"Performance" improvements on a Ford 460?

Two caveats to frame up this topic:
1. I LOVE modifying my cars and trucks, it's a sick obsession of mine.
2. That said, I've cooled on it a bit as I have now been around the block long enough to know that, quite often, my modifications don't improve things in the long run.

So, while I don't want a loping cam, loud exhaust, and blower sticking out the top of my 1996 Econoline (Jamboree Searcher 24D) I did a trial tow of my boat behind the RV and was a bit concerned about the performance, or lack there of. The boat and trailer weigh in right about 2900 lbs, certainly under the listed limit of 3500 lbs. My drive involved jumping on the highway for about 4 miles with a slight, very slight, uphill grade. If I had to guess I would say most of it was in the 10? range, with the steepest section maybe 20?. I did eventually get up to 55, but it took me a LONG time and the motor was really working. Oil temp remained steady but the water temp moved up a letter (the gauge reads "NORMAL" and in my past drives, even up over large grades, it has always bounced within the "R" but yesterday went into the "M").

The person I bought it from "did a tune up" before selling it and while I don't know how much I can trust him, the transmission fluid and oil both look fresh so I will give him the benefit of the doubt. I hear a small tick which sounds to me like a small exhaust manifold leak, but aside from that I have no reason to think the motor isn't running well. When not towing it maintains 55, and even 60, without a hint of drama.

So, aside from doing a full tune-up myself to ensure it is running well, are there any modifications people do to their 460 V8s in RVs?

Years ago I had a 96 Dutch Star with the 460 engine.  The only modification I can remember to the engine was replacing the cast iron exhaust manifold with headers.

Some performance gain but mostly because that engine, (Ford 460), has a history of problems with broken manifolds, broken head bolts, cracked heads, and vapor lock due to heat retention.

Part of the problem was that after pulling a long grade and heading down the other side of the hill. the breakage would occur from the cast iron manifolds cooling down too fast.

Easier to do the swap at home instead of on the road,

Where did you get the tow rating?  3500 lbs sounds like the tow capacity for an F350 van, your motorhome is taller and heavier so it may have a lower tow limit.

Slow and steady is just a fact of motorhome life, particularly when towing uphill.

Biggest bang for the buck for a 460 is headers. Fords 460 exhaust ports were not premium. Banks is the only manufacturer to offer 308 SS, 5/8" thick header flanges (no gaskets necessary) and the necessary heat shields. Without the heat shields your shift cable, E brake cable and starter will suffer. You don't want to be looking for those cables on that old of a chassis.
Adjust the TPS to 0.9-0.94 volts, key on engine off (drill out or remove the mounting bushings for adjustment slack). Adjust the EGR valve Position Sensor to 0.85 volts, key on engine off (you will have to extend the shaft).
Pull spout plug on TFI module and set timing to 12 degrees.
All those items made my 95 460 get up and go. Then I wanted more. See my signature. GRIN

You are correct, your tow rating is 3,500 #s.

Richard

Lou Schneider said:

Where did you get the tow rating?  3500 lbs sounds like the tow capacity for an F350 van, your motorhome is taller and heavier so it may have a lower tow limit.

Slow and steady is just a fact of motorhome life, particularly when towing uphill.

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This was based off of the information tag on the RV itself from Fleetwood. It also lists this on the hitch itself.

And I certainly don't mind slow (whenever I can I am driving my 1968 VW Bus around town), I just want safe. It seemed as though it would have a hard time pulling up and over any significant grade while maintaining a safe pace.

I as well went through the cracked manifold problem with my old class C motorhome. was quite costly. Another problem i ran into was trying to replace the spark plugs on my 460. Could get to 5 of them but one took me hours and I never could change it out. I heard later that you actually have to jack up the side of the motor to get at that one plug. Who knew.

Bill

It seemed as though it would have a hard time pulling up and over any significant grade while maintaining a safe pace.

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Depends on what you consider a "safe pace".  That rig is unlikely to get over any significant grade above about 40-45 mph, even without the trailer in tow. Though probably not much different with it.  The E4OD transmission is as much or more the problem as horsepower - it has two cruising gears (3rd + OD) and two low gears (1st & 2nd), with a largish gear-ratio gap in between.  As soon as you get beyond what 3rd can handle, your speed drops dramatically.
I'll second House Husbands suggestions about the Banks Headers, or even the full Banks Kit for the 460. It's addresses most of the 460's shortcomings as an engine.  Doesn't help the tranny, though.

A de-tuned engine has to work harder to develop the same horsepower. I have the same engine, a 1996 460 in a 1997 30 foot class c. What I found was the previous owner had retarded the timing to 6 degrees. I set it to 12 and it made a noticeable difference in power.  I would have advanced it more except for 2 reasons. Advancing the spark caused a very mild knock accelerating hard up steep grades before downshifting, and the check engine light occasionally shows a lean condition at higher speeds. I tried cruising at 75 mph just for a test and now it easily goes up slight inclines without downshifting and doesn't run the least bit hotter than normal. That is using regular gas not premium.

Another thing to consider on a rig that old is the brakes. Old brake fluid can cause the pistons in the brake calipers to get sticky and keep the brakes slightly applied. If you notice a slight hesitation when starting from a dead stop that doesn't sound like the engine or if you feel heat radiating from one or more wheels you may need new brake calipers and definitely a brake fluid change.

Thank you very much for the suggestion! I will try to dig into the engine after our trip this weekend to see if there is anything "simple" like that to address. We have a 275 mile round-trip with two ranges to cross while towing the boat so this will be a real test.

As for the brakes, I just replaced the front rotors (both were cracked) and pads which were almost non-existent on the non-piston side. Now that you mention it, I wonder if that was from rubbing due to the brakes being sticky. I'd imagine a brake fluid flush is at least in order.

A brake fluid flush and check the rubber hoses between the chassis and wheels.  They can deteriorate inside and act as a one way valve, trapping fluid in the wheel assembly so the brake doesn't release.

Crack the bleeder valve open with no pressure on the brakes.  If a small spray of fluid comes out as the piston releases, the hose is plugged and is not letting pressure drain back.

If your 460 is carburated, changing the timing gears and chain to a 429 will give you a little more power and helps improve fuel economy; don't know if this will work on a fuel injected motor though.