timing chains stretch



timing chains stretch

Postby grumpyvette » November 2nd, 2011, 6:48 pm

" GRUMPYVETTE? I ran Cloyes chain 12,000 miles on the street and decided to change cams, I was amazed at how much it had stretched in that little time,any ideas"

ALL TIMING CHAINS STRETCH OVER TIME, the BETTER/MORE EXPENSIVE ONES TEND TOO LAST FAR LONGER, and PROPER LUBRICATION HELPS THEM LAST LONGER, but theres a HUGE difference in quality between import brands and some of the better domestic brands and every name brand has CHEAP entry level timing sets that are most likely cheap import clones, not the original high quality parts so you need to research what your buying, its obvious that a $20 timing set musty be significantly different from a $120 set, so you need to ask WHATS THE DIFFERENCE it helps to put the timing chain in assembly lube with moly and marvel mystery oil mixed together and heat it all up in a pan,its just a time proven method of insuring all the metal surfaces are bathed in hot oil that will seep into all the micro surface irregularities and form a protective film before the engine reaches operational temperatures and before there significant oil flow thru the engine, insuring a slightly improve lubrication during that first critical engine start-up process, its not mandatory, but every thing you can do to reduce wear helps
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IF YOU HAVE A LINE HONED BLOCK< CALL CLOYES AND REQUEST THE NUMBER OF THE MATCHING TIMING SET WITH THE SHORTER CENTER TO CENTER DISTANCE

ON CLOYES SETS the SHORTER CHAINS used ON LINE HONED BLOCKS ,GENERALLY HAVE A PART NUMBER ENDING IN EITHER -5 or _10 INDICATING A .005 or .0010 TIGHTER timing set

THERE ARE TIMING CHAIN TENSION-ER KITS AVAILABLE

http://www.speedwaymotors.com/S-B-Chevy ... ,3229.html
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http://www.spottsperformance.com/Timing%20sets (pontiac)
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http://www.cloyes.com/Portals/10/TechTi ... ral%29.pdf
http://www.cloyes.com/pdf/Cloyes_2010_HP_All_Apps.pdf
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drilling the pass side oil passage plug with a 1/32" bit so oil constantly sprays on the timing gears helps extend chain and gear life.
BTW one little trick you might want to know is placing a timing set in a pot covered with a mix of moly assembly lube about 15%-20% and marvel mystery oil about 80%, add a cooking thermometer and heat to about 230 degrees on a stove , stir it with a metal fork slightly to remove air and let it cool slowly before installing it, this tends to get the lube into the rollers and reduce wear.
its also a real good idea to drill the pass side oil plug under the timing cover with a .036-.040 drill so oil constantly sprays on the timing chain during use,and while IM discussing cam timing sets Id say that about 90% of the time a good CLOYES timing chain set should be used on street cars vs a gear drive if that's one option your thinking about.
theres a BIG difference in quality between the entry level and good quality parts made/ sold by cloyes


http://www.summitracing.com/parts/CLO-C3023/ ($17)
http://www.summitracing.com/parts/CLO-9-3145/Application/?query=Year|1999&prefilter=1
($92)

the Cloyes 9-3649X3-5. Single roller with billet crank gear for the newer single roller BIG BLOCK CHEVY MARK V- and ESPECIALLY MARK VI with plastic timing cover engines that won,t allow use of the older thicker dual roller chain timing sets.


RELATED INFO
viewtopic.php?f=52&t=1793&p=4553#p4553

viewtopic.php?f=54&t=2187

http://www.summitracing.com/parts/CLO-C-3023X/ ($21)

http://www.summitracing.com/parts/CLO-9-3100A/?rtype=10 ($130)

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=4548&p=12128#p12128

probably 90% of the timing sets being installed are installed with the crank gear flush with the shoulder on the crank snout and with never a single thought being given to proper alignment being an issue, and with thousands of those engines making well over 100K miles before the timing chains replaced, that doesn,t mean they are correctly aligned it just indicates that the basic design is rather forgiving as to the conditions it will continue to function in without causing major problems AND THAT in most cases the manufacturing tolerances are close enough to correct to have few issues with wear. but Id also point out that most engines are not running at near their full power potential and most engines have basic flaws costing them both some horse-power and durability problems


Chevy for years used NYLON gear teeth on aluminum gears, its not like they were concerned with getting the alignment correct to the last possible 2-5 thousands of an inch, they designed the timing sets to be easy to install and reasonably durable and run QUIETLY , and yes they eventually realized that was a HUGE mistake! but in this thread we are dealing with building an engine correctly, to gain all potential hp, and enhance durability here, not in merely allowing it to run once assembled
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TRUE DOUBLE ROLLER TIMING CHAIN SETS FROM QUALITY MANUFACTURERS TEND TO BE MORE DURABLE

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ON CLOYES SETS the SHORTER CHAINS GENERALLY HAVE A PART NUMBER ENDING IN EITHER -% or _10 INDICATING A .005 or .0010 TIGHTER timing set
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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