Jump to content
Welcome Guest! Please read more information about our club!

Failing Valve Guides?

wil84911
wil84911
in Engine & Drivetrain

Featured Replies

comment_532283

before drawing any conclusions you should get new correct plugs, drive for a week and pull them again. For all you know those plugs could have looked that way when installed (used plugs). It happens.

If the car is not smoking, pulling strong, no misfires, chances are it need nothing but running.

 

Edited by Dave WM


comment_532295

I should say that failing valve guides is not a bad guess, although seals would be more specific.  They will leak more oil at idle under high intake system vacuum and dirty up the plugs pretty quickly.  Then when you start driving much of that will burn off.  My original engine had bad seals and would run rough after putting around town, then would clear up after I gave it one of those high rev tune-ups.  It was fun for quite a while to have a reason to go beat on the engine, trying to figure out why it ran so much better afterward.  After I removed the engine and took the head off, I noticed oil draining down the intake and exhaust valves after just a little while.  The seals weren't sealing at all.

There's quite a bit on the site about changing valve seals.  Pretty easy, I think, and might make a big difference.

In short - I second madkaw's thought, in Post #2.

  • Author
comment_532297
6 minutes ago, Zed Head said:

I should say that failing valve guides is not a bad guess, although seals would be more specific.  They will leak more oil at idle under high intake system vacuum and dirty up the plugs pretty quickly.  Then when you start driving much of that will burn off.  My original engine had bad seals and would run rough after putting around town, then would clear up after I gave it one of those high rev tune-ups.  It was fun for quite a while to have a reason to go beat on the engine, trying to figure out why it ran so much better afterward.  After I removed the engine and took the head off, I noticed oil draining down the intake and exhaust valves after just a little while.  The seals weren't sealing at all.

There's quite a bit on the site about changing valve seals.  Pretty easy, I think, and might make a big difference.

In short - I second madkaw's thought, in Post #2.

Thank you. That's the plan. Drive it with new plugs, recharged k&n filter and monitor. 

  • Author
comment_532323
22 minutes ago, Travel'n Man said:

On more. Does your car have a AFR Meter? If not that needs to be your first purchase in my opinion


Sent from my iPhone using Classic Zcar Club mobile

This? Reads 5 consistently when given a little throttle. 

 

IMG_8610.PNG

comment_532326

That's a fuel pressure gauge.  5 psi might be a little high for Webers, but I don't know Webers.  Float bowls and valves are all similar though and 5 seems a bit on the high side.

AFR stands for Air Fuel Ratio (even though air actually contains fuel) and AFR meters are used to help make adjustments to hit a certain fuel air ratio.  But the old school ways will work also. No offense Travel'n Man.  People have tuned many carbs before AFR meters came about.  They're great for fine tuning but he can make a lot of progress just by eye, and butt, from where he's starting.

comment_532327

I still do not have a AFR for my triples. Still on my list. I have gotten the plug reading to a nice light tan color with out it so far.

Are you running an electric fuel pump?

Stock mechanical pump?

Both together?

Do you have a FPR installed?

5 psi is a little too high. It could be actually even higher. I am not too keen on some of those gauges.

Float levels definitely need to be verified as well before anything else.

  • Author
comment_532346
I still do not have a AFR for my triples. Still on my list. I have gotten the plug reading to a nice light tan color with out it so far.
Are you running an electric fuel pump?
Stock mechanical pump?
Both together?
Do you have a FPR installed?
5 psi is a little too high. It could be actually even higher. I am not too keen on some of those gauges.
Float levels definitely need to be verified as well before anything else.


Both fuel pumps I was told.


Sent from my iPhone using Classic Zcar Club mobile

Create an account or sign in to comment

Go to topic listing

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.