Hi all, Im not sure if this is the right place to post something like this, but if its not could somebody help me out? Thanks. I was wondering if anybody knows what kind of horsepower/torque output my engine has, its a 390 with dome pistons, 9:1 compression, & an elgin RV cam, I'm not exactly sure what the duration & lift is, but i have the papers, so when i find it ill let you guys know, it also has an HEI ignition, other than that it has the intake, exhaust, carb, & everything else from a 1965 352, its in my 65 F250. when i ordered the engine, the guy said it should make close to 400 Ft lb. of torque, & I'm sure it does, it has all the power i need, but if anybody has a better idea of what RPMs that kind of power kicks in at would be great, its got great power from about 1400-3500 RPM thanks everyone
Need better specifics to provide an estimate. What is your static compression ratio? What are your cam specs? What intake manifold and carb do you have? Headers or manifolds?
RV = recreational vehicle, RV cams are made for low and mid range torque, towing trailers or in motorhomes. 1400 - 3500 sounds about right. They were popular because they gave a boost in HP where you need it most, did not louse up the idle or low speed running, and actually improved gas mileage. If it runs good and has plenty of power drive it and enjoy it.
yea, i ordered it with the RV cam for towing & hauling stuff, i cant even feel a cord of firewood in the bed, the intake is just the stock cast iron 2bbl from a 65 352 from a truck, and the carb is the 2 bbl auto light, i think its about 500 CFM. and it has the stock 65 log exhaust manifolds. other than the long block, everything is stock 1965 F 250 with 352. the static is 9:1 i believe, its the only thing they mentioned so i guess i just figured it was the static,
the carb is an auto light 2100 that came with the truck in 65 on the 352 , the cam is an ELG-E966P the pistons are SIL-1130, other than that everything on the motor is stock (other than that it's a 390, not a 352) does any of that info help at all?
My 352 with a 600 cfm Holley 4 barrel, Edelbrock heads and intake, 9.5:1 compression, the same Elgin 966 cam, and FPA headers makes 325 hp, and 375 ft-lbs torque. Your 390 won't breath near as well and that will choke top end HP some, which will be limited as that cam really excels below 4500 rpm, but falls off quickly above 5500. That being said, I would expect around 275 Hp, and 350 to 380 ft-lbs of nice flat torque out of the 390 with the longer stroke.
Here is a scan from a magazine puff piece on Edelbrock kits. Most of the "RV" cams are similar on duration and lift. You'll lose some of the top end with a 2 barrel, but the torque peak shouldn't be too different. It'll just drop off quicker as the RPM goes up.
well it feels to me like the torque really drops off quickly after about 3800-4000, if i shift past 45 at all it really docent improve the acceleration, my best 0-60 time is probably shifting at around 4300. if i compare it to anything, i wouldn't say it feels like a gas engine at all, it feels just like my dads 7.3L power stroke diesel in the lower RPMs
It feels that way, because the torque does start to drop off after 4500 with the Elgin cam. My 352 torque peaked at about 3800, your 390 probably peaks a bit sooner due to the longer stroke. FE's are not high winding small blocks, they were designed to pull big heavy cars around, at the lowest rpm possible. Ford designed the FE at the hey-day of the 2 speed auto, when you needed lots of diesel like torque.
yea, that sounds about right. my best acceleration is when i hit it at about 2000, it's a real torque monster. & i get about 10-12 mpg, i just wish i had an overdrive so i could actually go the speed limit without winding the crap out of it
I would doubt you have domed pistons and only 9.5:1 unless you have huge chambered heads. Even my 428 CJ had a substantial dish and still yielded 10:1 or better. Watch for detonation.
but if anybody has a better idea of what RPMs that kind of power kicks in at would be great, its got great power from about 1400-3500 RPM Seems that you've answered your own questions. An RV cam builds cylinder pressure and power at low Rpms with a trade off of lower high RPM power. A race cam builds power at higher RPMs with a trade off of lower power levels at lower RPMs. If you want lower Rpms and faster cruising speed then a rear end gear change or an over drive Trans is what you need.
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