Noisy Valve Train

[73RRBob]

Hello Everyone,

It's been quite a while since I posted on here last, however I do read the topics and find them very informative.

I have a fairly new 512 stroker in my 73 RR, I've driven it for about a summer and found towards the end that the valve train on the passenger side was a little noisy i.e. almost like "chatter". I pullled the VC and felt for excessive play, didn't find any except on cylinder 8. It was a tight fit but I was able to fit in a  .006" feeler guage, is this acceptable or is it excessive?

Thanks in advance for your help

[c00nhunterjoe]

In looking at your old posts, its a hydraulic roller. So there should be preload on the lifters. 1 of 2 things has happened.  The rocker adjuster came loose, or you wiped a lifter/cam. To go from preload to .006 lash, thats a ton and would be evident by looking at the threads on the rocker compared to the others.

[73RRBob]

Thanks for the advice....

I didn't look at the threads but it makes sense. If it appears to be loose, then I guess I would follow HS's instructions on setting preload and see what If there's still play. If there is, then would a compression test in that cylinder compared to other cylinders tell me that it's a wiped lobe or lifter? I'm guess yes.

Does that make sense? Thanks again.

[John_Kunkel]

.006" lash with the engine off might mean nothing. Hydraulic lifters can bleed down when sitting.

[73RRBob]

Guys, after re-reading my post and your replies, it occurred to me that I may've miscommunicated my findings.

When I said there's some play in the rockers, I meant to say side to side movement of the rockers.

With #8 I/E rockers on the heel of the cam, there was .006 clearance between the intake rocker arm and the spacer or shim, which when talking to Randy is nothing, if anything maybe not enough as Randy says that 015" - 020" Is acceptable bolt to bolt (1 cylinder).

My whole post was due to the "rattle/chatter" I can hear on the passenger side of the VC. I doesn't appear to go away when she's fully warmed up.

Can anyone tell me how I can compress a video file down to 400kb to upload here so you guys can have a listen? Maybe that's a better way to diagnose the issue.

Thanks
Bob

[XH29N0G]

I think what you have to do is to make video and post on youtube using the upload link and then post a link to that video here.

[73RRBob]

Thanks, that's what I'll do in the the couple of days guys.

[73RRBob]

As per your advice, here is a link to a YT video with my engine idling. It's a hydraulic roller cam with Harland Sharp 1.6 rockers. The sound doesn't go away once the car is hot and it wasn't this noisy right after the rebuild.... it was about a summer after that it started getting noisy.

The sound on my iPhone is crappy, The sound in reality,  sounds more Deep and like a knocking, not Sharp and ticking
Like in the video. I hope that makes sense, the engine has a few thousand miles on it.

https://youtu.be/nUBH8i7DPEU

What do you guys think?

Thanks Bob.

[firefighter3931]

Bob,

What oil are you using ? Did the noise start after a recent oil change ? I heard one make similar noise when the owner switched to full synthetic oil from std oil.

Are you using baffles inside the M/T valvecovers ? It's possible the rocker arms are hitting the baffles assuming you have them installed in the M/T covers. Seen it before with those covers and Harland Sharp rocker arms.

What cam are you using ? What rocker arm ratio ?


Ron

[73RRBob]

Hi Ron,

I am using full synthetic oil. However, the sound was there before the oil change. Yes, there are baffles inside the MT Covers. I only pulled the passenger side to check but didn't see any signs, either on the baffle or Rockers of rubbing, but it doesn't mean they're not making contact right?
I suppose I could remove them from both sides and see if that fixes the problem. Failing that, I could change the oil to mineral based and give that a go, since The oil before the full synthetic was semi-synthetic.

The HS Roller rockers are 1.6 and the cam is a Comp Cams 650 lift and 248/252 @ .050".

Thanks
Bob

[c00nhunterjoe]

Make sure the pushrods are not hitting anything either.

[firefighter3931]

Hi Bob,

Here is what I would do :

(1) Remove baffles. The contact point is the adjuster which is the highest part of the rocker assembly with the valve fully open. With .650 lift i would be surprised if it wasn't making contact with those M/T valvecovers.

(2) While the VC's are off run the valves and make absolutely sure you have enough pre-load. Don't forget to account for the aluminum head expansion when setting the pre-load. I usually add .004 to compensate for thermal expansion.

(3) Change to a semi synthetic oil. I like Brad Penn 20/50 semi synthetic and have been using it for years in two different street/strip builds.

Update us on your results 


Ron

[73RRBob]

Hey guys,

Thanks for the advice. I took off the baffles on both VC's, no difference. Harland Sharp states on their website that most of their rockers will have clearance issues with stock VC. Even though, M/T aren't stock, they are not that tall either.

HS also recommends removing the bolts from the VC but leaving the VC in place and have your hand rested lightly on them while  cranking the engine to see if they move, they do not.

However, I'm not convinced that they are NOT rubbing because I see a very slight amount of the orange paint removed on some of the corners of the rockers (where the rocker contacts the valve stem.

I'm thinking the only way to know for sure is to run the engine with the VC's removed on both sides. I don't have scrap VC's and was wondering how much of a mess it will make? I've seen people cut cardboard and place them around the valve train to reduce splash.

I would like to try this AND change the oil to semi-synthetic to see if that solves the problem BEFORE i mess with the rockers. I've never adjusted them but will if I have to, with your assistance. Thought I'd try the easier methods first.

I did check one set of rockers (cyl on the heels of the cam and there's actually LESS clearance ( side to side) than what HS recommends between cylinders ie (.015 -.020)

[73RRBob]

hello everyone,

This is a follow up to my noisy valve train. Just to refresh everyone's memory, 512 stroker, victor heads/1.6 Harland Sharp Roller Rockers with 1.650" offset.After checking a few things such as baffles, M/T Valve covers, changing oil back to semi-synthetic from full syntec to no avail, I decided to take it to a shop, I believe they found the source of the noise/knock.

There is interference between the underside of the rockers and the valve retainer or valve spring. The shop told me that the springs are too big for my application. They only took off the passenger side but found at least 2 pushrods slightly bent.

I checked the build sheet which shows 929 comp cam springs, I called comp cams, they told me that the 929 springs are 1.553", but Harland Sharp tech page shows that the rockers I have will clear a 1.650" spring. My lift is 640/648" and it's a comp cam roller.

I measured the retainer with a vernier caliper 1.450" springs are 1.540", i'm not an expert with the calipers but these numbers are very close. The pushrod diameter is .375" and they are marked with 10.000 .080. If you take a look at the pics, you can see the interference, the pushrod also have a wear band closer to the top. If you see the video, you can see the clearancing  done on the heads. It seems tight. The passenger side is noisier than the drivers side, and the wear marks show more interference on the passenger side. The rockers in the video are from the drivers side, the rocker pics are from the passenger side at the shop.

I need help guys, where do I go from here? Randy from HS Tech said that I could send the rockers back to him and he can shave some material off underneath and while he doesn't like doing it very often, he has had to a few times and there hasn't been any issues.

The victor heads have been cnc'd. There should not have to be the need to clearance them if from the factory they say these rockers will clear 1.650. I understand heat and expansion might come into play, but how much? I'll attach some pics and the video link to youtube.

https://youtu.be/SjNTE7MtnV8



Thanks guys in advance.

[73RRBob]

Forgot to mention one more thing, the lock nuts for the adjusters are supposed to be 7/16" 12 pt. Unless I'm going crazy, the 7/16" 12 pt wrench is too small and a 1/2" has too much play where I'm afraid of stripping it. I feel like taking the motor back to the builder, who is supposed to be a local reputable builder, but he had once of his guys look at my car and the noise and he told me that it was common for these rockers to be noisy like this, however, the noise didn't sit well with me, it's not just a clicking sound, it sounds like a clacking or even resembles a knock. Not taking his word for it, I took it to the shop who found the interference. I wonder what lock nuts those are on there? It's like a 13 mm but even that doesn't fit snug.

Thanks again in advance. The car will be going in for body work in September and I really want to figure this out, it's depressing because it's a fresh build with about 1000 miles on it, if that.

Bob.

[cdr]

Contact Mike @ B3 Racing he makes a custom geometry correction offset shim for the rocker shafts. it will give you room for the springs. will have to get new pushrods
http://www.b3racingengines.com/