Problem checking p-v clearance with our lifters! (long)

[Zero Signal]

I'm in the process of installing my new combo. I got the cam in and it degree'd perfectly right off the bat. So I proceeded with checking the valve train geometry. I first put some clay on the piston to check the piston-valve clearance as I checked lifter preload, two birds with one stone.

I bolted up the head over the #1 cylinder without torqing. I installed an intake and exhuast rocker. I turned the engine to load the lifters and let them bleed down for 5-10 min. before checking the preload. I checked the preload and it was pretty high since I had the heads milled. I threw on a .060" shim on both and they both check out between .030" and .040" preload. Everywhere I check, the allowable is .020" to .060" but I did read somewhere that is had to be .020" to .030" I'm not sure if this is the case

Ok so I took off the head and checked the clay. Seems good. I had at least .125" clearance but I don't what the allowable is?

So with the geometry looking ok with the shims, I installed all the rockers, torqing them down alittle more every few minutes as the lifters bled down. I finished at 20 ft-lbs. I re-checked the preload and it only increase by alittle, so it seems ay-okay.

Now this is where I started to get worried and this leads to my big question. I noticed that *some* of the springs were compressing too much. I figure .060" should be ok, but they were going down to .024" But I noticed that it was becuase those particular lifters weren't completely bled down. OK so now I'm so confused! Here is the big question . . . how where does the lifter sit during operation?? Does it pump ALL the way up, or does it stay half way bled down or what? I'm not going any further until I know I won't destroy the motor once this fires up. If I need new springs, fine. BUT now how do I correctly check the p-v clearance and what is the allowable p-v clearance anyway? I'll be talking to the engine builder this week about it, but I'm pretty sure I could get some expert help here too.

When I checked the total lift at the spring with the bled down rocker, it was at .357" or so which is obviously waaaay low. So is the lift going to pump up by .176" for a total lift of .533"? If so, the p-v clearance is wack.

Here is what I'm putting in:
- Fully worked GT40's
- Comp Cams 270H-R10 cam (.333 lobe lift, int/exh, built in 4° advance (106° ICL)
- Proform 1.6 rr's (so .533 total lift)
- Stock pushrods - I have an adjustable pushrod checker in case I need it.

 

[Killercanary]

They will pump ALL THE WAY UP! So, your figures are wrong and you are right not wanting to run it yet. You need "checker" springs, or a way to make your lifter act as a "solid" because without oil pressure the lifter will bleed down due to the spring pressure and give you false figures. I use checker springs when I check mine (they are a VERY soft spring and they will are not strong enough to push the oil out of the lifter, but they are strong enough to keep the valve closed. They are only a few bucks, but you will also need a valve spring compression tool to remove the springs on the heads and install the "checker" springs.

 

[Killercanary]

These are similar to what you need.

http://store.summitracing.com/defau...arch&DDS=1&N=115&target=egnsearch.asp&x=7&y=7

i got mine from Comp I believe but they look the same as this. Don't worry about measuring preload on a hydro lifter, tighten the rocker until you reach zero lash, and then give it a 1/2 to 3/4 turn and you'll be good to go and it won't matter with your PTV clearance when they pump up completely because you will be checking PTV with the lifter fully pumped up so the valave isn't going to get any more "lift" than at that point.

 

[RIO5.0]

If you have an old lifter you can make a solid real easy....remove the circ-clip and pull the spring out....find some small washers and stack them in so you can install the top and the circ-clip will still assemble...very easy to make...when you take the lifter apart youll see what I mean....this way you know you good....You adding your gasket thickness to your PV readings???

I think intake is .080-.100 and exhaust is .125...all min dimensions...

 

[Zero Signal]

Paul: That's what I thought on them pumping all the way up! Then I don't get the .020-.060" preload. Wouldn't that preload actually open the valve even on the base of the lobe once they pump up?? I'm using pedestal mount rockers, so they need to be torqued all the way down. I only checked becuase I was afraid that the pushrods might be too long. I still have a feeling they might be. Hell I might even install the stock rockers if I have to. I doubt the rollers are worth a ton of power.

Rio: Yeah I took into account the HG thickness. I think I will take a trip to the junkyard and find some lifters to hack and re-check everything! The larger than stock valves aren't help matters either.

At this point, I'm more concerned with doing this right rather than just getting it done. I don't want sweaty palms when I turn the key

 

[RIO5.0]

Solid will take all the variables out...If you were closer I'd send you one...I kept my old ones and made some solids for peeps...
I did my PV on the engine stand and in the car once to...in the car sucked as I had to undo the springs and used the drop the valve method...works, but not fun...Both ways I had mucho clearance.....
I run shaved Thumpers and the Steeda 19, Scorp 1.6....I needed longer than stock PRs to...

 

[Zero Signal]

I was also wondering, do you install the lifter with the hole on the side facing up or down? Since it's flat it's one or the other. I ended up putting them all facing up, but they can still be removed easily. I made the mistake of not paying attention when I pulled the stockers out

 

[mytight95]

the hole installs upward so they don't have any problem pumping up.


jason

 

[Zero Signal]

the hole installs upward so they don't have any problem pumping up.

That's good to know! I'd rather not have to redo all of those!

I think I will order up a valve spring compressor and checking springs from Summit. The springs are like $4 and the compressor is $20. It's meant for stud mount rockers, but I'll remove the rocker and make it work with a bolt/washer to get the springs off. I'm gonna do what I can to avoid removing the heads and buying new gaskets.

I also noticed how chinsey our lifters are around the roller pin. If this project drags out long enough, I may end up buying new ones.

 

[blksn955.o]

I am re-doing, well for the first time doing it proper, my valve train geo.

I got a solid lifter like rio is talking about from Tmoss, I was having a sim. issue with cheking and wanted to get my pushrods measured for correct length.

First I installed the "solid" lifter.

Then I Installed the Rockers and put the adj. PR until it had drag and did not spin freely.

I then put a light (LIGHT COAT) coat of grease on the valve head/tip and ajd. the rocker tip until I got the correct pat. on the valve head/tip by using shims.

I have been asking some questions and am at the point I was wondering about pre-load on the lifter as I am using a "solid" one. The info I got was that it realy doesnt play a big role "some use the preload, some dont" and they get results from what I hear both ways...I am going to add the pre-preload to the adj. pushrod and then see how it affects the patt on the valve...I just want to see for myself.

I think the trav. of the rocker on the valve head/tip is the important thing and the correct lenght PR for that travel. The 20-30 preload as far as I could see would be "maybe" some noise at idle when the lifters are not "fully" pumped up but even then they still will be getting pumped up to some extent. This thinking of mine is why I kinda see the remark about not playing a large enough role as making sence.

 

[Killercanary]

I run pedestals too and my torque wrench clicks off when set at 20ftlbs at approx 3/4 turn past zero lash. Our lifters are setup to minimize maintenance, and the preload serves as a "cushion" for wear in the valve train before it needs re-adjusted. That small preload you add to it by turning the rocker bolt 1/2-3/4 past zero lash just allows that much of an area to "wear" before it needs adjusted. Think about it, if you sink the plunger into the lifter .020" the pushrod, rocker cup, rocker tip, etc can wear .020" before there will be a lack of contact between the plunger and the pushrod (in other words the lifter can make up .020" in length due to pumping up with oil when its first set and keep contact with the pushrod until there is more than .020" od a distance between the two) and ultimately the rocker and the valve. Does that make sense?

 

[Zero Signal]

Yeah that makes plenty of sense. So the problem would then be that my pedestals would need to be shimmed way up to match the 1/2 to 3/4 turn from zero lash. The rocker pedestals need to make contact with the head's pedestal right? If that's the case, I'm starting to think I need shorter pushrods. I'll throw the adjustable pushrod in there and see what I come up with.

Also . . . I'm wondering how to pump the lifters up. Some people say " . . oh yeah just use an old distributor and a drill!" but not a single detail on how you do that Isn't there a way to directly turn the oil pump? I don't see the drill having enough power to turn the whole motor via the cam.

Thanks for all the help

 

[Killercanary]

John, with milled heads you will typically need shorter pushrods, but that's not always true. I run a slightly thinner than stock head gasket on my car and I actually needed longer pushrods. You are about to see why I hate pedestals, they can be a major PITA to get the valvetrain setup when everything isn't "stock" anymore. The rocker fulcrum, the aluminum pedestal, the pedestal "tray" and the head must all be in contact. If you try to find zero lash and end up torquing your pedestals down before its found and the pushrod is loose, then you need longer pushrods or if its very close you may be able to mill a little off the bottom of the pedestal (check with the rocker manufacturer for the MAX you can remove as its not much, I took too much off of mine and I had to buy new pedestals and then longer pushrods), if your torque wrench clicks off before you have found zero lash or before you are able to get the minimum 1/2 turn past zero lash then you need shims for your pedestals to move the rocker up and away from the head.


ARP and others sell a oil pump priming tool. You remove the dizzy and stick the tool down into the hole and it connects to the oil pump driveshaft. The other end is setup for go into a drill. Connect your drill and start turning away, I can't remember if you turn it to the right or the left, but you'll tell after a few seconds which is right because when you start turning it the right way the drill will die WAY down! Hope that helps.
-Paul

 

[blksn955.o]

The turning the engine with a drill to keep the lifters pumped is why I ran a lifter that was made solid.

I have a 0 deck block and .065 mill on my heads. I read that it is more important to get the correct travel on the valve tip. So I got that setup first with the proper shim to get THAT travel correct first. Then used the adj. pushrod to see how long a PR I need for my setup. Even if you are worried about that .020-.030 pre-load its not much and just add that to the length of the PR after you get the numbers from the adj. one.

 

[Killercanary]

Just make sure you know how to use an adjustable pushrod for checking. The manufacture's will normally tell you if you need to add anything to your measurements to make up for the "cup" and the flat spot on the end of some pushrods. This can equate to quite a few thousandths if you don't add it when you need to, or do add it when you are not supposed to.

More often than not, if you get the proper length pushrods, your "travel"
will be on and the geometry will be right unless the rocker studs or the valve stem has been moved in some way.

At 1/2 of max lift you want the pushrod, the centerline of the rocker (from the pushrod cup to the center of the roller tip), and the valve stem to all be at 90* angels to one another. If you do this more often than not your valve tip travel will be spot on. When checking this though you MUST use a checker spring or a solid lifter because if you don't your lift values will be all over the place as the pressure from the valve spring will squeeze the oil out of the lifter.

 

[blksn955.o]

Yes you need to have either a test spring or a "solid" lifter to check the travel of the rocker.

The mid lift is what is very important to check the placement of the rocker.

the whole measuring part is funky...I have seen the "total", total without the ball ends, and one that was some kind of funky meas. but that was for some funky PR too though.

I was looking at some order forms and they asked what method you used and on what kind of checker.

Also if you buy a comp cams checker you can send it back in and they will check it for you and give you the correct PR...if you dont have a dial caliper to check it with.

 

[Zero Signal]

I have the adjustable rod with the same ball ends as the stock rods. So I was planning to get it to the right length and send it in to take out the guess work. I figure it will take longer but I don't really mind. That is, IF I need shorter lifters which I think I do.

I ordered two summit stock style lifters to hack, a valve spring compressor, and two checking springs. I got the spring compressor that you use while the head is on, it's the cheapo summit one. I got by with the $20 credit they gave me on my last invoice and $12 of my own, so no biggy on the cash yet.

I was gonna try checking the p-v clearance with the hacked lifter and checker spring by holding the valve down so it rides the piston on it's way up, then hold the rocker against the pushrod and find the minimum clearance I get between the roller tip and the valve stem tip.

 

[nmcgrawj]

If u have a dial indicator(20$ on ebay with a magnetic base) you can put it on the rocker start when the piston is down low, zero the indicator, push down on the valve and check clearance. Rotate a couple degrees and check again. You'll see the pattern and see the clearance get closer and closer than after TDC bigger and bigger. Really easy.

 

[Zero Signal]

Good call Nate, I might do it that way. I have the Summit dial indicator with the magnetic base and I love using it, lol. I'm an engineer so I'm entertained with this stuff. I will try your method since it's very straight forward.

 

[Killercanary]

I did it the way Nate mentioned. He was wrong about one thing though (sorry Nate!).

You'll see the pattern and see the clearance get closer and closer than after TDC bigger and bigger

This is correct except for the TDC comment. The distance will actually be closest a few degrees before (on the exhaust valve since the piston is chasing the valve as its closing) or after it (on the intake valve since the intake valve is chasing the pistons as it goes down) TDC (around 15* if memory serves me correctly). Its been a while so if I'm wrong on this you can yell at me Nate! Its best to check it at MULTIPLE degrees as the closest PTV clearance will NOT be at TDC, but rather a few degrees before or after it.