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Old 09-03-2012, 05:57 AM
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I've been told to check my Valve Lash?

It has been suggested to recheck my valve lash, by a friend and by Comp Cams. They both believe my low vacuum reading is from improperly adjusted valves.
I adjusted them Putting the engine at TDC #1 and doing 8 valves and then put at TDC on #6 and doing the remaining 8 valves. It did run better after the adjustment. You might be wondering why I need to readjust the valves, I replaced the lifters only, now I realize it was not a nessesary.
It's recommended to do one Valve at a time by Comp Cams: At #1 when th exhaust begins to open stop and adjust the intake valve. Turning the push rod tightne the rocker nut til I feel resistance then stop and go 1/2 turn or 180deg then tighten down and then when the intake valve starts to closestop and adjust the exhaust valve the same as the intake.
The engine is a Pontiac 326 with poly locks.
The 2nd method is to go to TDC of #1 adjust valves the same as above but instead of 1/2 turn after zero lash go only 1/4 turn, do both valves on #1 then go 90deg on the crank and do the next in the firing order.
I'm not sure which one I should use, what does anyone here recommend?

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Old 09-03-2012, 08:07 AM
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Quote:
Originally Posted by raguza123 View Post
It has been suggested to recheck my valve lash, by a friend and by Comp Cams. They both believe my low vacuum reading is from improperly adjusted valves.
I adjusted them Putting the engine at TDC #1 and doing 8 valves and then put at TDC on #6 and doing the remaining 8 valves. It did run better after the adjustment. You might be wondering why I need to readjust the valves, I replaced the lifters only, now I realize it was not a nessesary.
It's recommended to do one Valve at a time by Comp Cams: At #1 when th exhaust begins to open stop and adjust the intake valve. Turning the push rod tightne the rocker nut til I feel resistance then stop and go 1/2 turn or 180deg then tighten down and then when the intake valve starts to closestop and adjust the exhaust valve the same as the intake.
The engine is a Pontiac 326 with poly locks.
The 2nd method is to go to TDC of #1 adjust valves the same as above but instead of 1/2 turn after zero lash go only 1/4 turn, do both valves on #1 then go 90deg on the crank and do the next in the firing order.
I'm not sure which one I should use, what does anyone here recommend?
The Comp way is correct. I don't think you can do 8 of the valves in one position. As far as how much to tighten, 1/4 will work.
The issue for most people is determining the zero lash. It is not hard it just takes some practice.
I still like adjusting them with the car running if you can stand the mess. Turn idle down as low as it will go and stay running. Back off adjustment until it clacks, tighten to remove the clack then go 1/2 turn more, move to next valve. I still fell this is the best way but you need to be quick and it can get messy.
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Old 09-03-2012, 09:30 AM
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Adjusting valve lash

Here is an article on adjusting valve lash. I hope it will help you. Adjusting Valve Lash
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Old 09-03-2012, 11:41 AM
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Originally Posted by T-bucket23 View Post
The Comp way is correct. I don't think you can do 8 of the valves in one position. As far as how much to tighten, 1/4 will work.
The issue for most people is determining the zero lash. It is not hard it just takes some practice.
I still like adjusting them with the car running if you can stand the mess. Turn idle down as low as it will go and stay running. Back off adjustment until it clacks, tighten to remove the clack then go 1/2 turn more, move to next valve. I still fell this is the best way but you need to be quick and it can get messy.
I did it the old way, with the valve covers off, and it runs better, still have a miss and sputter.
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Old 09-03-2012, 11:42 AM
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Use the pushrod up down method instead of the spin the pushrod method to find the 0lash point.
You are getting the adjustment way way too tight.
The pushrod up/down method works a lot better.

Use the EO IC method to adjust each valve.
Or set the rockers with it running (warmed up)
Turn the idle speed down to minimize the oil mess.

Miss and sputter:

Once the valve are set correctly, do a simple engine compression test.
Then do a simple engine cylinder balance test using a vacuum gauge
to find the weak running cylinder.

Then inspect the ignition system for faults

Replace fouled spark plugs.
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Old 09-03-2012, 02:28 PM
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I set them with it running, loosen it up til it chatters, then thighten til chatter goes away and 1/2 turn and done. I still don't get rid of the lifter noise, I have a set of Comp Cams lifters #852-16, I think they bleed down. I can't get rid of the sputter. but it's much improved.
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Old 09-03-2012, 03:00 PM
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"Sputter" is a different issue from lifter noise.

"sputter" is a ignition problem or a carb problem.
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Old 09-03-2012, 03:07 PM
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I did the #1 #6 method for my Pontiac 400. No problems with lash. bt
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Old 09-03-2012, 03:16 PM
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well the carb is a Carter AFB 4242S from a 400 Pontiac, and the ignition is set to around 8deg BTDC, it's a petronix Ignitor with an Aceel super stock coil and the plugs and wires are brand new.
I relocated the coil onto the firewall above the heater box and the ballast resistor is next to it.
The cap is new but has aluminum in the towers not brass or gold.
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Old 09-03-2012, 03:58 PM
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Install a ground wire from the engine to the firewall.
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Old 09-03-2012, 04:20 PM
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Quote:
Originally Posted by F-BIRD'88 View Post
Install a ground wire from the engine to the firewall.
I have the ground strap installed from the Back of the head to the firewall, you thinking it's not making a good connection?
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Old 09-03-2012, 04:21 PM
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Quote:
Originally Posted by raguza123 View Post
It has been suggested to recheck my valve lash, by a friend and by Comp Cams. They both believe my low vacuum reading is from improperly adjusted valves.
I adjusted them Putting the engine at TDC #1 and doing 8 valves and then put at TDC on #6 and doing the remaining 8 valves. It did run better after the adjustment. You might be wondering why I need to readjust the valves, I replaced the lifters only, now I realize it was not a nessesary.
It's recommended to do one Valve at a time by Comp Cams: At #1 when th exhaust begins to open stop and adjust the intake valve. Turning the push rod tightne the rocker nut til I feel resistance then stop and go 1/2 turn or 180deg then tighten down and then when the intake valve starts to closestop and adjust the exhaust valve the same as the intake.
The engine is a Pontiac 326 with poly locks.
The 2nd method is to go to TDC of #1 adjust valves the same as above but instead of 1/2 turn after zero lash go only 1/4 turn, do both valves on #1 then go 90deg on the crank and do the next in the firing order.
I'm not sure which one I should use, what does anyone here recommend?
Your problem may be from the lifters you replaced. New lifters on an old cam is a no no. You probably got lobes wiped.
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Old 09-03-2012, 04:28 PM
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Quote:
Originally Posted by dgcantrellsr View Post
Your problem may be from the lifters you replaced. New lifters on an old cam is a no no. You probably got lobes wiped.
So I've been told, but before I replaced them it was still sputtering, at that time it had an Edelbrock 1405 on top.
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Old 09-03-2012, 05:01 PM
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From your old posts the XE256 cam you got needs tuning of the distributor curve.

will want 14 to 16deg at idle and 32 to 36deg at max advance.

(16 to 20deg mech advance curve limit)

Then: the vacuum advance rae and limit needs to be dialed in too.
15deg limit 8 to 12deg vac advance commin in at hiway cruise speeds.
Now you can start tuning the carb.

Edelbrock performer manifold and edelbrock/carter carbs:

The aluminum manifold is very touchy on its running temperture.
This is controled by the amount of exhaust flow up thru the heat riser passage.

Open full heat riser flow is always too much (manifold/carb way too hot)
usually blocked off or one side blockd and one side restricted (1/4 to 3/8" hole)
is just right.

Once you ahev corrected this, further carb body temp control is achieved using a edelbrock wood carb spacer
(divided style or 4 hole style) wood is a very good heat isolator.
Keep the fuel lines away from heat. Move and shield as required.

Now that you got the manifold plenum /carb body temp right and the ignition right
you will find dialing in the carb (any carb) real easy.

Start by verifying true TDC on your balancer/timing tab using a piston stop and get or make a balancer timing tape.

Or keep buying and trying new carbs until you are broke.
Box up and mail me any all the carbs you don;t like.

Last edited by F-BIRD'88; 09-03-2012 at 05:07 PM.
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Old 09-03-2012, 05:14 PM
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wow that explains why my carb is always hot, I have a rebuilt stock distributor with whatever advance they put init. I have the timing at 8* right now.
I got some work to do thanks.
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