[DeTomaso] Comp Cam's roller lifters

Daniel C Jones daniel.c.jones2 at gmail.com
Mon Oct 9 11:05:26 EDT 2017


> they are the ones with the big fulcrum bearing and were intended for
"endurance racing" or such

Those are likely the "Gold Race" rockers.  Very good parts though the
latest versions are different from the earlier ones.

> I also have the Crane guide plate conversion.  I am not aware of anyone
having problems with the Crane guide plate conversion system.

Crane recommends the rocker arm guide plate conversion kit (p/n 52655-16)
for open valve spring pressures of no more than 320 lbs.  Typical hydraulic
rollers for Cleveland V8s run closer to 400 lbs open pressure.  We have run
hydraulic rollers with springs of 140 lbs seat pressure and 320 lbs open
but that engine wouldn't make power over 5500 RPM.  You might get away with
320 lbs if running a beehive spring.  They don't seem to require as much
open pressure as conventional springs.  The weak link in the Crane kit is
the 5/16" bolt.  I bought a set of the Harland Sharp bolt-down adjustable
rocker arms for the  351C dyno mule from Randy Malik at R.M. Competition.
Randy says that as long as the threads in the head are in good shape, they
will withstand spring pressures in excess of 475 pounds open and over 625
pounds open when using the optional Jesel bolts.  You might look into
seeing if you can get better pedestal bolts.

> I was hoping to find a "kit" so the pushrods and lifters should provide
the correct geometry.

We often need different length push rods for the intake and exhaust sides
to get the correct geometry.  I've never seen that in any of the kits.
Adjustable length push rods for checking geometry are inexpensive.

Dan Jones

On Mon, Oct 9, 2017 at 9:46 AM, Daniel C Jones <daniel.c.jones2 at gmail.com>
wrote:

> > Don't forget that 'carbon poly' distributor gears are available now for
> the 351C which supposedly are compatible with all kinds of cam
> materials...do you have any experience with them yet?
>
> I've not personally run them but there are quite a few reports of them
> failing.  Apparently, they don't wear the cam but the gear itself comes
> apart.
>
> Dan Jones
>
>
> On Fri, Oct 6, 2017 at 7:01 PM, Mike Drew <MikeLDrew at aol.com> wrote:
>
>> Dan,
>>
>> Don't forget that 'carbon poly' distributor gears are available now for
>> the 351C which supposedly are compatible with all kinds of cam
>> materials...do you have any experience with them yet?
>>
>> Mike
>>
>> Sent from my iPad
>>
>> On Oct 6, 2017, at 11:51, Daniel C Jones <daniel.c.jones2 at gmail.com>
>> wrote:
>>
>> >> Does anyone have any experience with the Comp Cam's retrofit kit's
>> >   such as this?
>> >   There are two ways to run a hydraulic roller cam in a 351C.A  The
>> first
>> >   is to run link bar lifters.A  The other is to run the spider and dog
>> >   bones arrangement similar to what was introduced in the mid 1980s on
>> >   the 5.0L Ford V8.A  The Comp retrofit kit is the latter.A  We've run
>> >   both arrangements and there are some issues to be aware of.A  It
>> varies
>> >   from block-to-block and depends upon the size of the chamfer at the
>> top
>> >   of the lifter bore but, on many blocks, the oil feed is exposed at
>> >   maximum lobe lift on stock base circle cams.A  Some manufacturers
>> (like
>> >   Comp) will reduce the base circle of the cam so the OEM type lifters
>> >   can be used.A  As a rule, irregardless of how much lift that a
>> camshaft
>> >   has, the lifters generally all stop in approximately the same location
>> >   at the top unless the base circle is deliberately reduced which can
>> >   cause problems at the other end of the lifter bores.A  With a reduced
>> >   base circle cam, the OEM lifters will usually be safe at maximum lift
>> >   but some blocks will have interference problems with the dog bones.A
>> A
>> >   local shop which uses the Comp retrofit kit has a fixture to machine
>> >   the block for clearance but it can also be done by hand.A  Comps link
>> >   bar lifters have the oil feed (and associated band on the lifter) in
>> >   the same place as the OEM lifters so have the same problems at max
>> lobe
>> >   lift.
>> >   Other retrofit link bar lifters like the Crane, Gaterman (copies of
>> the
>> >   Crane), Howards (made by Gaterman), Lunati (made by Morel) have the
>> oil
>> >   feed placed lower on the lifter body and do not have the max lift
>> >   problem.A A  My favorites are the Crane link bars but they are quite
>> >   expensive.A  The Lunati/Morel hydraulic roller lifters cost about half
>> >   what the Cranes do and seem to work well.A  Be aware there are some
>> >   Chinese knock-offs of the Cranes that should be avoided (tested on a
>> >   spring load machine and failed).
>> >   Comps kit comes with pushrods, springs and timing chain set.A  Comp
>> >   doesn't make the timing chains and gets them from a variety of
>> >   manufacturers.A  Often (usually) the gears are from one manufacturer
>> >   and the chains are from another.A  There are some good and some very
>> >   bad chains out there so you need to verify the name on the chain
>> >   links.A  Avoid chains with no name or "Rolon".A  The pushrods are
>> >   shorter for the taller hydraulic roller lifters but may not be correct
>> >   for your engine.A  Due to tolerance stack up in the cam base circle
>> >   diameter, rocker arm, whether or not the heads and/or block have been
>> >   milled, the pushrod length you need may be different.A  Given the
>> >   angles involved with the canted valve heads, it is important to get
>> the
>> >   pushrod length and valve train geometry correct.
>> >   Have your heads been converted to studs and guide plates or are they
>> >   the original pedestal mount?A  What rocker arms are you using?A  The
>> >   spring loads required for a hydraulic roller cam may exceed the
>> >   pedestal mount bolt strength.
>> >   Another issue is distributor gear compatibility.A  The cam core can be
>> >   made from a variety of materials, generally either on of several
>> steels
>> >   or a SADI core.A  Unless you get a custom grind, Comp uses a SADI
>> >   core.A  SADI stands for selectively austempered ductile iron.A  SADI
>> >   cores are generally compatible with cast iron distributor gears.A  Be
>> >   aware the quality of cast iron gears varies greatly.A  Following
>> >   several cast iron gear failures, a friend Brinneltested several
>> >   different cast iron distributor gears and found that some gears
>> >   (especially those purchased from auto parts stores) were softer than
>> >   the OEM Ford cast iron gear and some were even softer than an
>> >   aluminum-bronze gear.A  Mallory makes a distributor gear for their
>> >   distributors that is made specifically for "austempered ductile iron
>> >   billets" and "proferal billet" cams.A  "Proferal" is a grade of iron
>> >   alloy that is used primarily for non-roller camshafts because of its
>> >   anti-wear characteristics.
>> >> I used the Crane Cams roller conversion kit, with a Crane 351C
>> >   hydraulic roller cam and lifters.
>> >   We've used the Crane kit before as well.A  It differs from Comp in
>> that
>> >   Crane uses an 8620 steel cam core of standard base circle.A  The steel
>> >   core requires one of Crane's compatible steel distributor gears:
>> >   A 52970-1 Ford V-8 70-82, Boss 351-351C-351M-400 for 0.500" shaft
>> >   diameter
>> >   A 52971-1 Ford V-8 70-82, Boss 351-351C-351M-400 for 0.531" shaft
>> >   diameter
>> >   As noted above, the size of the lifter bore chamfer determines whether
>> >   a standard base circle cam like Crane uses will work in a specific
>> >   block with OEM style lifters.
>> >   We've used both steel and SADI cores successfully (with the proper
>> >   distributor gear).A  The Gaterman/Howards or Morel/Lunati link bar
>> >   lifters are inexpensive enough that we no longer use the OEM style
>> >   retrofit kits.A  Rather than buying a kit with parts of unknown brand
>> >   and specification, I prefer to put together parts of known pedigree
>> >   that fit the application.A  A custom hydraulic roller cam is around
>> >   $100 more than an off-the-shelf grind which may not match your engine.
>> >> When Denny Aldridge built our 351C he used Comp Cams roller lifters.
>> >   Thank the lord above that he then dyno'd the engine - and found the
>> >   lifters would not stay up.
>> >   Plus one on the dyno testing.A  We found a link bar that had come
>> >   detached on a Crane lifter during a dyno test.A  This was back when
>> >   Crane went out of business but before they reorganized.A  Someone had
>> >   bought the remaining inventory and had sold the lifters without
>> >   realizing they had not been finish machined.A  The specific problem
>> was
>> >   the link bars had been pressed into place but the ends of the axles
>> had
>> >   not been peened to retain the link bars.
>> >   Dan Jones
>> > _______________________________________________
>> >
>> >
>> > Detomaso Email List is not managed by POCA
>> > Posted emails must not exceed 1.5 Megabytes
>> > DeTomaso mailing list
>> > DeTomaso at server.detomasolist.com
>> > http://server.detomasolist.com/mailman/listinfo/detomaso
>> >
>> > To manage your subscription (change email address, unsubscribe, etc.)
>> use the links above.
>> >
>> > Members who post to this list grant license to the list to forward any
>> message posted here to all past, current, or future members of the list.
>> They also grant the list owner permission to maintain an archive or approve
>> the archiving of list messages.
>>
>>
>
-------------- next part --------------
   > they are the ones with the big fulcrum bearing and were intended for
   "endurance racing" or such
   Those are likely the "Gold Race" rockers.A  Very good parts though the
   latest versions are different from the earlier ones.
   > I also have the Crane guide plate conversion.A  I am not aware of
   anyone having problems with the Crane guide plate conversion system.
   Crane recommends the rocker arm guide plate conversion kit (p/n
   52655-16) for open valve spring pressures of no more than 320 lbs.A
   Typical hydraulic rollers for Cleveland V8s run closer to 400 lbs open
   pressure.A  We have run hydraulic rollers with springs of 140 lbs seat
   pressure and 320 lbs open but that engine wouldn't make power over 5500
   RPM.A  You might get away with 320 lbs if running a beehive spring.A
   They don't seem to require as much open pressure as conventional
   springs.A  The weak link in the Crane kit is the 5/16" bolt.A  I bought
   a set of the Harland Sharp bolt-down adjustable rocker arms for theA
   351C dyno mule from Randy Malik at R.M. Competition.A  Randy says that
   as long as the threads in the head are in good shape, they will
   withstand spring pressures in excess of 475 pounds open and over 625
   pounds open when using the optional Jesel bolts.A  You might look into
   seeing if you can get better pedestal bolts.
   > I was hoping to find a "kit" so the pushrods and lifters should
   provide the correct geometry.
   We often need different length push rods for the intake and exhaust
   sides to get the correct geometry.A  I've never seen that in any of the
   kits.A  Adjustable length push rods for checking geometry are
   inexpensive.
   Dan Jones

   On Mon, Oct 9, 2017 at 9:46 AM, Daniel C Jones
   <[1]daniel.c.jones2 at gmail.com> wrote:

   > Don't forget that 'carbon poly' distributor gears are available now
   for the 351C which supposedly are compatible with all kinds of cam
   materials...do you have any experience with them yet?
   I've not personally run them but there are quite a few reports of them
   failing.A  Apparently, they don't wear the cam but the gear itself
   comes apart.
   Dan Jones

   On Fri, Oct 6, 2017 at 7:01 PM, Mike Drew <[2]MikeLDrew at aol.com> wrote:

     Dan,
     Don't forget that 'carbon poly' distributor gears are available now
     for the 351C which supposedly are compatible with all kinds of cam
     materials...do you have any experience with them yet?
     Mike
     Sent from my iPad
     On Oct 6, 2017, at 11:51, Daniel C Jones
     <[3]daniel.c.jones2 at gmail.com> wrote:
     >> Does anyone have any experience with the Comp Cam's retrofit
     kit's
     >A  A such as this?
     >A  A There are two ways to run a hydraulic roller cam in a 351C.AA
     The first
     >A  A is to run link bar lifters.AA  The other is to run the spider
     and dog
     >A  A bones arrangement similar to what was introduced in the mid
     1980s on
     >A  A the 5.0L Ford V8.AA  The Comp retrofit kit is the latter.AA
     We've run
     >A  A both arrangements and there are some issues to be aware of.AA
     It varies
     >A  A from block-to-block and depends upon the size of the chamfer
     at the top
     >A  A of the lifter bore but, on many blocks, the oil feed is
     exposed at
     >A  A maximum lobe lift on stock base circle cams.AA  Some
     manufacturers (like
     >A  A Comp) will reduce the base circle of the cam so the OEM type
     lifters
     >A  A can be used.AA  As a rule, irregardless of how much lift that
     a camshaft
     >A  A has, the lifters generally all stop in approximately the same
     location
     >A  A at the top unless the base circle is deliberately reduced
     which can
     >A  A cause problems at the other end of the lifter bores.AA  With a
     reduced
     >A  A base circle cam, the OEM lifters will usually be safe at
     maximum lift
     >A  A but some blocks will have interference problems with the dog
     bones.AA  A
     >A  A local shop which uses the Comp retrofit kit has a fixture to
     machine
     >A  A the block for clearance but it can also be done by hand.AA
     Comps link
     >A  A bar lifters have the oil feed (and associated band on the
     lifter) in
     >A  A the same place as the OEM lifters so have the same problems at
     max lobe
     >A  A lift.
     >A  A Other retrofit link bar lifters like the Crane, Gaterman
     (copies of the
     >A  A Crane), Howards (made by Gaterman), Lunati (made by Morel)
     have the oil
     >A  A feed placed lower on the lifter body and do not have the max
     lift
     >A  A problem.A AA  My favorites are the Crane link bars but they
     are quite
     >A  A expensive.AA  The Lunati/Morel hydraulic roller lifters cost
     about half
     >A  A what the Cranes do and seem to work well.AA  Be aware there
     are some
     >A  A Chinese knock-offs of the Cranes that should be avoided
     (tested on a
     >A  A spring load machine and failed).
     >A  A Comps kit comes with pushrods, springs and timing chain
     set.AA  Comp
     >A  A doesn't make the timing chains and gets them from a variety of
     >A  A manufacturers.AA  Often (usually) the gears are from one
     manufacturer
     >A  A and the chains are from another.AA  There are some good and
     some very
     >A  A bad chains out there so you need to verify the name on the
     chain
     >A  A links.AA  Avoid chains with no name or "Rolon".AA  The
     pushrods are
     >A  A shorter for the taller hydraulic roller lifters but may not be
     correct
     >A  A for your engine.AA  Due to tolerance stack up in the cam base
     circle
     >A  A diameter, rocker arm, whether or not the heads and/or block
     have been
     >A  A milled, the pushrod length you need may be different.AA  Given
     the
     >A  A angles involved with the canted valve heads, it is important
     to get the
     >A  A pushrod length and valve train geometry correct.
     >A  A Have your heads been converted to studs and guide plates or
     are they
     >A  A the original pedestal mount?AA  What rocker arms are you
     using?AA  The
     >A  A spring loads required for a hydraulic roller cam may exceed
     the
     >A  A pedestal mount bolt strength.
     >A  A Another issue is distributor gear compatibility.AA  The cam
     core can be
     >A  A made from a variety of materials, generally either on of
     several steels
     >A  A or a SADI core.AA  Unless you get a custom grind, Comp uses a
     SADI
     >A  A core.AA  SADI stands for selectively austempered ductile
     iron.AA  SADI
     >A  A cores are generally compatible with cast iron distributor
     gears.AA  Be
     >A  A aware the quality of cast iron gears varies greatly.AA
     Following
     >A  A several cast iron gear failures, a friend Brinneltested
     several
     >A  A different cast iron distributor gears and found that some
     gears
     >A  A (especially those purchased from auto parts stores) were
     softer than
     >A  A the OEM Ford cast iron gear and some were even softer than an
     >A  A aluminum-bronze gear.AA  Mallory makes a distributor gear for
     their
     >A  A distributors that is made specifically for "austempered
     ductile iron
     >A  A billets" and "proferal billet" cams.AA  "Proferal" is a grade
     of iron
     >A  A alloy that is used primarily for non-roller camshafts because
     of its
     >A  A anti-wear characteristics.
     >> I used the Crane Cams roller conversion kit, with a Crane 351C
     >A  A hydraulic roller cam and lifters.
     >A  A We've used the Crane kit before as well.AA  It differs from
     Comp in that
     >A  A Crane uses an 8620 steel cam core of standard base circle.AA
     The steel
     >A  A core requires one of Crane's compatible steel distributor
     gears:
     >A  A A 52970-1 Ford V-8 70-82, Boss 351-351C-351M-400 for 0.500"
     shaft
     >A  A diameter
     >A  A A 52971-1 Ford V-8 70-82, Boss 351-351C-351M-400 for 0.531"
     shaft
     >A  A diameter
     >A  A As noted above, the size of the lifter bore chamfer determines
     whether
     >A  A a standard base circle cam like Crane uses will work in a
     specific
     >A  A block with OEM style lifters.
     >A  A We've used both steel and SADI cores successfully (with the
     proper
     >A  A distributor gear).AA  The Gaterman/Howards or Morel/Lunati
     link bar
     >A  A lifters are inexpensive enough that we no longer use the OEM
     style
     >A  A retrofit kits.AA  Rather than buying a kit with parts of
     unknown brand
     >A  A and specification, I prefer to put together parts of known
     pedigree
     >A  A that fit the application.AA  A custom hydraulic roller cam is
     around
     >A  A $100 more than an off-the-shelf grind which may not match your
     engine.
     >> When Denny Aldridge built our 351C he used Comp Cams roller
     lifters.
     >A  A Thank the lord above that he then dyno'd the engine - and
     found the
     >A  A lifters would not stay up.
     >A  A Plus one on the dyno testing.AA  We found a link bar that had
     come
     >A  A detached on a Crane lifter during a dyno test.AA  This was
     back when
     >A  A Crane went out of business but before they reorganized.AA
     Someone had
     >A  A bought the remaining inventory and had sold the lifters
     without
     >A  A realizing they had not been finish machined.AA  The specific
     problem was
     >A  A the link bars had been pressed into place but the ends of the
     axles had
     >A  A not been peened to retain the link bars.
     >A  A Dan Jones
     > _______________________________________________
     >
     >
     > Detomaso Email List is not managed by POCA
     > Posted emails must not exceed 1.5 Megabytes
     > DeTomaso mailing list
     > [4]DeTomaso at server.detomasolist.com

   > [5]http://server.detomasolist.com/mailman/listinfo/detomaso
   >
   > To manage your subscription (change email address, unsubscribe, etc.)
   use the links above.
   >
   > Members who post to this list grant license to the list to forward
   any message posted here to all past, current, or future members of the
   list. They also grant the list owner permission to maintain an archive
   or approve the archiving of list messages.

References

   1. mailto:daniel.c.jones2 at gmail.com
   2. mailto:MikeLDrew at aol.com
   3. mailto:daniel.c.jones2 at gmail.com
   4. mailto:DeTomaso at server.detomasolist.com
   5. http://server.detomasolist.com/mailman/listinfo/detomaso


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