Hi y guys

I tried to search it but don't guess I phrased it right.

What's the consensus on enlarging the oil holes and passages in the head to get a greater volume of oil to the rocker arms????  Especially with a properly grooved cam and Dura Bond grooved cam bearings???

Needed or not???  Your thoughts and opinions please???

The 113 head queation.  Don't the 113 heads have hardened seats from the factory???

As always..........Thanks!!!!!!

Still asking, still learning

Missouri Mike 

I'd rather be lucky than good.................

    but good ain't bad!!

Mike, it seems that a lot of people on here have actually gone in the opposite direction by installing restrictors to the rocker arms when using a grooved cam. Which brings up a question; why groove the cam in the first place, then restrict the flow...

"The Master Cylinder"

Enjoying life at the beach in SOCAL

The groove in the center camshaft journal is machined deeper to help compensate for any potential wear that occurs in the cam bearing that can potentially close up the stock depth groove which will subsequently shut off the oil supply to the topend.  On my end, it’s easier to simply add a groove to the center cam hole in the block and circumvent completely having to route the oil to the cam journal and then back to the block again.  By design, the factory topend oiling system has a built in oil restriction at the cam journal whether it's by way of a crossdrilled camshaft or a grooved camshaft.  Any cam bearing wear with the newer bearings restricts this oil flow even further; hence, the different methods in which to get around this wear issue.

 

Regarding adding restrictors at the rockers due to modifying the oiling system for an increased oil flow to the topend, it’s much easier to restrict for an excess of oil than have to deal with the lack of it.  If the rockers are pressurized rather than allowing the overflow tubes stay in place, then the restrictors may not be needed.  I still run overflow tubes on some Y builds so the restrictors need to be in place in those cases.

 

The 471 heads were the only heads for the Y that came from the factory with hardened exhaust seats.  The 113 heads need hardened exhaust seats added for long term use of unleaded fuels.

Lorena, Texas (South of Waco)

Thanks for the replys.

Mike

I'd rather be lucky than good.................

    but good ain't bad!!

Another reason that most recently restrictors have to be added to the rocker stands is that some of the manufacturers have re-designed the centre cam bearing so more oil can reach the top end of the engine. When you deepen the groove in the camshaft and use this new style of centre bearing top oiling becomes excessive and can flood the return and possibly starve the bottom end of the engine.



Deeper grooving of the camshaft was the "fix" 40-50 years ago. It worked very well, we did this to every Y-block then.



Today, I would use Ted's method of making a groove in the journal behind the centre bearing then control the amount of oil to the top by using restrictors in the rocker stands.

marv

Ted and Marvh, I understand what you are saying but what gives me heartburn is the use of restrictors and the fact that people continue to use gasket sealant on todays gaskets. One globule of Silicon Sealer or Gorilla Snot (or another form of debris) is going to plug your restrictor then you will have NO oil to the rockers. And no, I not saying you guys use it.

Guess that could happen on an engine without restrictors also but would plug easier with a smaller hole.

I have seen it happen too many times in the past on OHC motorcycle engines to not mention it.

Just my 1¢ worth...

"The Master Cylinder"

Enjoying life at the beach in SOCAL

I do not know about sealer pluging restrictors have you seen how small the offset passage in the head is could plug that first. I left mine alone, groved cam bearing installed by a guy who remembers Y blocks, left the overflow tubes also. With todays oils it is not the problem it was years ago.

I dont think it was just the oil years ago that was the problem.It was not changing the oil and filter on a regular basis.With the previous flathead you could get away with adding oil instead of changing it.Also the bypass oil filter was an option on the flathead.I had the oil groove deepened on mine when I rebuilt it.Had to ad restrictors and now it flows just right.Not a big deal to ad and the oil flow can be fine tuned.

  

I recently bought a set of cam bearings from Schumann's because they offer a center cam bearing with a groove on the outside (and inside) of the bearing. I guess bearings were machined like this years ago to maintain oil flow even if the bearing spun a bit. I don't know if having this outside groove will require restrictors in the rocker stands or not.

Rono

  Ron Lane,  Meridian, ID

All good points to take into consideration...

"The Master Cylinder"

Enjoying life at the beach in SOCAL