Valve Float

[waddell87]

Hi Guy's
Does any one have any tell tale signs of floating the valves.
Everything was working good before I changed my DP from an older 21/2 meese to a 3 inch and electric cut out. My btm end power is good all my scanmaster readings are fine. butt, at over 3500-4000 rpm or 3/4 to WOT its sounds terrible especially with the dump open!
It's missing and stumbling best I can describe it. I'm guessing valve float because everything was good before. My valve springs are still stock.
Thanks for any Input all is welcome. btw plugs are good, gapped to .032 and wires and pack are good. I did a search but no definite answers.

 

[waddell87]

Anybody? Anything.

 

[BEATAV8]

that seems like an awfully low RPM to be having a valve float issue even with old stockers.

My Wife's car has the old 160k mile stockers on it still and it can make it up to 5200 or so before it just really lays down and snoozes. That's at 24PSI or so (more boost = sooner valve float)

 

[waddell87]

Thanks. I'm running 25 lbs boost, It's not really laying down and dieing just missing and hesitating. I'll try lowering the boost. I have a stock rpm guage so I started out lower. Closer were it starts missing would be over 4500.

 

["Turbo-T"]

Hi Guy's
Does any one have any tell tale signs of floating the valves.

Power drop off and possibly what seems like the engine is breaking up.

 

[turbows6]

It sounds to me like you need to check your ignition grounds and/or your ignition module is weak. My ignition module went bad and had similar problems that progressively got worse over the course of a week or two untill it was popping and running rough under any boost at all. New Delco module and it ran like new.

 

[waddell87]

Thanks Guys.

I'll check the Module just to be on the safe side.

 

[waddell87]

Thanks everyone for your help. Problem solved when I changed my valve springs. Some of them I could squeeze over half closed with one hand. She pulls very hard up top now, and will have it at the track this week with new and improved times. Provided I get my new rear seal to arrrrg SEAL. The car only has 25k on it but after 20 yrs they get weak obviously. It was a cheap upgrade and fix.

 

["Turbo-T"]

Wow, never have I heard of a valve spring that could be squeezed with one hand. They must have been very weak.

If I may ask did you remove your heads to change the springs? Or did you bring the piston to TDC and fill with compressed air to keep the valve up while using a valve spring removal tool?

 

[gusszgs]

Wow, never have I heard of a valve spring that could be squeezed with one hand. They must have been very weak.

If I may ask did you remove your heads to change the springs? Or did you bring the piston to TDC and fill with compressed air to keep the valve up while using a valve spring removal tool?

Ya, kinda curious myself on how hard it is to change out the springs. And what did you replace them with, brand wise.

 

[waddell87]

Wow, never have I heard of a valve spring that could be squeezed with one hand. They must have been very weak.

If I may ask did you remove your heads to change the springs? Or did you bring the piston to TDC and fill with compressed air to keep the valve up while using a valve spring removal tool?

Guess I'm 2 up on you then. Plus i've worked rigs for 21 yrs so probably have bit more hand strength than the avg. joe. but yes, they, not all, were quite weak.

Just remove valve covers. spark plugs and use hose from a compression tester kit. Plug in air and away you go.
I ordered Kirbans Valve springs and remover tool. Nice price.68 bucks. We did have to modify the tool to work. It was solid around so you couldn't press down on the spring to remove the keeper. easy fix though, just waste of time because I didn't notice it right away. By the way make sure you have a spare rocker arm on hand or a piece of pipe the same size with holes drilled in it to fit the tool on, to attach too head so you can compress the spring with the tool. Basically their tool is an old rocker with a S pipe. I used another pipe because i didn't want to remove my rockers in case I broke the little plastic tabs that hold rocker in place. S piece is used for leverage. Passenger side is...You guessed it... PITA, last one anyways. Small hands would help.Don't push too HARD on spring or you release the air and the you WILL have to remove your head to get the valve out. Hope I made some sense and it helps you.. Gnttpe.org has a piece written on it too.

Big difference tho..Holy Cow. I can't wait to see what mph i'm getting from the 1/8 to the 1/4. I was getting 18- 20mph gain before. hopefully 25+ now.

 

[scojack_2001]

Ive been meaning to do mine in my GN. Granted it still pulls good, but with 100,000 on the motor; I'd rather spend $200 to get the job done the a few thousand for a new motor. I did them on my old WH-1 when it had 135K on it and I gained 2/10ths just from those alone. No other mods. Really woke the car up.

I need to do the springs and a few other small things before I hit the track again.

 

[TURBOPOWERED68]

Guess I'm 2 up on you then. Plus i've worked rigs for 21 yrs so probably have bit more hand strength than the avg. joe. but yes, they, not all, were quite weak.

Just remove valve covers. spark plugs and use hose from a compression tester kit. Plug in air and away you go.
I ordered Kirbans Valve springs and remover tool. Nice price.68 bucks. We did have to modify the tool to work. It was solid around so you couldn't press down on the spring to remove the keeper. easy fix though, just waste of time because I didn't notice it right away. By the way make sure you have a spare rocker arm on hand or a piece of pipe the same size with holes drilled in it to fit the tool on, to attach too head so you can compress the spring with the tool. Basically their tool is an old rocker with a S pipe. I used another pipe because i didn't want to remove my rockers in case I broke the little plastic tabs that hold rocker in place. S piece is used for leverage. Passenger side is...You guessed it... PITA, last one anyways. Small hands would help.Don't push too HARD on spring or you release the air and the you WILL have to remove your head to get the valve out. Hope I made some sense and it helps you.. Gnttpe.org has a piece written on it too.

Big difference tho..Holy Cow. I can't wait to see what mph i'm getting from the 1/8 to the 1/4. I was getting 18- 20mph gain before. hopefully 25+ now.

Is there another way of doing this besides the Compressor tester and air supply?

 

[charlief1]

You can take a small rope and feed it into the cylinder through the spark plug hole. Then you bring the piston up until it stops. It works but is still a PITA.

 

[stagemonster]

It sounds to me like you need to check your ignition grounds and/or your ignition module is weak. My ignition module went bad and had similar problems that progressively got worse over the course of a week or two untill it was popping and running rough under any boost at all. New Delco module and it ran like new.

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