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Anonymous
Guest
I read somewhere that you can advance the timing gear on a 240 1 tooth (7.x*) to increase low end torque. Has anybody tried it?
DP
DP
Actually, it decreases torque. True, it moves the torque curve lower, but since the engine isn't spinning as fast at the torque peak as a result, it's not making as much torque either.
Unless you are counteracting the effects of a retarded cam --as in the case of later smog constrained 300s-- you're better off running a cam straight up.
Unless you are counteracting the effects of a retarded cam --as in the case of later smog constrained 300s-- you're better off running a cam straight up.
6bangerbill
Well-known member
The standard proceedure for street use with a performance cam is to advance your cam to attain a cranking compression of 190 t0 200 psi. With proper timing and AF fuel ratio, this should provide max street power on 91 octane. The cam advance or retard proceedure is a method of matching your intake closing event to your particular,compression,temperature,converter, altitude, cam or other engine features used in your particular engine combination. The ideal street -strip cam will usually require some retardation for max performance at the strip where high rpm hp is king. The method used to retard or advance a cam varies with motor type, but I believe Clifford sells a crank mounted cam timing gear for both ford sixes that has multiple key slots for timing purposes.A one tooth jump would probably bee overkill.
8) advancing the cam gear one tooth is a bad idea, as it advances the cam far more than 7 degrees, more like 16 or so(one tooth on a V8 is 16 degrees). you can advance the cam more like 4 degrees to improve low end torque, but like supermag said you dont increase the amount of torque, you just change the rpm peak.
typically, for a stock intake/exhaust system, its best to have the cam exactally as specified by hte OEM - there was a lot of R&D put into the cam to give it hte best overall output throughout the rpm range.
Not entirely true. The manufacturers also have to account for emissions whicj can lead to a retarded cam, in the case of the 300, it's 4°.
A
Anonymous
Guest
StRanger, is does that four-degree retard apply to all years and varieties of 300?
Are there offset keys that would allow drpepper to advance his cam timing less radically?
460 V-8 smoggers have the cam retarded eight degrees. I advanced mine to straight-up timing by hand-carving a new keyway in the sprocket, and it came out pretty close. The Kent engine in my '79 Fiesta uses a hardened dowel instead of a key to index the sprocket. In that case, I made a larger diameter piece of roundstock with an offset hole for the dowel, to change the timing. In that case, the brand-new hot-rod camshaft I bought had dialed in at six degrees out of spec, as delivered. Ya gotta check things out yourself!
Are there offset keys that would allow drpepper to advance his cam timing less radically?
460 V-8 smoggers have the cam retarded eight degrees. I advanced mine to straight-up timing by hand-carving a new keyway in the sprocket, and it came out pretty close. The Kent engine in my '79 Fiesta uses a hardened dowel instead of a key to index the sprocket. In that case, I made a larger diameter piece of roundstock with an offset hole for the dowel, to change the timing. In that case, the brand-new hot-rod camshaft I bought had dialed in at six degrees out of spec, as delivered. Ya gotta check things out yourself!
Per-smog 300 cams are straight up. Late model are retarded. Don't ask me when it changed though
On the 460 smogers you can order an early 429 timing set and solve that problem, the change was in the sprockets.
I don't know if the sixes were changed with the gear or the cam.
You can have a local machine shop broach a new keyway in the gear if you know where you want it.
In any event I would check the cam timing with a degree wheel before I made any changes. Then I would verify after said changes.
I don't know if the sixes were changed with the gear or the cam.
You can have a local machine shop broach a new keyway in the gear if you know where you want it.
In any event I would check the cam timing with a degree wheel before I made any changes. Then I would verify after said changes.
pickupman":2g9u4kk6 said:
Utter nonsense. If that were true there would never have been a "performance industry". Hot rodders have been modifying and tuning stock OEM components fpr better perfomance since shortly after the first factory vehicle was produced. Just because Henry built it that way doesn't mean it can't be improved upon.
Joe
SuperMag":2ok5xbwo said:
Well....maybe. On most modern high revving engines this is probably true. HOWEVER, in the case of a low-revving engine that is already somewhat breathing constrained, I wonder if this actually holds up.
Consider the Farmall Super M tractor as tested at Nebraska in 1952. Rated for max power at 1450 rpm, torque increased to 362.8 lb/ft at 845 rpm. This works out to a BMEP of over 200psi and it had a compression ratio of 5.9:1.
So what does this have to do with a Ford Six? Maybe nothing, but the Super M which I overhauled for a neighbor a few years back had pretty small valves/ports and I suspect that the cam was pretty mild as well. And it filled the chambers best at low speed.
A 300 Ford also has small ports/valves. Just what is needed for low-speed work. And at low speeds an advanced stock cam just may well improve volumetric efficiency to actually increase torque due to having more actual time for flow to start and then slam the door shut to keep the mixture contained for compression. Getting that intake open early to take advantage of the short rod acceleration of the piston and shutting it early just might make for a net increase in torque in our engines, albeit at a lower speed.
Torque is not dependant on rpm, it is a function of BMEP and displacement, therefore it matters not if the rpm range is lowered as far as peak torque is concerned. Lower rpm will result in less hp unless torque increases a whole bunch though.
I'm just guessing on all this but it sorta makes sense to me and the way my F-150 pulls at low speed with the (non-stock) cam advanced 4º makes me think I may be right. Too bad I'm not rich enough to actually dyno this thing with before and after results but that probably ain't happenin' in my lifetime.
If yer talkin' Chebbies or bent 8's then all bets are off
Joe
A
Anonymous
Guest
I knew about 429 gears and machine shop broaching, Stubby, but I'm a cheap b-----d! Well, also I sort of like having done that kind of thing myself.
I enjoy the sense of accomplishment that comes from pulling tricks like that out of the hat. 8)Similar threads
