question for engine builders on pushrod length.

[chimp koose]

Question for engine builders . How do you go about finding your proper pushrod length? I was wondering if I could use light weight springs and a solid lifter to get the length right instead of running a hydraulic lifter on a new as yet not broken in cam to avoid any wear . I have pretty heavy springs 460lb/in and do not want to wear a lobe . I could measure the solid lifter and the hydraulic to make up any difference in the math. Never done this with a hydraulic cam before , just rollers and solids . I am using 1.6 intake and 1.52 exhaust rockers . I would ask on speedtalk but it would end up as a 10 page post , don't need to start an argument.

[phat46]

Question for engine builders . How do you go about finding your proper pushrod length? I was wondering if I could use light weight springs and a solid lifter to get the length right instead of running a hydraulic lifter on a new as yet not broken in cam to avoid any wear . I have pretty heavy springs 460lb/in and do not want to wear a lobe . I could measure the solid lifter and the hydraulic to make up any difference in the math. Never done this with a hydraulic cam before , just rollers and solids . I am using 1.6 intake and 1.52 exhaust rockers . I would ask on speedtalk but it would end up as a 10 page post , don't need to start an argument.

I just went through this. I could not find a single solid lifter so I made my own. I used two bolts, I think 1/2", with a nut in between to hold them together and adjust the length. I found if I just knocked the corners off the nut and bolts they were a good fit in the lifter bore. Used a mic to set them to proper length. I ordered pushrods, the stock length was perfect, and the geometry looks perfect. The roller rockers made a witness mark right in the center of the valve stem.

[idrivejunk]

I must be lost  

Tack the plunger in an old hydraulic flat tappet. Or a new onesy from a parts store. Get an adjustable length-checking pushrod from a speed parts place if stock isn't perfect. I went through the dance too but with quick bleed down lifters, in which case the depth of the plunger in the lifter body can be visually confirmed with intake manifold off.

If any of that makes sense or is relevant, I may have read the question right. Thats all I got.

[chimp koose]

I have a box of new solid lifters to do the check . Was just checking to make sure you use a solid lifter to figure out the pushrod length as i didnt see how you would do it with a hydraulic. Ill put a ball bearing in the solid lifter pushrod cup and measure it and do the same with the hydraulic lifter to make sure they are the same length (overkill im sure )then be on my merry way. There are many theories about determining the proper pattern from going with a centered sweep to measuring max lift ( stock eliminator)to getting the rocker on valve centre at max lift( supposedly to reduce guide wear with big open spring pressures) . I am just going to center the sweep(as I always do). I will try to find the weakest springs in my stash to avoid scrubbing the lobes . I may have a few worn out stock ones . Thanks guys , I am probably over thinking again.

[chimp koose]

IDJ , you can make an adjustable pushrod by cutting one open and tapping both cut off ends . Dont remember the tap size but I do remember a stock sbc pushrod has the proper sized hole for a tap . Saves a few bucks!

[kb426]

Manley sold a plastic part that you slipped over the rocker arm stud and laid on the valve tip. Then you measured from the tool to the lifter for length. Is that not a decent way to do this? https://www.speedwaymotors.com/Manley-42132-Small-Block-Chevy-Pushrod-Length-Checker-7-16-Stud,28458.html

[enjenjo]

Manley sold a plastic part that you slipped over the rocker arm stud and laid on the valve tip. Then you measured from the tool to the lifter for length. Is that not a decent way to do this? https://www.speedwaymotors.com/Manley-42132-Small-Block-Chevy-Pushrod-Length-Checker-7-16-Stud,28458.html

That is what I always used. You still need an adjustable pushrod to double check the pattern on the valve tip, but usually you can get pretty close. I also use a light spring on the valves I am checking. Normally a damper is enough spring for pushrod checking.

[chimp koose]

I remember the manley tool but was it just for 1 rocker ratio? I have an adjustable pushrod and will do the rocker sweep. Getting pretty busy with body panels now and will likely get at the motor around easter.