I don't want to pull this to far off the originators question, but am on the verg of having my 92EFI 460 rebuilt/core exchanged at a local large engine shop. I asked about getting an RV cam and was told that they don't normally do them because the outcome of the idle in EFI's is hard to predict and some customers are unhappy. They also mentioned that it can effect the makeup of how clean the exhaust is which is a concern where I live. (testing)I may push the issue for the mild RV cam as I would like a bit of a performance boost and haul a heavy slide in camper. Deen Hylton's uphill speeds would be great.
How much would the idle be changed and can anyone advise of how much the smog control will be effected with the mild cam.

Thanks
Doug
1992 f250 460efi 4X4

 

Doug,

I can't tell you how my engine "smogs" as I'm lucky enough not to live in an area that tests. My idle is very close to normal and you'd never know it had an aftermarket cam in it unless I told someone (there is no "rump-rump").

Deen

 

I went with the speed pro hp535 pistons and crane h-260-2 cam. Truck is an 89 super duty and it really pulls strong in the 2000-3000 rpm range. The truck weight 9000 lbs with the dump bed I have on it and I pull a 6000 lb Goose neck trailer with a 10,000 lb back hoe on it. Old truck gets me where I want to go.

 

Just want to get this back to the top

 

i have my 1994 efi 460 apart on the stand currently.
and FYI it does have a retarded timing set. the "dot" that you line up on the crank timing gear is not directly inline with the tooth. it is offset to one side.
please correct me if i'm wrong, but i believe this means the timing set is not "straight up". a comp cams tech guy confirmed this for me and said that one of their compu-grind cams would be perfect because it is ground 4 degrees advanced + run a straight up timing set for a total of 12 degrees more of cam advance. he said this would highly improve the low end power and response.

 

Help! When I took my 1989 F350 460 apart to change the water pump, I discovered that the previous owner had replaced the original chain with a double roller. Sounds good, but it is a Ford unit and the cam gear is marked D8TE-BA then in another place are some numbers that are hard to read: 5256 or 5266 or ? I didn't spot any other part numbers. I think that means my 1989 has a 1978-era chain. Does anyone know what this might be off of and if it is 0° or a retarded timing set?
Thanks!

 

my '94 has a double row chain from the factory. it doesn't appear to be a true "roller" chain, but it is double row.
as far as i know the cam gears are mostly the same- the retard is on the crank gear.
somewhere on this board i found a link to a site that has pics of the "retarded" timing set.
the "O" timing mark on the crank gear is aligned with the keyway on a straight up set. and it is slightly misaligned on a retarded set.
hope this makes sense...

 

Thanks! Do you know if there is a Ford part number on your 2-row cam gear?
Jim

 

ttt

any cam updates/experiences would be most appreciated.

 

I just got thru with my second truck's engine. A 1996 F-350XLT 4x4. Engine has been upgraded with 10.2 Speed-Pro Pistons, H-Beam rods, 268H Comp Cams, grooved lifter bore, Ported and 2.19 valved F3TE heads, ported intake, toilet capacity oil pump, Moroso septic tank. I have been experimenting with the stock speed density system before I install the Mass Air and FMS 42lb injectors, Hooker Headers. So far it runs " Satisfactory" with the T-Stat removed, Air horn chopped, K&N, Cat took a hike, Air Intake sensor now resides in the front bumper for maximum fuel and timing. Runs lean above 3500 rpm though with stock 24lb injectors.

A 2-4 mpg increase has been observed in an engine that I built for a friend. A low miles 97 460EFI engine. Upgrades include 10.2CR Speed Pro forged pistons, moly rings, Comp Cams XE 256 Computer grind, MSD 6-A, Cloyes Roller Chain. Cropped intake tube. Engine has been installed in a 88 Ford F-250 4X4. With about 2 Points in compression increase and 0 degree chain and cam, Flowmaster exhaust, feels like a 100hp increase minimum. It will smoke the 33 inch tires without effort, with some timing alterations, it pulled a 10,000lb trailer no problem.

FYI, there are some 460efi parts for sale on www.808stuff.com

 

thanks so much for your info!how did it run with speed density before the mass air conversion?if i did these upgrades with the speed density system ,what should i expect?

 

Actually it ran somewhat OK, depends on how you look at it. It idles with a nice cam beat when cold and slightly fades away when warm, Pulls real strong to about 3.5k, low powerband due to the fact that the injectors are too small and combined with a stock computer. With no regard for fuel mileage (8mpg) at the time bieng, I pulled the stat and run the engine in open loop and relocated the intake temp sensor in the front bumper to fool the computer. But with the interactive Mass Air and 42lb injectors, 180stat, Headers, The engine runs like a cammed 5.0 SEFI, Strong Power right to 6K and the nice cam beat is present hot or cold and the mileage is somewhat equals to stock, depending on driving habit.

If you plan to stick with the stock speed density EEC-IV, I would recommend the 2nd set-up. 9 to 10 -1 compression pistons, Comp Cam computer grind, 0 degree roller chain, intake air temp sensor relocated to the air cleaner box, Flowmaster exhaust, MSD 6A

 

great info thanks again ,so with the air temp sensor being cooler relocated to the front ,the computer richens the mixture,never thought about that one,some guys measure the voltage from the oxygen sensor while its running,while they adjust the fuel pressure reg,i guess thats one way to know how rich its running,this motor will be for an rv,so won't be running in the higher rpms

 

twisted - sorry for the off topic question but
1) I'm very interested in doing the MAF conversion to my 97 SP F250, E4OD and have spoken with interactive. My application requires their most expensive kit $1600 (figures, always me). What info could you add about the kit? Was it worth the $$? Would you do it again?
2) Why move the intake air temp sensor to the air cleaner box?

 

The biggest cam-related thing that annoys the speed density EFI system your truck has, is overlap. More lift, longer duration is all fine as long as the overlap is minimal.

Speed density EFI utilizes vacuum to measure load on the engine, so it can adjust for acceleration, cruising, deceleration, towing, yanking stumps, and hauling appropriately. High overlap cams generally produce "wobbly" vacuum, if any, and therefore the speed density gets very confused very quickly.

That's the reason anyway... and one of several reasons why those of us who want to experiment with hotter engines, convert away from Ford speed density, to mass air like the Ford cars have since about 89 or so, to present.

Seperate of that, if you don't go overboard with the camshaft in lift and duration, generally the factory EFI will tolerate the cam change. It may take longer for your EFI computer to "adjust" to the new cam, but that cannot be helped. You can adjust or replace the EEC if you want or need to however. There are tools you can buy that help you tune it.

Also, as a quick "pick", the 94 E350 van EEC computer for both the 351W and the 460 have what I consider "wild" timing curves as compared to E150/250 and all of the F-series. Why? Who knows, but of the several EEC's I've played with, this particular EEC might be a cheap alternative to purchasing fancy tuning tools.