I tried to ID this Cam when I was assembling my motor but got no info. Now that I have the engine running it seems to be more than stock. I can't get the idle down any lower than around 700 and vacuum is 15. Runs a little rough and acts like it wants to die.





Little history bought a 292 engine from a guy that claimed it ran (64 F100). Said he had rebuilt it and punched it .030 over. When I got it home there was almost tar in the oil pan so I took it apart. Boiled the block and honed the cylinders to get a cross thatch back on the walls. Micrometered the rods, and crank and installed std bearings. Had new cam bearings installed when I had the block boiled. I added high raito rocker arms to a set of ECZ-G heads with a mild port and hardened valve seats. Pressurized the rockers and added a new oil pump (M 45). Also deep sixed the two barrel and installed a stock "B" 4 barrel manifold. I started out with a Holley 390 CFM that I rebuilt a while back and had sitting on the shelf. When I couldn't get rid of the rough idle I installed a brand new 450 CFM Holley. Same results as with the 390.

I'd really like to find out about this cam to know what I should expect as well as valve lash required. I'd hate to bend a valve in this new engine.

 

Just guessing that may be a Melling HP cam. I'd give them a call and run the numbers by them.
517-787-8172

 

Will do. Thanks for the lead

 

This is what happens when you get old and the memory gets foggy but I seem to recall that YB-1 in the casting was from the blanks made by someone and they could have gone to any number of cam grinding companies??? So I'm not much help.

 

Talked to Melling's tech guys this morning. They said it wasn't theirs and they didn't know who's it might be.

 

Is the cam still in the engine or did you re-pull it? If it's out you can measure it yourself with a caliper. Measure the base circle (side to side), then take a measurement from the lobe lift (top to bottom) then subtract the base circle from the lobe lift to get your cams lift.

(there is also a way to measure it in the engine.)

 

It's in a running engine. It's a bit of a PITA to pull the cam if I don't have to. I've never tried pulling a Y Blocks cam in the vehicle. Those lifters need to be held clear of the cam lobes to get the came out. I read somewhere you can hold them up with cloths pins but I've never tried it. Even the valley pan is hard to get out with the heads on.

 

Probably the best way to get some idea is to measure it yourself.

The easiest way to get a rough idea is to measure the valve lift. You should be able to measure that well enough with a tape measure or ruler but a caliper or dial indicator is best. If it is much over .415" with 1.54 rockers or .390" with 1.43 rockers, then you have an aftermarket cam. Since duration tends to get larger as lift increases, you can form a rough idea about what kind of cam you have based on the lift.

If the cam turns out to be bigger, then your carburetors actually are probably too small, which means you will need to do some tweaking to get it to idle properly.

At 700+rpm with those carbs, you're probably out of the idle circuit and pulling fuel from the secondary circuit, which could be contributing to your problem. An easy way to check is to use a mirror to look down the throttle bores while it is idling. If this is happening, there is a screw on the baseplate of the carburetor which can be adjusted to crack open the secondaries slightly to provide additional idle airflow which allows you to close the primaries. If you crack open the secondaries too much, then they will be activated all the time so this is a careful balancing act and it might take a few tries to get it dialed in but it is what you have to do to use a carb which is not meant for the application.

 

Charlie,
Are you saying to measure the lift off the pushrods? If so, do I need to measure both an intake and an exhaust?
Got thinking and I tightened the valve lash to.017 instead of .019 so that may be contributing to my issue too. How will I know what valve lash I need?

 

No. I am saying to measure the valve. However, if you have the means to measure the pushrod, which will be the cam lift, do that as that will be more accurate. If you measure the actual lobe lift and that is much over .283",then you have an aftermarket cam.
The standard 1957 cam was .270 intake and .283 exhaust. Most other factory cams will be smaller than that and any aftermarket cam which is similarly sized will not cause your problem.

 

It could be from a major company like Comp etc or even a small company, more phone calls I guess. You won't know what the valve clearance is suppose to be until you identify who ground it. I'm using an Isky E4 and it sets at .015 which surprised me. I hope you can get it dialed in and don't have to pull it .

 

Without knowing what the lash should be, the stock spec is safe, so use the stock spec. If you do find out whose cam it is, use their recommendation.

 

I'll try to measure the lift tomorrow and report back. I will put the lash back to .019 too.

 

For what it's worth the CWC marking is also for the manufacture of the blanks. And it seams these were used by Comp Cams. It might be worth calling them.

 

Thanks Jim,
I'll contact COMP and see what they have to say.