disappointing cam specs

cuzncletus

cuzncletus

Senior Member
I have a 46 59AB that was rebuilt .040 over back in the 70's and not run much since. When I did run it, it ran fine; quiet, smooth, no smoke. I pulled the heads to inspect it and found little to no ridge in the bores and no cracks around the exhaust valves. It also was rebuilt with Johnson adjustable style lifters and I thought a mild cam. However, when I put a dial indicator on several of the valves the total lift came out to .290 +/- .02. From what I've researched this is less than stock if I'm reading the lift right.

If the cam is worn it's worn pretty uniformly, something I've never seen before in worn out cams and brother I've had my share. That it ran quiet would seem to indicate that the valves aren't too loose. My dial indicator is a cheap Harbor Freight but seems right when I've miked pieces to compare it with. Am I looking at this correctly?
 
Higher lift is not what makes it a performance cam. The shape of the lobe has much to do with it.
Seem to recall looking at a chart of performance cams and seeing at least one with a lift of .295.
 
I understand that but I have no way to degree this cam. That's what's making me look at lift alone. I don't anticipate doing enough flatheads to make a degree wheel worth the investment.
 
There are degree wheels on line that you can print out and glue to a piece of cardboard for a one time use.
If the thing ran well before, put it together and use it until it has to come apart.
 
If I read your post correctly, you are measuring lift at the valve. The valve clearance would add another .012-.016" to your reading for gross lift. I don't have any 59 style cams to measure, but I have a couple of 8BA cams with total lift in the .300" range.
 
I have an old performance cam with .300 lift. It has a very broad nose. It is probably a regrind and that is all they could get.
 
I have measured 59A cams and lift is .300. So when you factor in the valve clearance, your cam is right on stock specs. That's not to say valve timing hasn't been changed.
 
All good info. Adding in the valve clearance would put it in spec for a stock cam. 51 Merc, I may shave the heads a bit then put it back together as it did run good and I don't think there's much chance of valve/head interference. "If it ain't broke, don't fix it." Almost.

The motor is going in a 29 A/V8 so even close to stock it should perform fine.
 
For typical road use the stock cam wins compared to a performance cam.

I was in the club hosting the Texas Tour a few years back. I volunteered to run last in a car full of tools in case anyone had troubles and needed help on the road. I was driving my / dad's stock 37 standard fordor sedan. That car has a bone stock 85 horse 21 stud motor in it. I did a full tune up on the car when we got it on the road including rebuilding the carburetor and distributor. It runs like a stock 85 horse motor should.

The second to last car on the tour was a 35 sedan set up for the Great American Race. They had an engine built by H&H with several upgrades, including cam. The folks in the 35 were taking performance measurements in their car in preparation for running in the rally. I had no trouble keeping up with them in the Texas hill country. The folks in the 35 were really impressed and though I had a hot engine in the 37. Nope, just a good running setup. You pay a big performance price in the normal driving range for a lumpy sounding idle.
 
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