Converting to Self aligning rockers

[Lynn]

Have read several threads on this, but can't find all the detail I want.

Short story: need to convert the heads on the 350 engine in my Studebaker farm truck for self aligning rockers (not sharing the whole story, suffice it to say I am a dumb a$$). Not using a roller tip, just stock Chevy self aligning. Do the stock valves stick up far enough over the retainers and split locks that the self aligning rockers will clear?

Anyone done this before? Plan is to pull the intake, rockers and push rods, put down a blanket of protection in the valley, hog out the push rod alignment holes in the heads with a drill, and put it back together with the self aligning rockers. I have not found any info on line to indicate if the stock type valves stick up far enough to make the rocker clear the retainer.

Any input is greatly appreciated.

Lynn

[Lynn]

Forgot to mention, I am running a Crane roller camshaft.

[Crossbreed383]

Why the conversion?

[Lynn]

Originally Posted by Crossbreed383

Why the conversion?

Was trying to save space. Hence the statement: "not sharing the whole story, suffice it to say I am a dumb a$$"

But, perhaps it will save someone else a headache. I foolishly re-used some low mileage rockers on this build. Every other wear part in the engine was brand new. At least one (haven't removed the other valve cover yet) of the aliging holes in one head is worn badly side to side. The slightly beveled wear pattern on the rocker caused side load on the push rod, and #6 intake push rod bent. Had to remove both rockers and push rods from #6 and drive it home as a V7. Head is now junk if I can't convert. They are just old 76cc truck heads, and not worth another set of valves if I need longer stem valves.

I know I could just buy a set of self aliging rockers and measure the clearance between the little aliging ears and the retainer/split locks. But, if it is too close, then I have a set of useless rockers.

[Lynn]

Thought I would provide an update just in case anyone else runs across this issue. Went ahead and bought a set of self aligning rockers and new push rods. Measured, and sure enough there is enough clearance between the aligning nubs on the rockers and the retainers, allthought he exhaust is pretty close with the rotators on there.

First, if I had listened to Eric, I would not have had an issue. He told me that he "always" uses new rocker arms on a new build as cheap insurance. Should have listened.

The rockers looked pretty good to the naked eye, but then, I may not have used the set I THOUGHT I was using. I just noticed a set of truck heads in the garage that have almost no mileage or wear on them. I am betting I was thinking of those when I re-used this set.

As for the conversion: it worked great. Didn't take nearly as long as I was expecting. Biggest issue was this was on my farm truck, so I bruised a few ribs laying on the fenders.

Removed intake, valve covers rockers, push rods and lifters. I lined the valley very well with paper towels, and then lined it again with paper towels laced with wheel bearing grease to catch any shavings.

Even though only a few of the push rod guide holes were worn side to side, I chose to convert all to self aligning rockers. I drilled out all 16 holes with a 25/64ths bit. Probably could have used a 3/8, but my good 3/8 bit was not so good. Drilled slowly and with almost no down pressure. The bit will want to bite and jam, so you have to go slowly.

After drilling I swept the area both above the hole and below the hole with a strong magnet multiple times, and carefully removed all the lining from the valley. Swept everywhere I could with a magnet again. Then used cotton swabs dabbed in grease to pick up any little bits left behind.

Once I was satisfied that there were no shavings (I think old guys used to call it "swarf") I put her all back together with new push rods and self aligning rockers. It is a hydraulic roller, so easy peasy to adjust the valves.

Did all of this last weekend. Was not able to drive it until today. Probably just as well, as that gave the RTV sealer on the ends of the intake plenty of time to cure. Runs great, and no unusual noises. Only drove about 10 miles, but I did not baby it by any means. Pretty hard to baby with that 6.66 rear screw. 60 mph is about 4k rpm.

These heads weren't particulary valuable, but I did spend a few hundred having them trued up and the seats cut for new SS valves. Spent less than $120 on Melling rockers and push rods