I have a Comp Cams solid roller valvetrain with their Hi Tech parts. I have about 3000 miles on it now and it runs great but I have had to adjust the valves 5 times now. At first they were about 4 thous out and now the last time after about 1000 miles they were out by 1 -2 thous.

Anyone have any experience with solid rollers ? If so did you have to do so many adjustments.

I have a Crane stud girlde and all the polylocks were locked tight when I loosened them off to adjust them. I just took the intake off and the pushrods and rollers on the lifters look fine as do the roller rockers.

Comp cams does not say anything about having to adjust so often but it is funny that in the Crane stud girdle box they mention that you should adjust three times before racing ? I am glad I read that at least I knew that is was not uncommon to adjust so often however I wouild like to know when it is going to settle down and hold an adjustment.

 

No different than any other cam. Your adjusting proceedure may not take you to the heel of the cam lobe. Try the NASCAR or drag racing method next time. It`s 100% correct every time.

 

Which is

 

stolen from the crane cams website...AND the way I do mine!!
....redvetracr


Setting Valve Lash on Mechanical Cams

All the valves must be set individually and only when the lifter is properly located on the base circle of the lobe. At this position the valve is closed and there is no lift taking place. How will you know when the valve you are adjusting is in the proper position with the lifter on the base circle of the cam? This can be accomplished by watching the movement of the valves.

1. When the engine is hot (at operating temperature) remove the valve covers and pick the cylinder that you are going to adjust.

2. Hand turn the engine in its normal direction of rotation while watching the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake valve. (Why? Because when the exhaust is just beginning to open, the intake lifter will be on the base circle of the lobe, so the intake is the one we can now adjust.)

3. Use a feeler gauge, set to the correct valve lash, and place it between the tip of the valve stem and rocker arm. Adjust until you arrive at the proper setting and lock the adjuster in place.

4. After the intake valve has been adjusted, continue to rotate the engine, watching that same intake valve. The intake valve will go to full lift and then begin to close. When the intake is almost closed, stop and adjust the exhaust valve on that particular cylinder. (Again, when we see the intake valve almost closed, we are sure that the exhaust lifter is on the base circle of the lobe.) Use the feeler gauge and follow the procedure described before in step 3.

5. Both valves on this cylinder are now adjusted, so move to your next cylinder and follow the same procedure again. In the future you may find shortcuts to this method, but it still remains the best way to do the job correctly

 

OK I have tried many techniques for setting valve lash but this roller cam is the biggest I have ever had. I have a question then that relates to the way I now set the lash. :

Is is possible NO. 1 cylinder lifters are not on the base of the cam if the balancer points directly to 0 degrees ? I know this is 0 degrees because I built the engine and I degreed the cam.

If it is possible they are not on the base then my method is not correct. My balancer is marked all the way around so I simply go to 0 degrees and adjust NO.1 lifters then turn 90 degrees and adjust NO. 8 lifter and keep turning 90 degrees and follow the firing order, worked fine on my other cams but they were smaller.

 

The method redvetracr referenced is IMO the easiest and most repeatable method for setting lash. One slight modification is to adjust one intake and one exhaust valve hot and let sit overnight. Recheck lash cold and now you have the correct lash setting for a cold engine.

Solid rollers can exhibit short life in street operation. More specifically the lifters wear and can lead to catastrophic failure. The more aggressive the valve timing and attendant spring pressure, the shorter the lifter life. I have learned the hard way about roller lifter life in street operation. It is the low speed operation and idling that ultimately take their toll on solid roller lifters. Keeping meticulous track of lash is the first line of defense. I would be very cautious if your lash is consistently increasing.

I've had lifters go away after approx 5-6K miles. The first time I had not fully appreciated the need to watch lash so closely and munched a lifter. I feel fortunate the collateral damage was limited to the cam, lifter and one lifter bore.

The 2nd set of roller lifters went away after almost 8K miles. This time I was ready and pulled the intake once I confirmed lash growth. Sure enough, the 2 lifters that exhibited lash growth had signs of excessive wear.

I have since upgraded to Crower Sever Duty lifters with the HIPPO (High Pressure Pin Oiling) option in hopes of obtaining longer life. So far 3K+ miles on an aggressive "street" cam and no lash change. But even w/ the Crowers (I've also heard good things about the Isky Red Zone lifters w/ pin oiling) I treat them as a consumable item, and remove the intake annually to remove and inspect the lifters. The roller wheel should turn smoothly with no play. Any "grittiness" or play in the wheel and its time to change them out.

Good luck!

Mark

 

This is the correct way. Simple and easy with a shut off engine. Many of the other methods of balancer reading and ect. are a waste of time. Take too long. A footnote on roller parts is that for racing applications where engine maintance is constant {after every run inspected} they are satisfactory, but they are not really street orientated. Too many pieces to fail at what there very use was intended for if not closely watched, namely high RPM`s.

 

I would like to add...I (personally) do all the intakes or all the exhausts on one side and then move to the other side. I also pull all the plugs so I am not fighting compression....redvetracr

 

MotorHead? how many were out .001 - .002?

You have to realize that setting valve lash is not an exacting science. I can have three of my friends set the valves and if I check them it's different than my feel for what's correct. Really less than + or - .004 is not a big deal.

I set mine which is usually more of a check and then spin the motor with the starter and my present cam is .018. So I verify that a .020 won't even fit in.

 

That'd tell me the lash was .019" not .018" That's what I call checking the lash by a go / no go method. I set mine up so that if the lash is supposed to be .018" that I can force a .018" feeler in but a .019" won't fit. The "drag" method just leaves a little too much variation for me. Most likely won't mean a damn thing performance wise, but I check lash to see if something bad is happening in the valvetrain. Your lash closes up, valves are tulipping or stretching, lash loosening up, something is wearing in the cam/lifter/rocker arm/push rod area. Either one can ruin your day and get very expensive if you don't catch it before something fails.

I've also seen ends of a engine gain more lash when warm than centers, so being as consistant as possible is important. Any kind of flex in the studs or rockers is going to throw all this out the window.

 

I have talked it over with a few local engine guys and come to the conclusion that I am being to picky, I am not going to worry about the lash ( I will still chaeck and set it every so often ) unless it is out by more than a couple of thou. But we all agreed that it is better to be like that than to let things go

 

SloRvette - My angle feeler gauges only have an .018 and an .020 My valve adjusting tools are very simple. Remote bump button to turn the motor over. T-Handle allen with box end tool. I don't fumble with a full fan out of feeler gauges I have only the two I need. To get .019 I guess I could fit together a .007 + .012 It's not that big of a deal.

From working years in the pits of fast paced circle track racing. Your working tool box should only have what you use 98% of the time.

Just like this cam. My last custom billet was .022 lash. I never really even looked at the new cam card. So for the first three months i was setting everything at .022 For some reason I cleaning out my desk and I looked at the cam card .018 setting.

It didn't seem to mind. I've got all good parts. and I'm only running 175# and 540# open with a 7500 red line.

 

Gkull I got my Vic Jr. intake off right now and going to tap it for a vacuum port like you did, did you have any pics of it ? and what drill/tap/fitting did you use ?

 

This is the best picture I could find. It's just one of those common brass fittings for 3/8th hose. Mine runs from the back of the manifold to the Power Brake vacuum attachement.

Off hand I don't remember the common national pipe thread. I'd get the brass addapter and then get the threader and correct drill bit size. It's been four years since this picture.

Hope that this helps!

 

another shot.

 

To the original poster.....i have a similar sized cam and have experienced the same thing. At first, my lash was growing about 6 thou every few hundred miles. After readjusting them about 3 times, I went over the valve train with a fine toothed comb and everything looked and felt fine. The only sign of wear was on the polylock. It looked like the bottom of the polylock was getting hammered down a bit. Since then, i've checked them about 3 more times (now with about 2500 miles), and they have stabilized quite a bit. Some still open a 2 couple of thou, but i still think it's the polylock. I've also learned to set them 2 thou tighter than what i want. So i set mine at .016 and after running it for a short time, they will check at .018 which is my target.

 

It's impossible to know for sure if you are on a cam's base circle unless you have the complete lift-crank angle data including the clearance ramps, which nobody has unless you have engineering drawings or measure the complete lift-crank angle diagram yourself.

One sure fire rational method to be sure you are on the base circle is to set the engine at TDC of the compression/power stroke on each cylinder, then adjust the inlet valve of the prior cylinder in the firing order, which is 90 past TDC; and also adjust the exhaust of the next cylinder in the firing interval, which is 90 BTC, so at TDC #1 you adjust 2I and 8E, and so on through the firing order.

Mark the balancer at 90 degree intervals, and then run through the eight crankshaft positions to adjust all sixteen valves.

Duke

 

Just when you thought you knew all the ways to do it.....

I might try that method, but it makes sense to believe that at TDC on say number 1 cylinder that both valves on number 1 cylinder would be closed as tight as possible meaning they were in fact on the base of the cam and that is the way I do it right now

The post about the polylocks is interesting and I am going to have to look at my polylocks because I use a Crane stud girdle on Comp Cams Hi Tech rockers I had to turn the ends of every polylock on a lathe to get them to fit in the rockers properly so they are actually thinner there.

 

Motorhead, i noticed mine were screwed up when i was adjusting one of the valves and when the feeler guage started to get tight as i was turning the poly, it sorta clicked and suddenly the feeler guage got super loose even tho i was still tightening the poly. My Polys had grooves machined into the bottom lip that had sorta flattened and created a detend in this particular poly. They finally all flattend and the rockers started holding lash. I hope that made sense to you.

 

You apparently don't understand mechanical lifter cams. They have clearance ramps that can be 100 degrees (crankshaft) long. Once the valve closes it can take up to 100 more degrees of crankshaft rotation for the cam to be back on the base circle, and the clearance ramp can start 100 degrees before the valve begins to open. Of course the valves are closed at TDC, but that says nothing about whether the lifter is back on the base circle.

I guarantee you that if you adjust the valves on the OE 30-30 cam at TDC they will be loose because both are still on the ramp. Unless you have an engineering drawing of your cam or have taken an accurate lift-crank angle diagram, you don't know where the opening ramp starts or the closing ramp ends because manufactures don't publish that data. The 30-30 cam duration from beginning of the opening clearance ramp to the end of the closing clearance ramp is over 540 degree long!

If you use my method you WILL be on the base circle. You can check whether you cam is on or off the base circle at TDC by checking clearance using my method, then check it at TDC and allow up to .002" runnout on the base circle, so check more than one cylinder.

Duke