Roller rocker installation and pushrod measurement

[ThePoose 37]

Hi all,

Starting to reassemble my engine and have run into my first question.  I've added Lunati roller lifters, Edelbrock Performer RPM aluminum heads and trying to install Lunati Voodoo roller rockers.  Looks like they "balance" on the valve and pushrod with the nut on the stud applying tension.  Since I need to figure out pushrod length, how far down the studs do I want to mount the rockers for a starting point?  Halfway?  .050 up from the base of the stud?  Something else?  First time I've installed these type of rockers, no instructions were included and my internet searches haven't been helpful.

Thanks for the help

[mwye0627 44]

I notice you've mentioned adding the Lunati roller lifters and roller rockers, but I must first ask if you have installed the corresponding Roller Camshaft?

If yes, then check the specs for your Edelbrock Performer RPM cylinder heads and then determine if the valves are longer than stock.  I've looked on the Edelbrock web site and they  list those heads as the valve springs being suitable for up to 0.575" lift.   Therefore it's possible that the valves could be either 0.100" or 0.200" longer than stock.

With that information you may be able to contact Lunati and see if they have any specific recommendations for pushrods for you.  At the very least they can recommend an Adjustable Pushrod and Very Light "Checking" Valve springs so you can determine the correct length yourself.

Take a look at this video to familiarize yourself with the procedure....      Just make sure your contact pattern is at the Center of the Valve Tip...

 

[barnett468 418]

Contrary to what the rookie in the video states, you do not try to center the pattern over the valve in the method he is using. you simply use the push rod that provides the narrowest pattern when doing it that way. He also failed to show the pattern on the top of his valve. This is probably because it was not defined enough. Getting a clear and consistent pattern is difficult, especially with light springs. I will try to post some better info for you later today if I get time.

 

 

 

[1969_Mach1 333]

It's true you want to minimize the amount of "sweep" across the top of the valve tip.  Traditionally, as well, the goal is to have that sweep centered on the valve tip.  From an engineering standpoint this will reduce side loading on the valve stem and valve guide.  That's not as critical with roller rocker arms.  But I would still shoot for that goal.  Most cam mfgs. have info checking push rod lengths.  Here is a little that Comp offers. http://www.compcams.com/Pages/417/valve-train-geometry.aspx 

[ThePoose 37]

Sorry, yes.  Lunati retrofit roller 20310514.  .500 lift on intake, .510 exhaust.  In my experience, the best I can say about Lunati's customer service is that it's non-existent (tried tech email, phone and live chat).  Rockers are 1.6.  Roller lifters are link bar.

I have the light springs and the pushrod length tool.  Should I not use the light springs?

Since all of the components were changed, I don't have any point of reference to start (or the experience).  My 5.0s all had pedestal rockers, bolt them down and then check pushrod length.  On this engine, for instance, with #1 intake on the bottom of the base circle, do I start with the fulcrum of the rocker centered vertically on the stud and adjust the pushrod tool from there, then trial and error until I get the tight, centered pattern?

I first used a stock length pushrod for reference and the base of the rocker seemed too close to the base of the rocker stud.  If ultimately there is just a lot of adjusting, that's fine.  I just was unsure if the goal should be that the rocker should be more or less vertically centered on the stud.

I hope I'm communicating clearly.  Let me have it if I'm not.

 

Thanks.

 

[mwye0627 44]

The light valve springs should be fine...   As it stated, use a Dry Erase Marker, NOT a Sharpie...   The dry erase marker should leave a clear pattern.   When using heavier springs you would have to use a Solid lifter or a hydraulic lifter that is sufficiently "Pumped UP' so that the force of compressing the heavier valve spring does not overcome the force of the plunger in the Hyd. lifter.

As stated above, the objective is to get the thinnest pattern on the valve tip, but also make sure to get that pattern at the CENTER of the tip.   A too long or too short pushrod can make the roller travel pattern too close to the edges of the valve tip.

 

[barnett468 418]

5 hours ago, mwye0627 said:

As stated above, the objective is to get the thinnest pattern on the valve tip, but also make sure to get that pattern at the CENTER of the tip.

Nope.

[barnett468 418]

 

Here's one simple method.

 

[mwye0627 44]

16 hours ago, barnett468 said:

Nope.

Sorry Barnett, but I too have been doing this stuff for a very long time...    In fact I was ASE certified Master back in 1974  back when it was still called NIASE, the National Institute for Automotive Service Excellence.

Other than being a tech, I am also a degreed engineer with 20+ years employed as both a Mechanical Design and Electronics Design Engineer.  To add to that, I worked as a crew chief for various drag racing teams since 1983 working on everything from 9 second super gas cars to 5.9 second 237 MPH Pro Mod cars.

Getting back to the issue at hand, I would NEVER run a rocker arm or pushrod combination that would create a valve tip pattern biased to the inboard or outboard side of the valve.  Such an offset would undoubtedly place a unnecessary side load on the valve and valve guide leading to increased and accelerated wear. The best possible rocker tip to valve tip orientation will produce as straight of a perfect up and down valve travel as possible without undue side loads. 

 If you really want to learn more about the dynamics of valve motion do some research and watch some stop motion video footage of engines and valve trains being tested on a SpinTron device...  It was a very enlightening experience for me and really opened my eyes to the dynamics of our own racing programs...   Just imagine valve lifts of 1.065" at 8600 rpm...   If your set-up is off just a little, the damage can cost tens of thousands of dollars...   No room for error...

Now, If you can show me Proof that your opinion is Truly the desired result for All situations, I am more than willing to be enlightened by differing views!

[ThePoose 37]

Thanks, Barnett. That video is exactly the kind of thing I was looking for.  That let's me know where the rocker should be (the geometry).  I'm still going to verify using the other method, too.  Which is why everything takes me so long.  Lot of good info.  Thanks, all.

 

[barnett468 418]

3 hours ago, mwye0627 said:

Sorry Barnett, but I too have been doing this stuff for a very long time...    In fact I was ASE certified Master back in 1974  back when it was still called NIASE, the National Institute for Automotive Service Excellence.

Other than being a tech, I am also a degreed engineer with 20+ years employed as both a Mechanical Design and Electronics Design Engineer.  To add to that, I worked as a crew chief for various drag racing teams since 1983 working on everything from 9 second super gas cars to 5.9 second 237 MPH Pro Mod cars.

Getting back to the issue at hand, I would NEVER run a rocker arm or pushrod combination that would create a valve tip pattern biased to the inboard or outboard side of the valve.  Such an offset would undoubtedly place a unnecessary side load on the valve and valve guide leading to increased and accelerated wear. The best possible rocker tip to valve tip orientation will produce as straight of a perfect up and down valve travel as possible without undue side loads. 

 If you really want to learn more about the dynamics of valve motion do some research and watch some stop motion video footage of engines and valve trains being tested on a SpinTron device...  It was a very enlightening experience for me and really opened my eyes to the dynamics of our own racing programs...   Just imagine valve lifts of 1.065" at 8600 rpm...   If your set-up is off just a little, the damage can cost tens of thousands of dollars...   No room for error...

Now, If you can show me Proof that your opinion is Truly the desired result for All situations, I am more than willing to be enlightened by differing views!

Unfortunately, your lengthy dissertation above is irrelevant to the op's question and is therefore not helpful to him. Your previous post was inaccurate the way it was written, it's that simple. If you elaborated on it and explained EXACTLY what you were trying to say, it would be useful, however, as you wrote it, it is not.

 

 

 

[barnett468 418]

2 hours ago, ThePoose said:

Thanks, Barnett. That video is exactly the kind of thing I was looking for.  That let's me know where the rocker should be (the geometry).  I'm still going to verify using the other method, too.  Which is why everything takes me so long.  Lot of good info.  Thanks, all.

No prob. Happy that what I posted was useful to you. The person in the video is Scott Foxwell. He has built many race winning engines and was partners with Chris Straub for a while. Chris is one of the premier cam designers in the US and designed the cam for Ed Morels drag car as well as the cam for a National Championship winning boat, therefore, it stands to reason that both Chris and Scott know how to properly set the push rod geometry up, or at least their method has been proven countless times to work well enough to win Pro level races.

Their actually is another approach to doing this, however, Scott's method (which I'm guessing he learned from someone else like most of us do), is one of the simplest.

In a perfect world, the rocker tip would be perfectly centered on the valve tip with the cam at half lift, however, do to production tolerances etc, this almost NEVER happens and the amount of side loading placed on the valve if the rocker top is off center a bit is nominal and nothing to be concerned about.

Years ago there were some rockers called "Half Lift Design" and someone is still making rockers with this design. Below is just a little info on them but its not something you should worry about getting.

http://www.baisley.com/rocker_service.htm

Push rod strength is also important, so hopefully you have push rods that are suitable for your particular app.

Spring surge is another factor to be aware of if you have a high revving engine but it's not something to be concerned about for most street apps.

 

 

 

 

 

 

 

 

 

 

[barnett468 418]

On 5/24/2018 at 10:13 AM, ThePoose said:

Lunati retrofit roller 20310514.  .500 lift on intake, .510 exhaust. 

 

What engine is this for?

[ThePoose 37]

351W. Please don’t tell me I’ve been led astray...

[barnett468 418]

56 minutes ago, ThePoose said:

351W. Please don’t tell me I’ve been led astray...

lol, not necessarily but it depends on several variables and your goal. I guess you could give us that info and people can offer their suggestions or you can just stick it in and live with it. You may be perfectly happy with it but I at least hope you have 3.25 gears or numerically higher.

 

 .

[ThePoose 37]

3 hours ago, barnett468 said:

lol, not necessarily but it depends on several variables and your goal. I guess you could give us that info and people can offer their suggestions or you can just stick it in and live with it. You may be perfectly happy with it but I at least hope you have 3.25 gears or numerically higher.

 

 .

Yes, will be at least 3.50 gears.  I wanted a cam with some decent low end, but could still take advantage of the heads.  Oh, and some lope.  My wife talked me into the lope.  All seemed to match up well with the Stealth intake.  After months of obsessing, and talking with a few skilled people I know, this appeared to be the best compromise.

[barnett468 418]

2 minutes ago, ThePoose said:

I wanted a cam with some decent low end, but could still take advantage of the heads.  Oh, and some lope. 

What heads do you have?

Do you have a stall converter?

 

[Bob & Sue 110]

On 5/24/2018 at 5:54 PM, barnett468 said:

 

Here's one simple method.

That's a good video explanation was easy to understand. 

The only thing I would add is after you've done your math to determine center line geometry I think his number was .355, 7.1 turns. I always use a dial indicator even though it's not necessary, either setup a 1" travel indicator or setup a standard indicator at the top of the throw & use .355 Jo block. I guess it's the machinist in me.

Didn't mean to add a new twist the OP will be fine doing it that way in the video.

Going to setup a 460 with an Isky cam, push rods  & roller rockers later today or tomorrow for a boat good refresher video.    

[ThePoose 37]

12 hours ago, barnett468 said:

What heads do you have?

Do you have a stall converter?

 

Edelbrock Performer RPM 60225 (1.90/1.60).  No stall converter, 5-speed.

For context, I started out with an e-303 as a reference.  I have that in my 91 Mustang.  Love the way it sounds and pulls pretty good at RPM.  Yes, the sound was part of the decision for this cam.  Then I started reading how the e-303 was old technology, which makes sense.  Did a lot more reading, which led me to a couple of Lunati grinds and a Comp Cams (don't have the number off hand).  The one time I got through to Lunati, they felt that the 20310514 would give a little more low end while performing better all around than the 303, especially in a 351 v. a 302.  The grinds with more low end had smooth idles and didn't really take advantage of the RPM band.  BS?  It made sense, but really I have no idea, because as much as I've tried to study what cam grinds mean, it just doesn't compute. 

So any thoughts are welcome as I've just started buttoning it up.

 

 

[barnett468 418]

ok, you are comparing a wimpy 302 engine with crappy heads to a much bigger engine with much better heads. the bigger cubes will provide more torque. the better heads will provide more power as well. you are not even close to utilizing the potential of those heads with that tiny lift cam and i would definitely use something else but some others might not. i would also rather take a loss on that cam to get one that would be far better for my application. it's not a horrible choice for that engine but it is not the best either imo. 

do you have an overdrive trans?

do you do much freeway driving?

do you want to rev past around 5500 rpm?

do you want to roast the tires?

what exhaust?

what is your compression ratio?

what pistons do you have?

did you install the heads yet?

how much of a "lope" do you want?

how "racey" do you want it to sound at idle?

 

is this too racey sounding or not racey enough?

 

[ThePoose 37]

do you have an overdrive trans?

T5 with 5th gear listed as .63 overdrive

 

do you do much freeway driving?

Not stop and go. I live in the country so there is a lot of open highway driving.

 

 do you want to rev past around 5500 rpm?

Not generally.  I’ll do an occasional Friday night drag for fun. But I’m also officially an old, so I have a mental block taking an engine much past 5500.  6000 would be max, but rarely.

 

do you want to roast the tires?

Yup. 

 

what is your compression ratio?

10:1

 

did you install the heads yet?

Yes

 

 

how much of a "lope" do you want?

 how "racey" do you want it to sound at idle?

Combining these two: On my crappy phone, the below video sounds pretty close to my e303 5.0. I like that sound but may be a tad too much. I want to be able to pull up to a light and not have the thing want to die. I have to give the 5.0 gas sometimes.  Also, something that still gives some vacuum. I’m going EFI but will need some boost to the brakes. 

 

I’m okay with leaving some performance on the table. I realize I bought more than I may currently need, but I wanted to leave room for improvements. 

[barnett468 418]

ok, xlnt. i will be back later this afternoon but below is one of the cams i would strongly consider that i think would be much better suited to your goals. it will have less lope than your e303 and your current lunati cam and will rev to around 5400 and will have lots of low end power in your particular setup and decent vacum and will work with efi.

http://www.lunatipower.com/Product.aspx?id=1668&gid=289

Make sure your heads are set up for roller cams and your valve reliefs are big enough

[ThePoose 37]

3 hours ago, barnett468 said:

ok, xlnt. i will be back later this afternoon but below is one of the cams i would strongly consider that i think would be much better suited to your goals. it will have less lope than your e303 and your current lunati cam and will rev to around 5400 and will have lots of low end power in your particular setup and decent vacum and will work with efi.

http://www.lunatipower.com/Product.aspx?id=1668&gid=289

Make sure your heads are set up for roller cams and your valve reliefs are big enough

Wow, thank you.  I'd looked at that cam earlier, but was worried about valve clearance with the lift.  Mainly being lazy about wanting to avoid possibly enlarging the reliefs, which is stupid with all the work I'm putting into the car.

Since you've been so generous with your time, another question: would that current Lunati cam be a good switch for the e303 in the 5.0L (edelbrock 60379 aluminum heads).  Or are they so similar is it worth the effort?

 

 

[barnett468 418]

exactly what pistons do you have?

is your other cam installed?

[barnett468 418]

2 hours ago, ThePoose said:

Since you've been so generous with your time, another question: would that current Lunati cam be a good switch for the e303 in the 5.0L (edelbrock 60379 aluminum heads).  Or are they so similar is it worth the effort?

The lunati cam is similar but will feel much different in a bigger engine with better heads.