Ratty tat tat under the valve cover.

wanab5150 · #1 (**permalink**) 10-22-2013, 10:38 PM

I know some of you have had rocker arm issues but I can't figure this one out. The engine is a Roush 427R/524 HP version with Scorpion rockers and unknown lifters and cam. Roush will not give out the specs. on the cam. The car ran flawless on a 600 mile trip 3 weeks ago and I did not hear anything unusual until I drove it several days later.

I heard a very faint mechanical noise I've never heard before. I could only hear it at about 2000 RPM cruising or on 3500 to 1000 RPM deceleration where it was the loudest. Even then, it was faint.

With my 5 year old ...never used...Harbor Freight stethoscope, I listened to the water pump, alternator and all the lifters through the valve cover. All sounded the same except the #8 cyl. That one spot over the valve cover seemed to have a slight tapping that was not consistent and did not sound anything like a loose rocker.....just an odd noise that was NOT coming out of the drivers side valve cover.

I checked all the rockers and all are free and none are cracked.. So my question is....Does this sound familiar to anyone. Depending which site you read some say roller rockers and roller lifters last a lifetime and others say they last 20-30K miles. I am in the process of re-adjusting the valve lash, confirming the header bolts are still tight and changing the plugs (just because they have 19K on them).

I had one guy state he has heard of the needle bearings in roller lifters flatten out with a high lift cam which will slowly lead to the valve lash being less but other than that I'm out of ideas. Any answers from the Peanut Gallery? Confused Tom. PS............. please pass this on to anyone you may think has an answer or good guess.

Gaz64 · #2 (**permalink**) 10-23-2013, 02:54 AM

Hi many miles has this engine done?

Pull the rocker covers, measure the valve lash.

Could be the start of a roller lifter failure.

patrickt · #3 (**permalink**) 10-23-2013, 06:36 AM

Tom, if you frag a lifter, it will be a very bad day.

If this was my engine, I would pull all the plugs and remove the valve cover on that side. Then place the tip of the stethoscope on the push rods, coming in from the back of the head. While you do that, manually rotate the engine using the crank bolt, a deep socket, ratchet, and long pipe (or your jack handle). If you can consistently hear a difference with that one lifter/rod, as you go through full rotations, and the other cylinders are reasonably consistent among themselves, and don't have the anomaly sound, then you're going to have to remove the lifter.

ERA Chas · #4 (**permalink**) 10-23-2013, 07:34 AM

Quote:

Originally Posted by wanab5150

The engine is a Roush 427R/524 HP version with Scorpion rockers and unknown lifters and cam. Roush will not give out the specs. on the cam.

Roush won't give you the cam specs because they're embarrassed. At 524 HP you're in no danger of having a high lift cam.
Open it up and check for a lost keeper and broken valve spring or damper.

jhv48 · #5 (**permalink**) 10-23-2013, 09:35 AM

I second the lifter problem. My Roush, at 13,000 miles when I rebuilt it, had a couple of marginal lifters. Replaced all of them. After the rebuild, I experienced a slight tapping noise. Come to find out, two of the brand new crower roller lifters were defective. Replaced them all again and so far all is good. If it is the lifter, you want to catch it early before it destroys the bore.

rodneym · #6 (**permalink**) 10-23-2013, 10:57 AM

Could it be a broken valve spring before all hell breaks loose?

Rick Parker · #7 (**permalink**) 10-23-2013, 09:03 PM

Another area to keep an eye on is the axle for the roller tip. It is heavily knurled on one end and then pressed in the rocker arm body. Sometimes they can work loose or worse the aluminum can begin to fracture at the area where the roller tip axle passes through the body, THEN it gets ugly.

MFE III · #8 (**permalink**) 10-24-2013, 06:42 PM

Quote:

Originally Posted by Rick Parker

Another area to keep an eye on is the axle for the roller tip. It is heavily knurled on one end and then pressed in the rocker arm body. Sometimes they can work loose or worse the aluminum can begin to fracture at the area where the roller tip axle passes through the body, THEN it gets ugly.

Ugly like this?

Rick Parker · #9 (**permalink**) 10-24-2013, 06:47 PM

AFFIRMATIVE!!!!, Lucky you caught YOURS early.

cobra 53 · #10 (**permalink**) 10-25-2013, 05:37 AM

Talking about needel bearings:

Found on cyl. nr. 1(exh.valve) a "hightech fixed" rocker stud!!!

Brocken thread and fixed with a file, and the rest or the thread was over tight in the nut.

Rocker was only holding in place with 1-2 thread on the stud and the nut fixed with the valve girdle!!!

Holding the rocker in the hand and turning the roller tip, totaly 7 of the needels are falling out fom the tip bearing. Dont ask me wher and how they are comming out.

Rico

Voyager · #11 (**permalink**) 10-25-2013, 10:59 AM

Tom - any luck addressing your faint mechanical noise?

I’m getting a slight (?) tapping sound from my 2 year old, 4000 mile Keith Craft 408. Could be normal, not sure.

Another winter project…

Bob

Rick Parker · #12 (**permalink**) 10-25-2013, 11:00 PM

Cobra53:
Those rollers look to be from the trunion bearings that are in the sides if the rocker arm. Replace the rocker arm set, and rocker studs. A single one of those rollers will lock up the oil pump if it is ingested through the pump screen, then you'll really have a problem. Suggest you pull the pan and clean out the bottom. The very small ends on the rollers appear to be missing from some of them. That will allow them to get misaligned and bind, perhaps creating the clicking you are hearing. You may find you need longer studs too. You've got some work ahead of you to get it right.

Gaz64 · #13 (**permalink**) 10-25-2013, 11:03 PM

Quote:

Originally Posted by cobra 53

Talking about needel bearings:

Found on cyl. nr. 1(exh.valve) a "hightech fixed" rocker stud!!!

Brocken thread and fixed with a file, and the rest or the thread was over tight in the nut.

Rocker was only holding in place with 1-2 thread on the stud and the nut fixed with the valve girdle!!!

Holding the rocker in the hand and turning the roller tip, totaly 7 of the needels are falling out fom the tip bearing. Dont ask me wher and how they are comming out.

Rico

A clear example of parts mismatch.

Pushrods too long, or studs not long enough.

The needles must be from the fulcrum, can't see how they would come out of the roller tip.

Scorpions clearly not as good as Crane, Harland Sharp, Jesel etc.

I'd be sending the engine back.

cobra 53 · #14 (**permalink**) 10-26-2013, 02:14 AM

Good morning again ??

Rick and Gary, you hit the nail!

After an good cup of strong cafe I moved to the snake nest.

Checked the replaced roller rocker and desmantled it. Not much amused about the resulte.

This means, I have to controlle all the rockers on the engine. Nice sunday morning work.

Roller rocker - YouTube

Gaz64 · #15 (**permalink**) 10-26-2013, 04:18 AM

Yes, thought so.

Now you need somebody to help you rebuild the valvetrain correctly, with better quality parts.

cobra 53 · #16 (**permalink**) 10-26-2013, 12:36 PM

No way to wait until Sunday - full of curiosity!

Mounted the better rockers back into the engine incl. one spare I got.
Adjusted valve lash and started the engine.

No more noises, but at higher engine temperature noises were starting again fortunately with less "chin chin chin"-noise.

So I took the rockers out at the passengers side. All rockers have a light diagonal movement in the trunnion bearings. One of those in a bad condition.

The two bad rockers were at cyl. 5 exh. and cyl. 1 int.

This would make sense regarding the noise located at front around the distributor area.

I think it will be time to think about what has to be changed and replaced.

I might need some help, as I have to order the right parts because of the high transport and Spanish custom / import taxes. 35-40%! depending on the day, if it is sunny or rainy

.

For now I want to thank you all for your kind help and I will be back with this topic lateron...

wanab5150 · #17 (**permalink**) 10-26-2013, 07:19 PM

We have multiple winners.......I checked all the rockers and they appear fine. I adjusted all the valves with 1/2 turn of preload. I turned the engine over several times with the starter the grabbed each lifter to confirm they were not loose. I found three that were loose with about .020 lash....wtf!

I assumed I did something wrong and loosened all the lock nuts again and started over. Again I cycled the engine and felt for loose rockers.....THERE THEY ARE AGAIN!

This time I rotated the engine and as the exhaust started to close I checked the loose rocker and it was snug??????????????? Then, I rotated the engine a bit and there the slop came back........On 3 rollers, no less!

Off came the intake and I found 3 lifters with slop in the needle bearings. The worst was .026 and the other 2 were about .020 slop. The rest were tight but I used a dial indicator and all were virtually immeasurable.

It made my day to find the bad roller lifters. Now I could use some recommendations on a new set. These have no name on them but have "AC8" on the side. I know nothing about rollers but am going to replace all of them..........Recommendations???

Also, I have a question regarding rebuilding the Roush engine at 15K miles.....Why?

FWB · #18 (**permalink**) 10-26-2013, 07:29 PM

for any roller application, Crower, or Morel i just don't trust anyone else.

i see Isky has a bushed lifter with no roller bearings but i have never used them nor have i ever talked to anyone that has. they look interesting though.

patrickt · #19 (**permalink**) 10-26-2013, 07:58 PM

There's like a billion hydraulic roller lifters out on the roads today -- these weren't solid rollers in an FE.

Must have just been really, really crappy parts. I would not be happy.

jhv48 · #20 (**permalink**) 10-26-2013, 09:14 PM

Quote:

Originally Posted by wanab5150

Also, I have a question regarding rebuilding the Roush engine at 15K miles.....Why?

My Roush was sucking oil down the valve guides at 13,000 miles. We did a leak down test and found a couple of cylinders were at 35% leak down. When we took off the heads to do the guides and seals, we found a couple of cylinder bores were scratched and the rest looked like they had 100,000 miles of wear. So, we pulled it apart and found two pistons with small cracks. That's why the full rebuild.
If your oil use isn't excessive, do a leak down and see what you find. If all is ok, just replace the lifters and leave the rest alone.