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Working on a 1955 block with 1956 #10 heads. My block is decked slightly ~.010, but my heads will need be cut at least .020. I am NOT building a race motor, just a stock rebuild with performance upgrades like a different cam when/where appropriate with cost.
Question: Should I attempt to find custom length pushrods or adjustable rockers? I have the rocker shafts and rockers already cleaned and ready to go, so I am concerned with cost. I DO NOT have pushrods yet. Thanks in advance for any advise.
Last edited by madmax442.com; April 3rd, 2024 at 01:31 PM.
If you are using a non stock camshaft then you will probably have to do something. If your rockers are in good condition I would lean towards custom pushrods. They really are not that terribly expensive. You might even be able to find something in a stock dimension. Most performance pushrods are available in .050" length increments for about $130 for a complete set. I'm sure that is less than what a set of adjustable rockers will be.
If you end up needing a custom length I have been using Manton. Any of the cam companies will have pushrods in .050" increments. Comp Cams, Erson etc. But you need to get everything done and put together first and then check and measure.
Yes, I will use a pushrod measuring tool with a light test spring once I have the heads on. Do you recommend using the 4 outer pushrods with holes, or just stick with the standard no hole Olds 324 pushrods for all 16?
Oh, I thought you had built a 324 based upon your responses. Thanks.
Bill may not have built a 324, but he has built, probably thousand of engines. When you start decking and milling , ANY engine, you need to measure pushrod lenght. There are members here that have built 324s . they will be along soon and answer your question about the pushrod oil holes . Wishing you sucess in your build.
Bill may not have built a 324, but he has built, probably thousand of engines. When you start decking and milling , ANY engine, you need to measure pushrod lenght. There are members here that have built 324s . they will be along soon and answer your question about the pushrod oil holes . Wishing you sucess in your build.
Yes, I understand I need to measure, I get that. I have also built many engines, just not a 324, there are some issues with finding parts, non-adjustable valve train, the oiling system, etc. I was just curious on what folks are doing is all. I read many folks use the outer 4 pushrods for extra oiling, but not do all 16 as that would starve the bearings. All the oiling for a Gen 1 top end comes from the rocker shaft.
Yes, hopefully someone with chime in. If not, I will just call Tony. Thanks.
I read many folks use the outer 4 pushrods for extra oiling, but not do all 16 as that would starve the bearings.
I was just looking at the oiling system and I am not sure if that would really help anything at all.
First of all are the lifters designed to meter oil up into the push rods ? Or do you use the later model lifters ? I don't know if they will even fit ?
And then all I can see it doing is maybe filling up the rocker shaft a little faster at startup ? Once the shaft is filled it really wont do much good that I can see. I don't buy the starving the bearings thing. You can only pump so much oil through the clearances in the rocker assembly. It does not matter if it comes from the block or the push rods you can still only pump so much oil through.
Ill be interested to see what you find out. I am always up for learning something new
Yes, I will use a pushrod measuring tool with a light test spring once I have the heads on. Do you recommend using the 4 outer pushrods with holes, or just stick with the standard no hole Olds 324 pushrods for all 16?
The first gen Olds didn't oil the rockers thru the push rods.
The rocker shafts were supplied with metered oil that was delivered by passageways in the block and heads.
None of the pushrods should have holes, They don't deliver oil.
Once you get the heads on, try assembling the rocker assembly with the original push rods.
Turn the engine so that the # 1 cylinder is in the firing position.
Grab the pushrods between your thumb and forefinger and try to move it up and down.
If you cannot move it up and down. Then it may be long enough.
If you can twirl it between your finger and your thumb it may be OK.
Turn the crank 1/8 of a turn and try the next cylinder in the firing order.
The first gen Olds didn't oil the rockers thru the push rods.
The rocker shafts were supplied with metered oil that was delivered by passageways in the block and heads.
None of the pushrods should have holes, They don't deliver oil.
Once you get the heads on, try assembling the rocker assembly with the original push rods.
Turn the engine so that the # 1 cylinder is in the firing position.
Grab the pushrods between your thumb and forefinger and try to move it up and down.
If you cannot move it up and down. Then it may be long enough.
If you can twirl it between your finger and your thumb it may be OK.
Turn the crank 1/8 of a turn and try the next cylinder in the firing order.
Yes, aware the rocker shaft supplies oil not the pushrods, just read somewhere folks use the outer 4 for extra oiling. So for the purposes of this discussion, I am sorry I brought it up. I am simply wondering where to get custom length pushrods for a 324. They will certainly be too long once I mill the crap out of my heads I picked up as the deck surface is pretty pitted (earlier post). The block will need to be desked as well. Unless I can find some thicker head gasket (don't want to), then the pushrods will be probably .040 to .050 too long. What do folks do? Live with the extra preload or where do you find the pushrods?
Yes, aware the rocker shaft supplies oil not the pushrods, just read somewhere folks use the outer 4 for extra oiling. So for the purposes of this discussion, I am sorry I brought it up. I am simply wondering where to get custom length pushrods for a 324. They will certainly be too long once I mill the crap out of my heads I picked up as the deck surface is pretty pitted (earlier post). The block will need to be desked as well. Unless I can find some thicker head gasket (don't want to), then the pushrods will be probably .040 to .050 too long. What do folks do? Live with the extra preload or where do you find the pushrods?
My point was that you may not need custom push rods.
The lifters have a .050 range of motion.
Ok, great point! So, that the preload spec, very helpful!
Double check that preload spec on the lifters you are using.
Most are 40 to 50 thousands that's why I threw that figure out there.
Rocker arm and shaft wear actually work in your favor.
You may be OK with stock pushrods.
April 3rd, 2024, 01:25 PM
