I have been looking to replace the 30+yr old timing chain in my 402ci and was talking to some buddies and gear drives came up(lots of talk of metal shavings and gear tooth pieces) But then again when i think of who its all coming from i just might as well ask a Baboon to paint its ass a different color.... Are they usable for long periods of time? Daily driver is what im asking,i know the louds are just that but i can deal with it just dont like the sound of metal shavings ewhwhwuhuhuuuuu or should i just get a double roller or something and call it good?
i just might as well ask a Baboon to paint its ass a different color.... I'd rather see them wearing pants.
I love gear drives, ya you do get some wear show up in the pan but straight to the pan not through the engine, can't beat the accuracy, and the sound kicks ass, the loud ones are really loud(better make sure thats what you want) the quit ones you can still hear pretty good too, they work fine for a daily driver IMO.
your old timing chain/gears lasted 30 years...i say just get a good Cloyes double roller and call it good
The timing chain is actually designed to absorb some of the harmonics in the valve train and not send the vibrations to the crankshaft. I'd get a good quality double roller chain !! >>>>.
I put a noisy Pete Jackson in my '66 elky back in '93. Just thought it sounded cool. It felt like some power was restricted compared to the double roller I previously had in it when I let loose on it. I would stick with a good double roller chain imo.
I used a noisy Pete Jackson in a 66 chevelle several years ago and had 0 problems with it. Worked great IMO, sounded cool too. It all depends what you want, either way works well.
Seems to me guys who like to run GDs for the noise want people to think they have a blower 'cause they think they sound the same...they don't. GD's will maintain cam timing more acurately over time than a chain IF the chain stretches - which they do. Part of the problem with chains (esp in a SBC application) is the lack of steady oil flow. I have found a little trick that helps. I file a shallow groove from the front cam bearing oil flow port OUT, then dress it down/deburr it. This allows for a little internal oil leakage to flow out and on to the chain set. Note: this needs to be a shallow and small groove. You'll see a little decrease in idle oil pressure but I've found it to be a good tradeoff. I wouldn't be afraid of a GD but if it's not a hi-perf application, it's probably not needed.
I agree with the arguement that if it lasted this long, a new good quality one should do as well if not better.
A bunch of engine builders I know would disagree, seems the hot setup is the Jesel belt drives. Not to mention the transfer of vibration by the gear drive to the valvetrain. Yep... a good double roller will do the job.... and for a long time... and for a lot less money...
Gear drives kick ass...they are more accurate over a long period of time. If chains last 40 years, how come every used motor I ever get my hands on needs a chain, upon inspection? ( yes...double roller, or not...) A good, repeat, GOOD double roller chain in a properly maintained engine, of course, MAY make it a long time. Of course, so might a gear drive... I'm using a single idler gear drive in my BBF right now...damned if I can find any metal pieces in the pan when last we pulled it to freshen it, and lo and behold, the teeth aren't just jumping off the sprockets in a suicidal dive into the crankcase... This motor has been together, AND raced, for over 15 years, and freshened...rings, bearings...some different cam swaps... Gear drive...still intact... had to modify the timing cover, though... Posers? Yeah...I guess if you are trying for that "false blower whine"... I wouldn't know, you can't hear mine over the open headers... Opinions are like....
The belt drives, as I understand it, are EVEN better yet,...softens the whole deal, AND maintains accuracy...Anyone know the life expectancy on one of those belts, though? It's all got ups and downs... Hell..."tradition" would dictate a fiber gear, and a single chain, though, wouldn't it?
How long have you seen a belt last? A chain last? Ive done some endurance motors with gear drives and no problems. Flecks in the pan could only meen a poor design,improperly setup or cheap gear drive. Its the oldest bullshit myth since the day they came out. If they were such junk than they would have dissapered long ago from racing. Ive seen the good belts fail and strech (5* or more)while running, chains also. They have thier place in racing just as all the others do for different reasons.
If you have EXTREME valve spring pressures, dual mags and a cam driven injector pump, you might need a gear drive. Otherwise, a quality chain does the job,
I understand NASCAR engine builders no longer use gear drives. When someone asked the manufacturer how come they still made them, the answer was, "the kids like em."
I would ask myself, "If the gear drive didn't make any noise, would I still want it?". If you answered "Yes", get it. If not, chain.
I would expect NASCAR yields as little leeway in what components they use ( and WHO'S...) as they do in the rest of the areas of variance...I guess I could be wrong. If they don't use 'em anymore, it certainly seems that they did fine during the years that they did use them, since racing kept on a-going... Either way, YES, for most purposes, a double roller chain is going to do your ass just fine, and you'll never know...but, lets face it, in MOST cases of "Traditional" cars...even a factory chain and sprockets will be fine. Most street driven cars, with mild motors, gears, etc...don't make enough power to hurt themselves, NOR is incredible accurate valve timing really that critical...hell, stamped steel factory rockers are ALL OVER THE PLACE.... The thing is, they aren't bombs waiting to go off, either...that's ridiculous...they would have NEVER survived this long if they had been... The thing with the chains is this: MANY moving parts in each segment = MANY wear points...each pin, in each hole, in each link...the chain, over time WILL, in effect, elongate. And gears are harsh...and belts break, and yadayadayada...
Been running one over a year , ordered the loud one but I think I got the quite one ! I also run a mini spool !
Well, as Hi! stated, they each have their place. I am not a particular fan of them for the street- to me it says redneck equivalent of "big spoiler" and "Fart-can exhaust"...but my tastes aside: If you decide to run one- at the MINIMUM, use a Pete Jackson unit. Don't even consider using any of the cheaper brands, unless you really are just a poser. They are too inaccurate, and too shoddy, to work well or last. When the gears are visibly not concentric....ya got problems.... A better choice are the single-idler units made by Milodon, which are more difficult to set up, but work very well. For anything serious, street or racing, I prefer those over the Pete Jackson units. The ultimate gear drives were made by the Summers Brothers (of Goldenrod fame); they were so beautifully machined I'd almost like to hang it on the wall as art. They are still being made, though I believe the company changed hands and I have not seen one recently. http://www.summersbrothersracing.com/camshaft drives.htm It really is difficult to beat a good timing chain set for the price. Incidentally, for those who don't know: the Comp sets (and some other brands) are simply reboxed Cloyes units...generally at a lower price. For example, the Cloyes 9-3122 True Roller (the "classic" type set as opposed to Hex-A-Just,, Street, etc.) for the BBF is $105.95. The Comp 3122 is $70.95....same set. You have to be careful as there isn't always a direct number correlation, and sometimes there isn't a direct equivalent... You also have to be careful to compare like sets. If one set is $45, and another is $90...there's a good reason.
I just talked with Lamar Walden about this two weeks ago. He ran Pro Stock back when it was new, and did very well (Building and driving the Berry Setzer Vega, among other things). On the engine dyno, a gear drive lost 23 horsepower over a double roller timing chain. This was on a 660hp 331-inch small block that beat Sox and Martin's Hemi. The best timing chain he and all the other Chevy racers ran, in terms of most power, was a factory nylon chain with aluminum gears. He told me the application it was from, but I don't remember. They threw it out after every race, and bought a new one for a couple bucks. (they were tearing down the engine every week and freshening it up). He said Grumpy Jenkins used it too, and a couple other names I recognized but forget now. Part of the reason it did so well was because it absorbed harmonics between the crankshaft and camshaft, unlike a steel chain and gears. He said that nylon chain is what led to the Jesel rubber band drives. He has no reason to lie or spin stories with me, and he's forgotten more than most of us will ever know. It came up, because I'm building a stroker 283 with him, and am trying to get the most power out of the package. He said a double roller is perfect. Currently, they're liking some made in Australia. There's two versions of it, and one of them has a bearing on the back side to reduce friction and keep thrust on the cam. -Brad
This is the one I am using...NO complaints, except your correct...PITA to set up... Luckily I had some assistance from a friend and a degree wheel, when we changed the cam!
That sounds completely reasonable...I believe it... Of course, I'm for not changing my chain and gears every race!
Yeah, I had to have that little talk with him too! He just smiled and said I should go with a double-roller. -Brad
BINGO! http://store.trackerdesigns.com/Mer...BRADANDERSON&Category_Code=Gear_Drives_Covers http://www.alanjohnsonperformance.com/01geardrives.html One more vote for the Cloyes double roller. I've been running a quiet gear drive in one of my cars for over 25 years. I don't have anything against gear drives but I do feel they are unnecessary for low horse power street use and they do cause a harmonics problem.
My opinion is they sound like shit. As stated earlier they do NOT sound like a blower. That noise would drive me crazy if I was in the car. I follow the majority of the recommendations here, get a good double roller chain and it will last a long time. Let your compression, cam and exhaust make the good sounds coming from your engine.
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