojet Research in ground Chassis Dyno), I was surprised to learn that the air/fuel ratio was dead-on over the full rpm range tested (2,750 to 4,750 rpm). Despite the negative comments on this forum about Edelbrock carbs, I mounted this one box-stock as per the directions, fully expecting to have to rejet on the dyno.

The results: Max Torque was 280 # ft. at 3,450 rpm. Dynojet Chassis horsepower measured was 203 HP at 4,500 rpm, for a net at the flywheel of 286 HP inferred. I won't try to post the curve graphic here, but the numbers follow:

RPM, Torque in #-ft.;
2750, 170;
3000, 208;
3250, 240;
3500, 280;
3750, 274;
4000, 266;
4250, 247;
4500, 234;
4675, 220;

Inspecting the plotted curve, the torque rises linearly from 2750 to the max at 3400. There is a flat plateau from 3400 to 3850, at which point the torque decreases linearly to 4675 rpm. Measurements of engine rpm vs. real road velocity show that the engine torque max occurs at a real road speed of 71 mph in overdrive. This shows that the slippage of the C6 torque converter is just under 10%. Current average fuel economy is 10 mpg. Interestingly, there is a small peak of an additional 10% torque riding on the rising side of the torque curve at 3125 rpm which corresponds to 65 mph road speed.

For the final details, the tires are 8.75-16.5, and dyno measurements were taken at 84 degrees F, 29.93 in-Hg and humidity at 27%.

Hope this helps someone!
Reply With Quote
  #2  
Old 07-13-2011, 03:10 AM
85e150six4mtod 85e150six4mtod is offline
Post Fiend
 
Join Date: Apr 2004
Posts: 16,215
85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation
You smog exempt?
Reply With Quote
  #3  
Old 07-13-2011, 03:35 AM
FrankGRUN FrankGRUN is offline
New User
 
Join Date: Jun 2010
Posts: 18
FrankGRUN is starting off with a positive reputation.
Should have addressed that. The 1982 E350 Cutaway on which the Motorhome is built does not require a catalytic converter but is subject to smog inspection biannually here in CA. Because of the complexity of the stock (and other) engine installation the visual inspection just verifies that various smog components are present. Then smog certification requires the standard dyno emissions testing. As currently configured and tested here, the engine is cleaner on all measured species than the smog certification test level. In fact, the engine emission is cleaner than the nominal baseline values for the 1982 460. This vehicle was not certified for sale in CA as new. Purchasers of Ford E350 Vans in CA did not have a choice of the 460 engine. This vehicle was certified for sale in Iowa as a 49 state vehicle and legally imported into the Peoples Republic of California in 1983. It was configured as a Dual Fuel (LPG and Gasoline) vehicle and I am returning it to that setup. Now, however, I will use the IMPCO Commander O2 sensor controlled system for better economy and lower emissions than the original version.
Reply With Quote
  #4  
Old 07-13-2011, 03:40 AM
85e150six4mtod 85e150six4mtod is offline
Post Fiend
 
Join Date: Apr 2004
Posts: 16,215
85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation85e150six4mtod has a superb reputation
Shoulda know'd you had that covered....
Reply With Quote
  #5  
Old 07-13-2011, 04:05 AM
Mark Kovalsky's Avatar
Mark Kovalsky Mark Kovalsky is offline
Post Fiend
 
Join Date: Aug 1999
Location: SE Florida
Posts: 11,094
Mark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputation
In the 70's the cam was retarded on the 460 to meet emissions. It made less emissions, but also less fuel economy and less power.

On a friend's 86 E350 we advanced the cam, if I remember it was 2°. This raised the fuel economy towing his large trailer from 5 to 6 MPG. That's a 20% improvement. The truck was never on a dyno, but it had noticeably more power, too.
__________________
Mark
Former Ford Automatic Transmission Engineer

“The good thing about science is that it's true whether or not you believe in it.” ― Neil deGrasse Tyson
Reply With Quote
  #6  
Old 07-13-2011, 04:38 AM
FrankGRUN FrankGRUN is offline
New User
 
Join Date: Jun 2010
Posts: 18
FrankGRUN is starting off with a positive reputation.
Very true. I wanted to at least go to a pre-71 timing gear or even replace the cam with a RV torquer but the access to the engine is a real downer. I had also been told that the stock Ford cam used in the RV designated engines was specced for lower rpm torque. Doesn't appear to be the case though. I've seen 1982 RV brochures that suggest torque levels of 350+ #ft at 2400 rpm! Haven't seen anything like it.
Reply With Quote
  #7  
Old 07-13-2011, 11:23 PM
jimbbski jimbbski is offline
Senior User
 
Join Date: Nov 2009
Location: Chicago area
Posts: 470
jimbbski is starting off with a positive reputation.
If you remove the grill, radiator, AC condenser, and the radiator support bracket you can access the front of the engine to change the cam. Not easy and alot of work but access is possible.
Reply With Quote
Old 07-13-2011, 11:23 PM
 
 
 
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Carb Jetting with Dual Fuel Setup FrankGRUN Fuel Injection, Carburetion & Fuel System 6 08-08-2014 12:16 AM
Power,Torque, Power Question LIKENIT Modular V10 (6.8l) 39 08-14-2007 10:54 PM
Why 390 ? Chas1234 FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428) 7 01-20-2003 02:33 PM
Dissapointed at the Dyno - 351 W jrocco Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W) 22 04-12-2002 09:32 PM
Dissapointed on the Dyno - 351 W jrocco Performance & General Engine Building 16 04-11-2002 01:54 AM


Go Back   Ford Truck Enthusiasts Forums > Ford Vans and other vehicles > 1968-2013 Full Size Vans

Tags
1983, 460, airfuel, carb, carbureted, curve, curves, engine, ford, horsepower, hp, motorhome, power, ratio, rv, torque

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump



All times are GMT -5. The time now is 02:43 PM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup