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Oil Cooling Jets for Pistons Anyone?


TheSwede

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By no means am i a NEWB. lol but nice coin phrase anyway.

I tend to lurk Alot on many many diffrent forums very seldum do i ever talk or post alot.

 

I understand engine blueprinting, tolerences and when and where not to do something. Aside from a Turbo aplication the equation for need is less revelent. With NA builds and supercharged builds, Heat can b released more freely by other means. On another note why not run water/meth injectioning to lower temps at the pistion? ( i could b wrong by no means am i acting on fact ) BY cooling the oil down further, the splash ( scattered oil from spinning crank and rods ) would further reduce heat on the pistions aswell. So why the added oil jet treatment to the underdome of the pistions? Is the risk of a faulty jet or instalation worth the risk of the whole engine?

 

 

But if this arises to be a better than not ( nessary evil ). The question then arises that would the added heat to the oil ( from the pistions ) need further cooling.

As stated Before its all a balancing game when building an engine. So can it be one without the other or should they both be combined?

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I was unaware we were discussing N/A applications. Turbo is the application being discussed, but the reasons for applying it to N/A are equally relevant.

 

I'm missing the 'heat can be released more freely'---please tell me how on Supercharged and N/A engines you release heat "more freely" from the crowns of the pistons. I'm all ears.

 

As for a jet being faulty being a logical fear....same could be said for a spraybar on the cam, drilled cam, or orifice in the timing chain lubrication system.

Or for that matter, a plugged main jet on a Weber/Solex....

Or a methanol tank running dry during daily driving...

 

This is a LONGEVITY modification, something you install and FORGET ABOUT, not continually mess, fiddle, adjust or play with. The proof exists that having the jets PROLONGS the piston life. It's NOT one of the modifications that you do that fails the engine if it malfunctions. That cylinder may not last as long. It is an INSURANCE POLICY---as most longevity modifications are. You add the jet to remove heat from the combustion chamber that would normally cause tolerances to have to be looser on the pistons. Please re-read the last couple of posts on the thread. I don't know why you catagorize it as a 'necessary evil'? If it's that big a deal for you, don't do it. Don't backhand the guys trying it and letting others know how it's done!

 

As for 'cooling oil down further' you miss the fact that oil needs to be at a given temperature to do it's job. You cool it all down, you loose horsepower through many different mechanisms.

Most engines running 2X factory horsepower already have an auxillary oil cooler on them to control temperatures. This question is a non-starter.

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Thanks again for saving me the typing, Tony :mrgreen:

 

One other thing - for the purposes of this discussion and for a given power output, Supercharging is exactly the same as turbocharging (possibly worse depending on the configuration) as far as heat that gets seen by the piston.

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I would think you can plug the hole in the connecting rod that normally functions as the oil squirter in the stock configuration now that you have dedicated oil squirters.

 

This would greatly decrease the possibility of the supplemental squirters negatively affecting oil supply to the main and rod bearings.

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I would think you can plug the hole in the connecting rod that normally functions as the oil squirter in the stock configuration now that you have dedicated oil squirters.

 

This would greatly decrease the possibility of the supplemental squirters negatively affecting oil supply to the main and rod bearings.

 

I think Tony D's answer here, would change your mind with doing this,

 

.......... you would see the jets are check-controlled. They will turn off at idle when not needed. ................

Edited by Noddle
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I think Tony D's answer here, would change your mind with doing this,

 

In my case its a moot point, as my rods don't have the squirter holes anyway. However, for someone else potentially doing this mod with stock rods, it might help with oil pressure at or near idle, where the holes in the rods are probably just more of a leak anyway.

 

My worry has been that I'll end up with a sort of plateau or stairstep oil pressure-to-RPM curve that flattens out at ~30psi due to the squirters coming in. This remains to be seen, but this reminder that I have one less thing consuming oil flow from the mains makes me think that it will probably even out. Hopefully. :unsure:

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  • 3 weeks later...

Okay, so here's an update after considerably less than 7 years :P

 

I finally got my engine back together and on the road today.

 

First startup was done with conventional 10W-30 oil, and I noticed that I was still getting good oil pressure then, but didn't look into it in any specific detail other than noting that it wasn't stuck at 30psi. Just wanted to run it in first. So anyway, good initial results for oil pressure.

 

Changed the oil and finished putting it back together and got it on the road today. So, with straight 40W conventional oil, stabilized at 180degF here's what I found so far:

 

1500rpm => 30psi

2000rpm => 40psi

3000rpm => 50psi

4000rpm => 65psi

 

So I think I'm in pretty good shape as far as oil pressure goes. I did go through and ported and smoothed out the oil passages as much as possible while I had it apart, so that may have helped a bit.

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  • 3 weeks later...

Bloody hell I´ve been missing out on alot here...hehe.

 

Sorry guys, new apartment, new job and a carcrash kinda kept me busy the past weeks... (watch out for yellow semis coming up behind you at redlights...)

 

Timz, amazed with your work.

Didnt think anybody would jump on the idea that fast and try it....actually thought I would beat u to it. :)

Please keep us updated....

 

Worst part is that I dont have much to add at the moment... Timz and Tony D has really kept this thread vibrant. :)

 

 

(And as always, exuse my bad english.)

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  • 7 months later...

Thanks.....any possible sources is good to know.

 

I'll have to use what fits best.

 

I haven't studied the SD engines too much beyond servicing a few forklifts and I've since moved on to boxy cars with two doors simply because it's hard to find body and interior parts for the older rear drive nissans.

 

http://farm9.staticflickr.com/8042/8023620398_c07e14aa62_z.jpg

Edited by HowlerMonkey
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