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Follow-up to "Do Roller Tip Rocker Arms Need Constant Adjusting?"

fine69

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'69 Convertible Vette; '72 Z28 Camaro Rally Sport
fine69 said:
I have a recurring problem with my roller tip rocker arms... they keep becoming misaligned with the valve/spring! I adjusted them last week, and the engine was running nice and strong. Today it started missing, sputtering and backfiring again. I removed the valve cover, and the rocker arms were misaligned again.
I have the Performer RPM .510 lift cam (hydraulic) and wanted to be able to use the LT-1 style valve covers. These are 1.5 ratio roller tip rocker arms.
I attached a photo. Is this milagnment and readjustment characteristic of these type of rocker arms? Should I revert to the standard style i.e., "shoe" type? Any suggestions/recommendations are appreciated.
Thanks!

This is a long post, and I apologize.

I decided to create a new thread as this problem is heading in a new direction.... I maaaay have a sticking valve problem.

In addition to the rocker arms becoming misaligned, a persistent problem has been misfiring and backfiring coming from the left exhaust.

What's been done:

- roller tip rocker arms replaced w/stamped type.
- guide plates readjusted.
- distributor replaced.
- points, condenser replaced.
- set timing, points, dwell.... not very well.

While the rockers now maintain alignment, I still have the misfiring/backfiring problem.

The technician from the machine shop worked on it today. He told me in the past he had worked on a set of brand new heads that had to be removed from a Camaro resulting from "old" gasoline. He said that the internals of the heads had become completely coated with a thick, sticky resin and actually affected functionality. No problem for them to clean, but of course this means removing and reinstalling the heads - but in the car this time.

My car sat dormant from March through November 2005 with approx 1/8 tank of gas. Last summer was pretty nasty, and I noted that some of the gasoline appeared to have evaporated. I simply added more, and didn't know I should have used some type of stabilizer.

The engine initially ran well when I first got it started, with a slight misfire (I presumed it was the distributor). I kept advancing the timing and it appeared to help - but the problem has now intensified.

Has anyone ever heard of this sticky valve condition from old gas? Could it truly affect brand new heads in this manner? It could possibly explain why the roller tips slipped off track.

Thanks and again, sorry for the dissertation. This is incredibly frustrating.

Ralph
 

wishuwerehere82

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Corvette
Red '82 Coupe,Sebring Silver '98 Coupe
Ralph,

I have seen old gas clog up a lot of carburetors in the past, but no valve stems. Sitting for less than a year would not constitute "old" gas in my opinion. Varnish can build up on your valve stems, especially if you have experienced a loss of coolant at some point and overheaded the heads.

After reading your previous post and seen how your rockers are moving off the valve stem, I do think you have a sticking problem with at least one of your valves.

If it was me, I would add a top cylinder lubricant like Marvel Mystery Oil directly through the carburetor throat and see if it will lubricate the stems enough for the problem to go away, then add a little to the gas to continue lubricating the valve stems as you drive. Just drip it into the carb while you rev the engine. It will smoke while you do it but it will burn off soon after you stop. That will lube the valve guides from the bottom through the intake, rather than through the valve seals. It should remove any varnish on the valve stems.

If it doesn't work, I would pull the heads and investigate the sticking. you may need to have some new guides installed, or you may have a bent valve stem.
 

Jack

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Dec 27, 2000
Messages
1,825
Location
Florence, SC (Timmonsville SC)
Corvette
71 War Bonnet Yellow VERT 71 BH Blue CPE (SOLD)
Ralph:
Weren't the BRAND NEW edelbrock rpm heads installed NOV 05 or since NOV 05? ... sticking valves from deposits in NEW heads having NEW bronze guides & NEW valves? ... sticking not so likely ... but if so, that's probably an EB QC issue from improper guide-to-stem clearance ... or a valve stem may've bent while guide plates were misaligned.
JACK:gap

-edit- but I'd sure try the MMO tip from wish82.
 

fine69

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Messages
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Location
Maryland / D.C.
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'69 Convertible Vette; '72 Z28 Camaro Rally Sport
wishuwerehere82 said:
Ralph,

If it was me, I would add a top cylinder lubricant like Marvel Mystery Oil directly through the carburetor throat and see if it will lubricate the stems enough for the problem to go away, then add a little to the gas to continue lubricating the valve stems as you drive. Just drip it into the carb while you rev the engine. It will smoke while you do it but it will burn off soon after you stop. That will lube the valve guides from the bottom through the intake, rather than through the valve seals. It should remove any varnish on the valve stems.

Pete, thanks for the tip. I'm going to try your Marvel Mystery Oil suggestion.
 

fine69

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Joined
Dec 12, 2004
Messages
975
Location
Maryland / D.C.
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'69 Convertible Vette; '72 Z28 Camaro Rally Sport
Jack said:
Ralph:
Weren't the BRAND NEW edelbrock rpm heads installed NOV 05 or since NOV 05? ... sticking valves from deposits in NEW heads having NEW bronze guides & NEW valves? ... sticking not so likely ... but if so, that's probably an EB QC issue from improper guide-to-stem clearance ... or a valve stem may've bent while guide plates were misaligned.
JACK:gap

-edit- but I'd sure try the MMO tip from wish82.

Jack. Yep these were brand new, out of the box heads from Summit.
Interestingly though, the heads were actually scratched up from shipment and needed to be milled before installation.

I did find it rather odd that old gas could have this much of an affect on a totally rebuilt engine.

Also, I just changed the oil and have only been able to take one short trip to the gas station (less than 5 miles total), and short test rides around the block. I'd say, a total of 25 minutes running time . I did notice that the oil has turned dark very quickly and that it (the oil) has a "sharp" smell... like gasoline.

Thanks for any advice.

Ralph
 

74bigblock

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Joined
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Messages
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Location
Barrington, IL
Corvette
2008 Z06
fine69 said:
Jack. Yep these were brand new, out of the box heads from Summit.
Interestingly though, the heads were actually scratched up from shipment and needed to be milled before installation.

I did find it rather odd that old gas could have this much of an affect on a totally rebuilt engine.

Also, I just changed the oil and have only been able to take one short trip to the gas station (less than 5 miles total), and short test rides around the block. I'd say, a total of 25 minutes running time . I did notice that the oil has turned dark very quickly and that it (the oil) has a "sharp" smell... like gasoline.

Thanks for any advice.

Ralph

Interesting... another person with a shipment from Summit that got banged up in transit... they don't pack their stuff very well. I just lost an intake manifold to their lack of product concern. Did you document the problem with Summit before you had them milled?

Hope you get to the bottom of your issue soon.
 

fine69

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'69 Convertible Vette; '72 Z28 Camaro Rally Sport
I used Marvel Mystery Oil Gas Treatment in the tank, and also used a product called Seafoam in the carburetor and in the crankcase.

It smoked like the dickens, but the constant backfiring stopped. Took her for a spin. Unfortunately, she still runs like garbage... spitting, sputtering, and no power.

Some things I noted:
  • To get a steady idle (i.e., prevent stalling), timing has to be advanced so much that the mark cannot even be seen with the timing light.
  • In the carb, on idle, gas drips sloppily from the left primary (this is the also side of misfire/backfires) - the drip is not changed at all by adjusting the mixture screw.
  • When I shut off the engine, it diesels (one "cough").
  • The gas/air mist continues to waft out of the carburetor after shutoff.
I worked on this between commitments today, but ran out of time. I'm going to re-check the TDC to make sure that I didn't miss a tooth or two when I replaced the distributor.
 

Sensei

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Messages
393
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Jacksonville, Fl
Corvette
'81 dark blue
Carb problems will drive you crazy! Did you have the carb rebuilt along with the engine? What carb are you using? God bless, Cris
 

fine69

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Joined
Dec 12, 2004
Messages
975
Location
Maryland / D.C.
Corvette
'69 Convertible Vette; '72 Z28 Camaro Rally Sport
Sensei said:
Carb problems will drive you crazy! Did you have the carb rebuilt along with the engine? What carb are you using? God bless, Cris

Thanks Cris,

It's a 650 cfm Edelbrock Thunder Series AVS. It was purchased brand new. I don't think the dripping thing can be normal...
 

ernbuild

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Joined
Mar 30, 2004
Messages
82
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BRISBANE/AUSTRALIA
Corvette
91/ZR1
similar problem

fine69 said:
This is a long post, and I apologize.

I decided to create a new thread as this problem is heading in a new direction.... I maaaay have a sticking valve problem.

In addition to the rocker arms becoming misaligned, a persistent problem has been misfiring and backfiring coming from the left exhaust.

What's been done:

- roller tip rocker arms replaced w/stamped type.
- guide plates readjusted.
- distributor replaced.
- points, condenser replaced.
- set timing, points, dwell.... not very well.

While the rockers now maintain alignment, I still have the misfiring/backfiring problem.

The technician from the machine shop worked on it today. He told me in the past he had worked on a set of brand new heads that had to be removed from a Camaro resulting from "old" gasoline. He said that the internals of the heads had become completely coated with a thick, sticky resin and actually affected functionality. No problem for them to clean, but of course this means removing and reinstalling the heads - but in the car this time.

My car sat dormant from March through November 2005 with approx 1/8 tank of gas. Last summer was pretty nasty, and I noted that some of the gasoline appeared to have evaporated. I simply added more, and didn't know I should have used some type of stabilizer.

The engine initially ran well when I first got it started, with a slight misfire (I presumed it was the distributor). I kept advancing the timing and it appeared to help - but the problem has now intensified.

Has anyone ever heard of this sticky valve condition from old gas? Could it truly affect brand new heads in this manner? It could possibly explain why the roller tips slipped off track.

Thanks and again, sorry for the dissertation. This is incredibly frustrating.

Ralph

Ralph had a very similar problem with mine. Complete rebuilt engine along similar lines to yours. Try changing the plugs as unleaded fuel can cause a build up of sorts around the porcilan causing them to short out, even when they are new. Trying to clean it off wont work either. Dont get a really expensive set first and try it. I tried all sorts of things to fix mine and most of it was plugs. The other was the butterflies in the primries were not shutting off fully and a small amount of fuel got down into the manifold causing it to diesel on as you put it.
Regards Ernie.:beer
 

fine69

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Messages
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'69 Convertible Vette; '72 Z28 Camaro Rally Sport
BAD NEWS

That "miss" turned out to be a broken exhaust valve spring in the #5 cylinder. I spent so much time looking at #3, I must have overlooked it. I'm walking away from working on her for now... this is a total bummer as I am sure that this will not be a matter of simply replacing the spring.

Thanks all for your help and suggestions....

-R
 

wishuwerehere82

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Messages
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Corvette
Red '82 Coupe,Sebring Silver '98 Coupe
Well, look at it this way, you found the problem.
This might be a good time to match the springs to the cam instead of using the ones that came with the heads.:)
This really sucks, considering these are new heads. But it is still early in the season, so you have time to get it right.
 

fine69

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Messages
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'69 Convertible Vette; '72 Z28 Camaro Rally Sport
wishuwerehere82 said:
Well, look at it this way, you found the problem.
This might be a good time to match the springs to the cam instead of using the ones that came with the heads.:)
This really sucks, considering these are new heads. But it is still early in the season, so you have time to get it right.

Thanks for the encouragement... these heads were supposed to be part of a system (i.e., Edelbrock Performer RPM system) and I find it troubling that the spring would break... and also wondering what caused it to break.
 

74bigblock

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Joined
Sep 30, 2003
Messages
1,163
Location
Barrington, IL
Corvette
2008 Z06
fine69 said:
Thanks for the encouragement... these heads were supposed to be part of a system (i.e., Edelbrock Performer RPM system) and I find it troubling that the spring would break... and also wondering what caused it to break.

Hopefully it was just a bad spring.
 

74bigblock

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Messages
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Location
Barrington, IL
Corvette
2008 Z06
Any news?? You got her running again?
 

fine69

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Messages
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Maryland / D.C.
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'69 Convertible Vette; '72 Z28 Camaro Rally Sport
74bigblock said:
Any news?? You got her running again?

Nope, not yet anyway. I'm moving away from the EB Performer RPM stuff and changing to a more appropriate cam... so I 've removed the cam and also the left cylinder head. The parts (cam, lifters, Performer (not RPM) manifold) are on order and the head's at the shop--- I'll keep you all posted.

Thanks for checking...

Ralph
 

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