Don Terrill’s Speed-Talk

I'm working on a set of 364 Buick heads (circa 1960). I have disassembled a few sets of these old nail-heads, but I have never seen any valve stem seals and there seems to be no room for them. Yet AERA says they have umbrella seals and the NAPA picture of the head set contents shows valve seals. I really don't think there is room for them, and I don't think all that much oil reaches the valves, especially if the rocker shaft assembly is worn, so I am not inclined to machine the guides for seals.

What do you old fellers with experience on these heads think? (I'm thinking Jack Vines......)

Thanks,

tom

Tom, try T/A Performance. They still have parts for the old nailheads.

having seen them recently they were more of a deflector similar to an older LA Chrysler.
But not like the old cadillac umbrella seal for depth.
But as mentioned T/A performance should have them in stock or diamentions

They must be very small to not interfere with the inner spring. I wonder if they disintegrate like the old Ford umbrellas did. There was absolutely no sign of a seal or any pieces of such in any of the heads I've disassembled.


tom

Buick didn't put valve guide seals on the Nailhead until 1966....and then they used them only on the intakes.

jack vines

PackardV8 wrote:Buick didn't put valve guide seals on the Nailhead until 1966....and then they used them only on the intakes.

jack vines

Thanks, Jack, THAT clears things up big time. I thought I was going crazy. Judging by how bad the guides were in these heads when I disassembled them, I don't think I want to restrict the oil to them. I relined them with phoshpor bronze liners and sized them at .0025" exhaust, .0015"-.002 intake, toward the tight side for both.

tom

IIRC they had a rubber flat seal that sat on top of the spring retainer. Was an old
trick to use them on SBC's that were long in the tooth and the customer wanted a
$5 rebuild for worn out guides. Don't remember what year nail heads...

GLHS60 wrote: ↑Tue May 19, 2020 3:03 am Jack, how did they get away with the lifter running square on the cam? I don't remember them having any unusual cam and lifter wear issues.'

IIRC, the lifter centerline is offset to the cam lobe centerline so the cam lobe pushes only on one side of the lifter, the force differential rotating the lifter.

PackardV8 wrote: ↑Tue May 19, 2020 12:21 pm

GLHS60 wrote: ↑Tue May 19, 2020 3:03 am Jack, how did they get away with the lifter running square on the cam? I don't remember them having any unusual cam and lifter wear issues.'

IIRC, the lifter centerline is offset to the cam lobe centerline so the cam lobe pushes only on one side of the lifter, the force differential rotating the lifter.

So, I understand the SBC cam is not exactly parallel to the crank center line ? If so, is this common?

Truckedup wrote: ↑Tue May 19, 2020 3:16 pm So, I understand the SBC cam is not exactly parallel to the crank center line ? If so, is this common?

We have a technical terminology problem. AFAIK, the SBC cam tunnel centerline is parallel to the crank center line.

Ok.....Thr old Chevy inline 235-261 and GMC 302 I messed with had the lifters offset to the cam lobes..The cam grinders told me the lobes are also ground to spin the lifters...

GLHS60 wrote: ↑Tue May 19, 2020 7:10 pm Appreciate the reply Jack.

For some reason I had it in my mind the lifters didn't rotate.

Thanks
Randy

Page 490: Column 2, lines 3-8.

http://wildaboutcarsonline.com/members/ ... _Buick.pdf

KJ, thanks for the link which explains the design. My IIRC was IFIRIC (in fact,i recalled incorrectly.)

Kevin Johnson wrote: ↑Tue May 19, 2020 8:23 pm

GLHS60 wrote: ↑Tue May 19, 2020 7:10 pm Appreciate the reply Jack.

For some reason I had it in my mind the lifters didn't rotate.

Thanks
Randy

Page 490: Column 2, lines 3-8.

http://wildaboutcarsonline.com/members/ ... _Buick.pdf

Interesting read....... and seeing them talk about things like pressure recovery in those stock heads...... back in 1953.
I also liked that part about the cam design and the lifter pump up at 5300 for the intake valves, and 5500 for the exhaust........ with the springs set up at 62/144.

I wonder if they continued to use chilled iron lifters and steel camshafts for the entire production run of that engine family.