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Re: Piston Cooling Jets on a Vair Engine
Posted by: joelsplace ()
Date: November 08, 2019 01:58PM

Yes it would be spraying the same amount all the time but on the up stroke the piston would be running away from the oil very quickly while it would be piling it up on the down stroke to sling it off at the bottom.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Piston Cooling Jets on a Vair Engine
Posted by: Pacerace ()
Date: November 08, 2019 02:50PM

As often as it is used on modern engines I doubt that's a concern. First and second gen Miata engines used them (engine derived from a turboed application and kept the squirters) and they rev to 7200 happily all day long. Higher than most rev their Corvair engines.

________________________________________________________

Chandler
Powder Springs, GA.



1965 Corvair Monza 110/4sp Coupe

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Re: Piston Cooling Jets on a Vair Engine
Posted by: joelsplace ()
Date: November 08, 2019 02:51PM

If it is factory they could possibly compensate for it somehow in the balance?

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Piston Cooling Jets on a Vair Engine
Posted by: American Mel ()
Date: November 08, 2019 05:03PM

joelsplace Wrote:
-------------------------------------------------------
> If it is factory they could possibly compensate for it somehow in the balance?


They could, but I doubt it.
I really believe that you are overthinking this.
A non-issue at best.

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, '62 Monza Wagon, '63 Spyder, '65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dualy, approaching 400K
17'Terry

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Re: Piston Cooling Jets on a Vair Engine
Posted by: Reds kid ()
Date: November 08, 2019 05:45PM

Have you thought of ceramic coating the top of your pistons. Its a very popular with diesel and turbo engine builds.

65 140 Corsa
Castaic CA

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Re: Piston Cooling Jets on a Vair Engine
Posted by: jjohnsonjo ()
Date: November 08, 2019 06:03PM

GM changed the the push rods to deliver less oil because the oil was picking too much heat from the heads. Flame on.

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa


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Re: Piston Cooling Jets on a Vair Engine
Posted by: Pacerace ()
Date: November 08, 2019 06:28PM

Also think about this. Even if it DOES affect the balance, both of the opposing pistons would be on the down stroke at the same time, so they would have the same oil pooling. I'm no engineer, but I don't think this is an issue at all.

________________________________________________________

Chandler
Powder Springs, GA.



1965 Corvair Monza 110/4sp Coupe

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Re: Piston Cooling Jets on a Vair Engine
Posted by: 63turbo ()
Date: November 08, 2019 06:37PM

Racers have done this on Corvairs over the years, and I know of one that was turbo'ed that did it also... oil spray jets drop the piston crown temperature 100-150 degrees, and most find that they can run more aggressive timing after doing it, and many have to run auxiliary oil coolers when adding the oil spray jets. No one has "balance" issues or oil control problems. The only "bugger" if there is one is that its a more complicated set-up. A few neat advantages of this are that the oil has a faster warm up time and more likely to boil off moisture and gas. The combination of water and gas and oil is a great way to wear out an engine prematurely!! The wristpin is oiled much better... this is REALLY important, as it is normally one of the most poorly lubricated and cooled and highly stressed thing in the engine. Because the oil is warming up faster, it comes into its best viscosity range quicker and this is also really important for the engine to live a long time, as cold oil doesn't lubricate very well! Lifters are more likely to work like they are supposed to when the oil is up to temp, the engine is typically a lot quieter the sooner the oil gets to temp. Really good idea to do it if you can stand all the extra work!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Piston Cooling Jets on a Vair Engine
Posted by: CoCoCo ()
Date: November 08, 2019 11:23PM

Don't some engines that use oil cooling squirt the piston through a drilled port in the connecting rod? And some (perhaps of the same design) only squirt at a certain point in the rotation when the crank and rod ports align, or something like that.

Mostly a motorcycle thing that's been done for 40 or 50 years, but I think the new Ford 7.2 pushrod gas V8 engine is going to utilize some sort of piston oiler.

Paul

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Re: Piston Cooling Jets on a Vair Engine
Posted by: CoCoCo ()
Date: November 08, 2019 11:31PM

Sorry, I missed page 2 of this. And looking around I see the oil cooling discussion is going on in a couple of other threads as well.

Paul

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Re: Piston Cooling Jets on a Vair Engine
Posted by: TedBrown ()
Date: November 09, 2019 06:50AM

Time for my 2 cents.

I have thought this is a great idea for a while and I agree with some that we might be overthinking the spraying/balance of the oil.

jjohnsonjo stated that "GM changed the pushrods to deliver less oil because the oil was picking too much heat from the heads". and Kevin (63 Turbo) mentioned an additional oil cooler.

I think these two opinions are the most valid. The heat from the pistons, wrist pin and connecting rod are transferred to the oil through the spraying/jet process. Now the heat is in the oil and needs to be transferred to the open-air through the oil cooler and engine surface. Modern engines use a water-cooled oil cooler which transfers the heat away more efficiently than air. Since most of this heat cant be transferred away from the engine, it circulates through the engine and raising the engine temp. The oil cant dissipate the heat and will start to breakdown the oil components and underserve the lubrication process. GM may have made that change because the heads can tolerate the added heat and serve as a better transfer agent than oil enclosed in an engine block.

I have added additional oil coolers and tested with limited success as the benefit was not worth the risk of an additional failure point in such a vital area of engine operation. I did build a water-cooled oil cooler that fit in the place of the standard oil cooler, but then I had the complexity of cooling the heated water and circulating. Dodge has one that is a lot cheaper to buy than build, but then I have Frankenvair (which never bothered me much, but horrifies others). Adding additional oil capacity with large pans only delays the inevitable, and the additional cooling of the aluminum pan is not where its needed.

I guess my point is that this is really cool (pun) and may help our engines, but we need to figure out how to transfer the heat from the oil in a more efficient manner than an air-cooled oil cooler. I can't back up my information (SAE papers, etc) other than experience, thoughts, and Redneck engineering.

**NEW** Dual and Four TBI KITS are now available.

Ted Brown
Anderson, SC
[www.Corvair-EFI.com]
Brown Injection Facebook
68 Monza Convert Auto - EFI
61 Loadside Auto - EFI/Smart DIS
61 Rampside - 4 speed - EFI
61 Greenbrier 4 speed - EFI
61 Greenbrier 4 Speed - Bad Motor

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Re: Piston Cooling Jets on a Vair Engine
Posted by: davemotohead ()
Date: November 09, 2019 07:34AM

jjohnsonjo Wrote:
-------------------------------------------------------
> GM changed the the push rods to deliver less oil because the oil was picking too much heat from the heads. Flame on.
-------------------------------------------------------
I think GM changed the push rod ends (The hole opening) only because the early design was cracking and chipping the ends of the push rods.







1960 4dr sedan caveman car
1961 Rampside (Chetside)
1962 Rampside (Barnside)
1962 Short Rampside (Shortside)
1962 Monza 700 Wagon
1963 Monza 900 coup (General Nader)

-----------------------------------
Rust Free Lancaster Ca

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Re: Piston Cooling Jets on a Vair Engine
Posted by: The Stig ()
Date: November 09, 2019 08:18AM

Who here has started a Corvair engine without the top cover? Silly indeed but I wanted to see it spin. The oil cloud at idle was 5 feet high. While I don’t doubt oil sprayers could help, there is plenty of oil flying around that I can’t imagine it affecting balance.

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Re: Piston Cooling Jets on a Vair Engine
Posted by: 63turbo ()
Date: November 09, 2019 09:03AM

TedBrown Wrote:
-------------------------------------------------------
> Time for my 2 cents.
>
> I have thought this is a great idea for a while and I agree with some that we might be overthinking the spraying/balance of the oil.
>
> jjohnsonjo stated that "GM changed the pushrods to deliver less oil because the oil was picking too much heat from the heads". and Kevin (63 Turbo) mentioned an additional oil cooler.
>
> I think these two opinions are the most valid. The heat from the pistons, wrist pin and connecting rod are transferred to the oil through the spraying/jet process. Now the heat is in the oil and needs to be transferred to the open-air through the oil cooler and engine surface. Modern engines use a water-cooled oil cooler which transfers the heat away more efficiently than air. Since most of this heat cant be transferred away from the engine, it circulates through the engine and raising the engine temp. The oil cant dissipate the heat and will start to breakdown the oil components and underserve the lubrication process. GM may have made that change because the heads can tolerate the added heat and serve as a better transfer agent than oil enclosed in an engine block.
>
> I have added additional oil coolers and tested with limited success as the benefit was not worth the risk of an additional failure point in such a vital area of engine operation. I did build a water-cooled oil cooler that fit in the place of the standard oil cooler, but then I had the complexity of cooling the heated water and circulating. Dodge has one that is a lot cheaper to buy than build, but then I have Frankenvair (which never bothered me much, but horrifies others). Adding additional oil capacity with large pans only delays the inevitable, and the additional cooling of the aluminum pan is not where its needed.
>
> I guess my point is that this is really cool (pun) and may help our engines, but we need to figure out how to transfer the heat from the oil in a more efficient manner than an air-cooled oil cooler. I can't back up my information (SAE papers, etc) other than experience, thoughts, and Redneck engineering.

I agree that the additional oil coolers have to be huge to get a small reduction in temp's if they are being air cooled by near still motionless air.
The oil cooler doesn't have to be quite so large if it is forced air, and many of the racers have their auxiliary oil cooling placed to get some ram air or use a electric fan. As long as the oil is staying between 220-265 you're oil temperatures are controlled well enough. For maximum heat extraction using a minimum amount of space, I think it would make some sense to modify the top shroud to accommodate a stack of coolers and do this on both sides of the engine, this way you can get maximum forced air cooling, and it wont look like a science project from hell! The other thing is that I've noticed...it seems like a lot of engines that have oil spray jets use a oil that's a bit heavier like an xw-40, instead of a xw-30, and it would seem like this would be a reasonable compensation for the higher peak oil temps with the oil spray jets.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Piston Cooling Jets on a Vair Engine
Posted by: 63turbo ()
Date: November 09, 2019 10:16AM

Here's a cool page to visit when contemplating additional oil cooling on Corvairs, complete with before and after test's!
[autoxer.skiblack.com]

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Piston Cooling Jets on a Vair Engine
Posted by: CoCoCo ()
Date: November 09, 2019 10:21AM

"Gee I love that kind of talk..."grinning smiley

Paul

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Re: Piston Cooling Jets on a Vair Engine
Posted by: RCSmith ()
Date: November 09, 2019 10:47AM

Some might find this simple mod of
slotting the rod big end helpful.

[www.lotuselan.net]

Ray C. Smith
'66 Corsa


Bergen County ,NJ

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Re: Piston Cooling Jets on a Vair Engine
Posted by: jimc ()
Date: November 09, 2019 11:09AM

Take a page from Porsche air cooled motors. In 1971 the six cylinder 911 motor used piston-cooling oil jets positioned above the 911's main bearings, aimed at the undersides of the piston crowns. They reduced piston-crown temperature by 50 degrees Celsius (90 Fahrenheit).

The motors were as much oil cooled as air (source Porsche Excellence Magazine),
and a dry sump oil system with a capacity of 14 quarts (dry). Their squirters ranged in size from 1.5 to 2 liter. Their system used an oil pump that delivered 65 liters of oil per minute: 17 liters are used for the squirters to cool the pistons, around 35 liters are used to lubricate the main and con-rod bearings, and the oil flow to the camshaft housing was reduced by about 50% to the 13 liters necessary to lubricate the camshaft bearings, valve guides and rocker arms. The oil pump had 1.84 times the capacity of the pressure pump to ensure a low oil level in the engine’s crankcase.

Jimc
1965 Corsa Coupe, two owner history


HACOA Member
CORSA 2017 Concours Senior Gold Award
AACA 2015 Award

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Re: Piston Cooling Jets on a Vair Engine
Date: November 09, 2019 11:25AM

Piston oilers on hi-output engines (100+ HP/liter) is a good idea, but does not come without a price. When adding these devices, you have to be honest with yourself about what the desired effect is.

If you currently aren’t failing crowns or ring lands, the complexity and friction losses are really not worth it. In engines used at hi-output for long durations, it can keep the piston crown and ring land metal from reaching critical failure temps.

I can tell you firsthand that a 0.8mm (0.0315”)hole flows a lot of oil with 30-45 PSI of oil pressure, even with 25W-50 synthetic oil at operating temp. So while it is pulling the desired temperature out of the piston, you are now overloading the bores and rings with oil, more so on our opposed engines vs vertical cylinders, because gravity does its thing on the vertical engines. The same volume oil pan is now cycling its volume more times per minute.

The oiling system DOES have to a designed to deliver the original amount of oil to the rod and main bearings, as well as the extra GPM for the oil jets.

If you must have cooling jets, get them tucked up as high as you can into the underside of the piston at BDC, and have them at a slight angle in order to sweep the stream across the piston during its travel.

As said before, the desired effect of heat removal happens, oil definitely warms up faster due to being concentrated at the heat source, but you have to size your oil cooling system to deal with that extra heat as well.

I’ve personally measured the friction on a 2.6L inline 6-cylinder engine making 300+ HP at 12-20 HP , depending on oil jet aim, volume, temperature, and oil viscosity. Again, this HP loss needs to be accounted for, as well as considering that oil usage may go up, as well as a likely increase in startup smoke due to the extra oil in the bores at shutdown that wicks past the rings when the engine cools. It’s amazing how much smoke literally a teaspoon of oil makes, it’s staggering.

The intent is to install them in the 3.0L Pressurized Pancake engine, but I intend to put 15-18 lbs of screwcharger boost to it, so I believe I’ll be at that point of having a piston life benefit.

To finalize, high boost or really high RPM engines can probably benefit from the extra cooling, but for your average hobbyist engine it’s probably overkill.

Hope this helps.

---------------------------------------------------------------------------------------------
You're unique, just like everyone else...

Johnny B
Central WI

Wife's '68, 3.0L, twin-screw compressor and fuel injected in the works...

Project Pressurized Pancake





Edited 2 time(s). Last edit at 11/09/2019 11:34AM by PressurizedPancake.

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