351 Cleavor Block?

[Bluedog]

Does anyone have any experience or knowledge about the 351 Cleavor? It's supposed to have the best of both worlds of the 351 Cleaveland and 351 Windor like bigger journals, wider pan rails to support a 4.25 crank, Windsor oiling system, etc. How good and reliable are they? Why haven't they been more widely adopted if they are so good. A company called Fontana Automotive who created the aluminum Cleavor block in 1985 is selling the block for $3750 which seems like a pretty good deal. Thanks for you input!

Bluedog

[dewulfmd]

The Cleavor was originally a combination of the 351 Cleavland heads with a 351 Windsor block (yes they would bolt on). A special intake manifold was required to mate the two. By the way, this was how Ford developed the Boss 302. I forget the name of the company that made the special Cleavor intakes (I believe there was just one company).

I always wanted to try the combination, but never had the money to experiment with. It combines the great flowing Cleavland heads with the superior oiling system of the Windsor. The perfect setup.

I never heard of a special block, however, the Cleavland heads needed to be modified (coolant holes drilled and plugged).

Does anyone have more info?

[dewulfmd]

Also, I believe there was a special pistion required

[Daniel Jones]

> Does anyone have any experience or knowledge about the 351 Cleavor?

Yes, I have one that is forming the basis for a stroker motor for
my Pantera.

> It's supposed to have the best of both worlds of the 351 Cleveland and
> 351 Windor like bigger journals,

Actually it has the Cleveland's smaller diameter main journals.
Smaller journals mean the oil is at lower speed for a given diameter
which is good for lubrication.

> wider pan rails to support a 4.25 crank,

Yes it uses the wider 351C pan rails.

> Windsor oiling system, etc.

The internal block passages are designed like a Windsor but the oil pump
and pan are 351C parts.

> How good and reliable are they?

I can't say anything about reliability yet as I have to build my engine.
However, there are several Pantera owners running them that I know of and
I haven't heard of any real problems. One guy I know did have problems
with his because a machine shop attempted to align-hone the main bores
instead of align-boring. This ovaled the mains as the hone removed more
material from the aluminum block than from the iron main caps. With a
rigid cutter, align-boring cuts equally from both. The same guy also
noted that dowel pin location was off on his block (or was it the cover?)

> Why haven't they been more widely adopted if they are so good.

They weren't really marketed for street cars. They were designed as a
race block for sprint car use, back before any of the Ford Motorsport
or Dart race blocks were available. They've found their way into drag
cars and street cars (primarily Panteras) since then. Originally, the
price tag was quite high. When they were introduced in 1985, they were
$4100 but the price has come down in recent history due to competition
from Ford Motorsport. Fontana also makes other racing blocks, including
a 4 cylinder aluminum block used in certain sprint car and boat racing
classes.

> A company called Fontana Automotive who created the aluminum
> Cleavor block in 1985 is selling the block for $3750 which seems
> like a pretty good deal.

- 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 (could use the retro-fit reduced base circle stuff)
- 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).
- 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
- 351 Windsor timing chain
- 351 Windsor timing cover gasket
- 351 Windsor water pump ('70-up)
- 351 Windsor end seals (intake end rails)
- 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
- Studs/bolts for block and head combo (available from ARP or Fontana)
- 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).

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 thousandths 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 also helicoils the mains.

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).

Will need to custom fabricate a thermostat housing to coolant pressure
tank pipe.


Hope this helps,
Dan Jones

[Daniel Jones]

> The Cleavor was originally a combination of the 351 Cleavland heads
> with a 351 Windsor block (yes they would bolt on).

Yes but that is quite different than the Fontana aluminum block
which is a true hybrid of Windsor and Cleveland features.

> Also, I believe there was a special pistion required

You needed pistons with valve notches to match the canted valves of
the Cleveland heads and a pin height to match a 9.5" block.

On the Fontana block you can run either Windsor or Cleveland heads
and the pistons need the corresponding valve notches. The high
port Motorsport heads (A3/B351/C302) were the racing head of choice
for the sprint cars.

> A special intake manifold was required to mate the two.

The intake company was B&A though they are now sold through Bush.

> I never heard of a special block, however, the Cleveland heads needed
> to be modified (coolant holes drilled and plugged).

For the Fontana, the high port and Yates heads are set up for either
(come with screw-in plugs). Windsoe heads bolt right on.

Dan Jones

[Jack Zupan]

I had a Cleavor engine for five years. It was a good running engine but I don't think it put out the power it should have. I sold the car but I always thought about going to a tuner with a chassis dyno to find that power. The idea is a really good one but I think it came out of necessity due to the crappy heads and engines that Windsors were a few years ago. Now there are any number of very good aluminum heads available for the Windsor and so the need for the combination is not as pressing. The company that makes the intake is located in Arkansas and I can give you their name and phone number if you need it. I think maybe Blue Thunder is making a manifold now too. The pistons are not custom but are Cleveland pistons and not Windsors. There are also Australian heads which are a combination of the closed combustion chamber of the 4-barrel head with the smaller runners of the 2-V head. I've not tried these but think they would be interesting.

Just my opinion but $3750 for a block is extremely high, especially when you can buy the new Dart block for just over 2 grand and it is bored for about 427 ci.

Jack Z.

[Daniel Jones]

> The idea is a really good one but I think it came out of necessity due
> to the crappy heads and engines that Windsors were a few years ago.

Yes.

> I had a Cleavor engine for five years. It was a good running engine but
> I don't think it put out the power it should have.

The B&A conversion manifolds were mostly for 2V heads which do not
flow near what the 4V heads do. Most guys ran plain old open chamber
2V heads which flow around 200 CFM. A good home-porter could get the
same numbers out of a set of DOOE 351W heads and save a lot of hassle
but, back then, good 351W intakes were hard to find.

Drag racers in the know would use 4V closed chamber heads, a 351W block,
and one of the Ford Motosport high port intakes which were available for
both 9.2" and 9.5" deck blocks and would bolt up to the 4V heads. 4V heads
with a bit of clean up work flow 300 CFM. That combo still works today.

> The pistons are not custom but are Cleveland pistons and not Windsors.

Incorrect. With Ford Windsor rods Cleveland pistons would be too far
down the hole at TDC due to the pin height and deck height differences
(Cleveland rods are shorter so would be even farther down the hole).
On 302's you could use an off-the-shelf Boss 302 piston (with 289 or Boss
302 rods) but the 351W blocks required unique pistons which were available
as an off-the-shelf item through B&A.

> There are also Australian heads which are a combination of the closed
> combustion chamber of the 4-barrel head with the smaller runners of
> the 2-V head. I've not tried these but think they would be interesting.

I have these on my Pantera now. They work fine on the street and allow
10.5:1 compression on pump gas with a flat top piston. A port matched
Weiand Xcelerator 2V is the intake of choice. Makes a great little
steet package but the Aussie heads still only flow 200 CFM or so. A
home porter can expect 225 CFM and good porter can pull 250+ CFM. For
a light car with some gear or a drag race application, 4V quench heads
are still the way to go. The best heads were the A3/B351/C302's
aluminum high ports which were an evolution of the iron Pro Stock high
ported 4V's.

> Just my opinion but $3750 for a block is extremely high, especially
> when you can buy the new Dart block for just over 2 grand and it is
> bored for about 427 ci.

The aluminum Ford Motorsport blocks are in the same price range as
the Fontana. Both the Fontana and Siamese bore Motorsport blocks will
go out to 454+ cubes. Comparing an aluminum race block to an iron race
block on cost isn't exactly fair but if you don't mind the weight penalty,
the iron race blocks are less expensive. Note that the iron race blocks
come in at 205 lbs (per the Ford Motorsport catalog). My Fontana weighed
in at 116 lbs. That's quite a bit of difference. Aluminum blocks can
also be easily repaird if damaged.

Dan Jones

[Jack Zupan]

"Drag racers in the know would use 4V closed chamber heads, a 351W block,
and one of the Ford Motosport high port intakes which were available for
both 9.2" and 9.5" deck blocks and would bolt up to the 4V heads. 4V heads
with a bit of clean up work flow 300 CFM. That combo still works today."

This may not be such a great combo on the street. I still have a set of closed chamber 4V heads but never put them on because the people I knew that had used them all complained about the lack of low end torque. Once the rpm's were up they would go like crazy however.

"The aluminum Ford Motorsport blocks are in the same price range as
the Fontana. Both the Fontana and Siamese bore Motorsport blocks will
go out to 454+ cubes. Comparing an aluminum race block to an iron race
block on cost isn't exactly fair but if you don't mind the weight penalty,
the iron race blocks are less expensive. Note that the iron race blocks
come in at 205 lbs (per the Ford Motorsport catalog). My Fontana weighed
in at 116 lbs. That's quite a bit of difference. Aluminum blocks can
also be easily repaird if damaged."

Actually I was thinking street car when I replied. I wouldn't but an aluminum racing block in a Cobra unless I was doing a lot of racing. In this case a weight penalty with a small block in a 2600 lb Cobra is really a non-issue.

Jack Z.

[Bluedog]

Daniel,
Thanks for your detailed reply! You are a fountain of information and I realize I have a lot to learn!!

Bluedog

[dewulfmd]

Dan Jones,

How does the Fontana block compare to the aluminum Motorsports blocks? Which is better for what?

Mike D.

[Rick Carnahan]

I just got my new motor back from the builder it is a 351w block with 351c austrailian heads with the matching pistions for this set up and I am looking at just shy of 470 hp at the crank. should make the old shell valley lots of fun.
If you need the name of the maker of the intake I can look and post it later just let me know.

[mike jackson]

I run the clevor in my 65 mustang. i use the boss 302 heads because the swap is a little easier. it is storked out to 410 C.I. I have a high port edelbrock high port intake with a 950 HP carb, but before that i ran the torker II intake for the cleveland with adaptor plates. a 700 lift roller cam, mild port work to intake and exhaust bowl area and ports. with port plates on the exhaust. the intake ports flow 335 cfm @700 and exhaust flows 225 @ 700. i use a stock 77 windsor block with a main girdle. 14.1 pistons, I have about $1300 in the heads; race valves, springs, titainium retainers, port work, and plates. I rev the engine to about 7800-8000 rpm. engine has about 60 passes on it with no issues. the first 25 passes i didn't even pull a valve cover. i have taken the engine apart and check everything over with no issues found. the car with me in it is, 3140lbs. it has a 4 speed, so its wheels up every pass. so far it has run 10. teens at 130 mph. the engine makes good power and I'm pretty sure this year it will go in the 9.80 area with a little more suspension tuning. Its pretty much up to you and what you like. I enjoy NOS stuff. have fun and see you at the races !!

[CobraV8]

Price Motorsport sells all kind of adapters for nearly every block- intake and head combination you can think of (www.pricemotorsport.com).

The part number for Windsor block with Cleveland heads and a 351 windsor intake is AP-16, if you want to use a Cleveland intake and 351C 4V heads on a 351W block you need adapter # AP 15.

They also sell an adapter to install CLeveland 2V heads on a 302.

[Keith Taylor]

I have a 351 Cleavor with a Jack Roush high rise intake. I need a low rise manifold to clear the hood on my 65 daytona coupe. Where can I find such an intake????

[stengun]

Howdy,

Ford's Nascar engine back in the early to late 80's was a Cleavor. It used a heady duty 351W block w/ 4-bolt mains (ala Boss 302) and an aluminum Boss 351/ 351 C-4V head. With this engine Bill Elliot ran a lap speed of over 211mph in '86 at Talladage in a T-bird stock car that weighed over 3600lbs. He hit a top speed of over 230mph going down the front streach. So, I guess it will work pretty good.

Paul

[lovehamr]

This is a great thread! up till now I thought I was very alone in the clevor world. Mine is in a 1970 Boss 302 and was built back in 1995 befor there were any reasonable cranks, blocks, heads etc, for Ford applications. Sure Fontana was there, Ford Motorsport was there but trying to pack the word "reasonable" into the cost factor was difficult for me at best. So I wanted more cubes for my Boss and being a Boss it had to have some sort of Windsor block and Cleveland type heads. My twisted view of things made me build this:

BLOCK
1969 Windsor block +30
1969 windsor crank stroked to 3.64"
Dodge 340 rods narrowed at both ends (machine shop said this was a *****! lol)
Boss 302 pistons TRW L2324F +30
Displacement = 371.44 ci I just call it 372 and had 70 Boss stripes made to match!

HEADS
1970 351 Cleveland
Intake ports filled, contoured and raised to replicate c302 ports
2.19" Stainless Manley intake valves
Flowed @ 335 cfm @ .800"
Exhaust ports smoothed and contoured
1.705" Stainless Manley exhaust valves
Flowed 212 cfm @.800" with no turbulence (apparently a problem with some Cleveland heads)
Crane double coils on all valves with stainless retainers
Crane 1.73 roller rockers
Compession ratio 11.20

Intake FMS 9424A351 Matches the redone intake ports great

Pushrods, custom 8.800 x 3/8 hardened for guide plates

Carb was a Holly 3 bbl 950cfm (that's right I said a 3bbl) now have a Race Demon 1050 (haven't tried that puppy out yet though)

All this and it's still a work in progress! LOL