[DeTomaso] Fontana/Clevor Block

[Daniel C Jones]

> Other than the price of the block, what other changes would I have to
> make if I went with their 9.2 inch deck height block?

I'm told Fontana sold the rights/tooling to his block to Shelby who
modified it to be more of a Windsor block.  I think Fontana still
sells the Clevor version but check to be sure.  In any event, here
are my notes on the Fontana:

Fontana Block Parts Interchange:

 - Available in 9.2" (Cleveland) or 9.5" (Windsor) deck heights.
   Mine is a 9.2" deck block.
 - Siamesed bore (dry wall, ductile iron top hat cylinder liners, interlock
   with flats on sides between bores). Absolute maximum bore is 4.155",
   though 4.125" is probably more likely (sonic test to be sure).
 - For large diameter bores, recommended headgaskets are Fel-Pro 1022
   (left hand) and 1023 (right hand).  These gaskets have 4.160" bores,
   are notched (one has 2 notches, the other 3 notches) and come with
   instructions.  Use Fel-Pro 1021 for bores up to 4.1".
 - Clearanced for standard full size starter (I'm using a mini starter)
 - Compatible with solid or hydraulic flat tappet lifters and solid roller
   lifters but does not have the tall bosses for OEM hydraulic roller
   lifters.  Can use the Crane link bar hydraulic lifters or reduced base
   circle cam.
 - 4 bolt main caps on all 5 mains, splayed on 2, 3, and 4.
 - Windsor rear intake manifold seal rail shape (requires SVO or Edelbrock
   dual end seal style intake).  Several 4 barrel carb intakes available
   (new and used).  Kelly Coffiled makes a compatible IR EFI intakes.
 - Windsor oil system layout
 - 2.750" main diameter (for Cleveland diameter crank), though I think
   Fontana will bore to 3" Windsor mains if requested.
 - 351 Cleveland main bearings
 - 351 Cleveland oil pan and gasket
 - 351 Cleveland oil pump and pick up
 - 351 Cleveland cam (13726548 firing order)
 - 351 Cleveland cam bearings
 - 351 Windsor distributor with Cleveland gear (or just Cleveland distributor?)
 - 351 Windsor timing chain
 - 351 Windsor timing cover gasket
 - 351 Windsor water pump ('70-up)
 - 351 Windsor end seals (intake end rails)
 - The head studs need to be longer than those for an iron 351C.  Exact
   length will depend upon the heads being used.  The Ford Motorsport high
   port (A3, B351, C302, C302B) and Yates aluminum heads, along with the
   Brodix BF300 heads, take longer head studs than iron 351C heads. In the
   case of my C302B heads on the aluminum 9.2" deck height Fontana block,
   the studs required are:

   8-1/4", 1/2" UNC x 2.25" on end end, 1/2" UNF x 1.25" on the other
   7-1/8", 1/2" UNC x 2.25" on end end, 1/2" UNF x 1.25" on the other

   I called ARP and they do not make studs that long in the above
   configuration. Fontana said hhe them in stock. Cost was $434 for a
   set of head studs, 12 point nuts and hardened washers.  However,
   even these were too short.  Joe is looking into getting the proper
   studs.
 - The Fontana block lifter bores are 41 degrees, same as a Cleveland.
   351W lifter bores are slightly different (45 degrees).
 - Will need a 351C type retrofit kit or link bar lifters to run a hydraulic
   roller.
 - Machined to accept M-6701-A351 two-piece rear main seal.
 - Pressure port drilled at back of block just above bellhousing flange
   (lowest pressure point)
 - Fontana recommends using M-6799-A302 oil restrictor kit, even though
   Windsor-based oil system (probably just for racing).
 - Small block Ford lifters (same for Cleveland or Windsor)
 - Small block Ford motor mounts (same for Cleveland or Windsor)
 - Fontana specific front cover (included), optional sprint car front cover.
 - Custom length pushrods
 - Screw-in, O-ringed, Allen head core plugs
 - Can be plugged at oil filter or oil pump base for dry sump (remove
   for wet sump).
 - Has wet sump provision but is currently plugged for dry sump (need to
   remove one plug).
 - Has pad for internal oil pump (not just external wet sump).
 - Ford Motorsport Cleveland-style canted valve aluminum high port cylinder
   heads (A3/B351/C302/Yates) require water passages be plugged like a
   Windsor block (per SVO cylinder head instruction sheet).
 - Windsor cooling system (Windsor thermostat in manifold or remote
   thermostat, not Cleveland in-block thermostat).
 - Drilled for hydraulic of solid lifters.  Can use hydraulic flat, solid
   flat, or solid roller.  Lifter bosses not tall enough for OEM hydraulic
   roller (could use reduced base circle retro-fits).
 - Lifter bore angles are non-stock
 - Bare block weight = 116 lbs
 - Per Super Ford magazine article on Pantera engine, assembled engine weight
   is 404 lbs (Fontana block, high port heads, Ford Motorsport intake).
 - Gasket deck is 0.900" thick and head stud holes are 2.5" deep (9.5 deck?)
 - All core and oil galley holes are threaded for pipe plugs
 - Each cylinder is fitted with a 4.270" O.D. dry wall iron sleeve providing
   for a maximum bore of 4.155".
 - Numbers one and five main caps reatined by two 0.500" studs and two
   0.375" studs.  The three center caps are held in place with two 0.500"
   hardened studs and two splayed 0.375" Allen head cap screws.
 - 356-T6 aluminum
 - Distance between camshaft and crank centerline is 4.07", same as a 351W.
 - Custom front cover is needed because Fontana uses a Cleveland oil pan.
 - Coolant flow path is same as a 351W (no return passages in upper front
   corners of block like a Cleveland).

Torque specs:

 Head studs                115 ft-lbs
 Main Studs 1/2" diameter  100 ft-lbs
 Main Studs 3/8" diameter   35 ft-lbs
 Main Studs 7/16" diameter  55 ft-lbs

 Run head studs into block with 10 ft-lbs maximum.  Apply light coat
 of silicone RTV on N.C. thread of head stud.  Re-torque head studs
 after initial running.  Engine should be at room temperature for
 re-torquing.

Instructions to Restrict Oil to Lifter Galleys on Fontana Clevor block
(see illustration of rear of block):

 1. Tap 7/16"-14 through rear lifter galley openings.  Stop before threads
    reach lifter bore or when nose of tap appears.
 2. Clean block and install set screws, 5/16" long, 0.073" hole, and use
    Loctite.

Basic Instructions for Cleavor Block (already performed on my block):

 1. Deburr and polish interior surfaces of block
 2. Bore sleeves to size
 3. Hone to final size
     automatic hone - use Sunnen JHU625
     hand operated - use Sunnen AN501
     finish should be 14 to 23 RMS
 4. Match up water coolant passage holes in block to holes in head gasket
    by hand grinding block.
 5. Install torque plate to seat sleeves
 6. Deck block.

General Notes:

Joe Fontana recommends the main bearing clearances be 0.0015" to 0.0020"
cold (will grow a 1/2 thousandth hot).

Roush pins the cam bearings from the top on his race motors so the cam
bearings do not walk fore-and-aft (material is relatively thin there so
be careful).  Roush may also helicoils the mains but Fontana only suggests
that for repair.

Aluminum expands more than iron.  The aluminum block and heads can expand
by more than 20 thousandths when hot.  Note that this is more than the
lash on a "tight lash" solid lifter cam (required lash of 16 thou is less
than the expansion).  You need to set the lash hot.

Miscellaneous Notes (Pantera-specific):

351W waterpump on Fontana front cover will position the pulley in the
same spot as Cleveland and has water outlet on same side but new accessory
brackets will be needed (Windsor type to match the front cover).  Pantera
vendors should have these (I think I got mine from the Byars Brothers).
May need to custom fabricate a thermostat housing to coolant pressure tank
pipe but this will depend upon your heads and intake and how you route
the coolant through the cylinder heads.  Price Motorsport Engineering
and CHI both make a bolt-on thermostat housing that places the thermostat
level like a 351C so a 351C water neck will bolt right up.

> Any other reasons not to go this route?

Tod Buttermore is working (in his spare time) an aluminum 351C block
but it's anyone's guess when they will be on the market and how many
will actually produced.

Dan Jones