71-73 351c original cam specs

[Don65Stang]

I did some research on this*. Here's what I found for the various 4V engines:

Engine; Duration degrees: int, exh; lift: int, exh; timing opening & closing degrees; overlap degrees

70-71 closed 4v. Part #D0AZ6250B. Casting mark: backward "B" followed by "R".

266, 270; .427, .427; 14-72-70-20; 34

71 CJ.

270, 290; .480, .488; 18-72-82-28; 46

72-73 CJ. Part #D2ZZ6250B. Casting mark: backward "B" with a "V." It looks like "BV", again with the "B" character being backward.

270, 290; .480, .488; 14-76-78-32; 46

71 Boss 351 (mech cam).

270, 290; .477, .477; 34-76-86-24; 58

72-74HO (mech cam). Note: perhaps this cam continued to be used in Australia until 74??

275, 275; .491, .491; 17.5-77.5-77.5-17.5; 35

*The primary source I'm deciphering the data from is the "Ford Cleveland 335-Series V8 Engine" by Des Hammill.

Edited 8/18/12.

I found some more cam data. I've not compared to the above info yet.

http://home.comcast.net/~jelerath/mustang/Specs/cams-fr.html

351 Cleveland Camshaft Comparison

Part Number

Name

Type

Lift-intake/exhaust @ valve

Degrees of Duration

Characteristics

Recommendations

D0AZ-6250-B

'70-'72 351C 2V

Hydraulic

.400"/.400"

258/266

Stock

Stock

D0AZ-6250-C

'70-'71 351C 4V

Hydraulic

.420"/.450"

268/280

Stock

Stock

D1ZZ-6250-A

'71 351C Cobra Jet

Hydraulic

.481"/.490"

270/290

Great Performance Cam

Stock

D2ZZ-6250-B

'72 351C Cobra Jet

Hydraulic

.481"/.490"

270/290

Same as above, except indexed 4 degrees retarded

Use multi-index crank sprocket to advance 4 degrees

D1ZZ-6250-B

'71 351C Boss

Mechanical .025" Lash

.477"/.477"

290/290

Original Boss Cam {out of production}

4 Speed and Low Rear end gears Recommended

Same as above but after market.

Speed Pro #CS173R or Melling #24224.

290°/290° duration @ 0.004"

0.505"/0.505" lift

Exhaust valve opens at 84° BBDC

Intake valve closes at 74° ABDC

62° overlap

219°/219° duration @ 0.050"

114° lobe separation angle

Intake lobe centerline = 109° ATDC

SUM-K5200

Summit Racing

Hydraulic

.484"/.510"

{204/214 @ .050" lift}

Good Street Cam

4 barrel and headers suggested

322193

Competition Cams 260H High Energy Cam

Hydraulic

.484"/.484"

260/260 {212/212 @ .050" lift}

Good towing and RV cam

Stock

322213

Competition Cams 268H High Energy Cam

Hydraulic

.494"/.494"

268/268 {218/218 @ .050" lift}

Good performance cam, pulls strong, nice lope at idle

Headers and performance intake recommended

SUM-K5201

Summit Racing

Hydraulic

.509"/.509"

{218/228 @ .050" lift}

Good all around performance

4 Speed or high stall converter and Low Rear end gears Recommended

322224

Competition Cams 270H Magnum Cam

Hydraulic

.519"/.519"

270/270 {224/224 @ .050" lift}

Good street cam

Headers and performance intake recommended

M-6250-A341

Motorsports SVO

Hydraulic

.510"/.536"

292/302 {214/224 @ .050" lift}

Good all around Performance Cam

4 Speed or high stall converter and Low Rear end gears Recommended

D2ZZ-6250-A

'72 351C HO {High Output}

Mechanical .025" Lash

.490"/.490"

275/275

Lower duration provides good low rpm performance

High stall converter or 4 Speed recommended, as are lower rear end gears

322254

Competition Cams 280H Magnum Cam

Hydraulic

.530"/.530"

280/280 {230/230 @ .050" lift}

Good performance cam

Headers, performance intake suggested

00093LK

Lunati Cams

Hydraulic

.536"/.562"

{224/234 @ .050" lift}

Strong mid-rpm torque, 2000-6000 rpm

Headers, performance intake required

322344

Competition Cams 292H Magnum Cam

Hydraulic

.560"/.560"

292/292 {244/244 @ .050" lift}

Good Street/Bracket Race cam

Headers, performance intake required

M-6250-A342

Motorsports SVO

Mechanical

.580"/.606"

296/306 {248/258 @ .050" lift}

Very radical-race only camshaft

May require notching of piston heads for valve clearance, very high stall converter or 4 speed, and very high rear end gears

D1ZX-6250-FA

351C OHO {Off Highway Only}

Mechanical .025" Lash

.589"/.612"

326/334

Very radical-race only camshaft

May require notching of piston heads for valve clearance, very high stall converter or 4 speed, and very high rear end gears

 

[marks73]

That's because big brothers never tell!

 

[RacerX]

Any idea as to the part numbers or identifying markings for these cams?

I believe the 73 CJ cam is the same as the 72, it's just retarded 4 degrees for the 1973 emissions changes implemented that year.

 

[cobra3073]

From everything I have seen, the 1973 351CJ shared the exact same camshaft as the one found in the 1972 351CJ. According to the "Hollander Interchange Manual", the part number for both camshafts is D2ZZ6250B.

The casting number is what looks like a backward "B" with a "V." It looks like "BV", again with the "B" character being "backward."

I do not know how to recreate that character (the backward "B") on this keyboard but hopefully y'all will have an appreciation for what I am trying to convey. LOL

BT

 

[Don65Stang]

I don't have the Ford part numbers. Perhaps the rest of the cam part numbers are in BT's reference "Hollanders Interchange Manual". I'll update the post with any that turn up.

It looks like the 71CJ cam is very similar to the 72/73CJ cam with the 72/73 cam having a 4 degree retarded grind. Then in 73 it was retarded again by 4 degrees at the distributor.

 

[marks73]

I knew you'd find it. Good to know!

 

[droptop73]

If I recall correctly the cam retard in 73 was in the timing chain not the cam.

Thanks for the great info Don!

 

[Don65Stang]

I have data for a few aftermarket cams that I can add if there is any interest.

 

[Don65Stang]

Updated original post with more cams & part numbers.

 

[1hotboss]

Updated original post with more cams & part numbers.

How does one identify an original 71 Boss 351 cam

 

[Spike Morelli]

If I recall correctly the cam retard in 73 was in the timing chain not the cam.

Thanks for the great info Don!

Not likely done with the chain. My money is on the crank gear keyway indexing. In building engines, I have found that cam timing is RARELY what you think it is "straight-up", or, "dot-to-dot. Many modern cam grinders will automatically grind their cams about 4 degrees advanced. Using cheap, and inexpensive timing chain sets are almost always off. Add to that, an aftermarket crank, which may have the keyway slightly off from where it should be. Seriously, I've had to use the 6 degree retard keyslot on a crank gear, to give me 4 degrees advance at the cam.....that's how off it all can be with aftermarket cam, aftermarket timing gearset, and aftermarket crankshafts. Even when overhauling a bone stock engine, I always check the camshaft degreeing, and I use a computerized devise made by CamLogic, which is accurate to a TENTH of one degree....closer than you can get with a wheel and pointer set-up. There's lots of power and torque lost to not setting the degreeing and just bolting the cam in dot-to-dot.This cam is right on the money for it's grind, at 110 degrees ( O.K., it's actually two tenths of one degree advanced), but damn close enough to the 110 called for. This engine is an early ( 63 ) Ford 406 FE, going in a hot flatbottom boat, using a factory Ford crank, Holman/Moody solid camshaft, and quality Cloyes true roller timing set.

 

[Dozz302]

Just wanted to confirm that the 1972 cam had a Upside down "V" then a "B" next to it. Also what about any paint codes or other markings such as "Ford" or "Fomoco". Also where did you get the info on some of these cams. I can find nothing on the upside down "V" next to a "B" for the 1972 cam ID. I have a lot of Ford books but on that cam they show no identifying markings like on so many other Ford cams. I have a 1971 high compression engine and if I rebuild I would use the 1972 cam and just advance it 4 degrees. I read it was worth 30 HP. I will only use a Ford cam.  

 

[Hemikiller]

Much of that info comes from the Ford shop manual and the Master Parts Catalog. Snippet below of the 351 engine cams section showing the ID markings. 

 

[Don C]

To add to the mix, here's what I've gathered over the years:

EDIT: Updated and corrections

 

[73inNH]

if I rebuild I would use the 1972 cam and just advance it 4 degrees. I read it was worth 30 HP. 

Is there a procedure to do this (advance the cam 4 degrees)? 

 

[Don C]

Is there a procedure to do this (advance the cam 4 degrees)? 

Get a timing set with multiple keyways in the crank sprocket, like this one, that provides for advancing the camshaft.

1971 FORD MUSTANG Cloyes Gear 9-3521X9 Cloyes Street Billet True Roller Timing Sets | Summit Racing

 

[73inNH]

Get a timing set with multiple keyways in the crank sprocket, like this one, that provides for advancing the camshaft.

1971 FORD MUSTANG Cloyes Gear 9-3521X9 Cloyes Street Billet True Roller Timing Sets | Summit Racing

Don-

Thoughts on the home mechanic doing this? I've never swapped a cam, but do most of my own work on my cars.

 

[Don C]

They aren't that hard to do, assuming the cam bearings are in good condition, and not worn out of specs, scored or pitted. If the cam bearings need replaced the motor has to come out and a cam bearing tool bought or rented. If you're just wanting to advance your existing cam that is pretty straight forward. The timing set should come with instructions and the keyways will be marked for advance or retard degrees.

 

[midlife]

Since when did Shelbys come with a 351C engine?