[DeTomaso] Dizzy gear blues - Dan or someone help please?

[Daniel C Jones]

> Windsor motor, MSD dizzy, brass gear.

Brass is indeed the wrong material for a distributor gear.  Bronze,
on the other hand, is used often for steel solid roller cam cores
and some race flat tappet cams.

> It appears the teeth on the brass gear are about 1/2 worn through -
> this means the wrong gear for the cam, correct?

Bronze gears are sacrificial and can wear at a rapid rate.  Is this
in the Kirkham with hydraulic roller cam?  If so, you'll want the MSD
steel gear or the Ford Motorsport steel gear (same as the stock gear
on a roller cam 5.0L) unless the cam core used is solid roller type
core.  If that's the case, then you may want to use the Crane steel
gear (see below).

> Do I replace w/ steel or iron gear?  Is this a Napa item?  Ford item?
> Or am I staying home next weekend?

That depends upon the cam core that you have.  Below, I've attached
what I wrote up for 351C's so the part numbers apply to 351C/351M/400
and 429/460 distributor gears.  There are similar gears for Windsors,
of course.

1. Cast Iron Distributor Gears
 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.  However, Comp Cams claims there -8 part
 number hydraulic rollers (which use a cast iron core) are compatible with
 standard cast iron cam gears.  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.  MSD says its
 iron distributor gears are surface-hardened a few points higher than stock
 gears because most performance flat-tappet cams are ground on better quality
 (harder) cores.

 2. Ford Motorsport Steel Gear
 P/N M-12390-J (1.421" OD, 0.531" ID, for 351C) in the FRPP catalog.
 From page 105 of the 2005 FRPP catalog: "Steel gears are compatible with
 billet steel camshafts (hydraulic roller type)".  Comp Cams also claims
 the Ford gears are compatible with their -8 austempered ductile iron
 hydraulic roller cam cores (Comp also uses the -8 cores for some solid
 street roller cams).  One tech I spoke with at Comp said the Ford hydraulic
 roller cam gear was prefered over a standard cast iron gear. According to
 MSD, the Ford mild steel distributor gears (as fitted to engines with factory
 hydraulic roller cams) are 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 5.0L Ford racers have used the
 Ford gear on steel cam cores without incident.  Also, Keith Craft uses
 the Ford steel gear on both iron flat tappet and steel roller tappet
 cam cores.  He said about 4 years ago, he started having cam gear wear
 problems with standard flat-tappet iron cams from both Comp Cams and Lunati.
 He switched to the Ford steel gears on those camshafts and has had no more
 problems.  He told both Comp and Lunati about it but both companies reacted
 as if he were crazy.  BTW, he uses the M-12390-J p/n gear on FE engines.
 Apparently FE and 351C/429/460 distributors have the same outside diameter
 and MSD has an FE distributor with the proper inside diameter.

 3. Crane Steel Gear
 Crane has a coated steel gear which they claim is compatible with induction
 hardened or carburized steel roller cores, as well as iron flat tappet cores.
 Their website refers to it them as "specially coated and processed steel
 distributor gears using either cast flat faced lifter or steel roller
 camshafts".  They list two part numbers for 351C distributors:

 52970-1 Ford V-8 70-82, Boss 351-351C-351M-400 for 0.500" shaft diameter
 52971-1 Ford V-8 70-82, Boss 351-351C-351M-400 for 0.531" shaft diameter

 Crane does not recommend the use of their gears on camshafts that have been
 previously run with other types or materials of gears.  Rob at Blue Oval
 recommended this gear.  Comp Cams did not recommend this gear on their -8
 cores.  Mike Trusty ran a Crane gear and had it fail in short order.  Asa
 Jay currently runs Crane's gear on a Crane steel roller cam.  I'm told but
 have not verified that Crane's earliest steel gears were made like the Ford
 gears but their new gears are different.  It may be the case that Mike's gear
 was the early version and Asa Jay's the late?  In any case, I've spoken with
 several people who are running the current Crane gears with no problems.  Asa
 Jay was kind enough to remove his distributor and check the gear and reported
 it had a normal contact pattern and wear.

 4. Mallory Distributor Gear
 Mallory makes a distributor gear for their distributors that are made
 specifically 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.

 5. Bronze-Aluminum Distributor Gears
 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.

 6. Comp Cams Carbon Ultra-Poly Composite Distributor Gear
 Also meant as a replacement for rapid wearing bronze gears, Comp has a
 composite material gear.  These are currently only available for Windsor
 Fords and small and big block Chevys.

Ford instructions caution that the hole should not be used for alignment
purposes.  Ford Motorsport instructions for fitting distributor gears:

 http://www.bacomatic.org/gallery/album24/FordInstShtM_12390_ABCDEFGH

> Next question:  how much damage, if any, do these brass filing do to
> my motor?

Depends upon how much got past the oil filter.  The usual Ford oil
filter has a bypass valve bult into the filter which can allow
unfiltered oil to bypass the filter.  The bypass can also fail,
causing a loss of oil pressure.  Next time around 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 still
have the 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.

Dan Jones

P.S.  I got the shirt you sent, thanks!  Been meaning to send a
message but have been very busy.