Pushrod squirting oil

All Models and Years
User avatar
ossieoz
Posts: 84
Joined: Fri Jun 30, 2017 2:41 am

Pushrod squirting oil

Post by ossieoz »

Hi there, bench started my 102hp engine yesterday. Before i started it up i double checked cold valve lash adjustments... followed Dave Motorhead’s video on how to cold adjust.

Eventually it started :) i had my 1/3 valve covers on each side and noticed that on one side a couple of pushrods were squirting a hell of alot of oil (cylinder 3 exhaust pushrod and cylinder 5 intake pushrod). On the other side just one pushrod squirts sporadically (i think it was 4th cylinder intake pushrod.

This squirting of oil is so much that it squirts out of my 1/3 valve covers and can even squirt past my bench and onto the floor. I’ve never seen this type of excessive squirting before, is this normal?

I’ve taken off the rockers and replaced the rockers and rocker ball as they looked a little worn. But this didn’t solve the problem of squirting. Checked the pushrods and they looked ok.

The actual squirting is coming from the pushrods, i can see that as when the the pushrods rotates the squirting follows this rotation.

What could be wrong? Or is this normal?

This 102hp engine was a ‘total’ rebuild by a guy on a island called Friday Harbor, in Washington. I bought it on e-bay and had it shipped to Sweden.


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.
64powerglide
Posts: 1604
Joined: Tue Mar 25, 2014 9:18 pm
Location: Kalamazoo Mi..

Re: Pushrod squirting oil

Post by 64powerglide »

More is good, sounds like the oil pump is working fine.
64Powerglide, Jeff Phillips

Kalamazoo, Mi..
66vairguy
Posts: 4498
Joined: Tue Dec 21, 2010 3:44 pm

Re: Pushrod squirting oil

Post by 66vairguy »

Well it turns out "more is good" isn't that good.

There are several things that cause variation in oil flow up the pushrod. The lifters make a difference. Did you inspect your pushrods to make sure they were not plugged? Also GM made two different pushrods!!

Bob Helt, who does a lot of Corvair research, found there were two different types of pushrods. The newer design had a smaller hole at the lifter end. In fact I've seen the difference myself while inspecting a number of spares. Bob H. found GM statements explaining the change was done to REDUCE oil flow to the head. Why? Excess oil flow to the head was causing the oil temperature to increase during normal operation.

Yes some will say - isn't cooling the head a good thing? I suppose if you are going racing and install a big oil cooler the answer would be yes, but these cars were built for street use that involved a wide range of operation. Finally - hundreds of thousands of Corvairs were made with the lower volume pushrods and they ran without issue!!

Today it's not unusual to find different parts from different years in an engine. The stories I could tell about the things I find when taking old engines apart.

The oil pressure has little to do with oil flow up the pushrod. The lifter pumps oil up the pushrod and if you extend the lifter plunger two far out during adjustment that will reduce oil flow up the pushrod. Some do this to prevent lifter pump up due to low pressure stock valve springs that can't close the valve fast enough at high RPM by just turning down the rocker nut until lash closes (quiet). For best lifter function, and to allow for wear, a HOT running engine adjustment is 1/2 turn or the rocker nut after the clicking stops (zero lash). This is the accepted practice now. I would do a HOT running adjustment after a few hours of break-in if you have a new camshaft and/or lifters. The racers tend to go with only 1/4 turn after the clicking stops, but not recommended for street use.

Finally - GM used a variety of lifters in the Corvair. The variations are minor, some supposedly pump more oil. To this day the arguments as to why still go on. It's a moot point now since only a couple versions are made and they are the same as used in the SBC engines. The Mellings with the deep shoulder (supposedly aid in engine assembly to keep the pushrods centered) are preferred.
User avatar
acarlson
Posts: 454
Joined: Wed Nov 02, 2016 5:54 pm
Location: Dahlonega, GA

Re: Pushrod squirting oil

Post by acarlson »

I had the exact same problem when I first fired up my rebuilt Corsa turbo. I was told that high engine RPM can increase the oil flow up the pushrods. I was running about 1500 RPM at the time and had oil squirting out over the top of my cutoff valve covers. I was using new lifters from Clark’s. Except for the mess I wasn’t too concerned and the engine is running fine today. You can check out my first engine startup from here http://www.cincotek.com/corvair/rebuild.m4v

If you watch to the end you’ll see the pumped out oil on the plastic ground cover :eek:
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
User avatar
ossieoz
Posts: 84
Joined: Fri Jun 30, 2017 2:41 am

Re: Pushrod squirting oil

Post by ossieoz »

acarlson wrote:I had the exact same problem when I first fired up my rebuilt Corsa turbo. I was told that high engine RPM can increase the oil flow up the pushrods. I was running about 1500 RPM at the time and had oil squirting out over the top of my cutoff valve covers. I was using new lifters from Clark’s. Except for the mess I wasn’t too concerned and the engine is running fine today. You can check out my first engine startup from here http://www.cincotek.com/corvair/rebuild.m4v

If you watch to the end you’ll see the pumped out oil on the plastic ground cover :eek:
Good to hear that some one else had the same ’problem’... thanks for the info :)


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.
User avatar
ossieoz
Posts: 84
Joined: Fri Jun 30, 2017 2:41 am

Re: Pushrod squirting oil

Post by ossieoz »

66vairguy wrote:Well it turns out "more is good" isn't that good.

There are several things that cause variation in oil flow up the pushrod. The lifters make a difference. Did you inspect your pushrods to make sure they were not plugged? Also GM made two different pushrods!!

Bob Helt, who does a lot of Corvair research, found there were two different types of pushrods. The newer design had a smaller hole at the lifter end. In fact I've seen the difference myself while inspecting a number of spares. Bob H. found GM statements explaining the change was done to REDUCE oil flow to the head. Why? Excess oil flow to the head was causing the oil temperature to increase during normal operation.

Yes some will say - isn't cooling the head a good thing? I suppose if you are going racing and install a big oil cooler the answer would be yes, but these cars were built for street use that involved a wide range of operation. Finally - hundreds of thousands of Corvairs were made with the lower volume pushrods and they ran without issue!!

Today it's not unusual to find different parts from different years in an engine. The stories I could tell about the things I find when taking old engines apart.

The oil pressure has little to do with oil flow up the pushrod. The lifter pumps oil up the pushrod and if you extend the lifter plunger two far out during adjustment that will reduce oil flow up the pushrod. Some do this to prevent lifter pump up due to low pressure stock valve springs that can't close the valve fast enough at high RPM by just turning down the rocker nut until lash closes (quiet). For best lifter function, and to allow for wear, a HOT running engine adjustment is 1/2 turn or the rocker nut after the clicking stops (zero lash). This is the accepted practice now. I would do a HOT running adjustment after a few hours of break-in if you have a new camshaft and/or lifters. The racers tend to go with only 1/4 turn after the clicking stops, but not recommended for street use.

Finally - GM used a variety of lifters in the Corvair. The variations are minor, some supposedly pump more oil. To this day the arguments as to why still go on. It's a moot point now since only a couple versions are made and they are the same as used in the SBC engines. The Mellings with the deep shoulder (supposedly aid in engine assembly to keep the pushrods centered) are preferred.
Thanks for the info :)


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.
joelsplace
Posts: 1939
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: Pushrod squirting oil

Post by joelsplace »

Keeping the oil from getting too hot as a reason for less oil flow to the heads is not a good design parameter for anyone that uses good oil and maintains their cooling system. If you use an oil that can handle the extra heat such as a modern synthetic which wasn't available to them back then more oil flow to the heads should make them run cooler and result in fewer dropped valve seats.

"hundreds of thousands of Corvairs were made with the lower volume pushrods and they ran without issue!!" I wouldn't call all the dropped seats no issue.

The extra oil flow was in the original design and I would bet that it was changed because of lack of maintenance of the cooling system by customers and aging castings with more flash than the engineers ever allowed for. A lesser of two evils thing. If you keep the oil cooler clean and don't suck a bunch of leaves or rags into the fan then more oil to the top end would be good for the engine. Modern synthetics can handle a lot more heat anyway. The hotter the oil runs up to the point it breaks down the more heat the oil cooler can reject and the cooler the overall engine temps should be. This is because the greater the temperature differential between the oil and the cooling air the greater the efficiency of the cooler.

I want to run 2 folded fin coolers like others have done and modify some lifters to get more oil to the heads.

Does anyone know if the lower flow changes were made around the time A/C became available?

I do realize that this is a case of "what is better?" vs good enough for most situations. I'm just thinking of maximizing the life of all my Corvair engines as I try to get to the point of only driving Corvairs so I can dump my water pumpers. I am driving my '66 Sport Sedan today in the downpour here in 70 degree DFW Texas.
157 Corvairs, 5 Ultravans and counting
Northlake, TX
User avatar
ossieoz
Posts: 84
Joined: Fri Jun 30, 2017 2:41 am

Re: Pushrod squirting oil

Post by ossieoz »

joelsplace wrote:Keeping the oil from getting too hot as a reason for less oil flow to the heads is not a good design parameter for anyone that uses good oil and maintains their cooling system. If you use an oil that can handle the extra heat such as a modern synthetic which wasn't available to them back then more oil flow to the heads should make them run cooler and result in fewer dropped valve seats.

"hundreds of thousands of Corvairs were made with the lower volume pushrods and they ran without issue!!" I wouldn't call all the dropped seats no issue.

The extra oil flow was in the original design and I would bet that it was changed because of lack of maintenance of the cooling system by customers and aging castings with more flash than the engineers ever allowed for. A lesser of two evils thing. If you keep the oil cooler clean and don't suck a bunch of leaves or rags into the fan then more oil to the top end would be good for the engine. Modern synthetics can handle a lot more heat anyway. The hotter the oil runs up to the point it breaks down the more heat the oil cooler can reject and the cooler the overall engine temps should be. This is because the greater the temperature differential between the oil and the cooling air the greater the efficiency of the cooler.

I want to run 2 folded fin coolers like others have done and modify some lifters to get more oil to the heads.

Does anyone know if the lower flow changes were made around the time A/C became available?

I do realize that this is a case of "what is better?" vs good enough for most situations. I'm just thinking of maximizing the life of all my Corvair engines as I try to get to the point of only driving Corvairs so I can dump my water pumpers. I am driving my '66 Sport Sedan today in the downpour here in 70 degree DFW Texas.
Thanks for the input


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.
66vairguy
Posts: 4498
Joined: Tue Dec 21, 2010 3:44 pm

Re: Pushrod squirting oil

Post by 66vairguy »

Fact is most of the dropped seats are traced to the larger valve 140HP heads. The other engines with the smaller valves don't seem to be an issue until approaching 100K miles or if the engine is badly overheated due to a broken fan belt and the driver kept going. The #5 cylinder seat issue is usually a ripped hose from the top of the fan shroud to the heater box. Some just block off the hose connection on the fan shroud (that hose is difficult to install). Also the heater box flap must be intact or it leaks air in the off position.

Installing deeper seats fixed the 140HP heads. I've yet to find anyone that with a 140HP engine that dropped a seat when the deeper seats were installed PROPERLY. The local head re-builder has done them for decades and has not had a return due to a dropped seat.

Feel free to run more oil to the heads and install a bigger oil cooler, my point was it is not needed for NORMAL driving.

I would not worry about A/C, I pulled apart a 66 110HP engine with 94K miles on it that come out of a factory A/C car and the seats and valves were still functional. Unfortunately the owner didn't change the oil that often and the crank was badly worn. Now most folks use fans on the A/C condenser and some claim the engine runs cooler at idle and stop and go driving with the A/C on. I have not confirmed that, but with R134a and the bulkhead LM condenser the Corvair engine fan CFM is inadequate at idle to keep the high side pressure within normal operating range on hot days. A fan(s) on the condenser fixes the issue.

GM tested Corvairs at their desert proving grounds in the summer and the cooling system was adequate. Turbo charged Corvairs are another story. Corvair engineer Benzinger gave a good talk about them at a convention.
User avatar
ossieoz
Posts: 84
Joined: Fri Jun 30, 2017 2:41 am

Re: Pushrod squirting oil

Post by ossieoz »

66vairguy wrote:Fact is most of the dropped seats are traced to the larger valve 140HP heads. The other engines with the smaller valves don't seem to be an issue until approaching 100K miles or if the engine is badly overheated due to a broken fan belt and the driver kept going. The #5 cylinder seat issue is usually a ripped hose from the top of the fan shroud to the heater box. Some just block off the hose connection on the fan shroud (that hose is difficult to install). Also the heater box flap must be intact or it leaks air in the off position.

Installing deeper seats fixed the 140HP heads. I've yet to find anyone that with a 140HP engine that dropped a seat when the deeper seats were installed PROPERLY. The local head re-builder has done them for decades and has not had a return due to a dropped seat.

Feel free to run more oil to the heads and install a bigger oil cooler, my point was it is not needed for NORMAL driving.

I would not worry about A/C, I pulled apart a 66 110HP engine with 94K miles on it that come out of a factory A/C car and the seats and valves were still functional. Unfortunately the owner didn't change the oil that often and the crank was badly worn. Now most folks use fans on the A/C condenser and some claim the engine runs cooler at idle and stop and go driving with the A/C on. I have not confirmed that, but with R134a and the bulkhead LM condenser the Corvair engine fan CFM is inadequate at idle to keep the high side pressure within normal operating range on hot days. A fan(s) on the condenser fixes the issue.

GM tested Corvairs at their desert proving grounds in the summer and the cooling system was adequate. Turbo charged Corvairs are another story. Corvair engineer Benzinger gave a good talk about them at a convention.
Thanks 66vairguy for this info. My 80hp engine did have dropped valves in cylinder #5. The heating in my Greenbrier was not connected, there was no heater fan unit attached at all... So do i understand you correctly that I should block off where the heater hose is attached to the engine shroud?
IMG_2443.JPG
D


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.
User avatar
terribleted
Posts: 4588
Joined: Sun Apr 18, 2010 2:36 pm
Location: Atlanta, GA
Contact:

Re: Pushrod squirting oil

Post by terribleted »

He was actually commenting about the top hose outlet for the fresh air feed needing to be blocked off or working properly (valve in heater box closing and hose in place and not torn). If you are not running any heater hoses, blocking the outlets in your photo is also a good idea so that the airflow goes out the rear of the engine as designed and not out the heater outlets.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia
User avatar
ossieoz
Posts: 84
Joined: Fri Jun 30, 2017 2:41 am

Re: Pushrod squirting oil

Post by ossieoz »

terribleted wrote:He was actually commenting about the top hose outlet for the fresh air feed needing to be blocked off or working properly (valve in heater box closing and hose in place and not torn). If you are not running any heater hoses, blocking the outlets in your photo is also a good idea so that the airflow goes out the rear of the engine as designed and not out the heater outlets.
Thanks for clarifying that terribleted :)


1961 Greenbrier, 1962 Rampside and 1964 Monza cab.
joelsplace
Posts: 1939
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: Pushrod squirting oil

Post by joelsplace »

I've only had one dropped seat in an 80hp and it wasn't #5 IIRC it was #2. No indication of why as far as any clogged fins or oil cooler. Haven't had a 140 drop one yet but I shouldn't have said that...
157 Corvairs, 5 Ultravans and counting
Northlake, TX
64powerglide
Posts: 1604
Joined: Tue Mar 25, 2014 9:18 pm
Location: Kalamazoo Mi..

Re: Pushrod squirting oil

Post by 64powerglide »

Why would anyone say to block off the fresh air outlet, if the air lever is pushed down & letting air pass through are you going to tell me it might make the engine overheat. Yes the warm air might get pulled by the fan but some cars have fixed vents in the heater boxes that blow hot air into the engine compartment too. Sounds like bull to me!!!!
64Powerglide, Jeff Phillips

Kalamazoo, Mi..
joelsplace
Posts: 1939
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: Pushrod squirting oil

Post by joelsplace »

The only time I understand that the fresh air is used is when you want to reduce the air temperature for the heater. That's in the winter when the engine doesn't need as much cooling. I've heard of a lot of #5 seat failures that were attributed to the fresh air hose. It is a giant cooling air leak right at #5. I've never had it happen but I don't drive with missing fresh air hoses.
157 Corvairs, 5 Ultravans and counting
Northlake, TX
66vairguy
Posts: 4498
Joined: Tue Dec 21, 2010 3:44 pm

Re: Pushrod squirting oil

Post by 66vairguy »

64powerglide wrote: Thu Feb 22, 2018 10:40 pm Why would anyone say to block off the fresh air outlet, if the air lever is pushed down & letting air pass through are you going to tell me it might make the engine overheat. Yes the warm air might get pulled by the fan but some cars have fixed vents in the heater boxes that blow hot air into the engine compartment too. Sounds like bull to me!!!!
Maybe you should go read the information again instead of sayin "sounds like a bunch of bull to me". Great attitude.

As Terrible Ted said - the heater box blocks off any fresh air from the top shroud until you move the lever down to get heat. In the middle the lever moves the mixer flap to allow in cool air and mix it with the hot air form the lower shrouds. Both air paths are pressurized by the fan. When the heater is off on warm day it does NOT affect the engine air flow IF THE FLEX HOSE AND HEAT BOX FLAP ARE INTACT. Now you often find leaks. Personally I take everthing apart and make reapairs, but it's a lot of work. Most just take off the upper fresh air hose and put a plate over the hole on the top engine fan shroud. Yes the heater will still work IF you turn on the electric blower.

Feel free to go to the Corvaircenter forum were this has been discussed many times. Your comments suggest you don't understand how the Corvair hot air heater works.
Post Reply

Return to “Ask your Mechanical Questions here”