drwet

To be honest, I'm not sure it really matters that much. When I did mine, I didn't get the impression the lifters were being compressed by the checking springs. They're really light. Therefore I added half the travel of the lifter to the length of my pushrod calculation, but its really very little. I think full travel of a lifter was about .060 - Howard's provides that information with the lifters. Had I not made that correction to the length calculation, my length would have been off by .03". Not enough to make a difference since you are going to select your pushrod length to the nearest .10" anyway.

I would not pump up your lifters, Howards specifically tells you in their instructions not to soak the lifters prior to installation. You are supposed to install the lifters, set the preload on them, and then use your drill attachment to lube the engine and fill the lifters.

drwet

I did not measure the width of the sweep. I was looking for the shortest sweep, and centered on the valve. I found both occurred at the same point.

NewbVetteGuy

Thanks for putting the #'s in context. That really helps.


Adam

jb78L-82

Not sure what to say!

I followed the procedure out lined prior without checker springs and removed a few rockers this past year to check the wear after 4 driving seasons on the valve tips on a few valves and the sweep was perfectly centered, even on both sides....I used 7.15 inch pushrods with my setup with AFR 180 heads, no decking of the block, and .015 head gasket:7.15 pushrod length + .05 howards preload estimate with oil in the roller lifters=7.2 total pushrod length with a pumped up roller lifter with oil.

rklessdriver

Use checker springs. The drill idea is going to be a mess and may or may not keep the lifter pumped up. Changing 2 valve springs is not a big or complex job.
Will

augiedoggy

I know this is an old thread but for the sake of folks who actually sometimes use the search function like myself for info rather than reinventing the wheel by asking the same questions over and over,
I wanted to chime in and second the same results with my setup as I tried measuring both without and later with a checker spring on the valve and jb78L-82 measurments and reasoning is sound once you take the .050 preload into account.. I went with the 7.144 length Howards rods myself mainly because they are only less than half the cost of 7.150 rods (This is on a 355 with dart iron eagle heads, harland sharp rockers and the same .015 shim gaskets. and a retro roller cam with enginetech retro lifters with are physically identical to the lifter Howards uses.

jb78L-82

Yes this procedure ^^^for measuring pushrod length for aftermarket cams and heads does work and verified now for 7 driving seasons in my L-82 355 roller cammed engine and it works, perfectly!

You need to know the wet (oil filled) pre load height of the roller lifter which reduces the actual required pushrod length ever so slightly (.05 inch in my case) as installed in the motor,filed with oil with the motor running.

Below is my post #37 from above and reiterates 2 points from few years ago:

Comp cams clearly states that you do NOT need checker springs using the proper pushrod length tool and, again, neither Howards or AFR, recommended checker springs when measuring for proper pushrod length with their components:

"From a forum member back in 2008:

"As near as I can tell it looks like the pushrod checker is made from a regular Comp Cams pushrod! :-) The feel and weight of it is the same and it even has the oil hole in it! Heavy springs...no problem! I used it with the Comp 921 springs without issue. My only caveat is that the tool should probably not be used when turning the engine over with the starter as it felt like the narrow area (where the two parts of the pushrod separate) catch on the head a bit while traveling up and down in the head."

Neither AFR (in my case) nor comp cams with either the steel checker tool or the checker tool made from an actual pushrod mentions using checker springs when measuring for the correct pushrod length.

From com comp cams website:

"Other companies offer their own versions of pushrod length checking devices, funny little plastic things with complicated instructions to calculate the length." A non comp cams pushrod checker will require checker springs...........

augiedoggy

I just used this adjustable pushrod and it had no issues with the regular spring. I did later install a checker spring (and got the same end results) because was questioning myself after everything I was reading saying the truniun center and roller tip should be 90 degrees from the valve post when setting it up but thats not exactly the case for me with the harland sharp 1.6 roller rockers and +.100 valves which I have now read is common. I get the tightest sweep pattern in the center with 7.2 rods which will be 7.14-7.15 with the lash of one full turn which = .050. I installed the adjustable rod with the adjustment end down near the lift to prevent interference with the guide.

jb78L-82

Exactly my experience: needed a 7.2 inch pushrod dry and ordered a 7.15 inch rod to account for the oiled preload running in engine...worked beautifully now for 8 years..

REELAV8R

Is the tightest sweep you can get in the center or can a tighter sweep be had off center? How wide is the sweep that you have now?

NewbVetteGuy

Just to close out on what I ended up doing:

I went overkill, like usual.
I left my lifters soaking in engine oil for at least a month while I handled other engine assembly items.

I bought the $9 Comp checker springs.
I already had a good spring remover from swapping springs.
-I hacked up my old distributor (ground the gears off) and primed the engine with my 18v drill.

I used the Straub / Foxwell 90 degree method for getting the geometry right and measuring pushrod length, but I ALSO checked the sweep pattern by coloring the top of the valve with a marker and rolling the engine over a few times. The 90 degree method yielded the smallest sweep pattern for me vs. longer or shorter.

The big trunion Comp Ultra Pro Magnum rockers required me to place them pretty far up the rocker studs to achieve 90 degrees but I went with an upgraded stud size AND continuing the overkill theme, I added a Jomar stud girdle so the studs will be fine, I'm sure.


Adam

NewbVetteGuy

P.S. Auggiedoggie, great as always to geek out with you on a hobby on the interwebs.

Always cracks me up how whenever I get a new hobby, I end up running into you on some Internet Forum about it! (I think it's probably been over 10 years ago I first ran into you on HBT! - probably the electric brewing forum...) -Helps that you keep the same forum name everywhere; lol!

-Any chance you're going to NHC/"Homebrew Con" in SanDiego this summer? (I still haven't decided...).



Adam