Charlie, I just couldn't not read this thread and say something about that gorgeous engine! This entire conversation is WAY above my level of expertise. Having said that, I can only hope that MY 292 turns out half as well as your power plant! I pick up my motor next weekend and will post pics and as much info about it as I can. I will be picking as many of the BIG brains on this site as I can when the actual build starts. My son- in-law is a mechanic but has NO y-block experience. It already has some of John mummerts parts installed, pistons, cam, timing set and a few more. I will need to get some more info about it before I can ask any "intelligent" questions. I am hoping to find someone reasonably close to mentor my son and I during this build. I hope that between that and folks like you, Ted, and others on this site that my engine will be something to be proud of. I've had my stock 55CV in 6 shows so far this year with (at this time) 3 more lined up. From what I've seen, Y block power is rare in these parts and I am truly looking forward to showing the people something unusual, beautiful and powerful. Man, I know I'm long winded but every time I log on, I just get more enthusiastic about my project. Anyway, I say Nice Job Charlie!! And thanks for the vicarious insperation. Rowen

Rowen
55CV
Woodland, Ca

Charlie,

I really appreciate the detailed info.

Very nice work. Looks really good.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

After driving it a couple days this week, it does seem like it might be a little more zippy at lower revs, but nothing like the improvement at high revs.  It sounds different, too.  Good different.

For those who are curious, I made the shims out of a strip of 3/4" wide 6061 aluminum.  I marked the center of the strip and allowed 1/8" between to cut them apart.  A spare rocker stand and transfer punches were used to mark the holes.



I then drilled them.



Cut them out and shaped them.  Some came out a bit wonky but it's not really a problem - I just make sure a good one is in the oil hole position.



New Smith Brothers pushrods next to an old one for comparison.  Because the rocker rotates toward the valve as the stands are raised, pushrods longer than the change in shim height are required.  These are 8.362", so a 1/4" change in stand height required about a 3/8" change in pushrod length in this case.



Everything in position.



and installed



I went with valve covers from spotlitekustomaccessories on eBay.  The taller covers required that I move the coil which required that I change the fuel line routing - both things that I had been wanting to do but it wasn't really that important.  With the old coil position, I could not remove the valve cover with the coil in place.  I can remove the valve cover in the new position and a raised base 14" air cleaner should fit, if needed.  The fuel lines just look less cluttered and more aesthetically pleasing now, I think.

Before



After.  Breathers will be used until I've had a chance to do some spacer testing.  Once I choose a spacer, PCV will be refitted.  The rubber fuel hose will be replaced with a hard line once I choose a spacer.



A bracket to ensure that the regulator stays in place, even though it is mounted right on top of hard fuel fittings.  Left plenty of room for a wrench to get at the fittings.





Lawrenceville, GA

I still have to replace the king pins.  Other than that, it's looking good for Columbus.  I plan to start on the king pins this week.  That should give me some time to put a few miles on everything and make sure it is good to go.

Ted actually has a tool for measuring travel across the tip.  Aside from that, blue the tip of the valve, run the valve through a few cycles and I measured the pattern with a caliper.  You can see the change if it is really bad but as you get closer to ideal, it becomes more difficult to tell by eye.



Lawrenceville, GA

Explain how to test the travel across the valve. Blue the rocker?

Frank/Rebop

Bristol, In ( by Elkhart) 

Sounds good Charlie. Is the truck fixed to make the trip to Columbus?

  Dennis in Lititz PA

I got it done.  Since I had the carb loose, I also increased the secondary jets from 65 to 67.  I went up quite a lot on the primaries but had not yet touched the secondaries.  Rob's experience with his carb give me a great ballpark for where the 570 should be for an engine like mine.  I figured it also couldn't hurt since I might have a bit more flow now.

It was about 11:00 pm so I went on a very short drive just to get it warmed up and see if I forgot to tighten any bolts.  It pulls freaking hard from about 4000 rpm now.  It scared me.  I didn't loose traction or anything it was just surprising - not like I'm used to.  I looked at my tach and it was at 6 grand in no time.  Can't say if it is because of the optimized geometry or jetting change, but something seems to have worked real well.  I might start thinking more seriously about a rev limiter.  Below 4000 feels about the same as did before.

Tomorrow I go for the official test drive, to a local cruise-in.



Lawrenceville, GA

You said one time, if you're going to err, err on being up to .050" higher than ideal, or something like that.

I got back out there and did it the low tech way,  bluing the tip and measuring the scrub pattern and the results indicate that 1/4" should be about right.

Shim, Scrub
0", .110"
.093", .085"
.197", .075"
.250, .065"
.297", .070"
.343", .075"

If the mid-lift method is accurate, and this is not a fluke, that makes for a quick way to get into the ballpark.  My previous finding with the Doves support it.  I determined that .150" of shim was best for those.  The Harland sharp rockers have a larger diameter roller, so everything else being equal, they should need shims which are taller by an amount equal to the difference in the radii of the rollers.



Lawrenceville, GA

Charlie.  I have to think that your dial indicator setup isn’t consistent when looking for maximum lift.  My own method of choice when checking valve train geometry is measuring the sweep across the valve stem tip and targeting for the minimum sweep to obtain perfect optimum geometry.  I have found though that by biasing the rockers at a point above where ideal geometry occurs, there is typically a power increase and that comes from the valve lift occurring at a faster movement of the rocker when it’s higher.  There are tradeoffs with that though.

Lorena, Texas (South of Waco)