To Geardrive or not?

[396_WAYS_TO_SPIT]

I had a PJ in a BBC high compression motor for 25 years...no problems..couldn't really hear any noise..would use one again..
Thats a loooong time to have a motor together How many hours did you put on it during a season.....2 or 3

[SmokinLowriderSS]

And the moral to the story is.........They both work. If geardrives were bad, they would not be on the market because people would be breaking engines with them. There is no "kind of broken" with a chain or gear drive, If either breaks, the results will be bad. Run what you want, they both work well and high performance engine builders across the land use both as well......Good luck
Exactly, both work fine, it's simply "which one do you want to use?"

[Bahner tunnel]

I have heard from a respected engine builder that the PJ style gear drive puts excessive pressure on the end of the crank by design. If I remember correctly he said it lead to issues with the front main bearing. This was on a large solid roller with monster 800lb. open springs.
The hot set up ( in his opinoin ) was the "fixed" idler gear style , like a Donavan or Milodon ect... It reduces the crank loading while having accurate timing, best of both worlds maybe?
Personally I'm a fan of a billet gear/chain set. At least until santa brings me a Jessel belt drive=the ultimate way to twist your bump stick.
Are any of your set-ups using real heavy springs and a PJ style geqar drive with out any crank or bearing issues?

[oldselmn8tr]

Not that it was by much but Hot Rod mag did dyno tests on this and the old roller t. chain still makes the best horsepower. I ran a gear drive in my 66 elky and after a while the whine drove me nuts so I put a t. chain back in. Now if it would have been a blower whine I think I could have put up with it.

[baddboyz03]

gear drive gear drive gear drive thats my story and im sticking 2 it!!
besides the deer can hear you coming. lol.

[BrendellaJet]

Not that it was by much but Hot Rod mag did dyno tests on this and the old roller t. chain still makes the best horsepower. I ran a gear drive in my 66 elky and after a while the whine drove me nuts so I put a t. chain back in. Now if it would have been a blower whine I think I could have put up with it.
I saw another test they did and the Gear Drive made more power.

[mdlfnsatx]

if youre looking for dependability, no changes in timing etc, its gonna be hard to beat the gear drive. thats why in the heavy equipment world most of youre industrial applications use either gear drive or a close example, but hardly ever a timing chain. if it were me, i would use a gear drive with no thought of a timing chain ever. timing chains all stretch, if at least when you first start the motor when installed new. but that is my 2 cents, hope it helps..