[KGTO]

I've used the same method as Cliff for years without fail. It ensures every time you're on the base circle, no guessing. Especially for large cams like Gach pointed out

[Greg Reid]

Originally Posted by Cliff R

One more thing that I do here and I started this about 20 years ago is to adjust hydraulic lifters so that I fully BOTTOM OUT the plungers in the lifter bodies and adjust UP. How many turns to back up the locknuts is a matter of personal preference and depends on what lifters you are using (plunger travel). A spin on that deal is to bottom out the plungers with a feeler gauge between the valve tip and rocker arm. Then just yank out the feeler gauge and move on. The only thing that you MUST do with this method is to wait a few moments with each turn of the adjustment nuts to push the oil out of the lifter. You know when this happens because the pushrod "locks up" momentarily with each turn on the nuts then a few seconds later (can take a bit longer with "S" or slow-bleed lifters) it will turn with slight resistance again. There is also no "grey area" whatsover when you bottom out the plungers because EVERYTHING locks right up and no matter how long you wait it stays that way.

Anyhow, that's how I do it here and can take credit for none of it. These methods were shown to me clear back in the 1970's by my "mentor", who was one of the most successful engine builders and drag racers I have ever known.........

What size feeler gauge do you recommend and how far up are you adjusting those locknuts?

[66sprint6]

So, I've done this a couple of times and I'm wondering if I'm doing it wrong. It's rather frustrating. I went through the instructions like in the link posted. I got the lock nuts and went through the valves, tightening the nuts until the pushrods were hard to rotate, then moving on to the next.
But I found that after moving on to the next set of valves, the ones that I tightened earlier seemed loose. The pushrods were again easy to spin with no effort. So after farting around with them, I lost the sequence and had to start again. After a while I was getting a little upset and stopped for the day. What was I doing wrong? I'm going to do this one more time, hopefully with decent results.

[78w72]

You need to set each rocker with its corresponding valve completely before moving on. following the steps in that link, you do one valve/rocker at a time then move on to the next one when its on the base circle of the cam, thats determined by watching a certain valve just start to open then the valve being adjusted is on the base circle, much easier to do this with the valley pan off. im sure some others will chime in to explain it better but if you realize whats being done, the link explains what valve to adjust when.

A big thing that confuses many people is how to get to zero lash... its definitely not when a pushrod is hard to turn... you determine zero lash by just barely tightening the nut to creep up on when there is no lash up & down with the pushrod, spinning it is a way to find that spot, but its when there is just barely a very slight resistance to spinning the push rod, no force required at all... & you only do it to that one valve being adjusted, not all or a bunch of them at a time. when rotating the engine some of the rockers/pushrods will lose the resistance you felt as the cam lobe moves up & down.

try re-reading that link again to get a better understanding of whats being done, or watch some youtube vids on the process, its the same basic steps as sbc/bbc adjustment.

[NatW_RI]

Something else to try - when I adjusted my preload last year I "colored" the pushrod with a silver sharpie at the guide plate after I backed the polylock loose.

I could then watch the mark as I rotated the nut by hand and easily see the pushrod start to move - that marked 0 preload.

I went even further and for my first adjustment took a really fine tool (can't remember what) and made a scribe mark into the sharpie to mark "0" and then removed the pushrod. I then used my calipers to scribe a 2nd mark for the amount of preload I wanted.

When I adjusted the 1st rocker I could then correlate the amount of turns it took to get to my desired preload as I watched the 2nd mark cross my reference point of the guide plate. Each new location I'd use the sharpie to help me get to 0 preload - movement was much easier to see than I would have expected it to be.

[shifty]

Below is from Cliff

One more thing that I do here and I started this about 20 years ago is to adjust hydraulic lifters so that I fully BOTTOM OUT the plungers in the lifter bodies and adjust UP. How many turns to back up the locknuts is a matter of personal preference and depends on what lifters you are using (plunger travel). A spin on that deal is to bottom out the plungers with a feeler gauge between the valve tip and rocker arm. Then just yank out the feeler gauge and move on. The only thing that you MUST do with this method is to wait a few moments with each turn of the adjustment nuts to push the oil out of the lifter. You know when this happens because the pushrod "locks up" momentarily with each turn on the nuts then a few seconds later (can take a bit longer with "S" or slow-bleed lifters) it will turn with slight resistance again. There is also no "grey area" whatsover when you bottom out the plungers because EVERYTHING locks right up and no matter how long you wait it stays that way.

__________________________________________________ _________________

Question - what size feeler gauge should I use?
"67 400/335 Crower 60243 cam, Crower 66056 lifters, stock rockers. Pushrods unknown but probably stock.

[Greg Reid]

Originally Posted by shifty

Question - what size feeler gauge should I use?
"67 400/335 Crower 60243 cam, Crower 66056 lifters, stock rockers. Pushrods unknown but probably stock.

Yeah, I asked the same thing a while back.

[1968GTO421]

Originally Posted by Greg Reid

What size feeler gauge do you recommend and how far up are you adjusting those locknuts?

Maybe a PM to Cliff will clarify this?

[Greg Reid]

Probably...or I could ask on his forum. I know I only get notifications on about half of my subscribed threads here any more and he probably does too.

[400 Lemans]

Originally Posted by 66sprint6

So, I've done this a couple of times and I'm wondering if I'm doing it wrong. It's rather frustrating. I went through the instructions like in the link posted. I got the lock nuts and went through the valves, tightening the nuts until the pushrods were hard to rotate, then moving on to the next.
But I found that after moving on to the next set of valves, the ones that I tightened earlier seemed loose. The pushrods were again easy to spin with no effort. So after farting around with them, I lost the sequence and had to start again. After a while I was getting a little upset and stopped for the day. What was I doing wrong? I'm going to do this one more time, hopefully with decent results.

Make sure when you line up your mark on the balancer that your actually on #1 TDC and not #6, before starting your sequence.

[Schurkey]

Originally Posted by 400 Lemans

Make sure when you line up your mark on the balancer that your actually on #1 TDC COMPRESSION and not #1, EXHAUST OVERLAP before starting your sequence.

FIFY.

[68WarDog]

On a new engine, I remove the valley cover, looking at each cam lobe base, removing any question of the lobe/ lifter orientation.

[Cliff R]

What size feeler gauge to use adjusting the lifter with the plungers bottomed out?

Pick your poison. What I do here during the engine build is to determine how much travel the lifters have right to start with. I can tell anyone reading this that there are a LOT of different lifters out there made for these engines and different amounts of plunger travel.

I like to run the plungers close to middle of their travel in most cases, but if don't have that info available or a way to measure just tighten them to zero lash, then on down till fully bottomed out counting the number of turns along the way. So let's say you have 3 full turns from zero lash to bottomed out, middle of the travel is 1.5 turns. Set one at 1.5 turns and use a feeler gauge to determine plunger height. Then set all of them to that dimension.


If you don't want to go thru all that just grab a .020" feeler gauge and run them all down using it and move on to something else. You can go tighter if they still make too much noise at your liking at .020", which some of these newer production "fast" bleed lifters will do.

In theory it really doesn't matter where you set them because the leak down rate controls the amount of noise and by design they will always maintain zero lash anywhere in their "range", but in the real World we've found that going closer to plungers bottomed out vs closer to zero lash just makes things a lot better in the overall scheme of things.

Also keep in mind that WAY back when hydraulic lifters were better made and better materials we NEVER had to worry about any of this. Just run them to zero lash, another 1/4 to 1/2 turn or so, button up the engine and NEVER look back.

Sadly, these days in the World or outsourcing, poor quality control, lack of attention to detail and companies trying to get good help and survive post COVID we are seeing WAY too many issues with these sort of parts.

I liked the good old days with cams and lifters. You NEVER had to worry about any of it, or "scrubbing" a lobe either. Just fire it up, run the engine for a few minutes, check for leaks, oil pressure, set timing, idle speed, put 100-200 miles on it, drop the oil, filter, take a gander at it, fill er back up with new oil, new filter, then drove it like you stole it!...........

[Cliff R]

PS: IF you are using Rhoads lifters they have several variety, or at least they used to when I was building engines. They come with instructions so best to follow their advice when making valve lash adjustments. Be prepared for some noise at idle speed, especially when the engine is really hot/heat soaked and the oil is thinned out. It hurts nothing but still doesn't sit well with some folks, so I would NOT go that direction unless you are prepared to have your new engine build sounding like a well worn out sewing machine.......FWIW.......

[Greg Reid]

Thanks for the detailed response. I have an engine on a stand that the vally pan isn't sealed on. That'll give me a good opportunity to play around with that procedure while visually observing the lifter travel.

[Cliff R]

Short travel lifters don't have nearly the room as other variety. Internally I've never seen any noticeable differences with them. Sometimes they just took a basically "stock" lifter and added a "special" retainer to it to provide a lower seat height for the plunger. I've seen some that were nothing more than a stock type lifter with a hardened steel shim added internally to shorten up the travel. With that said in theory they could all be dubbed "short travel" if you don't give them much room by your adjustments.

Lifters are also "grouped" into types by leak down rates. "S" or slow bleed could be rated as high as 120 seconds by the manufacturer. A "fast bleed" lifter might be as fast as 20 seconds or even less.

One needs to keep in mind here that IF you are using a fast-bleed design you are LOOSING some bleed down potential by "tight lashing" them. At the same time by using a feeler gauge vs just counting turns of the lock-nuts you are providing each one with EXACTLY the same amount of bleed-down potential.

I personally like fast-bleed lifters, like Rhoads because they truly do bring modern technology to these early engine designs, or variable valve timing and I can deal with the noise.........