loud rockers

[Kgbronco]

Alright fellows, I have built a new 331 stroker for the bronco and the rocker noise is stupid loud. I have a 91 roller block, RHS heads, Pro comp cam, lifters, guide plates and pushorods (35-410-8 is the cam number going off memory). I have a set of 1.7 scorpion roller rockers. The total lift is .600 which is exactly what the valve springs are rated for. I have checked rocker clearance, valve cover clearance, springs bottoming out and all are ok. I set the valves per comp cam directions and now have tried it all the way from 1/4 to full turn past 0. Can't tell much difference. Has anyone had any experience with similar situation?? When I say they are loud I mean it sounds like 16 tamp dancers under the hood. I know I have a short duration cam with a pretty good lift but It should not be this loud.

 

[DJs74]

Are the rocker arms full rocker or just rocker tips? And what was the reasoning for 1.7 ratio instead of 1.6?

If the 1.7 rockers were used by design to match the surrounding components and it all checks out, great... If not, that might be contributing to the noise


DJs74

 

[Amac70]

its just a loud set up. I equate mine to a sewing machine. fair amount of lift short duration equals loud. i run a 35 510 8 i can hear the lifters over everything else if standing in front of the truck.

 

[C Saporito]

Check your rocker arm geometry, especially if you used aftermarket parts from different vendors.

My pushrods rubbed on the head slightly at full lift, the noise was very loud but hard to see. Once I checked the geometry and changed to shorter pushrods the noise stopped.

 

[Kgbronco]

Alright, thanks for the replies. Motor was planned for 1.7 rockers from get go.
I understand if it sounded like a sewing machine, I've had that but this is more like tap dancers. With this new motor the exhaust is extremely loud (changing that next) and I can here rockers over that. I can actually here them at 40 mph with no top.

I triple checked pushrod length before installing and I pulled a rocker off last night and I have a nice small line in the middle 3rd of the valve. One thing I noticed is that I can twist some of the rockers depending whether valve open or closed and can easily make pushrods hit guide plates. Am I wrong thinking the pushrods should be going straight up and down in normal operation?

 

[C Saporito]

What size valves? Some aluminum heads actually spread the valves out to fit a larger diameter, if that's the case your pushrods would have to be on a slight angle to the lifter.
I can see it on my 408, but I'm not sure on the 302 based heads.

 

[DJs74]

Alright, thanks for the replies. Motor was planned for 1.7 rockers from get go.
I understand if it sounded like a sewing machine, I've had that but this is more like tap dancers. With this new motor the exhaust is extremely loud (changing that next) and I can here rockers over that. I can actually here them at 40 mph with no top.

I triple checked pushrod length before installing and I pulled a rocker off last night and I have a nice small line in the middle 3rd of the valve. One thing I noticed is that I can twist some of the rockers depending whether valve open or closed and can easily make pushrods hit guide plates. Am I wrong thinking the pushrods should be going straight up and down in normal operation?

Is this a new build and noisy from the beginning or did the tapping develop after the fact?

From your P/N 35-410-8 mentioned earlier, the camshaft / lifters are hydraulic roller - so it's possible you have may have a geometry issue as mentioned or the combination of the roller rockers and roller lifters together are just noisy.

the lobe lift on that particular camshaft is specified at .333 so with a 1.6 ratio rocker, you would've been at .533 valve lift but since you are running 1.7 ratio, you are actually at .566 valve lift, you gained 0.033" of valve lift with the 1.7 rockers so you might double check the spring coil binding. I know you stated the valve springs are OK to .600 but the cylinder heads have to be able to handle the lift too. Did you check the installed height of the springs spec and actual?

What cylinder heads?
Oil Pressure OK?
Power OK?
Everything functioning properly and just noisy or do you think the noise is causing ill performance?
Notice any considerable wear marks on the guide plates / push rod to cylinder head clearance?


DJs74

 

[Kgbronco]

Valves are 1.940 and 1.60, 20*. I'm pretty sure...

 

[ren71]

What kind of valve covers? Big sound difference between cast aluminum, thin tinny chrome, or sheet metal covers. I'd redo the adjustments again and make sure the hydraulic roller lifters are properly filled by soaking them in oil and pumping them manually.

 

[Rustytruck]

Sure the rockers are not hitting the valve cover?

 

[Kgbronco]

Dj, this is a new build and it was loud from the start. It is loud from idle to 4000 rpm. I have only driven it 30 miles because it's starting to worry me. I have a ton of dough in it and rather not do it again. The only thing that isn't new in it is the spider tray. I have RHS 3510 assembled heads. I checked coil binding on the engine stand because after measuring actual lift it was .600. Oil pressure is 30ish at idle and 40ish driving. I had to go back with stock pressure pump because the hv would not fit in my ford racing pan at time of assembly. I admit I was shocked it only oiled up about 1" over head when I started it without valve cover on. Power is really good.

 

[Lon L]

I feel your pain, I currently have my Bronco in the shop, among other things a new CompCam kit was installed . EFI guy suggested the Cam I think it is 349-50-8. Summit had the complete kit so it should all be matched. Once installed the engine seems to run great , however the ticking/tapping of lifters is quite loud. So it is still at the shop for further evaluation. They are supposed to pull the valve covers today. I hope that they find something, because I am not fond of the thought of having to listen to them click.

 

[Kgbronco]

I have cast aluminum tall valve covers, and they are not hitting. My problems never seem to be that easy. Lifters seem fine, in fact I called pro comp tech line to triple check if my lifters would handle my duration and lift and they assured me they would.

 

[Kgbronco]

Lon, I would love to hear what happens with yours.

 

[DJs74]

Dj, this is a new build and it was loud from the start. It is loud from idle to 4000 rpm. I have only driven it 30 miles because it's starting to worry me. I have a ton of dough in it and rather not do it again. The only thing that isn't new in it is the spider tray. I have RHS 3510 assembled heads. I checked coil binding on the engine stand because after measuring actual lift it was .600. Oil pressure is 30ish at idle and 40ish driving. I had to go back with stock pressure pump because the hv would not fit in my ford racing pan at time of assembly. I admit I was shocked it only oiled up about 1" over head when I started it without valve cover on. Power is really good.

If you don't see any obvious interference, everything is matched, performance is good, all vitals are good - you might just have a noisy valvetrain motor. I think I would call Comp Cam and tell them the story and see what they say since the components are primarily their brand except the rockers... no chance you have a bad header leak and just assume its the valvetrain is there??

I'm not sure what else to offer

DJs74

 

[DJs74]

Dj, this is a new build and it was loud from the start. It is loud from idle to 4000 rpm. I have only driven it 30 miles because it's starting to worry me. I have a ton of dough in it and rather not do it again. The only thing that isn't new in it is the spider tray. I have RHS 3510 assembled heads. I checked coil binding on the engine stand because after measuring actual lift it was .600. Oil pressure is 30ish at idle and 40ish driving. I had to go back with stock pressure pump because the hv would not fit in my ford racing pan at time of assembly. I admit I was shocked it only oiled up about 1" over head when I started it without valve cover on. Power is really good.

The RHS heads don't happen to have any ports in the ends that needed to be plugged do they? Just thinking that maybe there were some intersection ports drilled in the ends of the heads that needed 3/8" pipe plugs or something that got forgotten at RHS

DJs74

 

[Rustytruck]

I would worry if you have all of the oil plugs in under the timing cover. What oil filter are you using? maybe its bypassing. Did you check the slot in the rockers and make sure their not hitting the studs. 30 lbs pressure at idle and 40 lbs running seems low for a new motor. How much do you trust your pressure gauge?

 

[Amac70]

Heres a vid of mine for comparison, I can hear them inside the cab when driving. they would seem louder in this vid but the trans fan is also out drowning them out a little. If you listen right about 50 secs in you can hear the sewing machine good right before the fan kicks on.

[youtube]I-2meUCHInw[/youtube]

 

[Lon L]

Lon, I would love to hear what happens with yours.

I will post here once I have an update. Which I was hoping would be today.?:?

 

[savage]

I would worry if you have all of the oil plugs in under the timing cover. What oil filter are you using? maybe its bypassing. Did you check the slot in the rockers and make sure their not hitting the studs. 30 lbs pressure at idle and 40 lbs running seems low for a new motor. How much do you trust your pressure gauge?

I think for a rebuilt motor, the oil pressure seams low. My 302 ( not a roller) is rebuilt and at start up, 50 to 60 oil pressure, then when warmed up 45 to 50.