Banana grooves..

-
j par

j par

Well-hung Member
Joined
Jul 2, 2014
Messages
33,152
Reaction score
20,800
Location
Portland Oregon
So I just bought a used set of 273 rockers with non-banana grooves... While I'm certainly not afraid to grind in my own I'm just wondering how absolutely necessary they are or if it's just a brain tickler...???..
Any experience for opinions??...
 
I know the early BB that had mechanical rockers did not have them only the small blocks, not sure why.
 
Been down this road already........I have a set with a single hole and no Banana groove. Used on a hydraulic 340 application. It is quite obvious to me based on the wear pattern on the loaded side of the rocker shaft that a banana groove in this location is a must. I have procured a set of shafts that have 2 oiling holes, one of which has a banana groove in the aforementioned area. Just my opinion, others may disagree.

This response is moot if you are going to used them with solid lifters.
 
4spdragtop said:
Hijack! How crucial is the location of DIY grooves if you add them?
:popcorn:
Click to expand...

Fairly precise location for the grooves is pretty mandatory.
Otherwise it’s pointless having them.
You want them in the high load area so they retain some oil there.
 
@prorac1 did this fairly recently and has pictures. Maybe his slack *** will chime in. LOL
 
I would suspect that the groove location isn't as critical as having it there in the first place. Probably 1/32" give or take would be fine keeping in mind that the grooves must intersect the oil holes and taper to the edge of the rocker width without going past. Shouldn't be too hard to make a tracing from a grooved shaft and add the grooves to a non-grooved shaft with a grinder. Really it's not too cosmic, what you want is a channel with oil under pressure the width of the rocker's thrust face on the shaft
 
RustyRatRod said:
I tagged him. Has he answered yet? There you have it.
Click to expand...
1355331549061.jpg
 
CFD244 said:
Been down this road already........I have a set with a single hole and no Banana groove. Used on a hydraulic 340 application. It is quite obvious to me based on the wear pattern on the loaded side of the rocker shaft that a banana groove in this location is a must. I have procured a set of shafts that have 2 oiling holes, one of which has a banana groove in the aforementioned area. Just my opinion, others may disagree.

This response is moot if you are going to used them with solid lifters.
Click to expand...
I have plenty of non-adjustable hydraulic rockers.. I wouldn't use adjustable rockers and not use solid lifters to me that's just kind of a waste...
 
I have been using adj rockers on Hyd liters. (flat tappet and roller) for me, it not a waste to get the right push rod length and set the preload of the lifter were i want it.
If your building a bone stock eng then maybe they would be a waste........but if i had them i would be using them even on a stock rebuild.
O wait were taking about banana grooves.............I like bananas, Never had enough spring pressure to think much about them................
 
Take a thin kerf cutoff wheel or a Dremel and just make the cuts a little shy of the rocker width and dress the edges with a file. Not critical, just need to spread the oil...now some mechs have full grooves.... ?
 
The grooves I've had on mine were not parallel with the shaft. Almost if you could take the edge of a triangle file and put it at a 20° angle to the shaft right over the hole and file until you get a certain width that is already pretty much scorn into these older shafts anyways...
I was thinking putting the shaft in my vise in a soft cloth of course with the holes facing up and again going at somewhat of a less than 45° angle right across the center of the oiling hole and filing until I get the correct width which would probably be pretty close to the correct depth...
The heads that I have which are left overhead from the duster before I put on the speedmasters or 596 heads rebuilt with new k line guides hardened seats and 202 valves... I think the Crower Springs were 135 to 340 ? Spring pressure... I originally had 273 rockers on them (banana grooved) before I bought the Hughes roller rockers.. I stupidly sold them after they were machined for spring clearance and I filed the tops of the adjusters for comp locking adjusters...
I have to give everything on this a severe cleaning and pull out one of my heads to get them all clearanced correctly over the springs... I remember the machine shop at the back cut them..
 
I don't think the alignment is critical. As long as the grooves go through the oiling hole, that's all that's important. The purpose of them is to allow a larger surface area of oil between the inside of the rocker arm (or bushing) bore and the shaft. That's why the standard stamped paddle rocker shafts don't have nanner grooves. They just aren't necessary there. I'm not certain every adjustable rocker shaft had nanner grooves, but they are a really good idea.
 
RustyRatRod said:
I don't think the alignment is critical. As long as the grooves go through the oiling hole, that's all that's important. The purpose of them is to allow a larger surface area of oil between the inside of the rocker arm (or bushing) bore and the shaft. That's why the standard stamped paddle rocker shafts don't have nanner grooves. They just aren't necessary there. I'm not certain every adjustable rocker shaft had nanner grooves, but they are a really good idea.
Click to expand...
I can assure you they didn't all have them as I have a set without them that's the point of the thread bonehead..
 
j par said:
I can assure you they didn't all have them as I have a set without them that's the point of the thread bonehead..
Click to expand...

I thought that was the case. Shut up, stupid.
 
You must log in or register to reply here.
-

Back
Top