Timing and ignition question

[xDiesel]

I've been considering putting gear-drive on my 350. Some people tell me its not a good idea others say it is, but no one gives me actual reasons why. What are the pros and cons to gear drive? Will it be worth it in the long run? As far as I know its the same as chain driven timing and I really like the sound that gear drive makes.

Also, how can I convert my stock ignition to HEI? Is it hard to do?

[Longhorn Man]

I've always felt it was kinda poser-ish... like the early pro-street stuff, where there wasn't enough engine to spin the huge tires, or more recently, the import craze, where they'd add a butt load of guages and stickers and think they had a hot rod.
Blower whine should mean blower... not I wanna sound like I have a blower.

[502tripower]

I have seen them work for some folks but, most of the time they are nothing but a headache and fail leaving the owner with expensive repairs.... Like Longhorn man says if you want the sound a blower then by all means build a blower motor....

[68GMCCustom]

some people like the sound of a gear drive...that's why they make both "quiet" and "noisy" versions. not quite the same as "blower wine".

[xDiesel]

I'm not looking for a blower whine, the truck is not by any means a "hot rod" or drag truck, its a workhorse. Its getting a plow when its done, I just want to know if the gear drive is worth it. If not then I won't waste my money and stick with chain drive.

[Longhorn Man]

I don't think there is any performance advantages... esp at the non-hot rod performance levels.
I didn't mean to imply that YOU were a poser or a fake.

[piecesparts]

So ---Tell US why you want a gear drive. What is it, about the gear drive intices you to spend the money on it? I have seen some guys with these and the noisy ones are just plain irritating and the longevity is not that good. Go with a quality gear set and chain and get the attention from the HP that you build into you motor, not the noise that you make.

[68GMCCustom]

my understanding is that a gear drive holds timing better...since there's no stretching of a chain going on.

[WorkinLonghorn]

For a race car it might be some advantage,I don't know. For a work truck FORGET IT!!!

[67_C-30]

A truck engine will never see enough RPM to ever need the supposed more consistant timing advantages of a gear drive. In fact, most serious race engine builders don't even use them anymore. They use either a high-end true roller timing chain or Jesel or other brand belt drive. The dual idler gear drives for SBC's wear out really fast, and would begin to effect timing issues on a regularly driven engine WAYYY before even a stock timing set ever would...

[Alaskan]

If you want something that will last the life of the motor go with a "good" roller chain setup, and to keep the timing dead on advance the cam 2 degrees when you install it. That way when the chain stretchs you'll be in good shape.

[mrein3]

On the two engines I've rebuilt my machine shop guy has ordered me a slightly wider than stock timing set. Maybe somebody can help you with a specific part number. The stock ones usually make it 100,000 miles. So assuming this wider one is better, how long do you expect this truck to last? Mine is NOT a daily driver. Since the spring of 1994 I've put 27,000 miles on the truck. At the rate I'm going I should expect to have to deal with a timing chain in 2050, 42 years from now.

I think you'll be fine with a plain old chain and sprocket set.

Wait. I did the math wrong. I have 27,000 on the truck, only 2000 on the engine. Add another 14 years on to my figures. I expect to do a chain in 2064, I'll be 96 years old then.

[502tripower]

Originally Posted by mrein3

On the two engines I've rebuilt my machine shop guy has ordered me a slightly wider than stock timing set. Maybe somebody can help you with a specific part number. The stock ones usually make it 100,000 miles. So assuming this wider one is better, how long do you expect this truck to last? Mine is NOT a daily driver. Since the spring of 1994 I've put 27,000 miles on the truck. At the rate I'm going I should expect to have to deal with a timing chain in 2050, 42 years from now.

I think you'll be fine with a plain old chain and sprocket set.

Wait. I did the math wrong. I have 27,000 on the truck, only 2000 on the engine. Add another 14 years on to my figures. I expect to do a chain in 2064, I'll be 96 years old then.

Sh!t...I'll be dead...

[Billla]

Hot Rod magazine did an interesting test on gear drives and found no horsepower gains...and very little with timing stability. The gear drive is really for situations where the valvetrain is really being worked hard - high spring pressures, etc.

A good Cloyes Tru-Roller isn't going to have any trouble with any engine that's streetable I sure wouldn't install the cam advanced, as there are other impacts to that decision. The impact of a stretched chain is variance in timing - not just retard.

[xDiesel]

The reason why I was considering it is because of durability and chain stretching, but if they really have no improvement with a gear drive then I'll stick with chain and sprocket. Thanks for all the input.