Need a valve train diagnosis.
Thread Starter
TECH Senior Member
iTrader: (9)
Joined: Dec 2001
Posts: 5,395
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From: Estero, FL
Need a valve train diagnosis. After sheering a Harland Sharp rocker arm off at the PE130 open road race, I had to use 2 factory rocker arms as a crutch for a while.
Last weekend I took the car to a car show and on the way home when I came to a stop light I noticed a VERY loud ticking noise. It did the same thing right before the rocker arm let go at the race.
Today I finally get a chance to pull the valve cover. The first thing I do is check for tightness on the 2 factory rockers (ticking came from this location useing the "screwdriver stethascope"). The intake rocker was WAY loose. So I grab the TQ wrench and take it down to 22lbs. Even after that the rocker was still VERY loose. There was about a "1/4 gap between the rocker tip and the valve tip!!! I pulled the rocker off and got the pushrod out and gave it the roll test. Perfectly straight.
So it boils down to 3 things that I can think of.
1) Collapsed lifter
2) BIGTIME bent valve
3) Broken spring
I am pretty sure it isnt the spring, it still appeard to be in good shape.
Info on set up.
Comp R lifters
MTI 7.4 rods
Factory rocker arms
Farrea valves
MTI dual spring that came with the heads and cam combo. I cant remember the manufacturer.
Last weekend I took the car to a car show and on the way home when I came to a stop light I noticed a VERY loud ticking noise. It did the same thing right before the rocker arm let go at the race.
Today I finally get a chance to pull the valve cover. The first thing I do is check for tightness on the 2 factory rockers (ticking came from this location useing the "screwdriver stethascope"). The intake rocker was WAY loose. So I grab the TQ wrench and take it down to 22lbs. Even after that the rocker was still VERY loose. There was about a "1/4 gap between the rocker tip and the valve tip!!! I pulled the rocker off and got the pushrod out and gave it the roll test. Perfectly straight.
So it boils down to 3 things that I can think of.
1) Collapsed lifter
2) BIGTIME bent valve
3) Broken spring
I am pretty sure it isnt the spring, it still appeard to be in good shape.
Info on set up.
Comp R lifters
MTI 7.4 rods
Factory rocker arms
Farrea valves
MTI dual spring that came with the heads and cam combo. I cant remember the manufacturer.
Hey NataSS,
I had the same problem with HS rockers, and they replaced the broken parts for free. All they asked is that I sent them the broken ones. Might wanna give them a call, Mike Becker is the name to ask for, if I recall correctly.
Are we the only people who had this problem? HS told me that it happens VERY rarely. Anyone else?
I had the same problem with HS rockers, and they replaced the broken parts for free. All they asked is that I sent them the broken ones. Might wanna give them a call, Mike Becker is the name to ask for, if I recall correctly.
Are we the only people who had this problem? HS told me that it happens VERY rarely. Anyone else?
Thread Starter
TECH Senior Member
iTrader: (9)
Joined: Dec 2001
Posts: 5,395
Likes: 1
From: Estero, FL
HS sent me new ones a while ago. But I havent had time to put them in. This is on one of the factory rocker arms that I was using until the new ones got in from HS.
How can you tell if a lifter has gone south on you?
How can you tell if a lifter has gone south on you?
I was wondering what was going on with this. There are likely many ways to figure this out.....try this: Take off both of the intake or exhaust rockers (whichever one it is) next to the bad one. Lay a ruler across their valve stems. The bad one should be the same height. If it isn't, you bent the valve. But if it is, your lifter is toast. There are more sophisticated ways to do this, but I think this should work.
You can also run a compression check on that cylinder. If the valve is bent, your compression will be way down.
Let me know if you need help buddy.
You can also run a compression check on that cylinder. If the valve is bent, your compression will be way down.
Let me know if you need help buddy.
