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Oil flow to push rods
Posted by: Afa1977 ()
Date: May 12, 2018 01:47PM

Oil flow to push rods low idle pressure 35psi

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Re: Oil flow to push rods
Posted by: RobertC ()
Date: May 12, 2018 02:19PM

What are you asking? Noisy rocker arms?

Idle oil pressure for a Corvair engine like others is "normally" around 20 lbs.

35 lb idle would indicate a "tight" engine (bearing clearances) or a bad gauge. Or, maybe the oil pressure regulator valve / spring has been modified?

Push rods have nothing to do with the oil pressure.



Edited 1 time(s). Last edit at 05/12/2018 02:21PM by RobertC.

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Re: Oil flow to push rods
Posted by: RobertC ()
Date: May 12, 2018 02:34PM

If this is a newly rebuilt engine, push rods have a small hole on the side of one end.

The end with the hole should be at the rocker arm.

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Re: Oil flow to push rods
Posted by: MattNall ()
Date: May 12, 2018 02:38PM

Have the Lifters been changed recently?

Many replacement put out very little compared to the originals and some aftermarket units..





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Re: Oil flow to push rods
Posted by: Afa1977 ()
Date: May 12, 2018 03:20PM

Talking about the volume of oil coming out of pushrod is minimal

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Re: Oil flow to push rods
Posted by: dryenko ()
Date: May 12, 2018 03:29PM

Not all that much is needed, especially at idle.
It will push more at operating RPM's.

Bob C aka Dryenko
Dobson, NC 27017

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Re: Oil flow to push rods
Posted by: cnicol ()
Date: May 12, 2018 03:41PM

Oil flow to the pushrods is a function of the lifters, not system oil pressure.

Every time the lifter moves up and down, a "piddle" valve in the lifter pumps a small quantity of oil into the pushrod. The only lifters with high oil flow at idle are original factory-installed lifters and the few aftermarket lifters modified by "The Source".

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
60 Monza coupe (sold, sniff sniff)
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

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Re: Oil flow to push rods
Posted by: 66vairman ()
Date: May 12, 2018 04:32PM

An article by Bob Helt - gone but not forgotten

"Posted by: Bob Helt ()
Date: July 09, 2014 03:01AM

Anyhow here is some interesting information I have discovered.
Sometime around 1962 Chevrolet changed the pushrod design adding material at the ends and strengthening the tips. This new design continued in production thru 1969. But they kept the same part number (3839661) that engineering protocall would have required changing due to other changes in the design.

Having come across NOS examples of both the old and new designs I decided to measure the hole sizes.

Shown in the table below are the actual measurements, despite the fact that the holes LOOK to be the same as before..


Entrance hole exit hole spit hole

OLD 0.091" 0.091" 0.051"

NEW 0.066" 0.068" 0.045" although it appears to be b slightly oval


You can see that the holes are all considerably smaller in the new pushrods.

Could this be the source of any rocker box oiling problems?

Bob Helt"

I have seen the different pushrods myself.

J.O. responded to Bob's post as follows:

"Posted by: jjohnsonjo ()
Date: July 09, 2014 02:49PM

Hi Bob, as I posted before my brothers early build 63 pumps rocker oil like crazy compaired to my 65. I know you like documentation, but I remember reading (a long time ago) that GM reduced the oil flow to the heads in an effort to reduce oil temps. The heads were adding a ton of heat to the oil. Can't remember or find the document.

J.O."



Edited 1 time(s). Last edit at 05/12/2018 04:33PM by 66vairman.

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Re: Oil flow to push rods
Posted by: Afa1977 ()
Date: May 13, 2018 04:41AM

Yes I have the Clarks valve cover for adjusting but I see no oil spraying on to valve springs already took apart to replace valve was stuck open. Took back to my machine shop they said lack a oil
on the guide there is oil coming out of the pushrod at rocker and a small amount seems to me is that something new

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Re: Oil flow to push rods
Date: May 13, 2018 08:37AM

As mentioned by RobertC in the 3rd post:
The push rods must be installed with the end with the side hole toward the rocker assembly.
Originally the pushrods had a blue ink marking on that end to assure that they were installed properly, unfortunately that marking is worn off these days.




Dan Davis ~ Pierce County, WA ~ CORSA Western Director + Corvairs NW + North Cascades Corvairs + Corvanatics
1966 Corsa Turbo coupe ~ ~ 1966 140 Corsa ~ ~ 1965 Monza 140/4 'Vert Sierra Tan/Fawn ~ 1964 Monza 'Vert (SOLD) ~ 1960 Monza Ermine White/Red PG ++ ~ 1965 Monza 140/4 Evening Orchid w/ ivory/black interior ~ 1962 Monza Wagon 102/4 ~ 1963 Rampside/Scamper ~ 1963 Red/Greenbrier ~ 1969 Ultra Van #468



Edited 1 time(s). Last edit at 05/13/2018 08:41AM by 1966-Corsa-GT-180.

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Re: Oil flow to push rods
Posted by: 66vairman ()
Date: May 13, 2018 08:39AM

While a rare event, improper adjustment can cause a lack of oil. Not saying this is your issued, but something to check.

As Craig stated the lifters pump the oil up the pushrods. For good operation the lifters should be set mid range at a minimum. Why? As the lifter starts to open the lifter internals collapses slightly forcing some oil up the pushrod.

I recall MANY year ago folks trying to get around lifter pump up on SBC V8's would adjust the valves so the lifters were fully extended, like a solid lifter. This did get rid of pump up, but also little or no oil was pumped up the pushrods. This was back before high tension valve springs and fast bleed down lifters used for racing.

Today the consensus for Corvair valve adjustment is: SLOWLY Back off the rocker nut until clatter, then tighten down 1/2 turn SLOWLY (allow the lifter to bleed down). If the cam is new cam and lifters it is suggested this be repeated after a break-in period.

Which guide was damaged? On a Corvair valve stem seals are only used on the intake valves. None on exhaust.

You did use a light source to make sure the pushrods were open?

Also before startup on of a new engine I usually prime the oil pump and check pressure. Too low and you have a leak, too high and you might have an obstruction (it's happened when a improperly punched gasket was used).

I also use a hand oiler to cover all the springs, rockers, etc. in oil before installing the valve covers as it takes a little time for the lifters to get oil up the pushrods.

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Re: Oil flow to push rods
Posted by: Afa1977 ()
Date: May 13, 2018 10:43AM

Thanks your post makes sense.the valve and guide damage was on exhaust valve cyl 2
When I removed The head of the valve was a little flared out like mushroom I could not pour through the valve guide I have a feeling he was installed the way since the motor only ran for a total of 25 minutes I couldn’t see that happening in that short of a time and the stem of the valve and the body goes through the valve guide talk to me like down I have looked at many videos on valves adjustment hot . I’ve seen videos of Corvair valve adjusting hot hasty know oil squirting the pushrod but coming out below . So I gather oil does not need to be spreading on the springs at auto and this will not cause valve guide problem thank you for your time

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Re: Oil flow to push rods
Posted by: Wagon Master ()
Date: May 13, 2018 12:30PM

Afa1977 Wrote:
-------------------------------------------------------
> Thanks your post makes sense.the valve and guide
> damage was on exhaust valve cyl 2
> When I removed The head of the valve was a little
> flared out like mushroom I could not pour through
> the valve guide I have a feeling he was installed
> the way since the motor only ran for a total of 25
> minutes I couldn’t see that happening in that
> short of a time.

Valve stem, guide and tip damage can occur quite quickly with no lubrication. If you couldn't pull the valve through the guide to remove it......how could it have been assembled that way?

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Re: Oil flow to push rods
Posted by: 66vairman ()
Date: May 13, 2018 01:00PM

Keep in mind the lifters and pushrods rotate when the engine runs. Unlike a SBC V8 the oil has to exit the the side hole of the pushrod at the rocker. Also note the rocker has a hole to allow oil to pass from the pushrod onto the rocker nut/ball.

I've seen pushrods with the side hole at the lifter by mistake and SBC rockers installed by mistake that DO NOT have the oiling hole.

davemotohead posted a picture once of the pushrods spinning and oil was slung in all directions as the pushrods rotated. There should be no shortage of oiling in the head.

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