Push rod

[hmgm123]

Are the intake and exhaust push rods different in length? On a 0540 Lycoming?

 

[grant]

On a new engine they should be the same length. After cylinder repairs they may or may not be the same.

Grant

 

[Mike Thurman]

On all Lycomings with exception of the up-stack the push rods are within the same length ranges and interchangable from intake to exhaust.. You have I think 4 different lengths (identified by part number or lines) for setting rocker clearance on either the intake or exhaust. But the pushrods and pushrod housings are interchangeable. On the up-stack either the intake or exhaust pushrod and pushrod housing is about 3/8-1/2 of an inch longer. You then have and intake specific pushrod avaliable in 4 lengths and an exhaust specific pushrod avaliable in 4 different lengths. Now the 0-320 motors have a shorter cylinder so they also have a certin lenght pushrod avaliable in different lengths for adjustment.. On a 0-360 or 0-540, straight valve motors take a shorter set of pushrods than an Angle Valve motor takes. Angle Valve cylinders are taller. Every time you cut a valve or valve seat you need a shorter pushrod.

 

[hmgm123]

Thanks Mike, I have an upstack supercharge 0540. Also what is the clearance suppose to be on the rocker and the spring? Also are the intakes runners tubes and the intake below the carb are suppose be smooth or coarse on the inside or does it matter? Also I am having problems with the intake gasket on the cylinder blowing out is ok to double up on the gasket or what do you suggest?

Thanks
Geoff

 

[Mike Thurman]

I do not have a book for that motor, But every hydraulic lifter motor that Lycoming made I know of is .028 - .078. with the lifters blead down. You should have the standard Lycoming 2 bolt intake gasket. You need to take the intake pipes off and surface the intake pipes and collars. If you have chrome intake pipes they will not be smooth. Lay the intake collar on a smooth surface,or hold two of them together bottom to bottom. You will have a big gap. Whenever I bolt an intake pipe on I hold the pipe on my belt sander and I have a tool I made to beat the collar flat. After I beat the collar flat then I surface them. They are usually bent so bad you cannot sand that much metal away. The collar has a groove cut in it that the intake pipe sits in. They make a collar with a deep groove and a shallow groove. Yours probably takes a deep groove. As far as the intake parts. All of the motors are rough castings from the factory. It seem to work for them. Some say that the roughness atomizes the air and fuel more than a smooth surface. I dont know for sure.

 

[hmgm123]

Thanks Mike, believe or not I already see that to be a problem with my intake not being flat to the collar. I went ahead and put some gasket maker that resist fuel on with a new gasket. You think that will be Ok for now.

Geoff

Happy Holidays

 

[Mike Thurman]

Fix it now or fix it later, If you have to pull the pipes to put the gasket maker on and put new gaskets, half the work is done. If you cant straighten them yourself send them to me and I will do it free of charge and send them back to you. I have to look but I think I remember you sent me a phone number. I will give you a call.

 

[Moritz]

THE PUSH RODS ARE DIFFERENT LENGHT. TO GET THE CORRECT LENGHT YOU MUST REMOVE THE HYDRAULIC LIFTER & COLAPS IT BY INSERTING A SMALL ROD INTO THE LIFTER TO PUSH THE BALL OF THE SEAT WHILE PUSHING THE OIL OUT OF THE LIFTER. THEN REINSTALL LIFTER PUSH ROD & ROCKER ARM &CHECK CLEARANCE BETEEN VALVE & ROCKER ARM. .025 TO I THINK .085". IF IT DOES NOT FALL IN THIS RANGE GET SHORTER OR LONGER LIFTER.