distributor gear info

grumpyvette

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From Sallee Chevrolet. http://www.sallee-chevrolet.com/PriceList/group2.041-3.726.html

http://www.speedunleashed.com/comp-cams ... gears.html

http://www.hotrod.com/techarticles/engi ... index.html

http://cranecams.com/index.php?show=bro ... 3&prt=2144

01103952 - Distributor, Late model HEI F/I, small cap. This complete distributor is used on late model V8 engines with fuel injection and computer controls. = 168.92 ( Does not say hardened gear or for roller cams )

01104060 - SBC Distributor Assembly, for Ram Jet 350. This complete distributor is used on the Ram Jet 350 port fuel injection engine. - 176.09 (RJ350 has a roller cam, but does not say this has hardened gear. so what is the diff. in this one and the one above? )

01104067 - HEI HO Distributor. This distributor has the melonized cam drive gear P/N 10456413 for steel roller camshafts. This distributor is required on all crate engines and roller camshafts that are made of steel. If engines are assembled not using this gear, it may affect your engine warranty. Use connector wire P/N 8917052 to ignition. Used with all small and big-block V8 High Output engine assemblies. Technical Notes: Components in these groups are interchangeable with small-block Chevrolet V8s. GM Performance Parts distributors cannot be used with "tall deck" Bow Tie block P/N 14044808. - 227.41 ( only one that says it's for roller cams, but this is a large cap HEI ).


10456413 - Distributor HEI Gear, large cap. You must use this gear with the new roller cams. This is a hardened gear. This distributor gear is used on all Chevrolet small and big-block engines, including steel roller camshaft engines. - 22.88

10469459 - Distributor HEI Gear, small cap. You must use this gear with the new roller cams. This is a hardened gear. Also fits some Mallory distributors. - 23.74
The bottom of a Chevrolet distributor housing can be and SHOULD BE! modified to spray pressurized oil onto the distributor drive gear. The extra lubrication will reduce distributor gear and camshaft gear wear. This is especially important when the gear is used to drive non-standard accessories, such as a high volume oil pump, or a magneto that puts additional loads on it and the cam. <P>When the distributor is installed, the bands at the bottom of the housing are designed to complete the internal right side lifter galley on all small and big block Chevrolet V-s and 90° V-6 engines. If you hand file a small vertical groove .030" wide x .030 thats the diam. that crane recommends Ive always used the larger .050 wide groove with no problems, deep on the bottom band (above the gear), pressurized oil running between the two bands will be directed downward onto both the gear and the cam This procedure is recommended for all Chevrolet engines no matter what material gear (cast or bronze) or what type of camshaft (cast or steel) you are using keep in mind the groove MUST be lined up with the cam gear when the distributor. is installed


Melonite QPQâ„¢ is a thermochemical process (ferritic nitrocarburizing) used for the case hardening of iron-based metals. In a molten bath of special salts, nitrogen, carbon, and small amounts of oxygen are diffused into the surface of the steel, creating a super-hard surface, called the "compound layer." Additionally, small amounts of carbon are pulled from within the substrate, toward the surface, creating a "diffusion zone," which exhibits a gradient of concentration of carbon and nitrogen, decreasing toward the core. Thus, the process provides both a hardening of the surface, and a gradient alloying of the substrate, which improves the ductility and overall strength of the material.


DISTRIBUTOR GEARS FOR BILLET STEEL ROLLER CAMS
should be Made from premium aluminum bronze alloy, these precision machined gears
are highly recommended for performance cam applications and are mandatory
when running 8620 steel billet roller camshafts


obviously youll want to verify the correct distributor gear material to use with the cam manufacturer, before using it and providing extra oil flow, to the gears should help reduce wear
http://www.summitracing.com/parts/LUN-89027LUN/

some of the better distributors with o-ring grooves have a small oil hole drilled between the o-rings that allows a steady stream of pressurized oil to enter the lower distributor shaft, the upper bearing is sealed so oil can,t exit into the upper distributor, but oil is routed to lube the lower bearing in the distributor, the oil exits to spray over the cam gear/distributor gear contact area, look closely at yours
 
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theres several likely reasons and the most likely is a combo of less than ideal lubrication flow and a material in-comparability between the cam and distributor gears, add the extra drag the oil pump is likely to produce after ingesting metallic crap from the gear wear..well...Id sure take a strong light and look down the distributor hole at the cam gear and hopefully its NOT similarly worn.its always a good idea to call the cam manufacturer and ask what is the correct matching cam gear and distributor gear set,and how its correctly installed.
some roller cams came with steel gears that require a bronze alloy distributor gear, if your experiencing that wear Id suggest inspecting the oil pump also as theres a good chance its damaged, due to the crud its ingested.
a tool like this should have let you now months ago something was wrong
viewtopic.php?f=54&t=938
check with the manufacturer anytime you have similar questions, on any valve train or ignition component.
but Id bet the stock distributor gear is what will be recommended,on any new engine build with a new cam installed.
this whole web site is designed to make it far FAR easier on guys wanting to build the required knowledge base required to learn the skills youll require to excell in this hobby.
:D:cool::rolleyes:

coat any new cam and distributor gears with a good moly paste lube

molypaste.jpg


READ THE RELATED INFO CAREFULLY AND USE A GOOD MOLY LUBE ON THE DISTRIBUTOR AND CAM GEARS


MSD-8561.jpg

most stock chevy v8 distributors will use this gear. .491 diam.
https://www.summitracing.com/parts/ado-10456413/overview/make/chevrolet



distr1.jpg

many aftermarket distributors will use this gear .500 diam.
https://www.summitracing.com/parts/msd-8561/overview/make/chevrolet


msd-8471.jpg

bronze distributor gears are generally used on billet steel roller cam cores
https://www.summitracing.com/parts/msd-8471/overview/make/chevrolet





http://garage.grumpysperformance.com/index.php?threads/distributor-gear-wear.1701/#post-5252

http://garage.grumpysperformance.com/index.php?threads/distributor-gear-info.1186/#post-4155

http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/#post-5890

http://garage.grumpysperformance.co...stalling-the-intake-manifold-distributor.464/

http://garage.grumpysperformance.co...ear-articles-you-need-to-read.282/#post-61429

http://garage.grumpysperformance.co...ting-rebuilding-hei-ignitions.2798/#post-7247

http://garage.grumpysperformance.co...y-in-building-a-good-engine.11682/#post-54682
while your worrying about your new billet steel roller cam tearing up your old soft distributor gear, you might want to think about swapping to a bronze tip fuel pump push-rod to prevent excessive wear on that expensive billet steel cam core on the front end ,
4607rod.jpg

cutting a grouve in your lower distributor oil band in-line with the begining contact point between the gears meashing will provide extra oil flow to the gears but having compatable materials and clearances will be critical, your cam manufacturer will know the correct distributor gear material to use., keep in mind a grouve in the blocks vertical tunnel wall above the cam gear for the distrib. rather than the distributor lower band can,t move as the distrib timing is changed
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distriboila.jpg




I read somewhere that the OEM small block roller cams (at least the more common ones like I'm looking at) were cast and did not require a bronze gear. correct?"

yes your correct in MOST cases

http://www.enginebuildermag.com/2009/07/properly-matching-your-camshaft-and-distributor-gear/

http://garage.grumpysperformance.com/index.php?threads/distributor-gear-wear.1701/#post-5252

http://garage.grumpysperformance.com/index.php?threads/shiming-a-distributor.251/#post-299
http://garage.grumpysperformance.com/index.php?threads/oil-pump-drive-shafts.123/#post-326
 
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