Team Chevelle banner

Setting Valve Lash for Cam Break In.....

13K views 26 replies 12 participants last post by  Wolfplace  
#1 ·
I just want to be 100% sure on this from others who have had successful break in periods for new cams. What method should I use while adjusting valve lash before inital start up? Is the IC/EO method alright or will that cause too much of the cam lube to come off since you will have to turn the motor over so many times to adjust all valves? Is there another way of roughing it in before cam break in initally to help keep the cam lube on? All Help and comments are appreciated...I'm getting close to firing her up and want to be 100% sure!
 
#2 ·
Originally posted by AllGoNoShow:
I just want to be 100% sure on this from others who have had successful break in periods for new cams. What method should I use while adjusting valve lash before inital start up? Is the IC/EO method alright or will that cause too much of the cam lube to come off since you will have to turn the motor over so many times to adjust all valves? Is there another way of roughing it in before cam break in initally to help keep the cam lube on? All Help and comments are appreciated...I'm getting close to firing her up and want to be 100% sure!
=
When I build an engine I adjust the valves at TDC for both the intake & exhaust, rotate the engine 90 degrees & adjust the next cylinder in the firing order, 90 degrees & the next cylinder etc. right down the firing order.

After breakin I recheck using the EO/IC method.
 
#3 ·
Originally posted by Wolfplace:
</font><blockquote>quote:</font><hr />Originally posted by AllGoNoShow:
I just want to be 100% sure on this from others who have had successful break in periods for new cams. What method should I use while adjusting valve lash before inital start up? Is the IC/EO method alright or will that cause too much of the cam lube to come off since you will have to turn the motor over so many times to adjust all valves? Is there another way of roughing it in before cam break in initally to help keep the cam lube on? All Help and comments are appreciated...I'm getting close to firing her up and want to be 100% sure!
=
When I build an engine I adjust the valves at TDC for both the intake & exhaust, rotate the engine 90 degrees & adjust the next cylinder in the firing order, 90 degrees & the next cylinder etc. right down the firing order.

After breakin I recheck using the EO/IC method.
</font>[/QUOTE]Thanks for the quick response...I just checked an older post I forgot about and this is the same response I got.

Does it matter if its TDC compression or firing stroke? I have timing tape I can put on the balancer that has 90 degree intervals marked, would that be suffiecient?
 
#4 ·
Sorry about that,, yes TDC firing which is obviously the same as compression.

If you were to do it on overlap both valves would be open slightly which would probably not be the best place to adjust them :D
 
#5 ·
If it's a BBC it can be abit easier.I always adjust the valves ... then do a victory lap ( especially if it has a stud girdle ).... run a drill in the oil pump and make sure oil is flowing ect ect and reapply lube to the lobes before putting the intake manifold on.... If a SBC and it's on an engine stand you can do the same thing before installing the oil pan and intake manifold. With it prelubed and the valves adjusted and the engine in the correct position there would be a minumum amount of turning of the engine to drop the dist and be ready to go.If doing this in the car it's abit harder to do but still doable.
 
Save
#7 ·
Originally posted by AllGoNoShow:
</font><blockquote>quote:</font><hr />Originally posted by Wolfplace:
Sorry about that,, yes TDC firing which is obviously the same as compression.

I thought there was two different strokes that both put the piston on TDC...one was firing and the other compression? DOes it matter which one? Sorry I'm still a little new to this! </font>[/QUOTE]=
Never be sorry for questions, it's how we all learn
Image


TDC firing & TDC compression are the same thing.
TDC overlap is the other stroke that the piston is up & both valves are slightly open.

Goes something like this starting at TDC overlap:
Piston is at TDC, exhaust valve is closing & intake valve has started to open.
Piston is going down & creating a low pressure area that the incoming charge of air & fuel are trying to fill.
Piston goes to BDC & starts back up.
Intake valve closes & compression starts.
Piston is almost at TDC compression or firing & the spark plug fires.
Piston is driven down on the power stroke.
Piston is close to BDC again & exhaust valve opens & starts emptying the cylinder
Piston crosses BDC again & start back up on the exhaust stroke continuing to empty the cylinder.
Piston goes back to TDC & you are now back where you started with the exhaust valve closing & the intake starting to open again.

The timing of when the valves open & close in relation to where the piston is in the cylinder is what keeps Master Brookshire up nights :D :D
 
#8 ·
So, doing this won't wipe the cam?

Would it be better to do the abbreviated method mentioned in some other posts before the cam is broke in? Then just do the IC/EO after break in?

When you say reapply lube to the cam lobes, you mean through the openings below the manifold, correct? Obviously I'm not going to remove the cam.

Would assembly lube be okay to apply to the cam?


I don't have a remote starter and I read someone broke off a grade 8 bolt turning by hand. But, I'm assuming that was because the plugs were in?

Sorry, just read alot about people destroying cams and want to be sure it's broken in before I do too much. This is my first time doing this.

Also, is there a good IC/EO method described step by step somewhere? I've got one that came with my cam. But, I'd like some supplemental material.
 
Save
#9 ·
No matter how much lube you put on the cam, you will have to rotate the engine to get it started. Once around and whatever is going to wipe off is gone. The cam lobes are Parkerized to provide lube retention and scuff resistance during the initial critical period. Have a timing light all hooked up so you can get the timing correct right away before the exhaust heats up too much. I use a 36° mark on the balancer and set the timing to 36° as soon as it starts.
 
Save
#10 ·
How many times will I have to turn my engine when adjusting the valves?
36°? Isn't that a lot?
What are the risks if I do the shorter method? Will it just be noisey? Will I risk damage to valves? springs? Cam?
I read on some other boards about people saying it's better to adjust with the engine warm. How is this possible. Don't you have to adjust them using some method before inital startup?
The sheet that came with my cam mentioned the IC/EO method but doesn't say when to do it.
 
Save
#11 ·
While the engine is still on the stand is where you should adjust the valve lash for the first time while in the assembly process. After the engine is installed in the car and after it has been ran enough to break in the cam, while it's still warm adjust the valve lash again. The EO/IC method is IMO the best method.
 
#12 ·
i would'nt worry to much about wiping the lube off the cam, esp if you used the good stuff-what i would worry more about is the first 15-20 minutes of running, dont let it idle real slow, bring it up to 1500-1800, and give it a mild tweak every min. or so, then you will be ok
thats the most important part of the cams life
roller cams you dont need to do that
i dont use it, but there is a guide to adj valves where you bring it up on tdc, adjust certain i/e valves, rotate it 360 deg, then adj. the rest
 
Save
#13 ·
Originally posted by forcd ind:
i dont use it, but there is a guide to adj valves where you bring it up on tdc, adjust certain i/e valves, rotate it 360 deg, then adj. the rest
That's the one I was asking about. But, it seems most of you don't think that method is acceptable, even just for break in.

I guess I can still add assembly lube or cam lube though those slots while I'm adjusting the valves, just to be safe. I don't have any cam lube (it was added at the shop that built the short block). But, I have some Sta-Lube assembly lube that I used on the pushrods and lifters. Hopefully that's acceptable.

Next time (knowing what I know now) I'll use a roller cam
 
Save
#14 ·
Wow, talk about bringing a post back from the dead!

I used the Wolfpace 90-degree method for breaking in the cam initially(after asking this question)and then reset the lash using ICEO afterwards. All went well. As onovakind mentioned, have a timing set light handy. I did not and had the timing way too retarded and some of the headers glowed, and the engine overheated a few times and had to be shut off before I figured it out.
 
#15 ·
Originally posted by 72ElCaminoSS:
How many times will I have to turn my engine when adjusting the valves?
36°? Isn't that a lot?
What are the risks if I do the shorter method? Will it just be noisey? Will I risk damage to valves? springs? Cam?
I read on some other boards about people saying it's better to adjust with the engine warm. How is this possible. Don't you have to adjust them using some method before inital startup?
The sheet that came with my cam mentioned the IC/EO method but doesn't say when to do it.
=
If you adjust the valves at TDC in 90 degree increments you will only need to turn the engine over twice.
Here it is again:
All you do is put the engine on #1 TDC firing or compression, adj. both valves on that cylinder, rotate the engine 90degrees or 1/4 turn & do
#8, 90degrees & #4 etc. down the firing order.
Simple, quick, accurate & easy.

I always do it twice so I know I didn't screw up but if you are confident you did it right it probably isn't necessary, just a good idea in my opinion.

If you have aluminum heads adjust a solid cam .004" tight cold, iron heads I just adjust at spec.

After the cam is broken in recheck using the EO/IC method.
When the exhaust valve starts to open, adjust the intake. When the intake has opened all the way & has started closing, adjust the exhaust.
Again, quick, easy & about dummy proof,,,, even I can't seem screw it up,,, :D & all you need is the knowledge of which valve is which, a starter button along with a feeler gauge & wrench of course ;)
As for checking warm, it's the same as cold only warmer
Image


You should always recheck hot as this is how the engine runs but if you did it correctly you will find them very close.

Buy a remote starter button, they are cheap & will save you a lot of aggravation.
Also, go to GM & buy a bottle of EOS or get Cranes breakin concentrate & add it to your oil before starting the engine.
I prefer to pour it all over the cam before installing the intake but if the intake is on at least pour it in the oil before prelubing so it ends up everywhere.

BTW, I NEVER use the generic valve adjustment precedure you mentioned in your post with a performance cam.
 
#17 ·
There are a few ways to do this....I always have followed the method at the bottom of this page and has always been extremely accurate...

http://www.totalengineairflow.com/tech/valvelash.php

I just did half of my cylinders tonight....when each cylinder was at TDC, I looked at the lobes on the cam of the cylinders that I was adjusting, and they were dead on base circle....very accurate..

Good luck..
 
#18 ·
Allgonoshow,

One way I get around the timing problem at start up, is to use an old Dist with points in it. On some cars, I have had to rig up a spare coil, switch, etc, which I feed in the car (for the cars with Electronic ign). You can set the engine to TDC on #1 (Compression Stroke), use an ohm meter to set the point (to where they just open). This sets your timing at 0 degrees, which will work fine for breaking in the cam. Once I start the engine, I just watch the oil and water temp, and have never had a problem.
Once the cam is broken in, I switch back to the MSD, HEI, etc, and set the timing.

Fred.
 
Save
#19 ·
You can set the engine to TDC on #1 (Compression Stroke), use an ohm meter to set the point (to where they just open). This sets your timing at 0 degrees, which will work fine for breaking in the cam.

Retarded timing is one of the causes of exhaust overheating on an engine undergoing break-in. It would be much better to set the total timing to 36-40° immediately on startup. Have your timing light hooked up and ready to operate as soon as the engine lights.
 
Save
#20 ·
Onovakind67,

Yes, I agree, but at zero it won't overheat the engine, at least I have never seen it. The neat thing about this, is you can set the engine up first, at whatever timing mark you want, by just adjusting the Balancer to the mark (timing) you want. So if you want 10 btdc, move the Harm balancer to 8, 10, 12, etc. Then just rotate the Dist till the point just start to open. The timing will be right on, and this is easy when you only have one person. I know that at 13 degrees, I have a total of 35, simply cause I happen to know the dist I use. Using the timing light is a great idea, but would be a pain for me, as I always like to watch the gauges.

Fred.
 
Save
#21 ·
Originally posted by yanniz:
There are a few ways to do this....I always have followed the method at the bottom of this page and has always been extremely accurate...

http://www.totalengineairflow.com/tech/valvelash.php

I just did half of my cylinders tonight....when each cylinder was at TDC, I looked at the lobes on the cam of the cylinders that I was adjusting, and they were dead on base circle....very accurate..

Good luck..
=
This is also an excellent way but I don't bother with it as you either need an outstanding memory which leaves me out :D ,,, or you need to keep track of too many things.

I just find it a lot easier to go down the firing order for initial set up & then just watch the valves go up & down with the EO/IC method
Kind of the old K.I.S.S. deal at least for me cause simple is good :confused:
 
#22 ·
i hate to make this any more confusing , but you should make sure your balancer mark is correct
you can use the top dead center method, make sure the mark lines up with zero-i have seen stock balancers move 10-15 degs or more(outer ring) on cars that have seen high rpm-it sure throws you off trying to set things
 
Save
#23 ·
Mike
The KISS method has been a thorn in my side....I just can't get it right. "Just Stupid"
I have just used your initial setting of rotating my engine 90* and following the firing order for my valve adjustment. I you the same methods as part of my maintenance procedure of adjusting the valves.
Now when setting the valves lash on a solid cam what type of feel do you use.
1. I have seen people insert the feeler guage and tighten down on the nut which has some resistance when trying to insert the guauge back in for verification.
2. Some will install the feeler guage and just have a very slight drag.

Which method is correct for setting lash and does it makes a different using a Solid or Hyd cam as per tight or light drag feel?

BTW: I check over and over again during the buildup process to ensure the balancer and TDC was correct, plus my balancer has the marking every 90* which aid me in TDC method.
 
Save
#24 ·
Originally posted by DEEBOO:
Mike
The KISS method has been a thorn in my side....I just can't get it right. "Just Stupid"
I have just used your initial setting of rotating my engine 90* and following the firing order for my valve adjustment. I you the same methods as part of my maintenance procedure of adjusting the valves.
Now when setting the valves lash on a solid cam what type of feel do you use.
1. I have seen people insert the feeler guage and tighten down on the nut which has some resistance when trying to insert the guauge back in for verification.
2. Some will install the feeler guage and just have a very slight drag.

Which method is correct for setting lash and does it makes a different using a Solid or Hyd cam as per tight or light drag feel?

BTW: I check over and over again during the buildup process to ensure the balancer and TDC was correct, plus my balancer has the marking every 90* which aid me in TDC method.
=
LOL,,,
The "feel" is kind of an acquired thing I guess & I like a slight or noticeable drag on the feeler gauge after the thing is set.
Problem is slight is a very subjective term so,,, consider how much drag is on a bore gauge when measuring a cylinder or bearing clearance.
This is about the best description I can give you for what I consider a "slight drag"
Stop & think of what the reading would be if you could use a dial indicator to measure the clearance by putting it right over the end of the valve on top of the rocker & lifting the rocker off the tip of the valve.
This is pretty much what you are trying to accomplish with a feeler gauge.
A company called P&G used to make a gauge that measured the clearance with a dial indicator but this goes back a LONG TIME :D
It snapped in place between the retainer & rocker & "preloaded the rocker with a fairly heavy spring kind of like the spring load in a rod bolt stretch gauge & measured the clearance when you pushed the rocker down against the valve tip.

Now,,, with hyd cams you are only using a feeler gauge if you are using some of the "anti pump up" stuff or trying to simulate a solid lifter & it can get a little "pissy" :rolleyes: .

The rest of the time adjusting hyd lifters is pretty much a no brainer as you are just taking the lash out & adding whatever preload you like running.

Hope this helps a little,,
Image
 
#25 ·
Back when I worked on diesel trucks for a living, we did about a bajillion lash adjustments. It's known as "run the overhead". One of the best tools I ever bought was a set of angled (bent @ 45deg)"stepped" feeler gauges. Good ones from the Snap-On guy. Ditto what Mike said about "slight drag", it really is something you develope with practice. I found that the stepped gauges allowed me to check my work much more acurately. Use the next size smaller to check for "too tight" and the step on the right size will tell you if it's "too loose". Once you've done that, you will have a "feel" for "just right".
 
#26 ·
Thats like the old Go/No Go feeler guage?
 
Save
You have insufficient privileges to reply here.