Howdy, newbie to the site, what a fantastic site

Got some questions on cams and performance
I've got a 96 OBD1 460 in a HD F-250 w/ 5sp on dual fuel (propane or gas)Dual K&N cones on the intake, cat converter missing
Cruise is 2200 rpm @ 65 mph
Occassional trailer puller up to 10k lbs, daily grocery getter
I would like better power at cruise, find pulls hard at 2700 + rpm but is really not great at 2200
mileage seems to bee the same at 65 mph or 80 mph(read too much $ on speeding tickets)
Has any tried the comp cam P/N34-255-5? with or without the pre 72 timing chain set? would the timing chain change be enough alone?

don't really want to spend a lot of money on performance, but would like power at lower rpm, not crazy about headers, but will be redoing exhaust in the spring, thinking of a 4in single (diesel style)

Primarily running on propane, but I need to maintain drivability on gas as well, even if it has to be premium

Any thoughts would be appreciated, thanks

Waiting to awake the monster

 

I can't find the cam you've listed on my DD2000 cam disk. I've found a 34-245-5 with advertized duration of 288-304 and also 34-254-5 with advertized duration of 298-316. Both are WAY TOO BIG for towing or general street use. You need something like the 34-231-3 which is the CompXtreme 4X4 cam. Don't go anymore than 268 advertized duration for towing. I had a custom cam ground from Comp cams just for towing...my advertized duration is 249-265 or 206-211 @ .050
Another thing, when running propane you experiance an 8-10% HP LOSS! The only way you can make that up is to run more compression. Of course when you switch back to gas you'll end up detonating...no happy compromise here.
Headers are a pain, but they will give you that low end torque your looking for. I found that headers and the gear change from 3:55's to 4:11's made a huge differance for me. Deen

 

Is the CompXtreme 4X4 cam Speed Density friendly? Will a chip need to be used in conjuction with it for full benefits?

 

Thanks for the info guys
went to compcams site and found the specs for 34-255-5, looks lke this
@ 050 212/219 with 114 lobe seperation, and a lift of 495 tech said it is already advanced 4 degrees when I asked him about the pre 72 gears set but he was in a hurry, so I thought a second opinion might be wise.
I am not looking for a power gain so much as to move the toque curve to a lower rpm

BTW the grind # for this cam is FF XE 256 H14 if that means anything to you
Cheers

 

Rabidranger, you have to run a mild cam to be speed density friendly. I think the 4X4 Xtreme would be O.K. but I'd also call CompCams back and ask...they are the Xperts

Old5, I don't think you'd gain much at 2200 RPM with that cam. Even with my purpose built grind my seat of the pants felt like I lost a little below 2400-2500 RPM when towing. I cruise at 2700 RPM at 60 MPH which is right about where the power range builds.

 

Hay ther DeenHylton, You say now 4.10s what did you have to start with?
and why the change?

 

>Hay ther DeenHylton, You say now 4.10s what did you have to
>start with?
>and why the change?

I originaly had 3:55 gearing. I use my truck for towing 95% of the time and tow a race trailer weighing around 9000 lbs. I like to be able to maintain the legal limit or a little higher even when going through the mountains (5000' elevation). It took the 4:10's and engine mods to achieve this. Deen