Gear drive VS chain cam drives

[grumpyvette]

Gear drive VS chain cam drives,

 

 

 

Id first point out that a CLOYES true roller chain cam drive will work just fine in most applications, but you need to check the slack every 20,000 miles or so under the conditions most guys put street engines, but I constantly hear guys repeating the MYTH that gear drives cause harmonic loads to be transfered to the cam, Ive tested, and checked extensively and the gear drives tend to maintain the correct timing longer and have no bad problems and certainly last far longer than the chain drives WHEN CORRECTLY INSTALLED AND INDEXED

 

well, My opinion differs here!,

I tend to favor QUIET gear cam drives

 

in PERFORMANCE ENGINE BUILDS,over chain drives , because chain drives get slack and tend to allow the cam timing to vary with rapid engine load changes like durring shifts

 

except in cars with KNOCK sensors, where the slight gear whine might cause the knock sensor to randomly retard the ignition timing.

Ive used several different brands and find nothing wrong with a CORRECLY INSTALLED Pete Jackson dual idler gear drive, in fact I’ve used that (QUIET) Pete Jackson gear drive, in the 383 that’s been in my corvette for several years with zero problems

as with most parts, installation must be correct, clearances checked, ETC. or you’ll HAVE PROBLEMS!, READ/UNDERSTAND THE INSTRUCTIONS, and ASK, QUESTIONS and know the reasons and answers , before installing any part or you’ll probably run into problems, Id have changed several chain drives bye this time, but the same gear drive I installed over 8 years ago still works fine and maintains the correct clearances

but Ill also point out I run a high volume oil pump, a 10 baffled QT oil pan and have extra oil jets drilled (#60 drill bit)in the oil passage plugs behind the cam gear

 

http://www.engineersedge.com/drill_sizes.htm

the two outside plugs

 

the idlers seem to sort of float front to back. I guess install the balancer without the timing cover and check?

 

that’s part of the install process place (with the gasket) using a large lump of modeling clay , and dial calipers

 

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=2079569&PMT4NO=9937412

 

 

http://www.officedepot.com/ddSKU.do?leve...rue&An=text

 

 

Under the timing cover and test bolt it in place, remove the clay an carefully measure the clearances..

(BTW spray the inside cover and the block with WD 40 first it tends to prevent the clay from sticking)the axles on the idler gears should have about a .002-.010 clearance between the cover and the block, this keeps the gears running in the same basic track once the engines assembled, you don,t want the axles to bind/or be in constant contact, under tension with the cover, as that might tip/bind the gear, and a light coat of moly on the gears won’t hurt. This frequently requires a light touch of a file to shorten the axles a few thousands, but youll not know without TESTING for the correct clearances with the clay

 

youll also need the retaining plate, cam button and loc-tite

 

http://store.summitracing.com/partdetail.asp?part=MOR%2D60460&N=115&autoview=sku

 

[dr_hunt]

Gear drive, the only way to fly!

[olie05]

great info!

 

how does it all compare to a belt drive?

 

forgive the newbish question

[331CI 280z]

My car is equipped with a gear drive!!!

[grumpyvette]

"how does it all compare to a belt drive?"

 

belt drives are generally far more expensive, at $470-$1000 vs $160-$500

they run quieter and have advantages

http://store.summitracing.com/partdetail.asp?part=CCA%2D6507&N=317828+115&autoview=sku

 

http://store.summitracing.com/partdetail.asp?part=PJJ%2D350%2D91C&N=400293+115&autoview=sku