Rhoads V-PROs - mid-lift rocker geometry - push rods measurement
 

I've been corresponding with Jack Rhoads about measuring for new push rods with the Rhoads V-PRO lifters. In an email he wrote, "Bottom out plunger when determining pushrod length and ADD about 0.020” to the pushrod." No explanation why you add it or what it does. I didn't really think anything of it until I started to really think about it. So I called him and got even more confused. He did mention that the V-PROs plunger travel is 50 - 60 thou. So I got more intrigued about why he wants to ADD 20 thou to the initial rod measurement. I've concluded that I really don't know so I sent him another email today with more questions.

If you have the rocker pinned in the sweet spot using mid-lift or the old witness mark method, why would you add another 20 thou and move the intake side of the rocker up more and not take into account rounding to the nearest 50 thou for the rod, or the additional bump you get when adjusting the lifters? I would think you 'd subtract some length, perhaps the plunger travel from low to high RPM so you can keep the rocker as close to mid-lift as possible when it's running at the higher RPMs...some constant that works with however you setup the lifter for you engine.

If you have any thoughts on this feel free to share.

So I spent some time last night writing a detailed email explaining my understanding and asked some specific questions. His reply was, "I think you should use any method that feels right to you. It can get complicated". So he didn't answer one question or provide any detail on why you ADD length to the measured pushrod. Not sure what you call that, but it's not tech help.

Let’s get some basics nailed down that can’t be disputed..

1)
Your lifters as you have posted have about .050” of adjustment range that they will work in just fine without noise if there made right.

2)
as any motor heats up any dimension that was a clearance will close up some and other will open up.
3)
As valve seats bed in and ware over time and valve stem tips and rocker arm tips ware what might have been a no gap / clearance condition will develop a gap.
4)
Aluminum heads will typically grow about .005” to .008” when up to normal operating temp, and iron heads will grow about 1/2 that amount.

Basically all you are doing when adjusting a hydraulic lifter is providing enough room for dimensions like above to change while maintaining a no clearance condition and also keeping the plunger from coming up against the clip ( be it round or flat C type) to hold the plunger from exiting the body of the lifter.

So basically you have been told in your corespondence that if you have a given push rod length that gives you good geometry at half lift then a push rod .020” longer will have the plunger compressed .020” out of that .050” you have to work with .
This is fine and as dimensions change when the motor is hot and things ware some you should never hear a clacking lifter or rocker.

I would subtract the .020” for the correct pushrod length with a VPro.

I agree with everything about wear and heat expansion. The V-Pros are adjusted from the bottom up using a feeler gauge at the valve to loosen or tighten the reduction in valve lift, duration, and velocity vs. from the top down to set a pre-load. So that's the conflict. Adding length if you're setup starts at the top of plunger travel makes sense, but all the published tech info at Rhoads emphasizes the bottom up procedure. Adding length to a rod that's already bottomed out seems counter-intuitive.

what do the instructions that came with the lifters say?

I've read past posts from you about V-Pros and it looks like you've used them a number of times. Thanks for your input. I would also lean toward subtracting 0.020" from the initial measurement that has the rod bottomed out and the rocker at a good spot, perhaps slightly more to move the rocker to mid-lift in the upper RPM (above 3500) range. Maybe that's getting too picky. My setup will use 0.020" lifter adjustment once the new rod is in place. That'll get the plunger just off the bottom of the lifter. 0.013" - 0.014" approximately, then as RPM increases the plunger will move up to provide full valve lift, duration, and velocity. At least that's the theory.

There are instructions on adjusting the lifter (assuming you have the push rods already in), but they don't have anything published on the website or with the parts about measuring for rods given good and proper rocker geometry.

You buy new lifters, rockers, and a cam, you clearly need new push rods, so not providing instructions for that procedure is a miss in my opinion.

I'm sure there are experienced engine builders that can read the lifter adjustment instructions and then figure out how to determine proper rod length, but for us guys that rarely go deep into these things, it's good to have some assurance on how it's done by the company selling the parts.

I don’t think any lifter instructions provide information on pushrod length. Once you get your pattern, you can determine length based on the amount of preload specified.

https://www.rhoadslifters.com/Pages/Installation.html

I should have posted I did not have time to do that could have made things clearer.

He should have said that the more change you want in duration between idle conditions and and rpm’s above 3500, then the more you should adjust the lifter as he recommends that being starting with the lifter nearly bottomed out.

I've read that sheet several times now and the one they supply with the parts is similar, but different.

There's no mystery on how to get the rod length with solid and std HFT lifters. I think what threw me off was the anti-pump feature and how the plunger changes position as RPM increases.

Many decades ago Rhoads adjusting instructions told you to bottom the lifter plunger and back it out a full turn. It has changed a few times since.

We usually round up when determining pushrod length for applications using Rhoads.

Valve train geometry is a bit complicated to explain. It gets trickier when folks double check their notes with others on the Internet. I believe that deters manufacturers from wanting to get deeply involved with advice. I have seen Jesel several times refer folks to their instruction sheet which is different than the "mid lift" theory. I've seen Jesel many times state the it's up to the end user if they want to follow their recommendations or set them up with the "mid lift" theory".

I had an issue with setting Rhoads from zero then tightening down. Spin the motor around then to see if I forgot one they had bled down(like they are supposed to) and the pushrod was loose!

Thank you Paul for your comments on this. I agree that the geometry can get tricky to understand. Round up? Yes. Better to be long than short. I suppose there’s a risk to mfrs if they put too much information out there about other parts they didn’t sell.

After all this overthinking, I can see how I’ll set the rod length. Easier to visualize now. Hold the rocker geometry as close as you can and make sure the lifter setup procedure can be done exactly as the directions indicate. The unknowns are how the rocker changes geometry as the lifter achieves full valve lift. A guy could subtract another 0.010” on top of the 0.020” initial deduction. A little bit of guessing but not really. I can only estimate the plunger lifts maybe 10 -15 thou between idle and high RPM.

Measured for pushrods last night. We attempted to setup with midlift. It didn’t work as expected. Once setup the rocker sat on the exhaust side of the valve tip. So the witness mark method was done and the initial rod length was reduced by 1/4”! My guess is the rocker arms are not designed to be setup exactly with mid-lift geometry. They’re designed to fit Pontiac. That’s all. Find a rod length to ride the roller as close to the center of the valve tip and be done.

I tried the mid lift scheme when it became the new rage marking the side of a roller rocker and it took me in a wrong direction... Not all rockers are the same meaning the relationship of the cup and top of the valve tip vertically speaking from the rocker fulcrum they are not just about inboard / outboard points of interest so some brands of engine family's might work, In spirit mid lift is correct to give the smallest sweep on valve tip but you can observe the tip markings to get there is easier for me > on a Pontiac <

Jay, didn't you build a 455 recently with V-Pro's? Could you tell us about how and why you set up your V-Pro's on that engine?
THanks
Jeff

From everything I’ve read, the narrowest pattern is preferred over the pattern closest to center of the valve tip. In some cases, the narrowest is in the center.

Narrowest pattern is preffered and if that happens to close to edge of valve stem then the brand of aftermarket rockers becomes suspect and if all else fails going .050 different length pushrod to get off the edge shouldn't effect sweep all that much........ Longer than oem valve lengths can alter where the pattern will center because physically the top of the valve stem is closer to the stud (rocker fulcrum) due to intersecting angles

When starting from a pushrod that is a set length, adding .020” (as Rhaod’s said) to the length then checking the pattern with a pushrod checker is correct. If you’re starting out using a pushrod checker with no idea what the length may be, to get the actual pushrod length you subtract the .020” from the pushrod checker length. What Rhaods was suggesting was not wrong, they were just starting from a set pushrod length, versus starting with a checking tool. In other words, for finding what the operating contact pattern of the rockers with V series Rhoad's, one way you add lash to the length, the other way you subtract it.

Vpro’s have an extra shim in them to raise the plunger so they can be set with less lash than a Vmax. If you follow the instructions for Vpro and Vmax with their corresponding recommended lash settings the plungers operate at the same height for both the Vmax and the Vpro. With the combination of the shim under the plungers and adding the .020” lash on a Vpro the position of the plunger is pretty close to the same as a regular standard lifter with 1 turn from zero preload. In other words the pushrod length for a Vmax or a Vpro is the same as standard lifter. I never seen that a different length pushrod was required on a Vpro versus a standard regular lifter. A Vmax running a ton of lash to pass a vacuum rule of a racing class might take a different length pushrod than a stock lifter, but for most street stuff the pushrod lengths will not change from a standard lifter. You can switch to V series lifter and use all the same valve terrain parts as regular lifters use.

Jay, an adjustable pushrod set at standard 0.050" increments was used to find the best valve tip pattern. The valve adjustment was set at 0.020" once the new pushrods were installed. Butler/Comp Hi-Torq HFT cam 230/236 was installed with the Rhoads lifters.

The noise these lifters make is noticeable. I don't mind at lower RPMs, but at cruising speeds, it's annoying. My understanding is that the lifters quiet down when they pump up and don't have time to bleed off as RPM increases. I can't hear any difference in the sound level at 1000 RPM vs. 3000 RPM. Do certain oils do a better job of decreasing the noise? Would increasing the adjustment from 0.020" to 0.030" have any effect on the sound they make at higher RPMs?

What's your method for checking/changing the adjustment once the engine has been running in the car? Do you prefer using a remote starter switch or rotating by hand to get a valve on base circle or a little of both? Just curious how someone with a lot of experience does this.

We use 10w40 or 15w40 with Rhoads. It sounds like you need to tighten up the lash a lot. Keep in mind there is hot expansion added to the lash once the engine is hot. If it is sounding like the lifters have some action yet and make noise at 3000 it is likely the hot lash is to much. They can do that clear to 4000 if you give them a lot of lash, even can go a little beyond that. I have set the Vmax at .040” before, probably .046” once hot, they were very loud.

That Bulter cam has aggressive profiles, it has Extreme energy profiles on the intake lobes and a less aggressive magnum profiles on the exhaust. Those cam profiles can make a lot of valve terrain noise even with regular lifters. If it was mine I would set them cold and tighten up the lash to .008” with iron heads, and .004” lash on Aluminum heads. Then you would end up with around .010” lash once hot. The biggest gains in performance and vacuum with V series lifters are with tighter lash settings, after the hot lash is much over .010” (maybe even less with that cam) all the Rhoads lifters really do it make more noise.

You are also likely not going to want to run the lash the same on the intakes and exhaust. I would keep tightening the lash up on both valves until your content with the balance of noise, low end vacuum and power. To make the valve terrain quitest, run the exhaust as tight as possible, and if you need more action from the Rhoads with less noise adjust intake lash wider, keeping the exh tight.

For cranking the engine over, I think I have used about all the methods possible, from doing them individually by rotating the crank, using a remote start switch, and even finding top dead center, adjusting 8, then rotating in 180* and adjusting the other 8. We have even set them while the engine was running and just went by the turns from where the plunger was bottomed out. The tighter you set the lash, the more reason to set them individually manually cranking the engine to make sure they totally bleed down.

Jay. That’s some great information. I’ve re-read your post a few times. When you refer to “lash” with these V series lifters, it’s setting the max plunger travel from the bottom up. Right? Rhoads uses the term “adjustment” in their documents. They suggested 0.020” for street but in a general sense not knowing the cam profile. Ok. So with this cam I can tighten up to 0.008” on the intake and less on the exhaust? Say 0.004”? So the exhaust behaves like a solid lifter?

So the more plunger action the noisier they get. Rhoads sez that a bigger lash at 0.030 provides better idle. I suppose that’s true but it’s also noisier. What isn’t happening in my case is a full pump up to the point where they quiet

Next step is to change oil to see if that has any affect.

I have more questions but I’ll save those for tomorrow.

I call it lash because I am a mechanical cam guy, maybe clearence is a less confusing description when following the instructions. With the plunger bottomed out you measure the distance (clearance) the plunger can move with a feeler gauge, it is like checking lash on a mechanical cam.

I was not referring to .008” for the intakes and setting .004” for the exhaust. Maybe I miss wrote the other post. I don’t know what your over all set up is, so I was intending to suggest for that aggressive cam start at .008” on both intakes and exhausts if you have iron heads, or .004” on both valves if you have Aluminum heads. Then if you desire more action from the lifters increase the adjustment on the intakes only, My reference to .004” was for if your engine has Aluminum heads. But yes you can set the exhaust to .004” and the intakes to .008”. If you want you can even bottom the plunger out so there is zero clearance cold, then it acts like a mechanical lifter. At .004” clearence set cold (with iron heads) once the engine warms up the V series lifters still gain around an 1” of vacuum over a normal lifter at idle. At .020” clearance the vacuum increase over a regular lifter is around 2.5” to 3”. At .030” they probably only gain .25” more vacuum than when set at .020”. They progressively do less as the clearence is increased.

I have never understood the Vmax gig, Why choose a lifter that bleeds down so you get the smaller cam effect but then reduce plunger travel to reduce noise ? seems counter productive as to why use the lifter to start with because the ability to effect low speed duration is lessened the closer the lifter plunger is to bottoming out in the lifter body
Not picking on anybody just trying to make sense of it all i don't believe this is the first post on this issue.

I like and have used a few sets of regular Rhoads lifters

If you know what the cam profile looks like (can measure this when a cam is installed) a good general rule for the street is to not set the V series plunger clearance so they operate looser (once the engine is hot) than where the tappet lift of the cam has 1* per .001” of tappet lift on the closing side of the cam. To find that, multiply that tappet lift by the rocker ratio for the max hot clearance. Generally that is the most clearance (hot) that a V series lifter is able to operate well on for the street. It is the quietest operation for the profiles performance gains with V series lifters. Going beyond that is also excessively hard the valve terrain.

I don’t use the Rhoad’s instruction blanket numbers for clearance, because the profile does make a large difference in how the lifters perform.

For a Compcams XE profile, it hit that acceleration at .006” tappet lift. All these cams have the close to the same acceleration at the clearances.

.006” X 1.65 = .0099”

On the exhaust with the magnum profile the same tappet acceleration is at about .007”

.007” X 1.65 = .0115”

For a Melling SPC-8, It hits that tappet acceleration at .009”
.009” X 1.65 = .0148”

For a Crower 60919, it has gentler ramps yet, it hit that same acceleration at .011”. Nearly twice as gentle ramp as an XE.

.011” X 1.65 = .0185”

For racing purposes it is fine to set the clearance higher than those numbers. But for the street, the valve seats and guides get beat up excessively if running more clearance than those clearence numbers.

The V series lifter has a lot of advantages, it doesn’t collapse like all the other hydraulic lifters when the engine gets to peak power. The regular Rhoad’s lifters will get beat on top end power by a regular lifter because they collapse and loose extra duration, that is even against a standard lifter. A V series will out perform both, it can be a lot depending on what the cam profile it and how many RPM it turns. It is just the nature of the way the originals bleed down. There is nothing you can do to change it unless you want to bottom the plunger of the original type lifter out and set them up similar to a V series. The problem with that though is if you happen to float the valves the lifters completely loose control of the valves. The V series has better valve terrain control, and is more tunable.

I am not sure if an original Rhoad’s could have the clearance set as tight as I have set the V series. Less than .020” clearance from the bottom of travel and there may be issues with oil getting fed up into the pushrods on an original lifter. I don’t know anyway, I have never tried that. The v series have a shim to raise the plunger off the bottom of travel.

Jay you made the case to use lifter A over B .. What i am stuck on is you have a Vmax but don't like the noise so you (rig) the plunger deeper in the body to reduce noise. That's the direction i have seen in a few posts and seems to me to defeat the big reason in using them by losing / decreasing the bottom end torque improvement, Maybe they didn't have the plunger in the right zone to start with... carry on

Oil: I will take your advice on oil weight. The 10w40 has several to choose from, the 15w40 appears to be marketed mainly to Diesel engines, right? Can you point to a couple preferred products in either wt?

Lash: I get the interchange of lingo. I'm not an engine builder, just an engineer that wishes he had more hands on experience with this stuff. I try to seek professional knowledge from those with a lot of experience and success. So taking the cam profile into account, the intake lash can be set to less than 0.010". Providing that intake and exhaust can be set independently, are you implying that exhaust lash should be tighter than the intake (based on the cam profile)? In a couple posts now you're indicating that exhaust could be set to near zero cold. I was guessing 0.004" as a starting point setting for the exhaust in my previous post, not referring to the aluminum head setting. My 455 has 6X-8 heads. Setting the lash looser than 0.010" makes more noise with minimal gains? Can't disagree.

Adjustment: Getting the cam on base circle isn't an issue, but I'm unsure how you determine when the lifter has fully bled out. AS you wrote, manually turning the engine seems like the best way to compress the oil out without introducing oil back into the chamber, which seems possible even at starter RPMs.

I can see why you would think that when I talk about running the lash or clearance ultra tight where the Rhoads are not doing much of anything. That is more for the exhaust side where someone wants a hot for the teacher type idle.

My main goal when I set V series lifters is to make them quiet and have nearly full action, adapt how each is set for the specific cam, make them operate pretty quietly and still have 90% of the actual action an original Rhoads does. More or less remove low RPM seat timing. Depending on the cam design, a Vseries can even have more action than a regular Rhoads and less noise. Rhoads lifters on an old RA4 profile act different than on a Comp Extreme energy cam. The original Rhoads are a one size fits all design. Which is honestly fine if you have a certain profile that works and you don’t mind the sowing machine noise Rhoad’s lifters make.

https://www.summitracing.com/parts/BPO-71586

You may be able to buy locally for better price i dunno

The Penngrade in Formula’s the link would be good. Driven GP1 15w40 is usually what I use, neither one is a diesel oil. There are some Diesel oils that work ok, most have a lot of extra detergents in them though. If you set the clearance tighter 10w30 should be fine with a Vpro. If you want to run a lot of clearance the thicker oil helps noise some.

Using something that has a little leverage to help push the plunger down makes it easier to bottom the plunger out. Then you can more gently push until it the plunger bottoms. Set the clearance, push on it one more time after it is set, and check it again. Watch for valve movement when the feeler guage is removed to make sure the feeler gauge is not holding the valve open.

Jay. I picked up the car last weekend and it still had some harmonics. I was told the fan clutch had leaked out while stored in the trunk so I knew I was going to replace it. I noticed it was spinning off-center at idle and the flanges on these new aftermarket ones are slotted (not drilled out). The new clutch had a brass bushing to properly index it to the water pump. So once installed that took care of the last of the harmonics. I don't ever recall seeing a bushing on that interface. No clue when the first clutch went in years ago either. This was never the major vibration source, but it did add to it.

However, the engine still has a buzz to it, not smooth...you can feel it whether accelerating driving or just taching it up slowly out of gear. Like there's some imbalance but it's constant. No pulsing. My first thought was it ws those lifters. I knew adjusting them would change the sound they make, but I couldn't make any connection with adjusting them and making the "buzz" go away until I was talking to an old time mechanic at a car show today.

Where our conversation went was that if 1 or more lifters within the intake or exhaust group were adjusted slightly unlike the others, you'd get different valve timing within that group of 8, which would lead to different cylinder pressures within that group. Different cylinder pressures alone (from wear) would have its own symptoms, but when you add in the valve timing, I think it would create a constant uneven pattern and create a slight constant vibration. What do you think, sounds very possible. I would try to be as accurate as possible when adjusting and have a minimal tolerance in the lash between cylinders for that reason. The more aligned the lash is among the 8 the smoother the engine will run. Not sure how many thousandths difference from one to the next would start to reveal symptoms, but given you're working in 0.001" precision, it wouldn't surprise me to learn it should be zero. All exactly the same.

So I'm a little reluctant to do this myself, but my understanding is that if you tighten all of the lifters down to zero, they act like your typical HFT lifter, you're just removing the low RPM variability. A guy could do that as a test to check the smoothness of the engine in a range of RPMs.

Do you use a dial gauge on each valve tip to improve accuracy when adjusting or can you eyeball it? If you're tightening to 0.08" I would think so, but I don't know for sure until I try myself. Tighten with desired gauge until valve just cracks open and then back off to close position with some resistance on the gauge when removing. You're recommending 0.08" on intake and how much on exhaust? Nothing wrong with the "Hot for Teacher" sound, but from your earlier thoughts, that's likely going to happen anyway given the exhaust would be tightened to less than 0.08".

With the cam you have I would start at .008” cold clearance. You can go tighter if you want, probably go tighter on the exhaust first. That cam should have good vacuum and low end power even with the clearance ultra tight.

I am not sure what you’re describing as a buzz and not smooth. That may be something not related to the valve terrain. Some people compare the noise Rhoad’s make to a mechanical lifter sound. I describe their noise as a sowing machine sound, like 16 small sowing machines. Maybe it is possible, but I have never noticed that an engine ran rough even if a couple of the clearances were too loose from setting them poorly. You don’t need to be overly worried about getting the clearance dead on exact. With in a few thousands won’t change things much. They all pump up at slightly different rates and have a little different blead rate between each lifter. Most people set them when first installed and never even look at them again. Normal lifters bleed rates are generally not super consistent either. These days consistent bleed rates on a standard HFT lifters is almost a comical thought.

The sowing machine from Vpro Rhoads always goes away once they pump up. The tighter they are set the sooner they pump up.

I'm trying to describe what I "feel" as the engine spins faster or pulls hard. It's a constant vibration that increases some with RPM and load. Similar to the harmonics from the bad flywheel and fan, but this is constant and not as intense. The engine doesn't have a smooth feeling like one would expect. I know it's not a watch, or some old Pontiac straight eight, but I think it should run smoother when cruising or pulling hard.

What I hear could be connected to what I feel. The lifters should quiet down at cruising speeds (2500 - 3000), but they don't...not enough to notice.

I researched more information on general theory about valve timing and how it can change a way an engine "feels". Nice and smooth or rough. The bleed down variability between lifters makes sense, but if half the intake or exhaust lifter settings are a couple thousandths different then the target setting, could that affect performance and make the engine "feel" rougher? If it's just 1 or 2, probably nothing, but if it's several, that would compound the effects.

I trust my engine guy, but he's never worked with Rhoads lifters. It's worth taking a another look at them and also tighten them down to fit the cam better.

Jay.

I went after the lifter adjustment Sunday. There was a learning curve to get a feel for when the valve just starts to open. I can see it, but the way the wrench stops at the point of lift starting, with a light touch after the plunger is bottomed out, seems to be consistent with each valve. Making some kind of lever to bleed the lifters thoroughly was time consuming. Some things I tried worked OK, other not so much. Finally found something in the toolbox I didn't think of that worked great. What I found was that I could bleed it down, but some lifters needed to be hit again, is that what you experience? Like it sucks some oil back in. I set the intakes to 0.008" and the exhaust as tight as I could, effectively at ZERO. Considered 0.003". I didn't complete the process, so if there's a reason not to set at ZERO, let me know. I can go through again. Good learning experience.

Crossing my fingers this tighter setting and going thru all of them again for consistency eliminates that constant vibration I feel. Could be from other things too. It's RPM related, not driveshaft or axle related.

Other things I've read that can cause a "constant" vibration are

Cooling fan - running a late 60s 7 aluminum blade. Good condition, but worth checking again.
Bellhousing alignment - matching GM bellhousing and gearbox from the same parts car. Pilot bearing showed no sign of unusual wear.
Cylinder miss or weak spark - hard to tell, but it's possible
Transmission rear mount - had an original 60s rubber mount, switched to a new rubber mount last year. The new one seemed to amplify the vibrations. Could put the old one back on and see if there's a difference.

I always go thru and set them twice. It is not unusual to find a couple that need set a little tighter on the second check.

From the description of how the engine feels uneven could the engine want more ignition timing? Do you have the timing pulled out some to break it in?

I’m not in a hurry so I will go around a second time. Should go faster without the bleed procedure to deal with. Still not totally pleased with the bleed down lever tool process but it works. I looked for a second and didn’t see anything I could buy so that’s that. Could make one or take and old claw hammer and modify it. What do you use or make to bleed them. They’re tough!

Set the total timing at 34d. I haven’t heard of retarding the timing a tad during break in. What the reason for that? Just easier on the cam?

Compression baseline will get done once the lifters are done. Also a check for healthy spark at all cylinders.

From the description is seems like you did a thorough job setting the clearance. It isn’t really necessary to go over them again. If I took my time I could get it first go around.

I do a lot of high compression pump gas street builds. I often work my way up to full timing.

It probably isn’t the timing. Just thought I would ask. The last adjustable timing light (Summit) I bought set the timing 15* retarded from actual. It made the engine feel uneven. Sometimes dampener rings slip to.

Goes much faster when the lifters are bled. Did them by firing order second time. Got to 10 and quit for the night. When bled all had the same action but 1. #8exh. It relaxed and you could tell when it bottomed out but you had to wrench slow. Something odd about its action. Still fluid in it but it was like it was pulling it back in when released. Thought it would be normal after more cranking but no.

Timing will be looked at. Butler 2 piece HB. Timing mark is on the hub.

I have no idea what they were previously set at. Told him to set at 0.020”. How can you tell? Had to undo the setting to bleed.

How hard do you have pull on the gauge to remove once you’ve locked it in? Light, medium or finger slicing?

I would describe it as the gauge has some extra drag and resistance before movement, then have medium drag.

Finished up. Started without pulleys to get a quick listen before I do the rest. Lifters are quieter at idle. No doubt. Tached it up. Has a different sound. Nothing bad happened

Nothing bad happened 😃

Rhoads V-PROs - mid-lift rocker geometry - push rods measurement
 

I’m curious to hear if adjusting the lash solved
your problem?


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First setup I tried was 0.008” intake 0 exhaust. Ran it. Nothing bad happened but the exhaust note at idle was odd sounding. Didn’t feel confidant about tightening them down to zero. Went back and set the exhaust at 0.005”. Rotated the engine to bring oil pressure back to the lifters. Fired it up again with no accessories, so run time was limited. Didn’t tach it up much but on the middle idle step it was smooth. At low idle it had a nice rumble. Tomorrow I’ll finish assembly and let it idle up to temp for 15 minutes to get the lifters normalized. Appears to take some time to fully bleed (oil in). Just my observation. Explanation below.

What I noticed from the first time thru then the second was how the lifters reacted when forcing the oil out. First time they took some significant force to bleed out. It was run for about 5 min after the first adjustment. Subsequent rounds the lifters gave up to fully depress the plunger took less force and some had minimal resistance.

I’m assuming the lifters will normalize and do what they do once they’re back in action. At that point I expect to leave them alone and not have to dick with them again.

The clearance can tighten up .002” on the exhaust once the engine is fully hot. I should have mentioned that, if your setting the exh clearance lazer tight you should at add the .002” to the cold clearance for an accurate goal for hot clearance.

I think you have a good handle on setting the Vpro’s. Hopefully it is ready to go.

Comparing this old post to what you just wrote is confusing. Can you clarify please?

I had it in my head that setting the lifter clearance at 0.008" COLD would result in 0.010" HOT. Clearly as things get HOT everything tightens up from expansion. I didn't think it through and bother to confirm with more questions.

Cold settings at 0.008" / 0.005" will result in 0.006" / 0.003" +/- when hot, correct?