Push rods

Brian Vickers · #1 10-01-2008, 12:33 PM

I am assembling my 100% overhauled parts (stock Lycoming O320D1A). On three cylinders both valve rocker clearances exceed (wider) than .080, as per the spec. in my overhaul manual. To put the clearance into the .028 - .080 range I need longer push rods. Is there a business that exchanges the rods? Maybe a good source of used parts? Brand new they are $22.74 each, plus shipping. Just trying to find out what those that have gone before me have done. Is this a part that is advisable to purchase new? Any counseling on this would be appreciated.

Sincerely,

Mark Burns · #2 10-01-2008, 12:49 PM

Quote:

Originally Posted by Brian Vickers

I am assembling my 100% overhauled parts (stock Lycoming O320D1A). On three cylinders both valve rocker clearances exceed (wider) than .080, as per the spec. in my overhaul manual. To put the clearance into the .028 - .080 range I need longer push rods. Is there a business that exchanges the rods? Maybe a good source of used parts? Brand new they are $22.74 each, plus shipping. Just trying to find out what those that have gone before me have done. Is this a part that is advisable to purchase new? Any counseling on this would be appreciated.

Sincerely,

Hi Brian,
Do all your pushrods have the same part #?
If not, you might be able to swap them around to different positions.
This is what I did to get my valve clearances in spec. I may have swapped around some rocker arms also, can't remember.

I remember being in your situation, thinking I needed a few pushrods.
But after changing positions on a few all was good.

Mark

Mel · #3 10-01-2008, 12:55 PM

Most any shop that works on Lycomings will swap with you.
In extreme cases it's also possible to make your own. They are just 4130 tubing with pressed in ends.

Brian Vickers · #4 10-01-2008, 01:04 PM

Thanks Mel and Mark,
Regarding part numbers; I am aware of the part numbers and corresponding lengths. Lycoming Service Instruction 1060J clearly explains this, and the numbers on my rods are ledgible. I have spent the better part of two hours swapping around the rods. Mel has a good suggestion about overhaul shops. There is a large FBO maintenance shop at my home base airport. I will call them to see if they have what I need. Very good suggestion.

Brian Vickers · #5 10-01-2008, 01:16 PM

Mel,

Great suggestion. The maintenance shop at my airport has all five of the sizes and offered to exchange with me, assuming my parts are servicable.

Thanks a million!!

rocketbob · #6 10-01-2008, 02:50 PM

Quote:

Originally Posted by Mel

Most any shop that works on Lycomings will swap with you.
In extreme cases it's also possible to make your own. They are just 4130 tubing with pressed in ends.

Next time you see one, look closely...they're spot-welded.

Don Jones · #7 10-01-2008, 02:58 PM

Brian,
What #'s do you need. I have 8 left over from my 320 OH. There are 3 different part numbers among them. They are at the hangar so I can't tell you what they are right now, but I will be out there tomorrow.
I will swap you if you can use any of them. I ended up buying all new because of the same problem you are having, so mine are probably too short as well, but it never hurts to look.

Quote:

Originally Posted by Brian Vickers

I am assembling my 100% overhauled parts (stock Lycoming O320D1A). On three cylinders both valve rocker clearances exceed (wider) than .080, as per the spec. in my overhaul manual. To put the clearance into the .028 - .080 range I need longer push rods. Is there a business that exchanges the rods? Maybe a good source of used parts? Brand new they are $22.74 each, plus shipping. Just trying to find out what those that have gone before me have done. Is this a part that is advisable to purchase new? Any counseling on this would be appreciated.

Sincerely,

Brian Vickers · #8 10-01-2008, 07:06 PM

Don,
Thanks for your kind offer. I need six #73415. This length will put all three cylinders right in the specified .028? - .080? zone with room for wear. My local FBO has two but they really don't want to trade for my shorter #73413 rods because they already have over a dozen. I am going to order new ones and get on with the show.

Thanks again

Mel · #9 10-01-2008, 09:06 PM

Brian,
Remember when ordering pushrods, the rocker arms are not 1:1. If I remember correctly the ratio is about 1.5:1.
In other words, .020" at the valve end does not equal .020" at the pushrod end.

Brian Vickers · #10 10-01-2008, 09:26 PM

Mel,
Thanks for the heads up. I have two different rod lengths. I will switch back and forth and get a measurement from them. Thanks very much for the tip.