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Discussion Starter · #1 ·
I just finished rebuilding a SBC 1977 350 and reused the 882 heads with push in studs (after a valve job) that came with the engine. I put in in a mild street performance Comp cam and matching springs, new Seal Power hydraulic lifters, new lift rods and the original rocker arms. The engine started nice after a cold valve lash at zero lash plus 1/2 a turn. Now after the engine is hot and trying to adjust the lifters by sound, I get everything quiet and running nice and then after a little time, or after shutting the engine off for a few minutes and restarting, the tapping noise returns. Are the studs pulling out or may there be an issue with the lifters? I have readjusted the rockers arms twice now and the tappet sound from the rocker arms keeps coming back. Any one have any ideas as to what might be cause this? I ran the engine for about 20 minutes at 2000 RPM's with a cam break in additive before adjusting the valves at idle.
 

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If the lash is set cold and is zero + 1/2 turn you shouldn't have to re-adjust. Are you still putting the 1/2-3/4 turn on them after you get them quiet?


Gun Laker said:
I just finished rebuilding a SBC 1977 350 and reused the 882 heads with push in studs (after a valve job) that came with the engine. I put in in a mild street performance Comp cam and matching springs, new Seal Power hydraulic lifters, new lift rods and the original rocker arms. The engine started nice after a cold valve lash at zero lash plus 1/2 a turn. Now after the engine is hot and trying to adjust the lifters by sound, I get everything quiet and running nice and then after a little time, or after shutting the engine off for a few minutes and restarting, the tapping noise returns. Are the studs pulling out or may there be an issue with the lifters? I have readjusted the rockers arms twice now and the tappet sound from the rocker arms keeps coming back. Any one have any ideas as to what might be cause this? I ran the engine for about 20 minutes at 2000 RPM's with a cam break in additive before adjusting the valves at idle.
 

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Discussion Starter · #3 ·
dgcantrellsr said:
If the lash is set cold and is zero + 1/2 turn you shouldn't have to re-adjust. Are you still putting the 1/2-3/4 turn on them after you get them quiet?
Cold lash was at zero plus one half and I turned the noisy rockers just so they were quiet plus about one half. The tapping returns later on the same rocker. I am wondering about maybe the studs are pulling out, or later today I thought maybe because I reused the rocker nuts. Could my issue be not using new rocker nuts? Also I have thought maybe there is not enough oil pressure at the lifters thus causing the lifter to loose pressure, because I am not getting a lot of oil through the push rods. It oils, but I feel it is on the low side. Thanks for your reply
 

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You could try to put a straight edge on the studs to see if any are out. They should be close to the same.

If you think the nut is backing off, Mark it with a sharpie or something of that nature.
 

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Gun Laker said:
I just finished rebuilding a SBC 1977 350 and reused the 882 heads with push in studs (after a valve job) that came with the engine. I put in in a mild street performance Comp cam and matching springs, new Seal Power hydraulic lifters, new lift rods and the original rocker arms. The engine started nice after a cold valve lash at zero lash plus 1/2 a turn. Now after the engine is hot and trying to adjust the lifters by sound, I get everything quiet and running nice and then after a little time, or after shutting the engine off for a few minutes and restarting, the tapping noise returns. Are the studs pulling out or may there be an issue with the lifters? I have readjusted the rockers arms twice now and the tappet sound from the rocker arms keeps coming back. Any one have any ideas as to what might be cause this? I ran the engine for about 20 minutes at 2000 RPM's with a cam break in additive before adjusting the valves at idle.
If you did the heads and changed the springs to match the cam and are using the stock rockers, You need to check and see if the rockers are slipping of the sides of the springs if it is you will probably have to add guide plates and a set of after market rockers. Do you have guide plates now? And i would add a set of poly locks.JMO....Cole
 

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Discussion Starter · #6 ·
NvrGrwUp said:
You could try to put a straight edge on the studs to see if any are out. They should be close to the same.

If you think the nut is backing off, Mark it with a sharpie or something of that nature.
Wow, both of those tips are great and both make great sense. I will try them tomorrow.
 

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Discussion Starter · #7 ·
eloc431962 said:
If you did the heads and changed the springs to match the cam and are using the stock rockers, You need to check and see if the rockers are slipping of the sides of the springs if it is you will probably have to add guide plates and a set of after market rockers. Do you have guide plates now? And i would add a set of poly locks.JMO....Cole
The rockers will move side to side a little when at zero lash, but I am using the original valves and there no guide plates. I will get some new poly lock nuts tomorrow and I assume yo may think using used nuts could be the issue.
 

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Gun Laker said:
The rockers will move side to side a little when at zero lash, but I am using the original valves and there no guide plates. I will get some new poly lock nuts tomorrow and I assume yo may think using used nuts could be the issue.
I have used the old nut's with no problems. But sometimes they just don't work out. I use poly locks and i will still use stock nut's i have even seen the stock nut's jammed with other stock nut's. But what i am talking about the rockers jumping off side is when you change the springs there will be more tension on them and with a stock rocker without guide-plates they have the tendency to slip off a little and you will never get them adjusted. And your pushrod length may be off also. When changing a cam and the springs it will throw the geometry off And push-rods and guide-plates might be in order and a set of new nuts or poly locks.JMO......Cole
 

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Discussion Starter · #9 ·
eloc431962 said:
I have used the old nut's with no problems. But sometimes they just don't work out. I use poly locks and i will still use stock nut's i have even seen the stock nut's jammed with other stock nut's. But what i am talking about the rockers jumping off side is when you change the springs there will be more tension on them and with a stock rocker without guide-plates they have the tendency to slip off a little and you will never get them adjusted. And your pushrod length may be off also. When changing a cam and the springs it will throw the geometry off And push-rods and guide-plates might be in order and a set of new nuts or poly locks.JMO......Cole
Do you have any suggestions as to the guide plates I should use and how are they installed, as I have never used them in the past. Thanks for your replies!
 

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Evil Wicked Mean And Nasty
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You can get them at jegs or summit somewhere like that. They go under your screw in studs but you will have to get a set to fit whatever size push- rod you are using. So they don't rub the sides of the plates. Just call one of them and give them your info on your set-up and they should be able to tell you what you need, Or go to a local machine shop and they can help you also they can even order what you need and put them in , It should'nt cost very much. They can even tell you if you do need a longer push-rod or not. Hope this helps. .....Cole
 
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