Reply to "Joules5: non bypassing oil filter"

> Camshafts are either made of cast iron or billet steel. You use iron gears
> with iron cams & steel gears with steel cams.

It's considerably more confusing than that, I'm afraid. For instance,
Comp recommends the Ford steel gear on their austempered ductile iron
roller cores. Kieth Craft uses the Ford and MSD steel gears on flat tappet
iron and roller steel cores, having had trouble with iron gears on both Comp
and Lunati flat tappet iron cam cores.

> The brass gears are supposed to be good with either type of cam, but they
> have a reputation for wearing fast & polluting your oil & motor with fine
> brass shavings.

I think you mean bronze. Bronze gears are generally thought of as sacrificial
but some of the bronze alloys can be harder than some of the cheap parts store
iron gears.

> The composite gears are relatively new on the market and I haven't heard of
> anybody using one yet.

I noticed Ford is carry one in the FRPP catalog for the Windsor. I assume
it's Comp's gear.

Here are my notes on 351C distributor gears:

1. Cast Iron
These are the standard distributor gears used on hydraulic and solid flat
tappet camshafts which use iron cores. Not compatible with most hydraulic
or solid roller cam steel cores. Some Comp Cams street rollers may be
compatible but not necessarily ideal. Note that some cast iron gears from
auto parts stores are substantially softer than OEM iron gears. Also note
that some cam companies use a harder core for certain race solid flat tappet
grinds which may require a bronze (or other material) gear.

2. Cast Steel
Compatible with hydraulic roller cam cores and with some street solid
roller cores (e.g. -8 Comp Cams street roller cores). P/N M-12390-J
(1.421" OD, 0.531" ID) from the FRPP catalog. According to MSD, the
Ford mild steel distributor gears (as fitted to engines with factory
hydraulic-roller-cams) is softer than the common ductile iron gears,
but harder than bronze. MSD also claims that Chevy uses a harder
cam core for it's factory hydraulic rollers and uses cast iron gears
but that its gears don't last as long as the Ford gears. Some racers
run the Ford gear on 8620 solid roller steel cores and iron flat tappet
cores.

3. Bronze-Aluminum
Generally softer than iron. Compatible with most cam cores but wears
rapidly. A bronze distributor gear is essentially sacrificial, wearing
the distributor gear instead of the roller cam gear. Usually specified
for solid roller cams. Note that hardness can vary from manufacturer to
manufacturer. If running one of these gears, you may want to run an
oil filter without a bypass so the filter catches the wear particles.
On a 351C, consider using Purolator oil filter number L30119. It's a
full size replacement for the FL-1A Ford/PH8A Fram filter. It has no
bypass spring in the middle but it does have the rubber flapper for
anti-drainback. The original application is for a 1978 Nissan 510, 2.0L
4 cyl engine (L20B) which had the bypass valve in the engine block.
This filter cross-references to a Fram PH2850, a Motorcraft FL-181,
and a Wix 51452. However, those filters have not been verified and may
have a bypass. It appears after 1978, Nissan went to a half height
filter. Purolator part number L22167 fits that application and does not
have the bypass spring but does have the rubber flapper for anti-drainback.
Race engines may want to run dual filters.

4. Machined 8620 Steel
A harder steel gear designed specifically for compatability with 8620
steel solid roller cam cores. Mike Trusty ran one of these and turned
it to powder in just a few miles. Asa Jay runs one and has reported no
problems yet. This may have been the early Crane steel gear.

5. Powdered Metal Composite with Anti-Friction Coating
Available for the 351C from Rob McQuarrie of Blue Oval Performance in
Colorado. He reports success using them on all cam cores. This is
supposedly the current Crane steel gear which Crane recommedns for all
cam cores, steel or iron.

6. Mallory Gear
Mallory makes a gear for their distributors that is made for
"austempered ductile iron billets" and "proferal billet" cams. It is
supposed to be compatible with the Comp Cams austempered iron cam cores.
As I understand it, the gear is heat-treated for compatibility.

More on the cam gear hardness problem. A few years back, a friend of mine
(Steve Grossen) ruined several cams and gears on a 351W which led him to
Rockwell (B scale) test several distributor gears. A generic auto parts
cast iron gear tested at 70, the bronze gear at 90, and the stock Ford gear
was 102. Note that the soft bronze gear was harder than the generic auto
parts cast iron gear. Steve eventually traced his trouble to a batch of cam
cores with improperly machined gears (Comp doesn't check each gear, only a
statistical sampling). Comp replaced the cams and eventually gave him one
with the "NASCAR" treatment" (filed, wire brushed on a wire wheel, and bead
blasted). Steve supplied some notes and photos of his ordeal which can be
viewed at Dave William's website:

http://www.bacomatic.org/~dw/sgdist/sgdist.htm

No matter what gear you use, make sure the gear is in the proper location.
A replacement distributor gear may or may not have a holed drilled in it.
Ford cautions that the hole should not be used for alignment purposes.
Position the gear to the proper location, then drill a new hole 90 degree
to the old hole. Dykem the contact pattern. Pull and inspect gear after
a while. Make sure the gear is not bottoming out and binding and that the
oil pump driveshaft isn't too long. MSD recommends using a moly lube to
break-in the cam/distributor gears. They say squirting it on the gear is
insufficient and suggest using a toothbrush to work it into the pores of
the metal.

I went with Crane's steel gear with my Crane hydraulic roller cam. Here's
some info from Crane's website:

Steel Distributor Gears

Crane Cams now offers six part numbers of precision machined, steel distributor
gears for popular Ford engines using steel roller camshafts. Roller lifter cams
are made from either induction hardened steel or carburized steel. Neither of
these materials are compatible with the normal stock distributor gears. In the
past "bronze" distributor gears were used. For street applications these gears
wear at an excessive rate and have to be replaced on a regular basis.

By using modern heat treating and manufacturing processes, Crane Cams has
developed a series of steel distributor gears that are compatible with both
induction hardened and carburized steel roller lifter cams. Crane Cams now
makes it possible to use a steel distributor gear that provides OEM-style
life-span, eliminating the need to frequently replace bronze alloy gears. These
new Crane steel gears are available for most Ford engines for both stock and
aftermarket distributors.

The use of these gears on camshafts that have been previously run with other
types or materials of gears, or the unnecessary use of high volume/high
pressure oil pumps, can be severely detrimental to the life of the camshaft
gear.

Note: The "Shaft Diameter" dimension referred to is the portion of the
distributor shaft that the gear registers on. It may be necessary to remove the
original gear to measure the shaft diameter correctly.

52970-1 FORD V-8 70-82, BOSS 351-351C-351M-400 FOR .500 SHAFT DIAMETER
52971-1 FORD V-8 70-82, BOSS 351-351C-351M-400 FOR .531 SHAFT DIAMETER

And from Comp's website:

Carbon Ultra-Poly Composite Distributor Gear
COMP CamsR is proud to introduce the latest in Hi-Tech distributor gears.
Manufactured from Carbon Ultra-Poly these gears represent the future of
distributor gears. We have them available for Small & Big Block Chevrolets with
.500 or .491 distributor shafts and Ford FW applications. These gears have
undergone stringent testing in various applications with positive results.
These super tough gears show great promise in solving the wear issues
associated with bronze gears in racing applications. COMP CamsR is pleased to
bring you another innovative product, call today for more information on these
gears and our other fine products.
Ford-FW Beveled Tooth Gear, Fits Shaft Diameter 0.530" w/ Beveled tooth

Now available for Ford 302-351W engines, the COMP CamsR Composite Distributor
Gear is the fix many Ford engine builders have longed for to overcome bronze
distributor gear wear problems. Made from Carbon Ultra-Poly, these gears have
undergone stringent field and dyno testing to ensure they exceed all durability
and performance claims.

Dan Jones