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I am installing a retrofit hyd. roller cam in my 383 buildup. I have a question regarding pushrod length. I am using an adjustable length pushrod to check for zero lash and pushrod length at the same time. This has proved to be a bit tricky since you have to sort of "guess" or "feel" whether or not to tighten the rocker nut or to adjust the pushrod length.
So far I am coming up with a pushrod length of about 7.25" inches. I think this is "ballpark" since the length of a oe roller rod is 7.2"
I was wondering if any of you guys have gone through this measuring process with good results? Did you end with with the same length pushrods for retro fit hyd. roller as OE hyd. roller?
fyi: cam is comp 286HR with retrofit hyd. roller lifters. Scorpion 1.5 roller rockers all mount on 7/16" studs in edelbrock RPM alum. heads.
Not sure what stage you are at with the build but I would recommend soaking the bottom section of all the lifters in some engine oil, this will guarantee an adequate oil supply at the wheels on fire-up!
Also no lube is necessary on the lobes, conventional oil is sufficient! Would also prime the short block BEFORE setting any preload on the lifters! This guarantees the plungers are in the correct location to begin.
On a side note what brand lifters are you using? There will be a .200" difference in the final pushrod lengths between certain brands?
Thanks, Gary in N.Y.
P.S. Just one more "tip" if it were being built here, I would "toss" those heavy-weight rockers for some lighter-weight stainless pieces. This is how we set up almost ALL of our 100% stock-appearing builds (photo below)! Stainless rockers today can be had reasonably priced, I would say under $160.00/16 for the 3/8" or 7/16" studs (preferred)!
Last edited by GOSFAST; 12-15-2018 at 10:35 AM.
Reason: C
Thanks for all the advice.
Just to be clear, i was suggesting using the new roller lifters with the old cam to measure pushrod length, then installing the new roller cam once it is close to prevent wiping the lube on the cam.
Is there really no special assembly lube needed for a roller cam during break in?
Everywhere i read notes assembly lube; not sure if it is moly lube for flat tappet and something else for roller.
I bought checker springs for the pushrod length measurement, but with it being my first time, i'm expepecting quite a bit of trial and error.
No, that would be a pointless exercise..... The base circle and lobes are different on the old and new cams..... the geometry at the rocker will be different as a result. You'd be wasting your time screwing around with the old cam.
No special assembly lube is required for roller cams and lifters. Regular old motor oil. Soaking the lifters to prelube them is also a good idea to help protect the hydro lifters plunger assembly as you rotate the engine over adjusting the valves. Having the lifter pumped up hard also makes finding zero lash easier for some people.
Don't worry about wiping the lube off the cam....Once you prime the oil system before start up, so much oil is going to flood the cam lobes via the lifter bores..... lets just say it'll be well lubed.
Will
Not sure what stage you are at with the build but I would recommend soaking the bottom section of all the lifters in some engine oil, this will guarantee an adequate oil supply at the wheels on fire-up!
Also no lube is necessary on the lobes, conventional oil is sufficient! Would also prime the short block BEFORE setting any preload on the lifters! This guarantees the plungers are in the correct location to begin.
On a side note what brand lifters are you using? There will be a .200" difference in the final pushrod lengths between certain brands?
Thanks, Gary in N.Y.
P.S. Just one more "tip" if it were being built here, I would "toss" those heavy-weight rockers for some lighter-weight stainless pieces. This is how we set up almost ALL of our 100% stock-appearing builds (photo below)! Stainless rockers today can be had reasonably priced, I would say under $160.00/16 for the 3/8" or 7/16" studs (preferred)!
Thanks for the advice on soaking the lifters. I have heard about this in the past, and I am planning on doing this once I get to this step.
It makes me rest easy hearing many have not used assembly lube on roller cams, but my cam and lifter kit came with some, so I think ill put some on there anyway. I've heard about clogging up the roller lifters with gunk, but i figure if i only put it on sparingly, then it should only benefit the break-in process.
Where are you getting full roller rockers for only $160.00? I bought the comp ultra pro magnum rockers, which are stainless, and are probably overkill, but I am tapped and installed screw in studs myself, so I want to have as much help with valve side loading as possible.
No, that would be a pointless exercise..... The base circle and lobes are different on the old and new cams..... the geometry at the rocker will be different as a result. You'd be wasting your time screwing around with the old cam.
No special assembly lube is required for roller cams and lifters. Regular old motor oil. Soaking the lifters to prelube them is also a good idea to help protect the hydro lifters plunger assembly as you rotate the engine over adjusting the valves. Having the lifter pumped up hard also makes finding zero lash easier for some people.
Don't worry about wiping the lube off the cam....Once you prime the oil system before start up, so much oil is going to flood the cam lobes via the lifter bores..... lets just say it'll be well lubed.
Will
Thanks for the advice, and I appreciate the direct and clear answer. It makes sense, now that i think about the cam base circle.
Lifter pump up was the wrong term I used in my description above but you get the idea. Also, I did soak my roller lifters in oil the night before I started the pushrod checker procedure as well, back in 2014 during the motor build.
I just checked my notes from Howards on the lifter pre load height and I was told for their lifters about .030-.060. I went with .050..........Turned out perfectly...........
12-15-2018, 10:26 AM
