I've got the machinists baffled

[jonmark1985]

Usually I just go a quarter turn on the rocker arms. Also I put the quarter turn on after I fell just a little pressure on the pushrod. You may try that, but I'm not 100% that it will work.

Are you running self aligning rockers or guide plates. Or do you your heads have a tight casting around the pushrods to keep them straight?

[bkf77]

I am using guide plates. I pulled the rockers off to check the position of the roller to the valve stem and at the same time I pulled the pushrods. I didn't see any shiny spots from the guide plates. The geometry of the rockers to the valves look good. From what I can tell, my pushrod length should be right on the money.

[jonmark1985]

Well with guideplates it should be fine.

How big of a cam are you running and have the heads been cleared for this amount of lift. Maybe the springs are binding or breaking. I'm not really sure of what is bothering the engine and making this noise.

[bkf77]

It has a Motorsport E303 cam. The lift is .498 int and exh. The heads have double valve springs rated to .600 lift. The machine shop disassembled the heads when I got them and checked them for use with my cam. I was told there would be no problem with the springs or the valve clearance.

[jonmark1985]

Ok, I was worried that you may have spring bind, but sounds like your fine.

How many pounds of open pressure are the springs at?

[bkf77]

I don't know what the open pressure is and don't have a tool to measure. I pasted the specs I have
available on the heads.
Procomp Motorsport's FORD 210cc - 302, 351W, 5.0, MUSTANG ,
Hy-Flow Aluminum Cylinder Heads-(Pair) ASSEMBLED with,
Intake Valves 2.055" + .100 (11/32" stem), Exhaust Valves 1.600" + .100 (11/32" stem)
4140 Steel Retainers 1.400 x 1.060 x .0690 , Valve Locks + .145
Dual Springs, Installed Spring Height-Intake 1.790/Exhaust 1.798
Spring: Intake, 130lbs @ 1.820 Exhaust, 145lbs @ 1.760, .600 Max Lift
Coil binds @ 700lbs.
Installed spring height should be checked with your camshaft specs of your application.
Other Information on these Heads;
356-A Aluminum Alloy Heat treated to T-6 specifications
Hardened Seats, 210cc intake runners, 60cc Combustion Chamber
20 degree Valve Angles....Will fit 302 or 351W Blocks
Square Raised Port Exhaust 1.360 x 1.410
Intake Ports Raised Roof, Std. Floor, 1.300 x 2.150,
Machined for Large Diameter Valve Springs, Pocket Cut for 1.650", 3 Angle Cut Stellite Valve Seat, Bronze Valve Guides
Machined for 1/2" head bolts or studs,
Takes Felpro 1250 to 1262 Gasket Set, Plug-AGF-22
Multi-Angle Seat Design & Features high flowing ports.
Fits Victor Junior , Edelbrock RPM, Professional Product Hurricane Intake Manifolds
Designed for Stud Mount or Shaft Mount Rockers only...not Pedestal!

[jonmark1985]

That shows the springs having an open pressure at 1.820/1.760. But your springs were installed at a height of 1.79-1.798. So your probably not running the 130/145 open pressure, but you're close enough I don't see it being an issue.

Could you see about finding the coil bind height of the springs in inches rather than lbs? I think it will probably be around 1.180".

[bkf77]

How would I find the bind height in inches?

[jonmark1985]

Do you know the manufacturer and part number of the springs? Contact them or check in an online catalog.

The real world way would be to put the spring and spring pressure gauge in a bench vise. Tighten the vice until the spring pressure gains crazy fast, thats when the spring starts binding. Then measure the height of the spring. If you have or had the heads "blueprinted" this will already be measured and noted.

[bkf77]

I don't know the spring manufacturer or the part number. They came on the heads. I tried to call the place where I got the heads but have not had an answer from them. Are you thinking that the springs maybe the cause of the noise? I still have the original cast heads for it. I have the motorsport springs on those. They were bought to match up with the camshaft.