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

Sun Jul 1 15:14:59 EDT 2007

thanks all!

Quoting Daniel C Jones <daniel.c.jones2 at gmail.com>:

>> 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.
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