Hypereutuetic pistons and nitrous??

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dustoff440

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Asked two questions in another thread:
Are 360 Magnum stock pistons hyper's as another member stated???
Are hypers more susceptible to meltdown with nitrous? I plan on taking 6-8 degrees advance out with an MSD retard along with all the other nitrous precautions. Am I begging for trouble using a 150 horse shot with stock hypers if they are indeed stock??
 
They don't melt down. They explode. Think of it this way... The alloy in a cast piston is like a grade 5 bolt. It bends easy if you hit it with a hammer, and can bend a bit back and forth before it cracks and breaks. The alloy in a forged piston is like a grade 8 bolt. It's harder to bend, and will bend with enough force, but not that many times before it breaks of. Hypers are like a chisel. Strnog, but very brittle. They don't bend, they don't change shape, and hit them hard enough, they shatter. The hammer is detonation. You can run NO2 if you have gapped the rings right and totally avoid detonation. If you dont do either, they will shatter off parts, or in their entirety.
 
They don't melt down. They explode. Think of it this way... The alloy in a cast piston is like a grade 5 bolt. It bends easy if you hit it with a hammer, and can bend a bit back and forth before it cracks and breaks. The alloy in a forged piston is like a grade 8 bolt. It's harder to bend, and will bend with enough force, but not that many times before it breaks of. Hypers are like a chisel. Strnog, but very brittle. They don't bend, they don't change shape, and hit them hard enough, they shatter. The hammer is detonation. You can run NO2 if you have gapped the rings right and totally avoid detonation. If you dont do either, they will shatter off parts, or in their entirety.

Ok, I'm sure I could avoid detonation with the MSD retard, however the rings are gapped for stock application. I don't remember what the gaps were as I put the motor together over two years ago. I had thought that the ring gap situation was critical only with large amounts of nitrous?????
 
No. The ring gap is specific to what you will be doing with the engine. The United Engine website has a chart that breaks it all down. Hypers can be used fine with a 500 HP shot from a Pro Shot Fogger as long as you follow the ring gap and piston clearance recommendations. Best thing to do is call United Engine and speak to Marco. He can splain it a lot better than certainly I or probably anyone else here. Pistons don't just "explode". They may "fail" as a result of something else. Running lean is the biggest enemy of a hyper piston, though.
 
No. The ring gap is specific to what you will be doing with the engine. The United Engine website has a chart that breaks it all down. Hypers can be used fine with a 500 HP shot from a Pro Shot Fogger as long as you follow the ring gap and piston clearance recommendations. Best thing to do is call United Engine and speak to Marco. He can splain it a lot better than certainly I or probably anyone else here. Pistons don't just "explode". They may "fail" as a result of something else. Running lean is the biggest enemy of a hyper piston, though.

Whats confusing to me is that I have seen plenty of guys who put on 100 to 150 shots of nitrous on motors as an after thought and hadn't clearanced the rings for it and had no problems. Not only that I've seen plenty who didn't have a built in retard and didn't have problems??????
 
The rings need more gap with Keith black Hyper to handle the heat expansion to start, then a lil extra for No2.

The hypers deflect heat to everything around it-chamber/rings etc..

How much more gap depends on the brand ALONG with the hp level of nos used, the speed pro's I hear need less, but I haven't run them, only their forged stuff.

If you cant tune and are reckless or have some freak mishap with electronics you may have issues and broken parts, but as for instantly shattering at the 1st crack of detonation, thats really reaching and f.o.s imo.

Truth -They are not as forgiving as a forged piece , they will not handle as much detonation as the forged and at a certain level of nos that becomes even less.

I have dropped a rod/piston assembly on the ground one time, The piston skirt no longer allowed installation into the cylinder from the H beam swinging against it on impact...I dead blow hammerd the skirt & measured till it fit again and allowed the proper skirt clearance and been running it ever since no issue 6500+rpm.
 
i ran a 125 shot through a 318 with keith black hypers..,,probably made 40 passes before i sold the motor. took me from a 14.10 to a 12.90. it held up nicely. check your plugs ofter, as they melt before pistons..i'd be more worried about your converter having an anti baloon plate.
 
Marko Glush at KB is a good dude. Worked with him many years ago.

The ring gaps on the hypers is different because the top ring is closer to the combustion chamber = more heat = wider gaps. Gap them for your end intended use.

Go at least one range colder on plugs and gap them tighter when running juice. Learn to read your plugs if you wish to run nitrous.

A fat N2O tune up is just as bad or worse than a lean tune up IMO.
 
Thanks for all the info guys. I'm leaning towards NOT running nitrous on those hypers. I can tune, but one electronics slip could cost me 2 grand which I don't have to spend right now.. I guess I'll save my coins for an all forged internals 408 stroker with a really good set of heads then I won't need nitrous. LOL
 
Years ago I read the car tech manual "how to install and use nitrous oxide for maximum performance" by Joe Petitt. It stated that the frequency of vibration that nitrous oxide and gasoline burns at will shatter a hyper piston. (Kinda like chrystal with an opera singer)
That said plenty of guys seen to run them okay. Perhaps he has refering to a 500 shot? (Mind you, he is a honda guy)
 
Years ago I read the car tech manual "how to install and use nitrous oxide for maximum performance" by Joe Petitt. It stated that the frequency of vibration that nitrous oxide and gasoline burns at will shatter a hyper piston. (Kinda like chrystal with an opera singer)
That said plenty of guys seen to run them okay. Perhaps he has refering to a 500 shot? (Mind you, he is a honda guy)

I'm not so sure i buy that part about the frequency. My understanding has always been that a properly tuned system is no more harmful than a turbo/supercharger.
 
OK, I'm even more confused now than before I asked the question about nitrous use with hypereutetic pistons. Let me add that I have also posed this same question on other automotive websites with basically the same results as here. 1/3 of you say go for it, one third say don't go for it. and the remaining third aren't really sure. Let me rephrase the question to get more direct answers.
1. Has anyone had problems with their motor that had hypers installed in it that you know for SURE were caused by use of nitrous.
2. Those that did have a problem, did you have the timing retarded at least 2 degrees per 50 horsepower of nitrous,...example, 150 horse shot---take out minimum of six degrees upon nitrous activation.
3. DID you also take other precautions such as installing spark plugs as much as two heat ranges cooler than stock.
4. DId you use a nitrous shot in excess of 150 horsepower?
5. DId you use 93 octane and add some after market octane booster as well.

I would like to hear from anyone who did steps 1-5 above and STILL had a problem.

Thanks
 
I ran a 360 with KB 191 piston and 915j heads for almost 10 years
with out problem ANY PROBLEM

I ran it for the first 3 years with out nitrous
the last 7 years I race it with 125 shot of nitrous

the cr. was at 12.33 and hade to used race fuel
when was using nitrous

the engine was as follow

1973 360 block .030 over
kb 191 piston
moly ring gap to a non nitrous engine
but was kind a on the loose side of the gap recommendation
mp .590 cam
915 j heads fully ported
holley strip dominator intake

it ran 11.50 with out nitrous and 10.48 with the 125 shot

I sold this engine to a friend and wasnt affraid

I blew the heads gasket twice but never punch a piston out
the fix was copper heads gasket if I were new I would used mls gasket instead easier to install

dont be affraid to use nitrous but use it with your brain
timing retard,good fuel,colder plugs and read them
 
What you're seeing is typical for a wide ranging audience. As for the immediate questions... I have run plenty of NO2 on cast and forged pistons. I do not reccomend, nor build engines that I know will have NO2 on them with hyper pistons. As far as the full of **** comments, it's personal opinion on my end, and the posters'. I've never lost one from this. I know people that have, but when you're loking at a rod with a piston pin in it, and no other piston material on it because it's all in the pan, I call it exploded. From the main caps and rod bearing backs we could tell it was detonating. Whether that was just on NO2, or something else, who knows. But the piston falied due to detonation, and failed compeltely IMO.
 
If someone says hyper pistons will shatter at the 1st sign of detonation, the are full of it.
I dont know who this applies to in this thread but I sure didnt quote anyone in my post.

Too many people can prove that thinking wrong for it to be fact, most already have on this thread.

Then there are some other who havent built anything at all or in the last 5-10 yrs, not even sure if they have a running mopar.

Experienced opinions are valuable.
'Hear say' from a sisters cousins uncle brother is worthless.
 
Did you ask in the other threads if any of those jokers had ever run nitrous at all? A lot of advice you get on these forums is from people repeating what they've heard other jokers say, or think they read someplace....

All the nitrous manufacturers say just about *any* engine will take a 100 shot.

Like I said in the other thread, I've run 15 lbs of boost on hypers and 150 shots over and over again, and I was always more aggressive on the timing than the manufacturer's recommendation. My only exception to that is that these were Ford 5.0s out of explorer SUVs.

I never hurt anything. If you stick with 100-150 and you run 93 Octane, and you do your timing retard and make sure you have a good fuel pump, and don't use a projected nose plug, you will not have problems. As I said in the other thread, I would probably not run more than a 100 shot on a dual plane intake. Everything melts, forged, cast, whatever.

When guys talk about blowing these things up, they are talking about a larger shot. 250 and up kind of thing. The hyper piston probably won'y tolerate that cylinder pressure, detonation or not.

There zillions of guys running 150 shot in the new mustangs and they've got hyper pistons *and* crack cap crap rods.
 
As long as you follow recommended ring gap and piston to wall clearance, it all only boils down to ONE thing with a hyper piston. Just don't run it lean.

...and I am sure the US Military would be interested in some of them exploding pistons for use as weapons.
 
:salut:
Did you ask in the other threads if any of those jokers had ever run nitrous at all? A lot of advice you get on these forums is from people repeating what they've heard other jokers say, or think they read someplace....

All the nitrous manufacturers say just about *any* engine will take a 100 shot.

Like I said in the other thread, I've run 15 lbs of boost on hypers and 150 shots over and over again, and I was always more aggressive on the timing than the manufacturer's recommendation. My only exception to that is that these were Ford 5.0s out of explorer SUVs.

I never hurt anything. If you stick with 100-150 and you run 93 Octane, and you do your timing retard and make sure you have a good fuel pump, and don't use a projected nose plug, you will not have problems. As I said in the other thread, I would probably not run more than a 100 shot on a dual plane intake. Everything melts, forged, cast, whatever.

When guys talk about blowing these things up, they are talking about a larger shot. 250 and up kind of thing. The hyper piston probably won'y tolerate that cylinder pressure, detonation or not.

There zillions of guys running 150 shot in the new mustangs and they've got hyper pistons *and* crack cap crap rods.

:thumrigh::thumrigh: :salut:
 
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