bowtie350_428

I know this may sound like a broken record, but I would like to settle this once and for all. I have been reading conflicting opinions on this board on whether or not Roller Rockers are noisy. The same goes for Dual True Roller Timing Chains (not gears) and Retrofit Roller Lifters.

I have a 350 SBC with a set Pro Magnum Full Roller Rockers, Roller Cam (XR282HR), Roller Lifters and Roller Timing Chain all from CompCams and the valve train is a bit noisy. It sounds like I've got mechanical lifters or loud fuel injectors. And yes, the rockers are adjusted correctly.

So lets hear your opinions. Is noise is normal for this setup or is there a problem somewhere?

I really don't mind the noise too much, I just get paranoid and would like to set my mind to rest. Also if I ever go EFI, I wonder how to keep the knock sensor from going crazy.

Magman

iTrader: (6)

Ive got the same issue and I'm running EFI. My Roller Rockers are almost as loud as my SVO injectors which are audible from outside the car. I have re-set valve lash three times and verified pushrod length twice before I purchased a Stethoscope to really "hear" everything. Turns out, the roller rockers do make some noise but, my injectors are slightly louder. Guess I'll live with it since it all checks out. I would imagine Roller Rockers would get noisier with higher lift, I'm running .544/.555.

bowtie350_428

Is the Rocker noise enough to freak out your Knock Sensor?

Magman

iTrader: (6)

Zero knock counts to date with over 100 miles w/ datalogs that including WOT runs.

kdrolt

GM used a different knock module (which is really a signal filter) within the PCM for the LT4 engine specifically because roller rockers were factory installed. The LT1 (on which the LT4 was based) didn't use roller rockers, so that engine didn't have the clatter that the LT4 had. So at least based on GM's experience, the roller rockers make more noise than non rollers, that's why they needed a different knock module to filter the signals from the block-mounted knock sensors.

As far as roller lifters are concerned, I don't think they are as much of a noise maker as rockers are because rockers are intermittent-contact devices -- while lifters are always in contact with the cam lobe (even if there is no lift). So you don't get the same clatter with a lifter that you get with a rocker arm. And FWIW GM got +5 hp by switching from flat tappet lifters to roller lifters, based on the power specs of the Corvette engine when they made the change from flat tappet to roller lifter (1986 vs 1987, IIRC). HTH.

406TPI

iTrader: (1)

I almost always get noise when I use Comp cams for some reason. I'm not saying they aren't any good, just seem to be a little noisy.

CAH383

I have the Crane Gold 1.6 RR's on my 383 and they are noisy. I have adusted too many times. I am also running LS1 injectors which I have heard are noisy in TPI style intakes. I just finally gave in to the fact that my motor is noisy. One night at my local hang out I had a guy with another 3rd gen stroker drive in, carbed even and it sounded just like mine. That made me feel like that must be the way it is.

bowtie350_428

Thanks for the responses. Maybe they are just like that. I am getting used to the noise anyway and have no complaints. I just wonder why they make noise. I am thinking of calling the guys at CompCams to see what they say.

Does anyone have anything to say about noise from the roller timing chain?

bowtie350_428

BTW, I almost forgot to mention, I have read some posts here where some believe that Rollers Rockers on a Hydraulic Cam should always quiet.

So if anyone here believes that they should NOT make noise and you actually have a set of quiet Roller Rockers, please lets hear your opinions as well.

Thanks

jbenge

iTrader: (2)

My comp cams hydraulic roller is a little noisy. You can't hear it inside the car or anything like that but you can hear it especially when the hood is open and you are standing near it. Its not obnoxiously loud but it does make noise. It seems like the retrofit hydraulic roller setups tend to make some noise especially with the fast ramp rates of the newer cams like the comp XE series. I've never heard any noise from the roller timing chain.

Jer82Z28

I have comps' pro magnum rollar rockers with rollar lifters and cam and my lifters make a lot of noise.
you can easily hear inside the car while driving and definatly with the hood open listening to the covers.

I've adjusted three times and no matter how tight i go they dont shutup.

If I knew these were going to be this loud i would have went with something else.

Lo-tec

I have a comp roller cam with the factory roller setup, and pro-magnum roller rockers. This was very noisy at idle when I put it together using a brand new set of stock GM roller lifters. It sounded kind of like a sewing machine. I have noticed this on a couple of different factory engines in my friends cars, a '92 vette LT1 and an '89 L98. Noisy noisy noisy! I recently switched to comp-R roller lifters and it quited down alot.

88305tpiT/A

iTrader: (2)

Yup mine are very noisy and Ive adjusted many times. Soulds almost like a small exhaust leak.

Dzhezkov

iTrader: (1)

If you adjust your rockers properly at engine operating temperature, they should make very little noise when up to temp, but they will likely make a racket when cold.

antman89iroc

I know this is an old thread but I just installed a set of full rollers and they are very noisy. In fact I believe they are causing a lot of knock retard. I have adjusted the timing down so far it runs like crap and still I get retard with the stock KS. Does anyone know of a different sensor that will work with the 165 maf computer? I am almost at the point of turning off the sensor and I really hate to do it. Any suggestions???

88305tpiT/A

iTrader: (2)

Mine actually quieted down with use and I have Comp Pro Mag full rollers on 2 motors, one with factory OEM roller lifters, the other with retro fit Comp roller lifters. Nither show significant knock counts though - even though you might be able to physically hear them.

Something I have heard of to reduce knock sensor sensitivity is that some guys used to space the KS off the block by adding a pipe thread standoff that screws into the block water jacket hole and then screwing the KS into that. the standoff reduces the sensitivity somewhat. I have heard of guys doing that to compensate for full gear timing sets, solid lifters and other stuff that would confuse the KS.

BTW, nice job finding this thread after 7 years!

55chevlover

I just installed a 91 TPI in my 55 Chevy with roller rockers.....it runs great at full throttle until about 3500 rpm then it feels like someone attached a train to the bumper. My valves are noisy and I wonder if the KS is picking up the rockers and retarding my timing. Is there a way to verify this is what is happening without an analyzer of some sort? I have adjusted many a lifter and I just can't quiet these down. I have debated on going to a roller tip or the factory stamped steel rockers just to verify my suspisions but I hate to tear it all apart a 5th time to adjust rockers. Any ideas or help would be much appreciated.

antman89iroc

Thanks for the input. I do have the brass standoff on the KS and I am going back thru the rocker setup to make sure everything is as close to perfect as I can. Will see if it quietens down. I don't really mind the noise just want to eliminate it as a source for the KR.

BTW 55 I don't know of a way to verify KR without a scanner. But it's fairly straight forward to download TunerPro and make or buy an interface cable. Tuning gets a little more involved but would probably be worth the effort. Even a stock motor in that shoe box probably needs a little tweeking. If you have changed anything like egr, removing the AIR tubes, purge can etc there is a need to alter the tune. If you have changed the CR, cam, intake tract/filter it will definately benifit from a retune. If you're just gonna "try" different rockers I go back to stock and see. RR's do seem to cause some issues but my guess is you also need a tune change too.

55chevlover

Thanks for your input... I had a retune done as I built the engine so most of that stuff has been taken into consideration. At this point I am just concerned that the rocker noise is jerking my timing around. I will probably talk to the guy who tuned the chip for me and see what his input is also. I wonder how much HP I will lose going back to standard rockers with 1.5 ratio as opposed to the 1.6 roller rockers? Where can I but a interface cable for the OBD1 plug? Any ideas?

antman89iroc

Horsepower 1.5 vs 1.6? I suppose it depends but not much. If you are also going from rollers back to stock maybe 5-10 hp. I think pulling the timing out would be cutting a whole lot more hp.

ODB1 cable and interface are available from moates.net (or .com?) get the cable and interface box. I think they were ~$80 + shipping. Or if you are handy and have a 232 serial port on your computer you can make one. I believe there is a link somewhere on the stickys. I made my first one for $0 by digging up free parts. But my new laptop doesn't have the old style serial port and I bought moates cable. Works great.

cuisinartvette

Yup!

ASE doc

I run Crane Gold Race narrow body 1.5s. I think that alot of my valve train noise is just because of the huge cam(240/240 @ .050 .560/.560). The ramps on the ZZX are very fast, producing alot of valve movement in a short span. It would have to be hard to keep that quiet.

I have never noticed any noise from double roller timing chains. Installed many of them. I run a Cloyes in this 355.

bk2life

..how about adding another 5 years.. LoL

NoEmissions84TA

iTrader: (1)

Nobody mentioned that aluminum valve covers amplify valvetrain noises.

DynoDave43

iTrader: (11)

Really. I would have thought that due to their density Vs. stamped steel, that they would be quieter.

Vader

Also late to the game, but did anyone notice the correlation between factory roller cams and single row roller chains, and shortly thereafter plastic rocker covers?

sofakingdom

iTrader: (1)

That is correct: that's why so many parts that were formerly "tin", are now cast aluminum.

For the record, ALL LSx motors (4.8/5.3/5.7/6.0/6.2 etc.) have roller rockers; Vettes, F bodies, Cadillacs, trucks, GTO, etc. I haven't noticed them being considered notorious for valve train noise or anything like that, over the last 20 years.

cardo0

I can eblaborate on this noisy issue. Has any owner verified rocker arm and p-rod clearance when installing roller rockers?? I say this because most owners are expecting bolt on of expensive parts w/o extra effort and details. Let's think about this. Does a roller bearing make more noise than a pivot ball?? I think not or your drive shaft U-joints would be screaming. . And your wheel bearings too.. And given your using aluminum rockers you have more dampening also.

So that leaves us with some mechanical interference of the rocker arm to the valve spring retainer, the rocker stud and the fit of the p-rod in the head slot or guide plate. If you look on Crane Cams w/s you will find specs for the rocker arm clearances but myself I use a small diameter un-bent paper clip and verify the entire motion of the valve lift from base circle to max lift and back down to the base circle. For the p-rods you want a very smooth slide through head slot or guide plate but no drag or binding - this is while still making a centered pattern on the valve tip with the rocker tip.

Finally let's look at the oiling of the rocker arm roller bearings and tip. You may have to watch the operation and inspect the oiling from the p-rods. You may consider the irreversible operation of cutting/grinding some slots in the rocker to promote better oiling. But use caution as you can't realistically undo what you cut out.

Hope this can help more than it hurts.

antman89iroc

I have been over and over on this topic. Cam swaps with larger base circle, various length pushrods, different adjustment methods, sheet metal vs cast valve covers etc.
I have come to the conclusion that the lobe intensity is the major factor in a noisy valve train. The only thing I haven't done is gone to a milder lobe. Currently running 229/237 and ~600 lift with 1.6's. I strongly considered going to 1/5s last go around but didn't think it would be enough difference.
I have had some reliability issues over the past years. Pushrods galling, roller lifter cups breaking, valve springs breaking etc. Most of that was traced back to springs getting fatigued and losing control of the valve train. After the spring change (now running 160/480 ouch!) and double checking EVERYTHING it has run a lot of daily driver miles and a couple dozen 1/8th mile trips. But it is as noisy as ever.
I have also paid a lot of attention to cars I am around or view on the internet. Lots of SBC and LS performance motors seem to have noisy valve trains. Even one of the "cam sounds" on Comps web site has a noisy valve train on the sound clip!
I even installed thick cast valve covers and extra heavy duty under hood padding. It did help with the hood closed, but then when you get beside the car you can still hear it bouncing off the ground and coming out from under the car.

DynoDave43

iTrader: (11)

Wait..what? I was right? Can I show this to my wife?