Valvetrain and Random Noise...
Thread Starter
Racer
Joined: Jul 2017
Posts: 364
Likes: 103
From: Atlanta
Valvetrain and Random Noise...
I have recently assembled and installed the following things:
- Blueprint 383 shortblock MLL-BP38318SP with installed roller cam and lifters
- AFR Enforcer heads with guide plates and rocker studs
- 7.3 BTR hardened pushrods (length measured correctly using pushrod tool)(contact pattern on top of valve is perfectly centered)
- Comp Cams High Energy 1.6 roller rockers
I have some valvetrain noise. I have tried adjusted the valves several times, including with the engine running, but I cannot seem to get the noise to go away. It seems like there is lifter ticking from #6 or 8 cylinders. I have also loosened, and tightened all header bolts as well. Here is a video of it running:
I also can hear something that I can only describe as a metallic grinding noise coming from somewhere I cannot isolate. You can mostly hear it when the sound is reflected off a hard surface such as another car or wall, but I admit that it is really hard to catch on video.
I have removed the rockers and inspected the pushrods, and I can see that a few of them have some ever-so-slight visible "brushing" marks on them from slight contact with the guide plates, but nothing I would say represents excessive contact (ie. No burrs or tangible texture).
Where should I start?
- Blueprint 383 shortblock MLL-BP38318SP with installed roller cam and lifters
- AFR Enforcer heads with guide plates and rocker studs
- 7.3 BTR hardened pushrods (length measured correctly using pushrod tool)(contact pattern on top of valve is perfectly centered)
- Comp Cams High Energy 1.6 roller rockers
I have some valvetrain noise. I have tried adjusted the valves several times, including with the engine running, but I cannot seem to get the noise to go away. It seems like there is lifter ticking from #6 or 8 cylinders. I have also loosened, and tightened all header bolts as well. Here is a video of it running:
I also can hear something that I can only describe as a metallic grinding noise coming from somewhere I cannot isolate. You can mostly hear it when the sound is reflected off a hard surface such as another car or wall, but I admit that it is really hard to catch on video.
I have removed the rockers and inspected the pushrods, and I can see that a few of them have some ever-so-slight visible "brushing" marks on them from slight contact with the guide plates, but nothing I would say represents excessive contact (ie. No burrs or tangible texture).
Where should I start?
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
You say the contact mark in the valve-stem is dead-center perfect.
But.
Because you are using 1.6 modified rocker arms, I question whether you have a spring retainer to valve guide clearance issue.
Or a rocker arm to retainer contact (rubbing) issue.
Both of these scenarios are not uncommon with 1.6 rockers. Things begin to bind, make noise.
But.
Because you are using 1.6 modified rocker arms, I question whether you have a spring retainer to valve guide clearance issue.
Or a rocker arm to retainer contact (rubbing) issue.
Both of these scenarios are not uncommon with 1.6 rockers. Things begin to bind, make noise.
Melting Slicks
Joined: Jul 2006
Posts: 2,291
Likes: 493
From: Salmon Arm, BC
I think what you're running into here is a noisy valvetrain due to a cam with very aggressive opening and closing ramps. I had a look at the cam specs and they match perfectly with Comps XR282HR camshaft. I had the XR276HR variety in my engine and noted a lot of valvetrain noise...much like a solid cam. I got sick of it and pulled the cam.
I recommend you do a search on the web about Comps XR grinds and the associated valvetrain noise that is widely reported.
I recommend you do a search on the web about Comps XR grinds and the associated valvetrain noise that is widely reported.
Thread Starter
Racer
Joined: Jul 2017
Posts: 364
Likes: 103
From: Atlanta
I will admit, I started off in the Ford world where 1.6 ratio was standard so I probably ordered these rocker arms without thinking... Looks like I'm ordering a set of 1.5 rocker arms, and I'll let you all know!
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Having the rocker travel centered on the valve stem is not the goal. Minimum sweep of the rocker on the valve stem is. That may or may not be a centered pattern on the stem.
Try again with the adjustable pushrod, only this time aim for minimum sweep and see where it comes out.
Try again with the adjustable pushrod, only this time aim for minimum sweep and see where it comes out.
