Hi there, well after finishing up the distributor work tonight i started it up to find a ticking noise from valve train, first time i've heard this. it diminished a little bit, but i decided to pull the cover and see.
Nothing looked out of sort, all the lashes were tight, nothing bent, etc. I wiped all the spring tops clean and fired it up, and found that the back rocker shaft was not getting much oil at all compared to the front.
the front valve spring tops were wet with oil, and the rears were still dry.
At this point, very sad.
So i pulled the whole shaft off and set it up on towels, and there is significantly more wear on the rear shaft than the front. oil around the area was a bit sludgy.....
Wesley, if you want to get far more oil to both rocker shafts in general, here is an old trick. That oil connector pipe that comes up from the block, that then goes into the center of where both front and rear rocker shafts meet, that then goes back into the block to drain. This pipe crimp it to not allow it to return back into the block. Obviously you have to crimp the side of the pipe that is returning oil, not feeding it oil. What this in turn does is allow all the oil to be fed to the rocker shafts and not just partially. Then the oil returns into the cylinder head drain holes. I have done this to every 235/261 inline six that i have ever owned and swear by it. Obviously GM not doing this in the first place is what caused premature wear of the rocker shafts, as well as the rocker arms. These photos show what it should look like crimped and this is on a 261 in liner in my 57 Pontiac.Try it you will like it. Cheers. George
-- Edited by long stroke on Monday 31st of August 2015 11:17:45 PM
Hi, yes the pipe on mine was crimped already, not sure how long ago there was an oil change, I suspect this car had been sitting longer than I was told.
I might have a line on a 235, hopefully the parts swap over? if not i'll clean it all up and run some thicker oil, and keep an eye on the oil pressure. I've got an email into rockerarms.com to see how much they want for a set.
thanks,
cheers
__________________
1962 4 door Canadian Laurentian, 261 cu.in 6 cyl, pwr glide
Wes, the valve train parts are the same between the 235 and 261. As you might already know it is the 216 that you would stay clear of. It looks like Rocker arms unlimited has the complete assembly rebuilt but they need your core. This is good to know for future reference. Good luck. George
__________________
1957 Pontiac Pathfinder Deluxe sedan restored 261 six
1974 Chevrolet Caprice Estate wagon low mileage original 400 V-8
Wes, in case you have not done this already. Also makes sure the hollow rocker shafts are perfectly cleaned out with a pipe brush and solvent. Also clean out with a smaller pipe brush, all the oil feed holes in the rocker arms. I have always used 20w50 or 20w40 in my old inline sixes. These motors had loose bearing specs compared to what motors became later. Obviously these oils would hurt the motors if you ran them in colder temps. I run my in liner from May until storage in October, so this heavy oil is not an issue. Continued good luck with your 62 261 in liner. George
__________________
1957 Pontiac Pathfinder Deluxe sedan restored 261 six
1974 Chevrolet Caprice Estate wagon low mileage original 400 V-8
I have a line on a 235 from a 65 chev Biscayne, is that valve train ok to use being 1965??? I hope!
Wes, a 1965 Chev would not have a 235. The 235 was last used in 1962 in the Chevrolet line. As of 1963 the Chevrolet in line six was of the new generation of motor, which had a V-8 type of valve train with individual rockers. You can use valve train parts from a 235 or 261 from 1955 to 1962. Cheers. George
__________________
1957 Pontiac Pathfinder Deluxe sedan restored 261 six
1974 Chevrolet Caprice Estate wagon low mileage original 400 V-8
thanks guys, the "235" i'm getting is a freebie from a co-worker, and i'll just have to double check what it is, maybe it's another 261! could be a hidden gem........
__________________
1962 4 door Canadian Laurentian, 261 cu.in 6 cyl, pwr glide