#21  
Old 05-26-2022, 07:29 PM
ignaro's Avatar
ignaro ignaro is offline
Senior Member
 
Join Date: Jun 2015
Location: Torrance, CA
Posts: 109
Default

Thanks everybody. I just re-lashed them all with a 3/4 turn. I had incorrectly thought the 7/16 studs were standard/coarse thread which is 14 threads per inch. Thanks Formulajones for pointing out they are actually 20tpi.

It still sounds like a sewing machine but I verified the rocker arms aren't hitting the springs. They're not.
Here's the thread from when I was measuring pushrods, for posterity: https://forums.maxperformanceinc.com...78#post6165678

My RPM is 700 according to this old dell tach. I'll assume that's correct. The X-pipe in my new exhaust really limited the chop in the idle which is too bad. Should've done something different to get the noise level bearable but keep the overlap sound. Video here: https://photos.app.goo.gl/VzhK9cnfLtx7syh5A

I also verified the flat part of the rocker arm is up against the poly lock. All good there.
Gonna drive it around a bit, I think this takes care of my rocker/lifter noise. Good to know this is normal, even if it'll take some getting used to.

I'll find a Pontiac shop here in LA and have them dial in the air/fuel ratio and timing. I'm sure it's still pretty fat.

  #22  
Old 05-27-2022, 09:50 AM
78w72 78w72 is offline
Ultimate Warrior
 
Join Date: Nov 2007
Location: iowa
Posts: 4,683
Default

Quote:
Originally Posted by ignaro View Post
Thanks everybody. I just re-lashed them all with a 3/4 turn. I had incorrectly thought the 7/16 studs were standard/coarse thread which is 14 threads per inch. Thanks Formulajones for pointing out they are actually 20tpi.

It still sounds like a sewing machine but I verified the rocker arms aren't hitting the springs. They're not.
Here's the thread from when I was measuring pushrods, for posterity: https://forums.maxperformanceinc.com...78#post6165678

My RPM is 700 according to this old dell tach. I'll assume that's correct. The X-pipe in my new exhaust really limited the chop in the idle which is too bad. Should've done something different to get the noise level bearable but keep the overlap sound. Video here: https://photos.app.goo.gl/VzhK9cnfLtx7syh5A

I also verified the flat part of the rocker arm is up against the poly lock. All good there.
Gonna drive it around a bit, I think this takes care of my rocker/lifter noise. Good to know this is normal, even if it'll take some getting used to.

I'll find a Pontiac shop here in LA and have them dial in the air/fuel ratio and timing. I'm sure it's still pretty fat.
i didnt see it mentioned but what oil are you using? SD performance & comp & some other members on here say that 10/30 is the best weight to use with HYD roller lifters & supposed to help with roller lifter noise, the sewing machine noise of the rockers in unrelated to oil.

  #23  
Old 05-27-2022, 12:39 PM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Manassas, VA
Posts: 14,658
Default

You can try bumping up the idle to 850, 700 is kind of low for that cam.

What's you oil psi at 700?

Not sure why people try to run such low or stock cam RPM values, makes no sense to me.


.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
  #24  
Old 05-27-2022, 12:40 PM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Manassas, VA
Posts: 14,658
Default

You did the pushrods correctly, the pattern is as good as it gets.

.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
  #25  
Old 05-27-2022, 02:01 PM
ignaro's Avatar
ignaro ignaro is offline
Senior Member
 
Join Date: Jun 2015
Location: Torrance, CA
Posts: 109
Default

Thanks all
I believe I'm running 10w30. My old chevy 350 liked molasses-thick oil so I forget what I bought for the new motor but it was 30 or 40 weight.

I actually regret getting the X-pipe with my exhaust. With open headers, it was choppy as hell (and ear-splittingly loud). I wanted to chill the sound out but it lost a lot of the thumpy charm and gained sewing machine sound. Yuck. Fwiw- 2.5" exhaust, X-pipe, and Flowmaster 44's. It sounds good but not what I was after. I want the slowest, choppiest idle I can get because it sets off Prius's alarms in the parking garage. That makes me happy.

Ty for the pushrod compliment! I put a lot of nervous work into that, haha!

The Following User Says Thank You to ignaro For This Useful Post:
  #26  
Old 05-27-2022, 02:47 PM
Formulajones's Avatar
Formulajones Formulajones is offline
Ultimate Warrior
 
Join Date: Jan 2012
Posts: 10,794
Default

Put some electric cutouts on it, then you can make all the noise you want any time you want with the flick of a switch

__________________
2019 Pontiac Heaven class winner

https://youtu.be/XqEydRRRwqE
  #27  
Old 05-27-2022, 04:51 PM
blueghoast's Avatar
blueghoast blueghoast is offline
Ultimate Warrior
 
Join Date: Jan 2011
Posts: 2,396
Default

Quote:
Originally Posted by Formulajones View Post
What rocker studs are you running? I'll assume 7/16 which is 20 threads per inch, that's a BBC rocker commonly used in Pontiac builds.

If so, your 1/2 turn of preload is still not enough for the Johnson lifters you are using. 1/2 turn on those studs will only give you .025" preload. 1 full turn is .050" preload.

If Johnson is calling for .035" + or - .010" then you would need about 3/4 turn of preload on the 7/16-20 stud to get you in that "range".

I would adjust them properly first and go from there.
X 10 Thats your problem.

GT

  #28  
Old 05-27-2022, 10:50 PM
turbo69bird's Avatar
turbo69bird turbo69bird is offline
Ultimate Warrior
 
Join Date: Feb 2005
Posts: 1,421
Default

Quote:
Originally Posted by 25stevem View Post
Just for ****'s & giggles I would confirm that when the valves are closed that the belly of the rocker is not touching the spring nor the retainer.
This relates to the question of push rod lenght/ geometry.
Yup have seen guys destroy a set of rockers this way

__________________
Happiness is just a turbocharger away!
960 HP @ 11 psi, 9.70 at 146.
Iron heads, iron stock 2 bolt block , stock crank, 9 years haven't even changed a spark plug!
selling turbos and turbo related parts since 2005!
  #29  
Old 06-02-2022, 06:50 AM
djseth djseth is offline
Junior Member
 
Join Date: Jun 2017
Posts: 5
Default

Quote:
Originally Posted by Formulajones View Post
What rocker studs are you running? I'll assume 7/16 which is 20 threads per inch, that's a BBC rocker commonly used in Pontiac builds.

If so, your 1/2 turn of preload is still not enough for the Johnson lifters you are using. 1/2 turn on those studs will only give you .025" preload. 1 full turn is .050" preload.

If Johnson is calling for .035" + or - .010" then you would need about 3/4 turn of preload on the 7/16-20 stud to get you in that "range".

I would adjust them properly first and go from there.
I have a Crower hydraulic roller cam and lifters and roller tip rockers. I also have the BBC studs, but I have my original heads. Should I also go 3/4s of a turn? I am at half a turn and I do hear some valve noise.

  #30  
Old 06-02-2022, 09:33 AM
Formulajones's Avatar
Formulajones Formulajones is offline
Ultimate Warrior
 
Join Date: Jan 2012
Posts: 10,794
Default

Quote:
Originally Posted by djseth View Post
I have a Crower hydraulic roller cam and lifters and roller tip rockers. I also have the BBC studs, but I have my original heads. Should I also go 3/4s of a turn? I am at half a turn and I do hear some valve noise.
1/2 turn on these studs is .025" so if your lifters require more preload than that then yes you'll need more than a half turn.

The most confusing part is these lifters are not created equal and it seems each brand, and even different types in the same brand call for different amounts of preload.

__________________
2019 Pontiac Heaven class winner

https://youtu.be/XqEydRRRwqE
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:50 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017