HELP - VORTEC 5.7 #7 Cylinder Rockers lack of oil
05-30-2023 | 11:02 AM
#11
Thread Starter
Gold Member
Joined: Oct 2000
Posts: 492
Likes: 9
From: Tampa, FL USA
The rockers have to be self aligning if there are no guide plates.
The early Vortec heads were known for the guides being too tight and hanging valves open under heavy load. The Chevy dealer used to bring me heads to open the guides up by .001" But it would be rare for it to be the same ones and the fact that only two rockers are getting hot is strange. Comp had a problem with the real early roller tip rockers having the oil hole drilled wrong and they would do that but that was a long time ago.
I have never been a big fan of 1.6 rockers on small blocks. I would rather get the right camshaft to begin with.
Unfortunately you are probably going to have to pull the head to see what is going on. Hopefully the engine came with some type of warranty ?
The early Vortec heads were known for the guides being too tight and hanging valves open under heavy load. The Chevy dealer used to bring me heads to open the guides up by .001" But it would be rare for it to be the same ones and the fact that only two rockers are getting hot is strange. Comp had a problem with the real early roller tip rockers having the oil hole drilled wrong and they would do that but that was a long time ago.
I have never been a big fan of 1.6 rockers on small blocks. I would rather get the right camshaft to begin with.
Unfortunately you are probably going to have to pull the head to see what is going on. Hopefully the engine came with some type of warranty ?
05-30-2023 | 11:03 AM
#12
Thread Starter
Gold Member
Joined: Oct 2000
Posts: 492
Likes: 9
From: Tampa, FL USA
The rockers have to be self aligning if there are no guide plates.
The early Vortec heads were known for the guides being too tight and hanging valves open under heavy load. The Chevy dealer used to bring me heads to open the guides up by .001" But it would be rare for it to be the same ones and the fact that only two rockers are getting hot is strange. Comp had a problem with the real early roller tip rockers having the oil hole drilled wrong and they would do that but that was a long time ago.
I have never been a big fan of 1.6 rockers on small blocks. I would rather get the right camshaft to begin with.
Unfortunately you are probably going to have to pull the head to see what is going on. Hopefully the engine came with some type of warranty ?
The early Vortec heads were known for the guides being too tight and hanging valves open under heavy load. The Chevy dealer used to bring me heads to open the guides up by .001" But it would be rare for it to be the same ones and the fact that only two rockers are getting hot is strange. Comp had a problem with the real early roller tip rockers having the oil hole drilled wrong and they would do that but that was a long time ago.
I have never been a big fan of 1.6 rockers on small blocks. I would rather get the right camshaft to begin with.
Unfortunately you are probably going to have to pull the head to see what is going on. Hopefully the engine came with some type of warranty ?
05-30-2023 | 12:56 PM
#14
Platinum Member
Joined: Jun 2004
Posts: 7,317
Likes: 1,032
From: frankenmuth michigan
Sounds like your issue right there., thats why I asked. We had a customer bring in a 97 or 98 tahoe, had new crate l31 vortec in it, he had changed the cam, put on regular roller rocker arms and it bent up some pushrods. With no guideplates OR self aligning tips, the rocker will roll off valve an eat/bend a pushrod, in his case it was # 8 and he ran it long enough to blow a plunger out of a lifter. I have some new takeoff gm selfaligning roller rockers, the real good ons gm uses in the crate engines I would sell. Id have to check the ratio if your interested, Smitty
05-30-2023 | 04:30 PM
#16
Registered
Joined: May 2020
Posts: 213
Likes: 50
From: Wyoming
Just looking at the picture, your roller isn't in the middle of valve. It's off to the side. It appears to have slipped off too. There's a nick out of the side of the roller.
I guess I can't post your picture. I saved it the drew arrows to the damage and circled the wear pattern on your roller.
I guess I can't post your picture. I saved it the drew arrows to the damage and circled the wear pattern on your roller.
