Noisy 383 after cam swap...

[tufamc]

hello all,

I have a 2bbl 383, I just swapped the cam for a Lunati VooDoo 302 cam lifter kit, more of a mild cam in a 440, and a bit bigger for a low compression 383... Don't blast me here, but here is what I did. Simply swapped the cam, lifters, summitracing (good) timing chain, did NOT degree in the cam, simply dot to dot, tho i did use a piston stop to find tdc on no.1. Reused stock rockers, rocker shafts, locks/retainers, now the springs....i reused what was there, only cuz the person I bought the car from, had the heads redone just before i picked it up (receipt showed new springs, tho i have no idea what they are) and about 1500 miles on springs now total. Soaked new lifters before install, plenty of cam lube/zddp, Valvoline vr1 20w50. reassembled, all seamed well...

Now the noise..... I had none/zero/nadda valve train noise before the swap...upon start up, the lifters clattered for like 5-8 seconds (thought no biggy, had that happen on other cam swaps)...now upon EVERY (cold) start there is lifter clatter for 2-3 seconds or so.....zero valve train noise at idle to 1500rpm, after that the valve train clatter gets louder, not super loud, just enough to say, hey that was not there before....cruising at 2500rpm, now that its on my mind, its all i cam hear!!

So I'm wondering if I have some bad NEW lifters?...I know some bigger cams just make more noise, but not really on a hydraulic lifter..

coil bind, with the new(ish) springs?...worn out rocker arm/shafts....what do ya all think??

I think I'm  just going to replace the lifters with parts store replacements, they have the Melling brand in stock

when i had the valve covers off, i could spin the pushrods that were not being pushed up buy the lifter, the ones that were on the flat part of the lobe, you slide the rocker side to side a little bit, in the pic you can see the light through the rocker/shaft, normal??


THANKS!!!

[Chryco Psycho]

Well the Lunati cam has more lift so the wear pattern on the rocker arms is probably shorter than what you had before , so the rocker is tipping over more & making a noise as it hit the ridge worn into the rocker arms . I have seen this before using old rockers with newer higher lift cams . Not sure what cam you removed .
The noise at start up is probably because the lifter bleeds down on the valves that are open & it takes a second to pump back up .

[tufamc]

Ok, makes sense, first shaft rocker v8, the old cam, I have to assume its the stock 2bbl camshaft, the OE timing chain was on it, when I put in a new chain/gear set when I first got it, 2 years ago, and it also had the 2bbl intake on it.....

So you think its just a new wear pattern wearing in...so should I just give er' a bit more miles?, replace only the lifters, or do it all....shafts/rockers/lifters....id rather not replace the springs (hate doing them in the car)...she is a old tired motor, never see light past 5000rpm

Thanks

[tufamc]

Oh BTW, the engine runs Awesome, night and day difference, zero driveability issues, just nosier, I swear it has 40-50 more Hp, according to my butt-o-meter, fun to drive.....can't even think what my stroker is gonna be like

[Chryco Psycho]

The best fix is new rocker arms , if you do that the PRW set may be a good option . The stamped rockers are not very accurate as far as the ratio goes though , even using a non worn set of stamped rockers should stop the noise . It doesn't look like you have coil bind assuming the picture is with the lifter at peak lift & the lifter has not bled down at all .
You used new Cam & Lifters correct ? If so there is no point in installing new lifters again . Just replace rockers & shafts . Do you have a part # on the springs , you maybe light on spring pressure but you may never have a problem if you keep it under 5000 RPM anyway .
Those Cams work very well , I am glad you are happy with result of the swap with the added power & good drivability 

[tufamc]

Yes used the NEW lifters that came with the camshaft kit. I will order a new set of rockers today, sense I'm there, ill do the shafts too, tho they don't look worn, must be made of harder material. That pic of the springs is at peak lift, by rotating the engine, judging by oh so sharp eyes, right after a warm engine shut down, i would think the lifters haddent bled down by them.

Thanks

JR

[bobs66440]

Did you check the lifter preload? It should be between .020-.040. I am running around .055 with no issues. If the preload is too loose, you will have noise.

[tufamc]

With a measuring stick?....NO, with my eye, YES. That said, I did watch the lifter cup, move in a "bit" while torquing down the shafts, seamed no more and no less, than the set up that was in there before...

On a side note, I do have new push rods (summit racing brand), but there the cheap o's with pressed tips, i reused the OE ones, because they are one piece....with the new rockers, should i use the new ones, or reuse the OE ones again?

[bobs66440]

While torquing the rockers down and watching the plungers "move in a bit", was each lifter at the BASE of each lobe as you went along? The adjustment needs to made at the base of each lobe. If the lifter was on any other part of the lobe, you are not getting proper preload.

The OE push rods should be ok as long as they're not bent and your spring pressure isn't too high. You really need to know the spring pressures to know if a pushrod is appropriate.

Did you check for coil bind on the springs?

[tufamc]

Ya I hear what your saying about the "adjustment"...but there is none (stock non adjustable). I'm fairly certain my spring pressures aren't too high, there new(er) but I'm sure they are just a stock replacement, don't think there is any coil bind,  rotated engine within 7min of shutting off, that where the pic if the spring came from, seams most of the noise is coming from the drivers side

[bobs66440]

I know the rockers are non adjustable. Thats what makes it such a pita and so important at the same time. Just because it worked with the old setup doesn't mean it will with this. There are slight differences in the components. The adjustment needs to be made with pushrod length. If you say everything is good, then I would check the rocker tips for a ridge as mentioned, but they would really have to be worn with a bad rigde to make such a noise IMHO.  

[Chryco Psycho]

We did the exact same thing , built a 383/438 stroker , , my customer installed the rockers & pushrods himself , fired it up , broke the cam in & it had a weird knocking noise ,disconnected the fan belt to eliminate water pump etc , tore into the engine & check a lot of things , finally asked about the rockers , he said he just used the original ones , pulled them off & looked at them & they have ridges worn into the tips  of some of them . Same situation , Lunati cam with a lot more lift , around .500 not the .440 the factory cam had , replaced the rockers with PRW Stainless rockers & the noise stopped .