Piston cooling jets?

[turbokinetic]

Has anyone ever considered or researched adding piston cooling jets to a GN-era Buick V6 engine?

The GM 60° V6 engines (at least the newer ones) have cooling jets on #'s 5 and 6 pistons only.

Caterpillar's high-HP engines use small metal blocks bolted to the inside of the block below each cylinder, with a hollow bolt into an oil gallery. This little block has 2 tubes that point up and direct a stream of oil against the underside of the pistons.

I wonder if there is a suitable place to mount cooling jets in a stock Buick block, without too much external pipework?

Just a thought!
Thanks,
David

 

[challengermike]

Alot of motors have them.They are usually in the other side connecting rods.Some of the aftermarket rods dont have the grove cut in to them to oil the other side cylinder,and it doesnt make any difference.The is no advantage to having them.If anything i would think it might cause more windage which would lower alittle HP.I dont see any reason to have them anyways,as far as i know theres no problem with theses engines with excessive cylinder wear.Other engines people go with crank scrapers and windage trays to keep the windage down to free up some horsepower.

 

[jhanson1750]

From what I understand they are not there as a lubricant for the cyl wall they are to cool the underside of the piston crown. I would just turn up the alky a little. Jon

 

[GARY HARVEY]

Isolating combustion chamber heat is best accomplished with the application of ceramic
material. Coating piston tops and combustion chambers is a easy trick, all that's involved is $$'s.
I use Calico Coatings in Denver NC.
ceramic coatings, teflon coatings, thermal coatings solutions with Calico Coatings

 

[Mad_Trbo]

Piston Oiler

Turbokinetic

Are you talking about a piston oiler?

If so I have looked into the process, after owning several cars with oilers (DSM and Toyo - Supra) I couldn't understand why Buick didn't incorporate this into their block design. Especially considering the fact these use to be the staple for Bush racing.

After a little research I found that the old bush racers did use oilers for heat extraction. They would drill the main bearing saddles in addition to providing a channel from that drilled point to the saddle oiling source. The point where they drilled the saddled would be angled so that a jet could be installed and which was fed through the saddle oil feed.

I see some points of opinion listed indicating this is not necessary and I suppose it is all relative to your application. My opinion is any time you can extract heat from your hardware you increase longevity. Additionally with this modification their are other benefits which will allow you dial / tweek your combination for more performance.

This modification along with the ceramic coatings mentioned previously make for a pretty solid platform for reliable power.

I have included a pic to help dial in your visual reference. You can see there are two drilled holes that have been threaded and angled so they oppose each other and spray into the cylinders.

Enjoy

 

[Mad_Trbo]

Piston Oiler Jet

Another illustration to bring it all home.

 

[GARY HARVEY]

Controlling piston heat is best done keeping mixture within limits.
The main reason racers used oilers was an attempt at correcting oil residue buildup which contaminated things from burnt oil deposits.
Excessive oiling has horsepower loss from what is know as to much windage.
Crankshaft design modification came into play along with rod design (to cool/oil the pin with the added benefit of cooling the piston). It's easier to center drill a rod through the pin area from the rod bearing throw.
Ceramic coating came into play in the early 80's and as racers discovered their use no longer had the need for oilers & oil improved at the same time able to stand higher operating temps before break down.
Typically a performance builder that knows his stuff has been using ceramics for awhile and if not
is most likely not a player.
For decades ceramics have been available to the public and I'm happy to say, it has put beans on my table.
Many have tried coatings in the past with no success, I suggest giving them another spin and this time deal with a coater with a proven track record.
NASA started it all and WE paid for the testing.
BTW first time I saw beehive springs was in the 50's on a modified flathead, Mr. Winfield was a marvel of invention (nice to see them back).

 

[SloGN]

you can drill and tap the lifter bore oil rails to install the oil jets to spray on the bottom of the pistons. i have seen this done on several buick engines with no ill effects. But the now modern way to do it is with the calico coatings.

 

[turbodave231]

I would be very careful how much oil you spray through piston oilers. The oiling system on these engines is very limited. You could end up dropping too much oil pressure before the oil gets to #5 and #6 rod bearing.

What type of failure lead you to beleive this was necessary on the BV6?

Dave

 

[Mad_Trbo]

Ceramics vs Oilers

Why is NASCAR still using oilers? With the budgets these teams have and any exotice material you can think of at their disposal, I am not sure I line up completely with the earlier statement.

I've been told with the rebuild process taking place after each race of approximatley 500 miles or less contamination isn't necessarily the issue. Heat is and where we fight for one or two horsepower gains through development. I feel there must be more gain than loss to oilers and the benefit of heat extraction vs loss through windage.

How modern is the idea of complete heat control through ceramic coatings. Aren't the 4g63 engines still using scquirters and alot of the european engines as well?

I am still learning and hence why I am openly discussing my ideas here.


As it relates to failures, I wouldn't say I have experienced a failure. It's just the idea of the added benefit. Kind of like going from an iron head to an aluminum head. I didn't make the change because my irons failed. I made the change because of the advantages derived through use of the aluminum vs iron heads.
As far as oiling systems, I have made the appropriate modifications to support additionaly oiling requirements of the spring squirters and piston squirters.

 

[Pablo]

I actually just recently posted something about this, my machinist proposed adding oilers just as mad turbo showed in his picts which I find quite interesting. The other method that I have seen is to drill the rods and have the oil shoot up from there.

The idea is to keep piston temps down. The piston doesn't have a whole lot of surface area touching things to transfer heat away from the crown. Heat has to travel down the connecting rod, through the crank, and block. The oiler helps reduce crown temperature and thus raises the detonation threshold. Think about it, the combustion chamber has a liquid medium directly on the back side of it cooling it constantly yet the piston does not.

Controlling mixture, timing, etc all play a part in combustion temps but in a racing engine you are always trying to push the edge of detonation if you want to win. The cooler you can keep the piston the more boost, compression, etc you will be able to run and thus more power. IIRC the new Ls9 has oilers as do a multitude of other engines.

Sure windage is a factor, but if you lose a few hp to windage that you make up with increased boost and then some, it is certainly worth it

I think the marginal oiling system is a factor, my machinist proposed using check ball nozzles that will only open under elevated oil pressure conditions so that at idle and part throttle cruise, the oil pressure will not be affected.

As far as coatings go, I would really like to see the data that shows a typical piston coating 12 microns thick can do a better job of keeping a piston cool than having a liquid cool the piston. I'd be pretty amazed if it did but I'm perfectly open to the possibility (however unlikely, considering that nascar still uses squirters)


I'm sure theres an engineer out there that can break it down by the amount of heat in combustion and the thermal conductivity of the coating or someone has measured this. If its anything like ceramic header coatings then its probably not going to look good once people see the numbers.

 

[Pablo]

What type of failure lead you to beleive this was necessary on the BV6?

Dave

I think its obvious, anything related to detonation could potentially have been averted by a cooler piston. Seems like what kills 99% of these engines.

 

[turbofabricator]

I drill a small passage all the way around the piston crown (using a drill bit bent into a simi-circle) and then pump R-134A from the AC system though the piston. It has netted me about 67.3 horsepower. You should SEE the crazy plumbing inside the crank case. I could show you a picture, but then I would have to ......................

I personally feel that piston oilers are a good move, if needed. In drag racing, I don't think it is used too often. Honda uses them, Toyota uses them, Mitsubishi uses them...........The OEM does NOT spend a nickle on anything, unless it's beneficial. Spray a little alky in the intake, and it'll do a better job cooling the piston, than oil. NASCAR frowns on alcohol. ('cept when it's painted on the side of a car.) If you want to attempt it, go for it. Piston oiling could cause an increase in oil consumption, but probably marginal, if any.
The holes in the block (in the pictures above) look WAY too big, in my opinion. Are you planning on tapping the holes and installing carb jets?

 

[turbofabricator]

Here is a typical piston squirter hole. http://img466.imageshack.us/img466/5347/pistonoffsetandpartszd0.jpg

 

[Mad_Trbo]

Carb Jet

The holes in the block (in the pictures above) look WAY too big, in my opinion. Are you planning on tapping the holes and installing carb jets?

Look closely in the second picture, there is a jet installed to meter the oil flow.

Additionally after further discussion, I may have to eat a little crow. I know how it taste and don't mind a spirited discussion that nets a learning experience. As it relates to heat control it turns out ceramic may actually be the better choice for numerous reasons we can discuss if every one wants to. Some primary benefits are as stated above, stops heat transfer upto a certain point and forces heat maintenance in the combustion chamber.

The squirters are good for NASCAR applcation because a large number of the pistons are custom. Meaning each builder may have to cut the piston for their build and the time required to have the pistons cut and coated does not meet some team needs as it relates to engine rotations. This said there may be some teams using this technology but if they aren't it's due to the turn around on ceramic coating coupled.

Now for my application I needed / wanted squirters for thermal control both related to the piston pin and the piston itself. I wish I would have known more about the thermal coating before ordering my pistons.

 

[turbobuick1]

I just want to add that on the new Pontiac Solstice turbo, GM has equipped its Ecotec engine with oil squirters underneath the pistons, as well as a ceramic coating to the pistons. They must have thought it was worth their time and money for increased durability. Just my two cents.

 

[Pablo]

Look closely in the second picture, there is a jet installed to meter the oil flow.

Additionally after further discussion, I may have to eat a little crow. I know how it taste and don't mind a spirited discussion that nets a learning experience. As it relates to heat control it turns out ceramic may actually be the better choice for numerous reasons we can discuss if every one wants to. Some primary benefits are as stated above, stops heat transfer upto a certain point and forces heat maintenance in the combustion chamber.

The squirters are good for NASCAR applcation because a large number of the pistons are custom. Meaning each builder may have to cut the piston for their build and the time required to have the pistons cut and coated does not meet some team needs as it relates to engine rotations. This said there may be some teams using this technology but if they aren't it's due to the turn around on ceramic coating coupled.

Now for my application I needed / wanted squirters for thermal control both related to the piston pin and the piston itself. I wish I would have known more about the thermal coating before ordering my pistons.

I would like to hear about this. I understand the concept behind keeping heat in the chamber with coatings but is there data to show that it is more effective than liquid at keeping a piston cool simply to suppress detonation? I for one would be quite surprised if a coating were more effective than a well designed oil squirter alone.

 

[turbodave231]

The GM Ecotec 2.0 turbo certainly isn't the first GM engine to use piston oilers. The GM High Feature V6 engine has been using piston oilers since its intro several years ago. The GM Powertrain engineers told me that the pistons would not pass durability tests without them. This is a N/A engine!! GM isn't going to add anything to an engine that increases cost if it isn't absolutely required.

I'm not against using oilers if they are needed. In my particular application, I honestly don't think there would be any measurable benefit. I'd be more concerned about drilling holes in the main bulheads and weakening the block in a major structural area. I certainly wouldn't do this on a stock block that already has paper thin bulheads.

From my point of view; I don't drive my car on the street. My engine rarely gets over 200 degrees F coolant temp and I have no data to suggest piston heat is a problem. I've inspected the pistons very closely and they show no signs of overtemp on the crown, pin tower or bottom of the dome.........and no signs of detonation damage either.

Very high output daily driven turbo Buicks may need oilers at some point. None of the Buick Stage 2 Engine developers ever saw the need for piston oilers, but maybe they overlooked this area.

NASCAR is a whole different set of engine criteria! They run their engines at very high loads, and very high RPMs for a long race. Their pistons have nearly no skirt and very little mass. Piston heat would most certainly be a concern.

Ken.......I'd like to see your R134-a setup!!

 

[SloGN]

NASCAR is a whole different set of engine criteria! They run their engines at very high loads, and very high RPMs for a long race. Their pistons have nearly no skirt and very little mass. Piston heat would most certainly be a concern.

Ken.......I'd like to see your R134-a setup!!

well nascar engines also need the oil squirters due to the intanse vacuum they pull on the crankscase with very high vac in the crankcase there is no oil in suppension to oil the piston walls and pins.


Teh toyota 2JZ twin turbo engines have oil passages inside the i beam of the connecting rod that feeds oil to the pin and skirts of the psitons. I think this is one good reason those motors can make 900 hp on stock internals

 

[Pablo]

well nascar engines also need the oil squirters due to the intanse vacuum they pull on the crankscase with very high vac in the crankcase there is no oil in suppension to oil the piston walls and pins.

This line has never made sense to me. Basic science would dictate that things actually suspend more easily when they are exposed to vacuum. If it were the other way around it would eliminate one of the reasons for a pump shot in a carburetor (or pump shot code in wet manifold FI systems for that matter).
Also, oil has a very low vapor pressure and is not a factor in an engine application. If I understand vapor pressure correctly, it means that pressure changes don't easily affect its state as a condensed liquid.
Beyond that, I don't think that oil lubricates the walls of the cyl and pins because it is suspended in some type of vapor form. I think its just flung around. So actually, if it did "suspend" that would be a bad thing.


Turbodave,

You may not have seen signs of piston overheating but think about this: The piston could be well within the temp limits of the alloy it is made of but could be significantly hotter than the rest of the combustion chamber and potentially hotter than what the octane of the fuel can support without detonation when pushed to its limit.
I think its telling that any serious racing engine has had particular attention paid to eliminating hot spots in the combustion chamber. I see a lot of cooling system modifications to this end, external plumbing on cylinder heads, very high in block cooling system pressures.. I've even heard of dimpled combustion chambers on the water jacket side to increase coolant to chamber surface area.
All this stuff yet the piston still has nothing cooling it at all? to exacerbate the problem, the piston has a very small amount of surface area through which it can transfer heat away. The rod, down through the bearing, main, etc. Actually Smokey Yunick touches upon this in his book when he is talking about the importance of bearing crush for heat transfer.

Anyway, just something I was thinking about.