JoeliusZ28

OK, ive done some reading on this and I know that it is perfectly normal for pro mag rockers to make some noise. I believe I have mine setup correctly but I cant help but be paranoid about it because I dont know what kind of sound these should be making.

I am not really concerned about the 'volume' of the noise I have, I am more concerned about the type of sound. When I listen to the engine under the hood, everything sounds normal - consistent, very light ticking all around. What concerns me is that driving the car it sounds as though I have only 1 or 2 "sewing machines" under my hood instead of several. It is not a loud sound at all, but I can still hear it with my cutout closed all the way up to probably 2500 RPM or so (light load) before engine noise begins to overcome it. It doesnt seem load dependent at all. Engine seems to run perfectly fine from what i can tell but the tune isnt 100% yet.

I do not want to risk damaging a lifter so Id like to know if this is normal. I pre-loaded my rockers *(1/6)* turn after doing the "spin test." Should I pre-load them more?

Thanks in advance.

krillformula

I have the exact same sound you are describing. At first I was a little paranoid but I guess it is the way they sound. I have checked preload etc. more times then I remember and also pushrod to guideplate clearence..
If I have the radio on and cruising at 2-3k rpms I cant hear it so I dont care anymore..

Green96Z

What kind of lifters do you have? Preload for stock lifters is 1/2 to 3/4 turn past zero lash.

wrd1972

The sewing machine noises are normal for all roller rockers. Just a fact.
Just insure your preload is set correctly. I run 1/4 PZL with mine, however some claim that if you run more preload then the noise will be reduced. However my experience tells me it does not matter.

Also the noise is amplified as cam agressiveness goes up. Mine were rather quiet with the LT1 cam. With my LE cam they are a bit louder.

I have wondered if aluminum body rockers might be any quieter that pro-mags. Who knows?

JoeliusZ28

stock/original lifters.

and actually I am not sure if it was an 1/8th turn or a 1/4 now - i guess if i cant remember I should go reset them...

slomarao

mine did the same thing for a week. After that it completely went away.

JoeliusZ28

well my memory came back to me, I did 1/6 of a turn for sure.

WS6T3RROR

Every set of pro mags i have ever seen/owned has been loud. The ones on my most recent setup in my 355 were so loud people accused me of having a solid roller in it. Cruising at low speeds you could clearly hear them inside the car and most certainly outside.

I switched to scorpion rockers and they were about 1/4 as loud as the pro mags were, you had to pop the hood and stick your head a foot from the valve cover to hear them much at all. Drove on them for 10k with no issues all were in good shape when I checked them before I sold them to a friend who has run them for 20k since then. I plan to use them on some other stuff and see how they work there.

I have since switched to shaft rockers and they do not make a sound. My injectors are all you can hear under there clicking now.

I hate lots of underhood noise.

Incidentally, if you have a problem it will be a noise that will cause you a great deal of concern. The normal roller rocker sound is kind of a flat sound, problem valvetrain sounds are very pronounced and more of a snap usually.

RallyBoy1

Dang, now I hate that I bought pro-mags! I also hate noises under the hood.

wrd1972

Not knocking the Scorpions, but the Pro-mags are stronger than the aluminum bodies and more resistant to punishment. But obviously a bit louder.

I am thinking of getting some scorpions in the near future as well to reduce the sewing machine noise.

JoeliusZ28

If the noise is normal i can deal with it, i just want to be sure of that. I dont consider it obnoxious, I havent had anyone but myself notice it. Basically Im just wondering if my 1/6 pre-load is too loose.

I drove the car again today and made some more observations. When the motor is cold I dont hear much of anything, the sound presents itself more as the engine reaches temperature.

It also seems that the noise is at its worst right around 3000 RPM with very little load... I would say that IF i have slack in the valvetrain this the condition it presents itself because the engine doesnt seem to run quite right although that could also be my spark timing. I didnt want to go any higher than that without load on the engine in case there is slack. But under load at RPM i hear nothing and the car pulls hard.

Last observation which i should have said before is that I believe i started hearing this sound when i switched from the conventional break-in oil back to the Mobil 1.

WS6T3RROR

Joeliusz28, that sounds exactly like all the pro mags i have had. Cruising through town in 3rd at 35mph you would swear to everything holy that i had a solid cam in it. After I heard it bouncing off other cars and buildings it was not a week before they were for sale here. The noise was better at cold temps than when it was hot, I believe it is due to the oil thinning out and running off faster whent he engine is warm. If it doesnt bug you then dont worry about it. Mine were most certainly louder under low/no load, and I did not notice them under wot or passing conditions.

wrd1972, you are absolutely correct about the strength. However, consider that the life of a part is related to the amount of stress it sees and the cycles of loading it sees and the materials strength. With most street cams and springs you will never find the service life of the rocker arm body if correctly designed, the bearings are a different story. Still yet rocker arms are a "throw away" item just like springs are, those little needle bearings aint going to last forever and nobody ever posts ratings for the bearings they use (shame shame). Its good from time to time to buy a new set and sell your old set off to somebody on ebay.

wrd1972

I started a thread a while back that never really took off asking who makes the best quality rockers. That takes into account the bodies and the bearings.

How about Scorpions, the new comp aluminum ones or Cranes?

WS6T3RROR

I dont think you will ever get a spec for the bearings from any of them, so it will be really hard to tell. The pro mag no doubt has a very large bearing in it compared to the others since it is much much wider and has a larger od on the pin. Size is a very good indicator of what the bearing can do, but quality factors in as well.

Generally the lower the load on the bearing vs what its maximum capacity is the life will be quite a bit longer. That is why its probably best here to just go with whoever has the largest bearing (likely pro mags assuming comp has a good quality bearing in there rather than a pos thats large to just avoid failing).

JoeliusZ28

WS6 would you recommend i try a tighter setting or just leave it alone?

As far as the noise issue goes I might just get a set of LT4 covers someday but I think the noise I have is very much on the light side right now compared to some videos ive been watching.