i have put together a 383 with a .480/.480 lift cam and 1.6 rockers. now i think my heads are set up fo about .500 max lift is this a problem? i dont quite remember if they are set up for more or not i bought them off ebay and forgot the lift specs but if it is .500 max then will cause what i am about to describe? i ask this becasue i keep finding out that after a little while i have valve taps and have to adjust them. this is the second time in about a thousand miles. i am also finding small amounts of metal shavings. i originally had a gear drive then went to a timing chain so im not sure if the metal is form that or am i destroying my cam with the 1.6 rockers. will going down to 1.5's help with this? this is the first engine i put together so im kinda new to all of this. any help is appreciated thanx vinnie

 

So that's .480" lift with 1.5 rockers right?
So .512" lift with 1.6 rockers? You may have just clipped the safety margin shorter, but who knows. I would hope you would have measured clearance at max lift when you were assembling it?
If you have to adjust your flat tappet lifters often, you've wiped a lobe off your cam. Especially if you're finding metal shavings.
Sorry

 

the last time i found some shavings the cam lobe was still ok from what i could see and feel through the lifter hole. so if this is still the case should i go down to 1.5 rockers? with 1.6 rockers pushing .512 the extra pressure is felt on the cam i take it then. or should i just give up on this cam and start over with a new cam and 1.5 rockers?

 

granted the cam is still in good shape, then i would suspect the rocker studs are pulling out of the heads unless they are pinned or are screw in type.

 

i believe that they are the screrw in type unfortunatly

 

I'd have it running, and pull the valve covers. Make sure all rockers are moving the same amount.
How old is this engine and cam combo?

If I was in doubt about the condition of the cam, i'd also pull the intake and remove each rocker and pushrod. Then pull out each tappet and check the bottom. Big mushrooms is the telltale sign of a wiped cam.

If the cam is 100% ok, and your rocker studs aren't unthreading or pulling out, then your locknuts could be bad. But i'd still be wondering where that metal is coming from?

 

I wouldn't panic just yet. A certain amount of metal will come off of a new flat tappet cam during break-in. It's the amount that you found and where you found it that's important. If it looks like silver metalic paint and you found it in a cut open oil filter, it's probably normal. If you found it draining the break-in oil out of the pan and it is flakes larger than a grain of salt and there's a lot of them, then it is bad news.
Also there's how you adjust the valves. If you zero lashed them and added a full turn and you had to relash them - not good. Also if you had to tighten them more than 1/2 turn each time.
I set mine at zero lash and had to tighten them twice in the first 20 run hours. Probably 1/4 turn each time. They're happy now.
Well, the good news is that if you wiped lobes they will get worse fast. In another 1000 miles it won't be any secret.
If you do have to change the cam, break it in with 1.5's then change to the 1.6's . It'll improve your chance of success.

 

well right now one of the rockers are really loose the whole rockoer moves around pretty good probably about a 3/16" gap between the tip and top of the valve

 

well after adjusting the driver side 3/4 turn after zero lash the threads on the studs show 4 - 5 1/2 threads and the metal shavings are real fine not chunky and it is found in the oil sitting in the heads and not noticeable until you feel around the bottom of the oil puddle. when i changed my intake gasket i never noticed any trace of metal in the lifter valley.

 

This is a rocker problem and not a cam lobe problem. All oil sent up there is filtered. There's no way metal from the cam lobes will get up there. Pull those rockers out not the cam. My .

 

well if i replace the rockers which are currently roller tip rockers should i stay with the 1.6 or go down to 1.5's? stay with roller tip rockers or go to regular rockers. dont quite have the money to go with rollers. either way im going to also add the crane kool nuts which have a set screw so i dont have to mess with the valve adjustments.

 

I would pull a few rockers and check for interference. If the pushrod length is wrong or the rocker is hitting the stud, getting more of the same rockers won't solve the problem. Pull some and see what is wrong first. The difference in power between roller and non-roller, 1.6 and 1.5 isn't that big anyway. I favor durability over an extra 2-5 hp personally.

 

heres what i found after pulling one rocker on the passenger side i noticed that the pivot ball under the locking nut is all scratched up. i would say that it is afe to say that could be the cause of the small amounts of metal in the heads is coming from. so should i replace these rockers then and go back to 1.5 oem style rockers? or will it be ok to just put the kool nuts on these rockers to hold my valve adjustments?

 

I would pitch them all in the trash. Don't forget that your oil pump will have to pump any future metal that they will shed. Rockers are easy to change, oil pumps and crank bearings aren't. If you need something for a short time get some cheap stock style long slot stamped rockers. Flush out as much metal as you can, change the oil and save up for some good rockers later.

 

what style and size rockers would you suggest i save up for? also whats the best way to flush the oil out of an engine?

 

Just thought I'd mention something else you might want to check that could be the source of the metal you're finding. Sometimes when you put 1.6 rockers on, it causes the pushrods to rub excessively where they pass through the guide holes in the head. Machine shops usually elongate the guide holes as a safety margin when you tell them you're going to be using 1.6's. From what I've been told, it's a 50/50 shot as to whether they'll rub or not without elongating the guide holes. So take a look at your pushrods where they pass through the holes in the head to see if there's been any abnormal wear occurring there. For replacements, I'd suggest the 1.5 stamped steel style ones with the roller tip like Comp Cams sells. Those rockers usually are already long-slot style too, so that eliminates the worry of them binding on the rocker studs from the extra lift. If you don't find any abnormal wear on the pushrod guides, you could probably go ahead and use 1.6's again. As far as the pivot ***** go, try to get the grooved ones. They allow more oil to get between the rocker arm and the pivot compared to the smooth ones. Locking style nuts are always a good idea, but they're not a necessity. Make sure to get the shorter locking nuts for the roller tipped style rockers if you do decide to buy some. The ones for full rollers are slightly over an inch tall, and the ones for roller tipped are about .880" tall. Summit specifies the height and application info on most of their locking nuts if you click on "make sure this part fits my application".