| Author |
Message |
norris
Samba Member
Joined: November 25, 2009
Posts: 501
Location: Texas
|
 Posted: Sun Jan 14, 2018 7:29 pm Post subject: Valve adjustment temperature |
 |
|
Does it not make sense to adjust the valves on a car with steel pushrods when the engine is warm? When I set mine at loose zero cold, the lash when the car is at operating temperature of 160-180 is around .008 to .010.
Would it possibly keep the valves open when cold? |
|
| Back to top |
|
 |
Glenn 
Mr. 010
Joined: December 25, 2001
Posts: 76911
Location: Sneaking up behind you
|
| Posted: Sun Jan 14, 2018 7:31 pm Post subject: Re: Valve adjustment temperature |
|
|
Room temp is best.
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare |
|
| Back to top |
|
|
modok
Samba Member
Joined: October 30, 2009
Posts: 26785
Location: Colorado Springs
|
| Posted: Sun Jan 14, 2018 7:32 pm Post subject: Re: Valve adjustment temperature |
|
|
It could.
There are complaints about poor idle when cold and if the valves were zero lash it would certainly idle worse.
If it bothers you, Scat and Web camshafts tend to have a much larger lash ramp so you can have it all.
IMo the ideal way is to have the hot lash be the same as the lash ramp of the cam, so it would be nice to know what the lash ramps are on the cam. |
|
| Back to top |
|
|
norris
Samba Member
Joined: November 25, 2009
Posts: 501
Location: Texas
|
| Posted: Sun Jan 14, 2018 7:50 pm Post subject: Re: Valve adjustment temperature |
|
|
| Just a thought....not trying to reinvent the wheel. |
|
| Back to top |
|
|
Dan Ruddock
Samba Member
Joined: October 25, 2012
Posts: 3594
Location: Sarasota, in my adopted state of Florida
|
| Posted: Sun Jan 14, 2018 8:17 pm Post subject: Re: Valve adjustment temperature |
|
|
For a street engine I like HD aluminum pushrods, then it is not an issue.
Dan |
|
| Back to top |
|
|
Glenn
Mr. 010
Joined: December 25, 2001
Posts: 76911
Location: Sneaking up behind you
|
| Posted: Sun Jan 14, 2018 8:26 pm Post subject: Re: Valve adjustment temperature |
|
|
| Dan Ruddock wrote: |
For a street engine I like HD aluminum pushrods, then it is not an issue.
Dan |
How is that?
I generally do valve adjustments in the morning when cold. And while I check them every 3000 miles, i rarely fine one or two that need adjusting. Loose zero makes it real easy.
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare |
|
| Back to top |
|
|
Vanillagurilla
Samba Member
Joined: November 21, 2017
Posts: 1061
Location: California
|
| Posted: Sun Jan 14, 2018 8:36 pm Post subject: Re: Valve adjustment temperature |
|
|
| I'm running chormoly push rods and do 0 lash while dead cold, I find it easier to back off the adjuster and tighten till there's resistance, lock it down and spin the push rod. Of you set your lash when cold to where it's tight but you can spin the pushrod with your fingers then your valves will seat when cold. Doing it this way I still don't have any valve noise when it's up to temp. |
|
| Back to top |
|
|
norris
Samba Member
Joined: November 25, 2009
Posts: 501
Location: Texas
|
| Posted: Sun Jan 14, 2018 9:23 pm Post subject: Re: Valve adjustment temperature |
|
|
| Vanillagurilla wrote: |
| I'm running chormoly push rods and do 0 lash while dead cold, I find it easier to back off the adjuster and tighten till there's resistance, lock it down and spin the push rod. Of you set your lash when cold to where it's tight but you can spin the pushrod with your fingers then your valves will seat when cold. Doing it this way I still don't have any valve noise when it's up to temp. |
So...you don't have any valve noise when fully warmed up with chrome moly pushrods? Set cold at loose zero?
Have you checked your lash at operating temp? Say 160 to 180 *?
The noise isn't bothering me....I would just like the lash to be closer to optimum when fully warmed up.....again, just thinking.....maybe I should stop thinking about it  |
|
| Back to top |
|
|
oprn
Samba Member
Joined: November 13, 2016
Posts: 12714
Location: Western Canada
|
| Posted: Sun Jan 14, 2018 9:52 pm Post subject: Re: Valve adjustment temperature |
|
|
Good question!
Is that much of a change normal for steel push rods?
If so then at -30 the valves would be held open and the engine would not start! |
|
| Back to top |
|
|
jason
Samba Member
Joined: August 07, 2002
Posts: 3444
Location: Garage
|
| Posted: Sun Jan 14, 2018 10:30 pm Post subject: Re: Valve adjustment temperature |
|
|
| It’s a good audible signal when you start running hot. |
|
| Back to top |
|
|
Dan Ruddock
Samba Member
Joined: October 25, 2012
Posts: 3594
Location: Sarasota, in my adopted state of Florida
|
| Posted: Sun Jan 14, 2018 10:37 pm Post subject: Re: Valve adjustment temperature |
|
|
| Glenn wrote: |
| Dan Ruddock wrote: |
For a street engine I like HD aluminum pushrods, then it is not an issue.
Dan |
How is that?
I generally do valve adjustments in the morning when cold. And while I check them every 3000 miles, i rarely fine one or two that need adjusting. Loose zero makes it real easy. |
How is what? I like the consistent valve clearance that I get with aluminum and it gives me more tune-ability. I can run it loose or tight without it too tight cold. With it tight it sounds like a hydraulic cam. With it a little loose you gain some low end but you will get some noise.
I make my own 7/16" aluminum pushrods which have very little flex. Don't get me wrong steel is a good way to go too but my preference is aluminum. If I ran drag only car I would run steel but would experiment with aluminum.
Dan |
|
| Back to top |
|
|
Vanillagurilla
Samba Member
Joined: November 21, 2017
Posts: 1061
Location: California
|
| Posted: Sun Jan 14, 2018 11:01 pm Post subject: Re: Valve adjustment temperature |
|
|
| norris wrote: |
| Vanillagurilla wrote: |
| I'm running chormoly push rods and do 0 lash while dead cold, I find it easier to back off the adjuster and tighten till there's resistance, lock it down and spin the push rod. Of you set your lash when cold to where it's tight but you can spin the pushrod with your fingers then your valves will seat when cold. Doing it this way I still don't have any valve noise when it's up to temp. |
So...you don't have any valve noise when fully warmed up with chrome moly pushrods? Set cold at loose zero?
Have you checked your lash at operating temp? Say 160 to 180 *?
The noise isn't bothering me....I would just like the lash to be closer to optimum when fully warmed up.....again, just thinking.....maybe I should stop thinking about it |
It's a snug zero, I can spin them by hand but they don't spin like bearings. It might help that I also am using 10mm chormoly studs to hold it together. |
|
| Back to top |
|
|
Vanillagurilla
Samba Member
Joined: November 21, 2017
Posts: 1061
Location: California
|
| Posted: Sun Jan 14, 2018 11:04 pm Post subject: Re: Valve adjustment temperature |
|
|
| Dan Ruddock wrote: |
| Glenn wrote: |
| Dan Ruddock wrote: |
For a street engine I like HD aluminum pushrods, then it is not an issue.
Dan |
How is that?
I generally do valve adjustments in the morning when cold. And while I check them every 3000 miles, i rarely fine one or two that need adjusting. Loose zero makes it real easy. |
How is what? I like the consistent valve clearance that I get with aluminum and it gives me more tune-ability. I can run it loose or tight without it too tight cold. With it tight it sounds like a hydraulic cam. With it a little loose you gain some low end but you will get some noise.
I make my own 7/16" aluminum pushrods which have very little flex. Don't get me wrong steel is a good way to go too but my preference is aluminum. If I ran drag only car I would run steel but would experiment with aluminum.
Dan |
How do you gain low end with a loose valve lash? Seems like you would loose if anything because your looking lift on the valve. Are you running aluminum with double springs? |
|
| Back to top |
|
|
modok
Samba Member
Joined: October 30, 2009
Posts: 26785
Location: Colorado Springs
|
| Posted: Mon Jan 15, 2018 12:31 am Post subject: Re: Valve adjustment temperature |
|
|
| Running duration has a big impact on idle, and lash changes the running duration. |
|
| Back to top |
|
|
Glenn
Mr. 010
Joined: December 25, 2001
Posts: 76911
Location: Sneaking up behind you
|
| Posted: Mon Jan 15, 2018 6:10 am Post subject: Re: Valve adjustment temperature |
|
|
| Dan Ruddock wrote: |
I like the consistent valve clearance that I get with aluminum
Dan |
Consistent? I think in the past 15,000 miles I maybe found 3 valves out of spec... and then just barely.
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare |
|
| Back to top |
|
|
gt1953
Samba Member
Joined: May 08, 2002
Posts: 13848
Location: White Mountains Arizona
|
| Posted: Mon Jan 15, 2018 8:17 am Post subject: Re: Valve adjustment temperature |
|
|
For me it is right after the morning coffee. Engine cold sitting outside then roll it in the garage. Loose Zero as long as you are able to spin the push rods seems fine. The smallest feeler gauge I happen to have is .0015.
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.
72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold}) |
|
| Back to top |
|
|
jason
Samba Member
Joined: August 07, 2002
Posts: 3444
Location: Garage
|
| Posted: Mon Jan 15, 2018 9:03 am Post subject: Re: Valve adjustment temperature |
|
|
| I think he means consistantly in spec. when hot and not what they end up. |
|
| Back to top |
|
|
Dan Ruddock
Samba Member
Joined: October 25, 2012
Posts: 3594
Location: Sarasota, in my adopted state of Florida
|
| Posted: Mon Jan 15, 2018 9:21 am Post subject: Re: Valve adjustment temperature |
|
|
| jason wrote: |
| I think he means consistantly in spec. when hot and not what they end up. |
Yep, that is my meaning. I also like the lighter weight. Dan |
|
| Back to top |
|
|
mark tucker
Samba Member
Joined: April 08, 2009
Posts: 23937
Location: SHALIMAR ,FLORIDA
|
| Posted: Mon Jan 15, 2018 5:55 pm Post subject: Re: Valve adjustment temperature |
|
|
| so what is loose zero? zero shouldent be loose or tight...you mean .001? I do set mine with the engine warm to zero. |
|
| Back to top |
|
|
Vanillagurilla
Samba Member
Joined: November 21, 2017
Posts: 1061
Location: California
|
| Posted: Mon Jan 15, 2018 6:45 pm Post subject: Re: Valve adjustment temperature |
|
|
| Cold engine, no feeler gauges. Loosen the lock nut, I like to back off the adjuster and then tighten untill I can feel the rocker tighten up and lock it down. Then check to see if I can spin the pushrod, some adjusters will tighten up when you tighten the locknut so I do it this way. |
|
| Back to top |
|
|
|
