Is there any specs on the groove for the grooved camshaft - depth and width? What is recommended? Another related matter - the holes in the center bearing that supplies oil to the rockers - should they be as big as the holes in the block? A friend told me that one of the oil passage holes in the cam bearing (the one toward the the crank?) overlapped the hole in the the block leaving the oil passage about 1/3 the intended opening size. The other holes in the bearing aligned ok Should the smaller hole be made bigger to the size of the block? Thanks

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Strictly from memory the '57 and up groove in the cam journal is u or v shaped and about .060 wide and deep. The 56 and earlier had a drilled hole through the center journal. The change from drilled to grooved happened at the '57 model year and seems to have been an improvement in oiling the rockers.  I once had a groove cut in a drilled cam and it seemed to work OK.  I now remember to order the cam for '57 and up to be sure to get the grooved design no matter what year the engine itself.

The oil is supplied to the cam bearing from the hole at the bottom of the cam bearing shell so I would say that it is very important that this hole be aligned correctly.  I have never held these bearing shells in my hands but I think in a set, all 5 shells are drilled for the 3 holes and have no groove.  They are the very first thing normally installed during a rebuilding (my machinist always does it for me) and proper installation is crucial to oiling the top of the engine, this is something a non experienced machine shop could easily get wrong.  Discuss it with your machine shop before they start because there is no replacable part buried deeper in the engine!

The center cam bearing on a Y block deviates a lot from the classic hydrodynamic design of journal bearings and still seems to work, but I wouldn't call it one of the engine's strong points.

Doug T

The Highlands, Louisville, Ky.

Paul,



John Mummert specifies .030"-.050" minimum groove depth. Do not widen (increases bearing wear) or cut "V" shaped (reduces flow as journal wears).

6 VOLTS/POS. GRD. NW INDIANA

Part of the problem with the grooved camshaft journal is that a ‘soft’ cam bearing will deform or wear into the groove just enough to stop the oil flow altogether.  It is a common practice to make the groove deeper in the camshaft center journal though with 0.060” total depth being expected to be adequate.  Not all cams as supplied will be this deep.  I’ve also talked to machinists that use to drop a long drill bit in the topend oiling hole in the block and punch a pair of larger holes in the cam bearing and then dress the bearing to assist in topend oiling.

 

An alternative for the top end oiling is to machine a groove in the blocks center cam journal hole that connects all three oiling holes together.  The center camshaft bearing is then installed in the block over this machined or cut groove.  With this block groove in place, no cam bearing or cam journal modifications are required and a full flow of oil is able to get to the rockers regardless of the camshaft or bearing design.  Any excess in oil that’s going to the topend can be reduced with the use of a restrictor placed either in the head under the rocker pedestal or putting the restrictor in the bottom of the pedestal.

Lorena, Texas (South of Waco)

Sorry about bringing up this old thread, but I've been searching to find the depth/width of the groove in the block behind cam bearing?  What should it be?

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

I have always cut the groove .032" deep (and kept stock width) in the camshaft journal since the early 60's when pulling wrenches for the LMM (Lincoln,Mercury Meteor dealer). That is depth on one side not diameter difference on the journal.

If I had the tools to do the groove behind the camshaft bushings I would do it that way today as the logic is better.



The last two 312's I just built in the last year I used the Clevite 77 SH-559S bushings. Just my personal preference is Clevite.



I had to place restrictors in both these engines to reduce the amount of top oil going to the rockers. I drilled a 5/16" allen screw and blind threaded the rocker stand so the allen screw would bottom out before hitting the rocker shaft. These were the only engines I ever had that problem with.



When reading the little note inside the bushing package I found that Clevite has changed the design of this camshaft bushing to allow more oiling to the top. The note reads The SH-559 bearings in this set are the latest design and supersede all previous parts. The elongated oil metering holes assure equal oil supply to the upper valve train under all operating conditions. They must be installed with the longest slot positioned toward the right bank and the middle slot positioned toward the pan



With this change in the bushing design over-oiling the top end and flooding the oil return galleries could be a problem. Restriction now maybe a necessity if that happens.



marv

any stock cam i measured was .015 to .017 deep or total .030 to .034.so you need to go twice that mutch.one side of the cam bearing slot only goes about 1/16 or a little more into the rocker passage hole.this was done to force more oil up the other side which never got enough.so its important to install them right.

So is it .032 deep on the groove in block, and same width as cam groove?

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

Good question Paul, because camshaft groove depth is really a simple but important link in oiling the whole rocker arm system.

I used the new Clevite 'slotted' cam bearings in my 292.  Only one bearing was slotted in my set so it looked different from the other four; clearly intended for the center journal.  After correctly installing, I used a very high tech method for flow; I blew down both deck holes and found one side was more restricted than the other.

Ted mentioned using a long drill.  That's exactly what I did.  My drill was precisely 1/4"  in diameter and I used a cordless drill.  Then, I de-burred the inside bearing surface.  In reality the drill bit may be smaller.  I sharpened the tip to a 'domed' shape so it wouldn't catch on the slots so bad as it cut (but that doesn't matter, either). 

My '59 OEM cam had a slotted center bearing with no holes.  I don't have a lathe, but I really didn't need one.  This slot is just a conduit for oil flow (but it should never be the bottle neck).  I simply put my cam in the center slot of my Workmate horse, used my angle grinder with a thin blade, and carefully ground as I rotated the cam by hand.  Slowly, the groove deepened to my satisfaction.  Was it sixty thousandths?  It really doesn't matter if it's more.  In fact, it doesn't matter if the slot is eccentric as long as the minimum deepth is enough.

Two schools play a big role in the next part.  To pressurize or not to pressurize; I pressurized both my rocker shafts.  Each of the two holes on all 16 rocker arms have great oil flow, and my oil pressure went UP when I pressurized my shafts.  Don't forget to 'center' your rocker arms, or slot the oil holes on the bottom of the shafts.

Resistance to flow creates pressure.  My increased pressure and good visible rocker arm flow proved that I needed no more restriction at the stands.

Flow takes the path of least resistance but more resistance raises pressure, which ensures all my rocker arm holes will be clear for many years down the road.  - Dave

Good question Paul, because camshaft groove depth is really a simple but important link in oiling the whole rocker arm system.

I used the new Clevite 'slotted' cam bearings in my 292.  Only one bearing was slotted in my set so it looked different from the other four; clearly intended for the center journal.  After correctly installing, I used a very high tech method for flow; I blew down both deck holes and found one side was more restricted than the other.

Ted mentioned using a long drill.  That's exactly what I did.  My drill was precisely 1/4"  in diameter and I used a cordless drill.  Then, I de-burred the inside bearing surface.  In reality the drill bit may be smaller.  I sharpened the tip to a 'domed' shape so it wouldn't catch on the slots so bad as it cut (but that doesn't matter, either). 

My '59 OEM cam had a slotted center bearing with no holes.  I don't have a lathe, but I really didn't need one.  This slot is just a conduit for oil flow (but it should never be the bottle neck).  I simply put my cam in the center slot of my Workmate horse, used my angle grinder with a thin blade, and carefully ground as I rotated the cam by hand.  Slowly, the groove deepened to my satisfaction.  Was it sixty thousandths?  It really doesn't matter if it's more.  In fact, it doesn't matter if the slot is eccentric as long as the minimum deepth is enough.

Two schools play a big role in the next part.  To pressurize or not to pressurize; I pressurized both my rocker shafts.  Each of the two holes on all 16 rocker arms have great oil flow, and my oil pressure went UP when I pressurized my shafts.  Don't forget to 'center' your rocker arms, or slot the oil holes on the bottom of the shafts.

Resistance to flow creates pressure.  My increased pressure and good visible rocker arm flow proved that I needed no more restriction at the stands.

Flow takes the path of least resistance but more resistance raises pressure, which ensures all my rocker arm holes will be clear for many years down the road.

Hope this helps  - Dave

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

Hi Dave

Nice to see you back on the site.

I always appreciate your input.

Regards


Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!