this is a complete newbie question regarding the head that I am cleaning up on my 1957 261 truck engine. The exhaust valves have caps like shown on the right in the attached pics. I believe they are called roto-caps?? As I'm removing and cleaning the valves, guides, springs etc. Ive found that of the four (4) rotocaps that I've removed, two spin freely either direction. The other two will also spin, but only in one direction; like they are ratcheting.
Which is correct, free spinning or ratcheting?
I'm also curious about the very hard almost white build up I'm finding on the head side of the exhaust valves. They are all covered in black oily soot, but below the soot is this hard buildup. It takes a wire wheel to remove. I've tried soaking in a number of solvents but to no avail. I've been wearing a mask when using the wire wheel, just in case it might be lead buildup.
Last edited by 1942-G506; 01/06/20237:26 PM.
WW2Chevy 1942 Chevrolet G506 1-1/2 ton 4x4 Army Cargo w/ winch
That baked-on residue is deposits left over from lead additives. If you're spending all day every day buffing it off a few thousand valves, it might pose a risk. Masks seem to be the magic cure-all for everything, so if it makes you feel better to wear one, go ahead. The positive valve rotators don't necessarily have to ratchet, so the ones that don't turn both directions are probably just dirty. They're the same ones that are used on small block Chevy V8's, so if you choose to replace them they don't need to be specific to a 261. Usually, the valve springs used with rotators are slightly shorter than the ones used for intake valves to compensate for the increased thickness of the rotators, so don't mix up intake and exhaust springs. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
When I had the 261 apart last summer I cleaned the valve rotators in solvent to get them to rotate freely. As with 1942's experience some would rotate both directions and some would not. I looked up their use on aircraft engines and came to the conclusion that they should ratchet in only one direction. I looked for new ones but couldn't find a listing so I used regular ones rather than risk using worn rotators.
1951 3800 1-ton "Earning its keep from the get-go" In the DITY Gallery 1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.
