Timing: Chain vs Gear Drive

[BigBrother-84]

Gentlemen,

I am absolutely not planning to play in Big Brother's engine.  Everything works well and I am fully satisfied.

But I am curious...

Do some of you have replaced their timing chain with a gear drive?  How does it perform?  What do you think about it?  I suppose it requires a different cover?

[mat in tn]

a gear drive is a very interesting thought. I like them in theory at least. there is a real metallurgic advantage. when you think of how steel responds to stresses and heat. a well-oiled gear drive will almost never wear out. the contact surfaces are broader than those of a chain. and steel resists compressing better than stretching at these stresses known inside the engine. the great 300/4.9 is a gear drive. its even better due to the two-gear design. no idlers added to the system. but this means that the camshaft rotates opposite the crankshaft. the biggest issue is normally noise. these with idlers seem to have a rolling buzz not unlike a motorcycle chain. some hate it and some don't. ford even used an aluminum gear cased in a type of reinforced plastic to reduce the noise on the 300. when I built mine 20 years ago, I opted for an all steel set and I have not heard it yet. I have seen a few "silent gears" with the composite falling apart and that is enough reason for me to not use them. as for the different cover, I'm not really sure but I have not fully researched that for different engines either. but on a 5.0/302 the cover matches the layout of the block so if it fits in the block recess, I expect it will fit within the cover also. the oil diverter inside the cover may need to be modified but that is only a speculation. 351w/5.8 should be the same.

[Rusty_S85]

BigBrother-84 wrote

Gentlemen,

I am absolutely not planning to play in Big Brother's engine.  Everything works well and I am fully satisfied.

But I am curious...

Do some of you have replaced their timing chain with a gear drive?  How does it perform?  What do you think about it?  I suppose it requires a different cover?

Dont do it.

Cons of the gear drive out weigh the pros of a gear drive.

Pro with a gear drive
-doesnt have slack with wear
-stable timing

Cons with the gear drive
-noisy
-transmit vibrations and harmonics directly to the camshaft from the crank shaft
-requires a cam button on some engines that dont have a thrust plate to keep the cam in place

I have taken many out and replaced with a standard timing chain as the gear drives are a racing gimmic that isnt supposed to be used on street engines.  Even if you get the silent drive it hums like a supercharger still just not as loud of a whine as the noisy drive has.