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Restoman
02-02-2007, 03:02 AM
Has anyone explored the posibility of converting the M20 timing belt to a chain? Of all the places I think we could do it. I bet peerless sees something he could add.

Turbo-Brown
02-02-2007, 03:36 AM
Only big problems I can see that'd need to be overcome are creasting a sealed enclosure for the chain so it can be bathed in oil and coming up with some kind of adjuster.

Guess some guides wouldn't go amiss either but that'd be relatively easy.

superj
02-02-2007, 07:54 AM
it weas discussed a long time ago but people gave up on it because of cost. if you can come up with something though, do post as i would love to hear about it.

ianlee91
02-02-2007, 07:58 AM
Only big problems I can see that'd need to be overcome are creasting a sealed enclosure for the chain so it can be bathed in oil and coming up with some kind of adjuster.

Guess some guides wouldn't go amiss either but that'd be relatively easy.

Could you take the timing chain mechanicals from a 5-series 6?

DJB
02-02-2007, 11:30 AM
Only big problems I can see that'd need to be overcome are creasting a sealed enclosure for the chain so it can be bathed in oil and coming up with some kind of adjuster.

Guess some guides wouldn't go amiss either but that'd be relatively easy.

Could you take the timing chain mechanicals from a 5-series 6?

Getting a chain and sprockets is not the problem.
The belt is on the outside of the engine oil seals. There is no sealing surface between the crank drive gear and the vibration damper disk, or the camshaft and distributor cap, or anywhere on the front of the engine.

You could run a "dry" belt with grease, but that would be very loud and have a short life. You would still have to fabricate better seals too keep grease mist out of the spark distribution.

peerless
02-02-2007, 01:44 PM
Timing Chain might seem nice but it would make service a real bitch. The crank nose would need modifications to make room for a timing gear and move the sealing surface outward. And what about water pump service?

But beyond all that, timing belts are fine if properly serviced. Look at some of your big time racing V-8, screw the chain, drop the gear drive, the hot set-up is belt drives. So after all these years of building horsepower and bolt on goodies, they have finally come around that belt drives are great.

Whats great about a belt drive. Its quiet, Inexpensive, Virtually no mechanical wear of parts(except belt and tensioner), And probably the best reason, No crankshaft harmonics are transfered to the drivetrain.

Besides being more durable than gear or chain drives, Jesel’s belt drive systems offer a number of advantages.

* Extremely accurate cam timing

* Reduces crankshaft harmonics

* Stronger than chains or gear drives

This is also what NASCAR has moved to aswell since they where getting timing chain failures in 500 mile races.

Keep the timing belt!

peerless
02-02-2007, 02:41 PM
http://popularhotrodding.com/tech/0606phr_03_z+pontiac_+engine+jesel_belt_drive.jpg

Thing-90ix
02-02-2007, 03:08 PM
Yup.

Why people seem to think a chain is better is a mystery.

smooth
02-02-2007, 05:51 PM
Yup.

Why people seem to think a chain is better is a mystery.

conventional thought probably thinks metal > rubber

I'd be interested in finding out what kinds of developments have been or could be made in the belt composition. if we do any engineering, I'd think we'd get most bang by making a more durable substance for the belt.

peerless
02-02-2007, 06:14 PM
Yup.

Why people seem to think a chain is better is a mystery.

conventional thought probably thinks metal > rubber

I'd be interested in finding out what kinds of developments have been or could be made in the belt composition. if we do any engineering, I'd think we'd get most bang by making a more durable substance for the belt.

Kevlar fiber would put some strenght into em. But realistly you wouldnt need something like that unless your pushing about 300+HP. Still be a nice upgade to any engine. I would imagine service life could be reasonably extended.

Kevlar Aramid is an organic fiber in the aromatic polyamide family. The unique and highly oriented structure of Kevlar creates fibers with extremely high tensile strength, six times stronger than steel on a pound for pound bases. Examples of the improvements realized are listed below:

Flexural Strength: The network of fibers and fibers rapidly disperses forces applied to the coating system thus improving flexural strength.

Tensile Strength: Additions of Kevlar fibers have been shown to increase tensile and tear strengths by factors of up to five times. Wear resistance, which is related to toughness and tensile strength is also improved severalfold.

Thermal Resistance: Kevlar retains its impressive properties from cryogenic temperatures up to 750°F (399°C). This unique property assures continued high performance under all foreseeable service conditions.

http://www.epoxyproducts.com/kevlar4u.html

M-technik-3
02-02-2007, 06:17 PM
Why go thru the hassle? 6 to 7 years E30's will be scarce sightings on the road. There will not be enough folks out there to sell this product to.

DJB
02-02-2007, 06:36 PM
I'd be interested in finding out what kinds of developments have been or could be made in the belt composition. if we do any engineering, I'd think we'd get most bang by making a more durable substance for the belt.

Belts and hoses have gotten much better over the years, without any big marketing campaign to let us know about it. Most good hoses now use aramid fibers ("Kevlar") and EDPM rubber. Belts don't usually use Kevlar itself because of its poor flex fatigue resistance, but have similar advanced fibers.

It's no coincidence that tire companies, Continental and Goodyear, make timing belts. They have pretty much the same requirements: very strong, constantly flexing fiber bands protected by a rubbery elastomer. In 1970 the typical long-life tire would last 15K miles. In the 1980's radial tires with steel "belts" and other fibers would go up 40K miles. Today it's common to see 80K mile "waranty life" aramid mixed-fiber tires. Those same advances are in the timing belts.

peerless
02-03-2007, 02:55 AM
Why go thru the hassle? 6 to 7 years E30's will be scarce sightings on the road. There will not be enough folks out there to sell this product to.

Bah, Rubbish I tell ya. The E30 is here to stay. :)

dom
02-03-2007, 07:19 PM
another thread about it:
http://www.e30tech.com/forum/viewtopic.php?t=851