I just fixed a blown head gasket and I’m having trouble adjusting my Cranecams 1.6 roller rockers. I went to shoebox’s website and adjusted the rockers with engine off. Now with the engine running, it idles fine, but when I’m driving, the car is sluggish. I don’t think they are on to tight because I do not hear any valve tapping. Could I have them on to loose? It’s just really hard to tell with the car running. I do hear an occasional slap, not very constant, is this a pushrod loose?

 

Having your valves too loose would cause you to loose lift, which could hurt performance. What preload is recommended for your Crane lifters?

 

I dont know the recommended preload. I just preloaded 1/4 turn and when doing that the nut didn't want to tighten up anymore.

 

I would amost think they're too tight. Does it seem like the starter is struggling at all during startup?

 

No, the car fires right up.

 

When you found they didn't want to tighten past 1/4 turn, did you figure out why? Was it just that the jam nut (or whatever you want to call it, on my Gold Race there is an allen head screw in the top that jams down to hold the preload) wasn't backed out to allow you to go deeper? Or were you by chance bottoming the lifters somehow (wouldn't think so but I would have questioned why it didn't turn further).

I've found that 1/4 turn is too little for me, I prefer 1/2 or 3/4. Currently I'm running 1/2. However, there shouldn't be a problem with 1/4 turn, just maybe a bit noisier afaik.

I'd suggest pulling the covers and re-doing the rockers. Also, I'd suggest 1/2 turn past zero lash (but anything 1/4 to 3/4 should be ok). To find zero lash, just spin the pushrod while you tighten until you start to feel drag from the rocker. Make sure the locks are turned out so you can get the adjustment that you want then tighten the locks back down nice and tight. Also, are you doing this with the car off or on? I've done it both ways, and had good luck either way, just if doing with the car off, doublecheck that you are adjusting the proper valves for TDC and BDC.

Good Luck.

 

Ok, please bear with me! I have never worked with 1.6 roller rockers before and I did not know that there was a allen screw inside the locking nut. So now my question is, how do I adjust my rocker with this allen screw? When I took off the rockers I never touched that allen screw.

 

Sounds to me like they might be a bit tight.

I just recently started messing with rr's also. The easiest way i found is to do it with the car running. Just loosen them one at a time untill you hear it start the clack, then re-tighten it untill it stops and then go 1/8-1/4 turn farther. Make sure that allen screw is backed out plenty far.

That allen screw is the lock thats keeps the rockers in adjustment.. If you adjust them with the car running once loosen it and retighten it and the rocker stops clacking get your allen wrench in and just snug up that set screw then get your wrench back on the rocker nut and go your extra 1/8-1/4 turn. This will make that lock good and tight and they shouldnt loosen up on you anymore.

Hopefully when you pull the valve cover all those locks are still in the rocker nuts and havent backed out and disapeared.

 

If they are too tight, make sure you check to make sure you didn't bend a pushrod.

Dan

 

Thanks for the replies! I’m beginning to think that my problem is not the valve adjustment. I have them set were I hear no valve noise and the car idles nice and smooth, but I’m having the same problem as I had with the blown head gasket. I HAVE NO POWER AT ALL!!! When I hit the gas, it as if I have no compression. Feels exactly the same as when I blow the head gasket.

 

No Problem. As stated above me, the allen screw just holds the adjustment. I kinda figured that that might be the missing piece of the puzzle. I've failed to loosen that allen screw once or twice and basically you can only relash back to whatever it was before (thus your 1/4 turn past). Just make sure it is screwed out a turn or so allowing you plenty of room to re-lash.

I get to zero lash (running or not, however you want to do it), then go in 1/2 turn (or whatever you want, 1/4 to 3/4), then tighten the allen down nice and tight. Some people tighten both another little bit to make sure the allen is well seated (however, I haven't had trouble with mine backing out, with just tightning the allen down).

My guess is that the rockers lash isn't even among the rockers and maybe it is throwing stuff off a bit. Hopefully it is that simple for you to get it running right again.

Good luck.

 

Thanks wile2k for your advice

I will try one more time in the morning adjusting the valves. If I don't fix it, I hate to say it, I will have to take it to a shop

 

ok, I have a stupid question for ya. Do you have a catalytic convertor on the car? You say you blew a head gasket, and if any anitfreeze got onto the cat. Consider it junk. They do not like contaminates like anitfreeze or raw fuel as if either of these hit the catalyst in the convertor, they become clogged or will dramatically cut down on exhaust flow. I had this happen to one of my T/A's and it felt like something was holding the motor back.

 

, well, I was typing while you were posting.

Sorry to hear you are still having problems. Maybe run a compression test to rule that out? Could also pull the plugs and see if they are all burning properly. Maybe have a cyl that isn't firing (sounds odd but I had that when I first got my T/A and it still seemed to run ok)? Just lots of things that could cause a loss in power, probably going to take some troubleshooting for you to figure out what the problem is.

Again, good luck.

 

scratch what I said, I just seen you dont have a Cat.