rocker arm shaft assembly

[davidmij]

I'm replacing my heads with an Edelbrock set, but I'm keeping my rocker assembly. (for now)

Per the Edelbrock instructions; "The intake valve has been moved away from the bore centerline compared to a 390/428 head. The intake rocker arm may need to be shimmed over .060". A valve spring shim of the proper diameter may be used."

I checked it with my feeler gauge and sure enough, it was off by right at .060". I bought the shims and tried taking the rockers apart. According to my T-bird shop manual the rocker parts should all just slide off once the cotter pin is removed. However the towers are pretty darn tight. Is it OK just to twist and turn them off or is there a better way? I hate to score up the rocker shaft.

thx, Dave J

[simplyconnected]

You should be able to run your OEM rocker shafts forever. Just make sure they are clean inside, the rocker arms have oil grooves inside and the shafts are not scored. Replacement rocker arms are available and inexpensive if you need any.

Rocker shafts are so HARD they cannot be drilled. Yes, the stands are tight but they are aluminum. Keep knocking them with a small hammer while the shaft is on a solid surface. They will move and there is no danger of peening the end of the shaft (mushrooming). I use a bit of sand paper on the shaft to get any varnish off before knocking the stands off.

CLICK HERE for my ROCKER ARM SHAFTS REBUILD site

BTW, Edelbrock says their aluminum heads will only fit bored 390's and 427 because they moved the valves in order to use larger diameter valves. Edelbrock valves hit the cylinder bores on a 352 so their heads will not work on those bores.

- Dave

[davidmij]

Thanks Dave!
Mine is a 390 bored .030 over so I'm good to go. I double checked piston to valve clearance too.

They are super clean as it was all rebuilt recently. Have no varnish, and excellent oil flow everywhere on the shafts. I also understand that they have to be reassembled with the oil holes downward for proper oiling of the rockers.

Some people said that they will work OK with the rockers not exactly centered, but I don't like the way it looks - looks like they will wear unevenly too.

Dave J

[simplyconnected]

The bottom holes in both your shafts should look like this:
RockerShaftOiling.jpg

These relief 'slots' were ground into the shafts to accommodate any rocker arm deviation from the center position on the valves.

If you clicked on my site in picture #3, I explained about OEM shafts having a notch at 5:00 O'clock position (next to the cotter pin bottom) and that if you don't assemble the arms and stands correctly, the oil holes will be blocked. Yes, the oil holes should be on the bottom of both shafts. Also check the shaft hole in your rocker arms. Mine had a groove that was washed out, blocking oil flow. - Dave

[davidmij]

My originals looked like that Dave, but the ones I have are a little different, they're from a 1967 390 car though. Here's what they looked like. The were super oily and super clean, I'll try to catch up with my pictures but these are some that I found online that show what mine look like.

I got the stands off quite easily by tapping it lightly with a plastic mallet. Hopefully I can get the intake back on the car and install everything this weekend.

thx, Dave

[simplyconnected]

Jonsey, what procedure did you use to measure valve clearance? This is important because I would hate to see these new heads destroyed. Did you advance/retard your cam timing?

Yes, these shafts appear to be aftermarket, which is ok. Many name brand companies make them for millions of Ford engines. The same shafts were used on all Ford, Mercury and truck hydraulic lifter FE engines from 1958-1976.

OEM shafts have the notch. Aftermarket shafts do not, so pay close attention during assembly.

For intake manifold assembly; countless engine builders have a devil of a time with intake gasket leaks. I use hardened washers under the bolt heads so the manifold can slide down more easily. After letting it sit, some of the bolts will need to be re-torqued because they loosen as the intake seats. I do not use the gaskets supplied for the front and rear block areas. They do a good job of preventing the intake from descending all the way down or in other words, those gaskets hold the intake manifold up. I build the front and rear areas up with Permatex Black, all by itself. You can do this in a couple layers if you like, just make sure the surfaces are 'lacquer thinner' clean. I also use my finger to 'work' the sealant in before laying a heavy bead in.

Another 'trick' I use is to leave the head bolts 'snug' until the intake is half way seated, just to ensure everything is square, then I torque the head bolts, then the intake bolts. A few thousandths is not a lot but it makes a difference because all the parts move around. Finally, there should be no water leaks, no vacuum leaks and no oil leaks. - Dave

[davidmij]

Weeeell,,,,,,,I had a friend help me. We did a mock up using some plumbers putty and put the heads on with the rockers etc. and hand turned it twice around. Didn't use the head gaskets so I added .038 to what I had. (That's what Edelbrock states their compressed gasket thickness to be.)

I used a thin metal ruler and it was just over 1/16 of an inch. So with the .038 it should be somewhere just over .100

My friend felt pretty comfortable that we were OK.

What do you think Dave? I know it's not very technical, but I think we're OK.

Dave J

[Yadkin]

I used permatex grey not black for the intake manifold front and rear seals. Build up ghd thickness in two layers. After assembly caulk in more from the outside.

[simplyconnected]

...What do you think Dave? I know it's not very technical, but I think we're OK...

A few thousandths isn't going to make much difference. We do things differently.

I install the heads and torque them. I leave all the plugs out and all the pushrods out except for one cylinder. I pressurize that cylinder and remove the springs. This picture was taken after I was finished but notice, I have an air hose fitting in #1 spark plug hole:


I remove both springs from #1 cylinder, and install both pushrods and tighten the rocker shaft.

There is a 'stack' going on, here. Everything in the valve train between the cam and the piston affect your measurement:
Block deck height (after it's shaved),
Head thickness (after it's shaved),
head gasket thickness,
Lifter height,
Pushrod length,
The oil baffle thickness under your rocker shaft supports,
the shaft support height,
the rocker arm ratio, and finally,
Piston depth (yes, aftermarket pistons have different heights than OEM pistons.)

With all these variables, calculating valve-to-piston clearance is impossible. At the factory, all these dimensions are the same (within tolerance) from engine to engine.

Using valves with no springs on one cylinder, two pushrods and everything else in place, bolted down, I rotate the crank s-l-o-w-l-y. I wrap a small wire around the keeper groves to prevent from dropping a valve. I hold on to the stem and gently oscillate it up and down to feel the piston. At the closest point, I measure between the valve top and the rocker arm tip with a feeler gauge. There is more to this than just that.

This job is much easier if you have solid lifters. Hydraulic lifters can give false readings if you don't have a good feel and an understanding of what's happening at the lifter. I want a measurement in a 'worst case scenario', like when the lifter is pumped up all the way, meaning the plunger is right at the circlip. Most lifters operate about twenty-five thousandths below this lifter preload but I want NO mistakes. It's just a measurement, but it's only taken once and it better be right.

I gingerly let the pushrod down onto the lifter and gently bounce it up and down to get a feel for when the metals meet and when the plunger starts to descend in a 'dry' lifter.

In my case, I do not use adjustable pushrods but that would be a very easy way to compensate for slight variation in a 'stock' build. Instead, I take my measurement and have pushrods made to order.

The last cam I installed was a hydraulic roller with Morel hyd. lifters that over an inch taller because they have a roller at the bottom and links (or dog bones) on top, keeping the roller square to the lobe. That means my original pushrods are over an inch too long. Even the finest adjustable pushrods (or adj. rocker arms) cannot be shortened an inch.

So, what do you do if valve clearance is too tight? They make a cutter that fits into the 3/8" valve guide. It simply cuts the top of the aluminum piston, giving as much valve clearance as you need. If you're a tool maker, an old valve set works with a small ball of steel welded to the outer edge of the valve face, and ground to a cutting edge. The new 'cutting valves' are inserted in the valve guides and turned with a 3/8" drill motor. Adjust the depth by entering the drill motor with a feeler gauge, then tighten the chuck and remove the gauge. - Dave

[davidmij]

Yeah, when I posted that I could just picture you shaking your head Dave. LOL
The part that concerned me the most is the hydraulic lifters. The rest should be fairly solid. I was told even the piston rods (if aluminum) can stretch or expand at high RPMS and temps. Mine aren't aluminum.

The first time I did the intake manifold I used studs to place it, and the distributor to align it. I didn't use end gaskets, just blue RTV, and I did like Steve said and caulked in more after it was bolted. The intake gaskets are Edelbrock. I'm using their installation instructions and will use the stuff they sold me, it's like a contact cement but I can't remember the name.

It all turned out well that time, hopefully this aluminum intake will be a lot easier.

DAve J

[simplyconnected]

Dave, don't worry about stretch because everything stretches, together.

I would be concerned about using clay or putty. Engine building must not involve 'slop'. You need exact, honest measurements that you can depend on.

Measure using the components your engine really has. Do not assume things you read are correct, either. I have found Ford manuals to be wrong, even on torque spec's.

The reason I built the 390 was not because I needed one but because documentation for building an FE is sp**** at best. I have documented starter motors, generators, and just about every engine part, to share this info-pictorial for free. - Dave

[davidmij]

Well it's all back together and running. I ran it without the valve covers to see that it was oiling nicely everywhere. Boy does that header paint smoke at first. My wrapped headers were getting a little tattered so I snugged them up and then sprayed a complete can of header (clear) paint on them to act as a hardener - soaked them thoroughly.
Anyway, I just put the valve covers back on so I need to let it set until tomorrow. I'll take it for a spin then.

Thx for all the help. They'll be no hotrodding until I get a rev limiter!

Dave J

[Yadkin]

Keep an eye on that rtv blue. I think it's too soft for that application. My engine builder recommended grey because its much harder. Black is between blue and grey with respect to hardness.

I'm curious as to your experience with running with the valve covers off. FEs tend to flood the valve train with oil and I can only imagine it going everywhere.

I've gone to lengths to reduce the flow to the heads and still got leaks on the valve covers with cork gaskets. I replaced with Edelebrock composite gaskets, spreader bars on the lower bolts and finally got them sealed.

[simplyconnected]

...I've gone to lengths to reduce the flow to the heads and still got leaks on the valve covers with cork gaskets. I replaced with Edelebrock composite gaskets, spreader bars on the lower bolts and finally got them sealed.

How are you reducing flow to the heads?
Sealing valve covers has never posed a problem for me. I'm using cork right now from Fel-Pro.
Make sure your surfaces are oil-free, like it says in the book. Then, use your finger to 'work in' a very thin coat of 'black' RTV to each surface. (If any oil exists, RTV won't stick.) I also coat the cork gasket, then I let it skin over for ten minutes before assembly. I do the oil pan the same way. Works every time. - Dave

[Yadkin]

I inserted 0.075" orifice restrictors in the oil galleries at each head. So the block gets full pressure and the heads get a reduced pressure.

"Gluing" the cork with rtv works also. But for these covers I prefer to not glue to make inspection and adjustment, and of course reuse of the gaskets, a lot easier.

The OE sheet metal covers can't be torqued to OE spec without distorting them. I straighten the covers on the bench over a wood block with a soft hammer. The torque to the spreader bars fully deflecting. Its probably less than half of the OE spec. Edelbrock designed these composite gaskets to seal with reduced pressure.