Has anyone put a gear drive timing chain in a 289/ 302. Any problems? Suggestions?

 

I was wondering the same thing a while back. The issue that came up was how often I planned on driving my truck. Most of the replies I got told me that gear drive puts alot of strain on your drivetrain, as there is no room for slack as there is in a chain. I figured that I would be driving my truck alot, and just wanted a reliable, heated, semi-stock, running 302.

If I were driving my truck only on the weekends, I would have probably gone with the geardrive.

Im speaking from what I was told, and not what I know as fact, so before you make the decision, listen to some of the pros.

good luck!
55forder

 

Thanks for the advice. I built several engines before for both street and racing. I have never heard of gear drives putting a strain on the drivetrain? The only problem I see is if the gear drive is defective and the teeth are not ground properly. Even then, I don't see how it puts a strain on the engine more than say a double roller chain? My question mostly was concerned with the install. I've heard people have problems with clearance from the timing housing. Some had to grind metal away to make it fit. Gear drives are recommended for engines with roller rockers, high lift cams, etc. They keep the timing correct without fluctuation at high RPM's unlike a roller chain. I was hoping someone with a 302 did an install and what brand gear drive they used. Thanks guys.

 

I'm not sure about the strain thing on the valve train.....I don't think so. My opinion of a geat drive is they are great......tough, acurate timing. the only draw back is the noise......only what someone told me.

 

I'm not exactly a professional engine builder, so take this for what it's worth (hey, it didn't cost nuthin'!), but I have built over one hundred engines of various makes, mostly for street & drag racing with some oval asphalt/dirt thrown in. We've used several brands of gear drives over the years, with varied results. I don't think there's one absolute, final, definitive answer as to what is right...& I don't want to drone on....but I personally prefer, for the street, a good, high quality timing chain set, like the Cloyes brand (most of the Crane, Comp Cams, etc. double-roller sets are actually the same Cloyes set, with sometimes a considerable savings in cost. However, Cloyes does make some low cost units as well, (compared to their normal double-roller line). The Hex-A-Just line is yet higher in price.)

Assuming the gear drive is installed correctly, I don't feel they noticeably stress the valvetrain. A case can be made, though, that they transmit excessive vibration to the distributor, possibly causing ignition fluctuations. On the street, I think you would never notice this unless your engine is on the ragged edge of detonation anyway, & even then you would be hard put to trace it to the gear drive. I do think they cause problems with optical ignition modules, such as the Mallory Unilite & others, due to the vibration. Honestly, I think most people use a gear drive for the sound anyway, not really caring about the hp difference (if any).

As far as installation....yep, it's a pain, more so on Chevrolets than Fords (IMHO). Some block/galley plug/cover grinding/milling may be required. Sometimes double-roller sets hit the block too. The dual idler setups are MUCH easier to install. My limited experience (at customer request) with some of the cheap, offshore-produced brands is that the machining is not good, with some of the gears being not concentric to the naked eye. One brand, mentioning no names (P*****m) was returned to the mail-order seller 3 times for machining defects. My personal preference for a street unit would be the Pete Jackson units; a Chevy 355 I built in 1983 is still going strong in 2004, with 150,000+ miles on the rebuild. The gear drive is just fine. The P.J. units I have seen recently looked fine in quality, too.

Damn, I DID drone on....

 

homespun, you may have drone on.... but your droning was very informative. Thanks! As I am building a street rod truck, I guess I fall in the category of the many other gear drive people, that I want the sound more than the effect of the gear drive. There is something about the whine that makes the gear drive intimidating. LOL... The engine may be a dog, but with the hood closed and the sound of the gear drive, people wonder. Of course, I prefer the sound of the gears of a supercharger better, however marital priorities must be taken into consideration. LOL..... Thanks for the info on gear drives.

 

I always wanted a gear drive. With the size of a 56 hood, you wouldn't be able to tell if it had a blower or not. But the gear drive for a 351C is $385. I bought a 52 Chevy that included a gear drive in the deal. We went ahead and installed the gear drive for giggles. I loved the whine around town and at cruise nights. We drove it to Indy for a Goodguys show. It drove me nuts on the road. At higher RPM's, the sound was anything but pleasant. Saved me all the money I would have spent on a gear drive for my 56.

 

If nothing else, the whine of the gear drive will drown out the whine of the kids. (Note to self: next rebuild, opt for "noisy" version of gear drive.)

Maybe that's the reason I keep working on my '55 & my '69 Corvette....fewer seats than kids.....!

Actually, if I had moderately unlimited funds (doesn't make much sense but y'all know what I mean) I'd use the Weiand/Holley Powercharger on a 302. Same noise, fits under the hood, & turns the 302 into a monster on demand. New they are a little pricey, but you can occasionally find one at the swap meets or Ebay. Holley can freshen one up if necessary, though as long as the belt wasn't installed incorrectly, & air cleaners were used, they seem to last forever. Not bad mileage, either....