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Re: Piston oil squirters in NASCAR engines

Posted: Sat May 16, 2020 2:48 pm
by Fusion Works
I'm wondering if there is a way to add a nozzle to the stock squirters? Like drilling a small hole and then brazing on an additional squirter?

Another option might be to come in from the opposite side of the block and feed them with a four AN line or some sort of stainless hard line with AN flare nuts. Then tap through the block into the underside of the cylinders to feed some squirters.

Re: Piston oil squirters in NASCAR engines

Posted: Sun May 17, 2020 3:31 am
by Kevin Johnson
ptuomov wrote: Sun May 03, 2020 4:56 pm Anyone had a look inside a newish NASCAR engine? I hear they have four or five piston oil cooling jets per cylinder. Which spots in the piston underside do all those four or five jets spray?
This might help:
http://www.superchevy.com/how-to/project-cars/sucp-0712-chevy-r07-nascar-engine wrote:The R07's camshaft resides higher in the block than the SB2's, thus allowing for a shorter/stiffer pushrod to be used. This dramatically improves valvetrain geometry at high rpm. The raised camshaft allows room for inboard piston squirters, which spray the underside of the pistons for additional cooling.

Re: Piston oil squirters in NASCAR engines

Posted: Thu May 21, 2020 8:28 pm
by j-c-c
I broached this question before, not sure if i got much of a response.

If piston cooling is so beneficial, why not incorporate a separately extra cooled, pressurized (?), and plumbed oil delivery circuit just for the squirters?
Its main goal is cooling, right?
It would likely feed off the central oil tank, and return with the normal DS pickups.

Re: Piston oil squirters in NASCAR engines

Posted: Fri May 22, 2020 2:42 am
by Kevin Johnson
j-c-c wrote: Thu May 21, 2020 8:28 pm I broached this question before, not sure if i got much of a response.

If piston cooling is so beneficial, why not incorporate a separately extra cooled, pressurized (?), and plumbed oil delivery circuit just for the squirters?
Its main goal is cooling, right?
It would likely feed off the central oil tank, and return with the normal DS pickups.
Image


But seriously, I was told by a factory engineer that an oiling solution for a known performance car was vetoed because it would have added $1000 to the sales price. I expect that a separate circuit and cooling system would exceed this.

Re: Piston oil squirters in NASCAR engines

Posted: Fri May 22, 2020 2:57 am
by naukkis79
j-c-c wrote: Thu May 21, 2020 8:28 pm I broached this question before, not sure if i got much of a response.

If piston cooling is so beneficial, why not incorporate a separately extra cooled, pressurized (?), and plumbed oil delivery circuit just for the squirters?
Its main goal is cooling, right?
It would likely feed off the central oil tank, and return with the normal DS pickups.
Why add complex things that won't bring any benefits? Piston cooling with oil from main galleries works just as fine. Suzuki build motorcycle engines where also cylinder head is totally oil-cooled, there was a additional low-pressure oil pump to circulate oil in head and oil cooler - but even in that configuration piston squirters are fed from normal high-pressurized side of oil pump.

Re: Piston oil squirters in NASCAR engines

Posted: Sat May 23, 2020 10:01 pm
by ptuomov
Shooting straight:



The piston is a more modern design than the ‘87 piston, so the jet angle and location was adjusted.

Re: Piston oil squirters in NASCAR engines

Posted: Sun May 24, 2020 12:26 am
by modok
The majority of high output gasoline and diesel engines spray oil at the pistons.

Now with direct injection, there is really less difference than ever. gas and diesel are almost the same mechanically.

Re: Piston oil squirters in NASCAR engines

Posted: Mon May 25, 2020 12:38 pm
by j-c-c
naukkis79 wrote: Fri May 22, 2020 2:57 am
j-c-c wrote: Thu May 21, 2020 8:28 pm I broached this question before, not sure if i got much of a response.

If piston cooling is so beneficial, why not incorporate a separately extra cooled, pressurized (?), and plumbed oil delivery circuit just for the squirters?
Its main goal is cooling, right?
It would likely feed off the central oil tank, and return with the normal DS pickups.
Why add complex things that won't bring any benefits? Piston cooling with oil from main galleries works just as fine. Suzuki build motorcycle engines where also cylinder head is totally oil-cooled, there was a additional low-pressure oil pump to circulate oil in head and oil cooler - but even in that configuration piston squirters are fed from normal high-pressurized side of oil pump.
1. benefits:
Cooler supply of oil, if as reported here a reduction of 77F ipiston temp is worthy, it seems like cooler oil would assist in gaining that goal
ability to modulate volume of oil as needed or fine tune oil spray
reduce stress on main oil system, whose failure leads to catastrophic failure normally, a squirter system does not have the same criticality, IMO
2. If Suzuki figured it it out as worthy bang for buck, seems like it should be doable
3. I agree, "Fine" is good enough for some
4. Might even go a step further and use a diesel injector pump style solution, very high pressure, and timed for best use of the oil striking the piston if there are benefits to found there I can't imagine much oil remains on a piston as it starts it upward trajectory.

Re: Piston oil squirters in NASCAR engines

Posted: Mon May 25, 2020 2:56 pm
by Kevin Johnson
j-c-c wrote: Mon May 25, 2020 12:38 pm ...

1. benefits:
Cooler supply of oil, if as reported here a reduction of 77F ipiston temp is worthy, it seems like cooler oil would assist in gaining that goal
ability to modulate volume of oil as needed or fine tune oil spray
reduce stress on main oil system, whose failure leads to catastrophic failure normally, a squirter system does not have the same criticality, IMO
2. If Suzuki figured it it out as worthy bang for buck, seems like it should be doable
3. I agree, "Fine" is good enough for some
4. Might even go a step further and use a diesel injector pump style solution, very high pressure, and timed for best use of the oil striking the piston if there are benefits to found there I can't imagine much oil remains on a piston as it starts it upward trajectory.
When I did the pattern for the RB26DETT I noticed that the pistons had squirters that fed into a chamber. When I returned the core to the customer after measuring I knew he was going to throw them away so I asked for one to keep. I even looked up the Aisin Seiki patent for it at the time. (This is a type of "cocktail shaker" piston cooling.)

The same engine had a wetsump that obviously had a great deal of thought put into oil flow.

The same engine had an inward protruding "hump" in the sump to allow easier external access to torque converter bolts. Nissan had started adding this feature to their engines. This was something that you would likely only notice if you had to design parts for families/types of engines for a marque over many years/decades. It was significant because the oil witness marks in the sump showed the severe disruption to windage flow and this costs power and heats up the oil. The oil control engineers had this forced upon them. Clearly, if they could have changed it they would have. It is an example of the frustrating constraints that engineers have when working out solutions.

Another engine that I designed parts for unceremoniously dumped draining oil from the head directly onto the rotating assembly -- that heats up the oil and aerates it. I corresponded with an engineer involved with the design. He said that they had met the target power output in the first iteration and there was no reason to do further improvements -- that all costs real money. He also explained that additional power output could be an issue in certain markets due to taxing schemes.

Re: Piston oil squirters in NASCAR engines

Posted: Thu May 26, 2022 11:27 pm
by NewbVetteGuy
I know I’m resurrecting a 2 year old thread, but I have to ask: has anyone measured EGTs before and after adding piston oil squirters to an engine?

I’m curious how much they reduce combustion temps and whether/ how much they might allow you to run more cylinder pressure on pump gas…
(EGT reduction?)

Adam

Re: Piston oil squirters in NASCAR engines

Posted: Thu May 26, 2022 11:30 pm
by NewbVetteGuy
On a marginally related note: if you’re not running piston oil squirters other than random windage, isn’t a piston’s only source of cooling the piston rings themselves?

If so, do ultra thin rings decrease the amount of heat that can be transferred from the piston to the cylinder walls and coolant system and by extension make oil squirters (or thermal barrier coated piston tops) an increasingly good idea?



Adam

Re: Piston oil squirters in NASCAR engines

Posted: Fri May 27, 2022 9:01 am
by dannobee
The intake charge will also help cool the piston.

Incidentally, for those worried about an oil pressure reduction when running squirters, the check valves can be set so that the squirters are shut off at lower oil pressures, such as when idling. They'd only come on with higher engine speed, likely exactly when you need to start cooling the piston and the excessive oil pressure was bypassing anyway.

Re: Piston oil squirters in NASCAR engines

Posted: Fri May 27, 2022 2:42 pm
by NewbVetteGuy
dannobee wrote: Fri May 27, 2022 9:01 am The intake charge will also help cool the piston.

Incidentally, for those worried about an oil pressure reduction when running squirters, the check valves can be set so that the squirters are shut off at lower oil pressures, such as when idling. They'd only come on with higher engine speed, likely exactly when you need to start cooling the piston and the excessive oil pressure was bypassing anyway.
Thanks. I haven't come across anyone using squirters on an SBC with check valves; only the BLP fixed orifice system; I'd love to find someone running with check valves.
-If the piston oil squirters require x% more oil flow, can't you also just upsize your oil pump to provide for at least that much increased oil flow and then the risk of oil starvation or low pressure at low RPM is mitigated? (That's my assumption, but I'm not certain.)

This is the diagram from JE that causes me to ask whether at least PART of the reduced oil and coolant temps that seem to show up when running thin rings is because the pistons are transferring less heat through the rings to the walls.

-I get that reduced friction = less heat into the oil and coolant, but less heat transferred through the rings to the bore because of reduced surface area in contact would do the same, right?

Image


Adam

Re: Piston oil squirters in NASCAR engines

Posted: Fri May 27, 2022 3:42 pm
by af2
Amazing we are talking about an engine that runs between 8000 and 9000. Why people think the Normal engine is even close really has me flabbergasted.

Re: Piston oil squirters in NASCAR engines

Posted: Fri May 27, 2022 4:51 pm
by PSA
Considering how much of the friction is from the rings I doubt they would help cool the pistons more by being wider.
Most modern engines also run oil with lower viscosity and that will also change things.
There's production engines that both come with and without oil squirter and there's no difference in what oil pump that's used (that I know of), but I guess some engine could potentially be at the breaking point. It's should also be more of a problem when the engine is hot.