Poly lock adjustment?

[Bonnewagon]

I was helping a friend with a fresh Chevy 350 and when it came time to adjust the roller rockers, it got messy. His place, not mine, so no proper tools and extra parts to help. Normally I like to adjust them dynamically with the engine idling, with the clips in place, or a cut down valve cover in place to catch the oil. His engine had a tunnel ram with dual quads that couldn't idle below 1500 rpm and the rockers had an oil discharge hole that squirted oil right at the lock and the rocker flung it right over the side of the head onto the headers. The clips didn't fit these rockers, and we had no gasket for the cut-open valve cover and the cover bolts had long shoulders to secure the wire looms so they were not clamping the cover down and oil poured right past. The oil smoked like the burning oil wells in Iraq, so I decided to adjust the poly locks statically and hope for the best. After having him bump the motor over and watching each rocker open and close I adjusted each lock to zero lash plus 1/4 turn, which is normal for a running engine. With the valve covers on and the engine running I could hear the rockers ticking a bit and I am sure I should have tightened up the adjustment more, but how much? This month's Hot Rod mag showed a static adjustment of zero lash plus 3/4 turns. Is that OK or too much? I know on a running engine that's too much, but what about a non running engine? How do you guys do it?

 

[V8 Rumble]

I did mine like you did. Zero lash and 1/4 turn then lock. Warmed the engine and checked again. For some reason you don't hear the clacking like you would with the stock type rockers while running. I followed this sequence which is good for flat tappet cams https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=video&cd=3&cad=rja&uact=8&ved=0ahUKEwi2l_HTks_JAhVKbj4KHcpQCL0QtwIIIjAC&url=https://www.youtube.com/watch?v=8ROU7D-6meY&usg=AFQjCNEbBI_wb6ycD31upH1Asx8iaWSF8A&sig2=TqgvEfIpKM1bwnO02TsRIQ&bvm=bv.109395566,d.cWw

At first I followed the gm performance crate engine procedure which I couldn't figure why they weren't tightening up properly until I realized theirs was a roller cam which did not work with flat tappet hydraulic cams.

Does he have a roller cam?

 

[pontiacgp]

is it a roller cam or tappet?

this is the procedure I use for my roller cam. Roller cams are always noisier than a flat tappet cam

Recommended Lash is Zero to ¼” turn Hot. To properly set the valve lash, warm up the engine to normal operating temperature (180 – 190 degrees F water temp) and follow the procedure below.

1. Position engine at TDC on # 1 cylinder in firing position. Adjust Intake valves on # 2 & # 7 cylinders. Adjust Exhaust valve on # 4 & # 8 cylinders.

2. Rotate Crankshaft ½ Revolution Clockwise. Adjust Intake Valves on # 1 & # 8 cylinders. Adjust Exhaust Valves on # 3 & # 6 cylinders.

3. Rotate Crankshaft ½ Revolution Clockwise. Adjust Intake Valves on # 3 & # 4 cylinders. Adjust Exhaust Valves on # 5 & # 7 cylinders.

4. Rotate Crankshaft ½ Revolution Clockwise. Adjust Intake Valves on # 5 & # 6 cylinders. Adjust Exhaust Valves on # 1 & # 2 cylinders.

 

[Bonnewagon]

It's a flat tappet cam, not a roller. He used to run solid lifters and set them that way. He initially set the rockers with no oil in the engine on a stand and thought that was enough. It was backfiring like crazy once the lifters pumped up. So in that video, the guy turned the lock to zero plus 1/2 turn. That would be right between where I set it and where Hot Rod set it- sounds like a plan. What I really want to do is set them with the engine running, but more work needs to be done to get the engine to idle down. EDIT- It was such a loud engine I had to use a mechanics stethoscope to hear the lifters clack at all. I gave up trying because of the smoke.

 

[V8 Rumble]

Is he using stamped steel covers? When I was setting mine I would still hear tapping and I thought I wasn't getting the lash right. but it was the roller rockers hitting the inside of the stamped steel valve covers. You can either bend them a bit or get wider valve covers. More of an fyi if that's the case.

 

[pontiacgp]

when he changed the cam and set up the new lifters with no oil I wonder if he damaged the cam when he started it to break the cam in.

 

[lilbowtie]

Static - just make sure you are on base circle.

 

[Bonnewagon]

He is using some tall chrome covers, they clear OK. I too am used to stamped steel rockers, they clack loudly after zero lash, easy to set. Are aluminum roller rockers normally noisy? I would think not. As for base, that's why I watched the valves open and close one at a time, no chance they are on a ramp. He has put it away for the winter and I am pestering him to go back in. I want to recheck timing as well as set the valves again while running ( I will bring a VC gasket as well as the correct adjusting tool) and then synchronize the carbs to get a lower idle. What is normal for a tunnel ram with dual quads? At 1200 rpm it just dies.

 

[monte olrac]

i did mine on a cold motor, zero lash and a 1/4 turn set and locked, but i grab my pushrod and move it up and down vs turning it until it starts to drag, haven't touch them since runs great. Now are these full rollers or roller tips? roller tips should not use a poly lock. and depending on the brand used they will normally make noise so don't try to over-tighten them to quiet them down

 

[pontiacgp]

I have never heard that you can't use roller tips with poly locks. All our circle track engines had roller rockers and poly locks. One our sportsman cars has a Leitch engine that had roller rockers and poly locks, that engine could rev up to 8,500 rpm

http://www.leitchperformanceengines.com/