Thread: Rebuilding The 331

Tweet

Newbie question -
When dissassembling the rocker assemblies for cleaning, must all of the rockers and springs stay in the exact same order as when they came off the shafts, or can they be mixed up when cleaning?

i would assume a 331 hemi with bushing style rocker arm assemblys. i think i would keep them in order stamp them or use one of those little etch writers to place them in order i dont know if the seperator springs really matter . i dont know if it makes a difference but just to be safe i would.
maybe one of the hard core hemi guys might chime in and give you a definite answer

It's been 30 years since I built a hemi, but I would advise you the same way as canadianal. The springs aren't critical but the rockers will have taken a "set" in their respective positions on the shafts and I wouldn't mix them up. The last hemi I built, I talked to Racer Brown on the phone (yes, I'm that old) and he advised tossing the springs and making steel tubes to fit the shafts and replace the springs, leaving about 0.005" play sliding back and forth on the shaft. This was to positively locate the rockers and prevent the rocker pad from falling off the valve stem which they can do with the springs.

It depends on how extensive your planning on going in your project. If your are doing a rebuild and while the valves are being done they also reface the rocker arm tips it shouldn't matter if they are mixed up.

If your just taking it apart to clean and inspect, the rockers should be kept with the valves they have run on and set up unique wear patterns with. The springs really don't care where they go as their main function is just to keep side pressure on the rocker to help it aligned with the valve tip.

The real big thing on these (and any other old rocker shaft engine) is to make sure the INSIDE of the rocker shaft is completly cleaned, which entails the removal of the end plugs.

Alright, thanks Mike. This will defenitely be getting new valves, and I will be sure to then clean inside the shafts. On the note of head work, does anyone have pictures of a safely ported/polished 331 head?

I seem to remember reading that the rocker pedestals are not all the same, only #2 and #4 are drilled for oiling. If they're mixed up then no oil to the shafts. It will assemble OK, just no oil flow.

We searched around and are going with small block Ford valves for our 331 rebuild. Stainless steel Manley Race-Flows for half the price of the stockers, using the 1.55" Exhausts and 1.85" Intakes (both are 0.05" larger dia than stock). I'd go with the more standard 1.60" and 1.94" diameters, but I just can't find any data on the seat/casting thicknesses for the early Hemi.

Since we're replacing the guides we're just using 0.3415" dia instead of 0.375". The Ford lengths are just a little bit longer, the machine shop trimmed them down 0.015" on the Intake and 0.060" on the exhaust. Going to Ford parts for the rest of the valve components as well.

Cheers, Mark

Boris,

Stumbled across this older article on alternate (or less costly) parts to obsolete early Hemi parts.

http://www.rodandcustommagazine.com/tipstricks/74878/

Regards, Mark

A good article Mark. As you noted however it is pretty dated.

Even 7-8 years ago early Hemi parts were just about non-existent. At that time what little bit that was available was drying up pretty rapidly and prices were through the roof.

It's a pretty disgusting feeling to have a nice standard crank that will clean up with polishing or just a .010 cut and only be able to get.030 under bearings for it (been there done that). Fortunately with the popularity of the early Hemis growing the market place now has a fair amount of alternatives available.

As an example Federal/Clevite bearing for a 331-354 run about $350 for the mains and $200 for the rods (and your limited to standard or .010). At that price, paying for the machine work to rework the bearing caps may make sense, but keep in mind you will have to add that cost to the price of being able to use the cheaper bearings.

On the other hand on the other hand you can buy the King bearings (which from what I've read have just as high quality and longevity) for $110 for the mains and $90 for the rods in sizes from standard .010, .020 and .030. Without having to add in the cost of extra machining the King bearings are a pretty good deal.

Additionally cams, lifters and even high performance oil pumps are now readily available without having to go to the trouble of having to do a bunch of custom 1 off fabrication.

That is a wonderful bit of information Mark. If you have time, could you please post what other non-obsolete parts you are using on your Hemi? I am trying to put together a list of alternate parts that could be used for a rebuild, and it seems as though information is all scattered about different individuals. Thanks for all your help.

Hi Mike,

The bearings are my next big concern. I had planned on using the King bearings from PAW, but recent threads on two other forums have given me doubts. The racers had praise for the product, the cruisers had complaints about longevity. I get nervous when I hear comments from a manufacturer about their proprietary "breakthrough" process, I trust the conventional babbit construction as used by CL/FM.

I'm on the fence on this one.

Thanks, Mark