Decided to sift through a box of old parts that came in the trunk of this `57 bird… found original timing set, a rusting ECK cam, two previously polished connecting rods, 7 flat top cast pistons, a dozen lifters, and two nearly complete rocker arm assy’s.

Not sure what to make of it except that the PO either chose or was forced by failure to rebuild the motor. Given that the block doesn’t match the 312 ci “D” code on the VIN plate, but the heads are “G” code, I’m leaning toward believing the original motor took a grenade.

The reason for my post though, is that I noticed each of the rocker arms (ECG 6564-82) had near a half dozen holes drilled through the collars and upper ridges (where the part # are cast). At first I thought it was a test for weight reduction, but then I noticed the rocker pivot rods showed a lot of scaring.

Do you suppose this was an attempt to combat an oiling problem that may have eventually led to the demise of the motor? Or was this an ole-school performance tric?

Brian

Noob, we ran lightened rockers back in the 60,s when very little info and parts were available and were racing using "seat of the pants technology". These were on 312 T bucket race engine in 60,s and no breakages! regards bill. 

bloodyknucklehill (1/7/2010)

---

bill, did you notice any gains at all? seems like if they'd survive drag racing abuse they may be safe for a street car... low buck, low tech stuff like that is right up my alley

Your welcome to the high ratio ones I found for the price of shipping if you want to experiment. They look just like bkh pictureposted, but they also have drill holes in the collars.

Brian

Low buck, low tech is still alive.  These go to 7k rpm and no failures yet.

Somebody got it wrong, "low budget is the mother of invention".

Noob (1/7/2010)

---

bloodyknucklehill (1/7/2010)

---

bill, did you notice any gains at all? seems like if they'd survive drag racing abuse they may be safe for a street car... low buck, low tech stuff like that is right up my alley

Your welcome to the high ratio ones I found for the price of shipping if you want to experiment. They look just like bkh pictureposted, but they also have drill holes in the collars.

Brian

Brian if that was aimed at me i'll take you up on that.. i'll shoot you a PM..

      Where you take the weight off is more important than how much. The further from the center of the shaft you can remove mass, the better. The adjusting screw is an excellent place to start.

Dan,

      The undrilled, locknut style factory 1.54's on my F code go 6500 with no sign of float. Begs the question why would you need anything more for street use?

Thought you might like pic of these Fenton rocker arms from my collection, they are new and probably could power a mack truck, they are thick and heavy, approx 6 oz,s compared to 4 oz normal, they have offset rib on top to let oil spray toward center of tip. Also i cant find them at moment but i also lightened the normal rocker arm at the tip like an FE rocker, that narrows the excess unused pad width once the arms are centered on valve tip, quite a weight reduction. best regards bill.

      Of course it would. Today we have Dove aluminum rockers (Ted's roadster and the EMC entry) as well as Beehive springs, stainless valves, Titanium retainers etc. Actually the stainless valves are heavier than plain steel. But my point being, for a practical street motor, you don't gain much with this stuff. Different story on a 9 second roadster.

  Your theorey is correct, simple Physics, but for practicality???????? Those rockers were probably done 50 years ago when nothing else was available. Drill 'em till they break and do the next set with one less hole! Also, as Ted and John will tell you, we've probably gained more with intelligent cam design than anything else.  

The aluminum rockers are bulkier in part due to just getting the strength back.  I have yet to run the Harland Sharp rockers for an evaluation but when I do, I’ll be limiting the rpms to 5500 so I may or may not see a problem with them being heavier.  As compared to the Dove rockers, the Harland Sharp rockers have a wider roller tip which is also larger in diameter and that is a player on the increase in weight on this particular rocker.  These rockers are also just beefier looking all over compared to the Doves.  I’ll finish up with the spacers today for the Harland Sharp rockers and then be ready to run these rocker assemblies in the near future.

Up until yesterday the test engine hadn’t been responsive to changes but headway was made yesterday when I removed the Red’s headers that had 2” head pipes and installed the headers from the EMC engine with mufflers.  Picked up a clean twenty two horsepower at which point I started trying out different ratio rocker arms again.  Now the engine was more responsive and this engine still has the dead stock unported G heads.

The idea of reducing Y block valve train weight seems to me to be a result of the old HRM mantra that the y block wouldn't rev because of heavy valve train components.  This was shown to be a result of the crappy solid pushrods which were not stiff enough to act as a good column.  I doubt that the y's rocker arm itself is a lot heavier than the stamped ball joint rockers for small blocks.  Ted, can you confirm?