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nitrous on hyperutectec pistons??

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Posted by: motorhead

i am just about finished building my 388. 383 .060 over, i am running a xe274 comp cam,i will be just at 10-1 comp with a set of keith black hyperutectic pistons, fully ported 882 heads, 750 eldelbrock carb, performer intake. the question is i was wondering 2 things what kind of power i will make and if i will be able to run around with a 50 shot on the street and maybe up to 100 on the weekends. any advice???


Posted by: Grape Ape

I can't say what power level you'll have with the engine, but it should easily be able to handle a 100 shot with hypereutectic pistons, and probably a 150 shot.


Posted by: motorhead

ive heard that the hyp pistons dont handle nitrous that well


Posted by: VETTKLR

Hypereutectic pistons take power adders as well as forged pistons. If you mess up your engine tune enough to screw up a hyper-piston, you would have torn up a forged piston as well.

Don't fear the hypereutectics. Remember this: LT-1's and LS-1's are running CAST pistons which are the cheapest and weakest of the bunch. They can run 150-200 shots all day long.

G-Monkey, this knowledge came from Mr. Tooley, himself. Last time I talked to him, all they were using were the hyper pistons to build their motors.


Posted by: MikeT

So, if you were building a motor for FI or N20 would you use forged or hyperawhatever pistons?


Posted by: VETTKLR

My motor has Ross custom forged flattops in it.


Posted by: 28

You always here of them goung south,but hell,ya never see one....I think it's a little overhyped..Kinda like the over heating BS on the 96 Cobras....There's 3 that I know that don't overheat and w/o the fix....(Well,2 now)....


Posted by: VETTKLR

Quote:
....(Well,2 now)....





I guess the third one in question has had the ultimate "fix" so it will never overheat, huh.




Posted by: Grape Ape

Hypers aren't as strong as forged, but they are good, and definitely stronger than standard cast. In this area, I'll stick with the 40+yrs experience with forged. I don't know a single engine builder who doesn't choose forged when given the choice. Brian is great and all, but his specialty is CYLINDER HEADS! He does those better than nearly anyone, but I ain't lookin' ta have him pick the parts for my shortblocks.


Posted by: motorhead

thanks for the info i think im just gonna stick with a 75 shot and maybe go up to 100


Posted by: VETTKLR

I know a dude here in town that used a $300 irrigation motor to power his Camaro down the track in the 11 second zone on a 175 shot.

Just keep a close eye on your plugs and spray the hell out of her!!!


Posted by: SVOno5oh

A lot of misinformation exists about hypereutectic pistons. This is a special casting process which yields parts considerably stronger than the older sand casting methods. The process was actually developed by Cosworth for applications in racing.

They aren't as strong as forged pistons, but they are better than cast like Grape Nuts said. I wouldn't pick them especially for a nitrous application, but I wouldn't be scared to run a reasonable amount of giggle gas on them either.

Forged pistons and hypereutectic pistons are two different animals. They require different bore clearances for sure. Forged pistons will probably handle more abuse, but detonation under pressure from boost or juice will kill either in a hurry.


Posted by: motorhead

thanks svo thats what ive read about the hypereutectic pistons. so do you think that its alright to run a 75 shot on a regular basis. i know that my current competition is a grand national


Posted by: LS1 Mopar Turbo

LT1 and LS1 are not cast pistons, who told you that? Are hyper go over to LS1tech.com and check it out. That is why both cars have such bad piston slap when cold.


Posted by: SVOno5oh

Almost all OEM pistons are hypereutectic these days. The name actually comes from the crystalline phase of the metal if you must know. The pistons are cast and cooled in the hypereutectic region of aluminum to get a certain crystalline structure. I can dig up a phase / temperature diagram if I must.... I think I've got in a couple of books here.

Whether or not you can run a 75 shot depends totally on your tuning! Got enough fuel and intake / exhaust flow then go for it. If you install a good kit per manufacturers direction, I bet it'd be fine.

On the other hand if you get greedy and keep pushing more and more... at some point BOOM!

I'm no nitrous expert, that's for darn sure. I just know hypereutectic pistons are a lot stronger than they are reported to be. I know for example that all of the ones lost in blown DOHC 4.6 Cobras are practically all on the same cylinder! This indicates a problem with the air / fuel mixture in that cylinder not with piston strength.

I've seen a bad fuel injector cause many a blown to hell piston on a turbo engine. Lean is mean, and too lean is BOOM!


Posted by: LS1 Mopar Turbo

Right you are anthony, that explains how someone like myself can run large amounts of boost in a Turbo Dodge even with cast pistons. If you have enough fuel for what you are doing you should be fine. 100 Shot to 150 wet shot on LS1 and LT1 motors are fine. I have seen LT1s with 140,000 plus miles on them that have had Nitrous on them since about 20,000 to 30,000 miles of course having forged helps but if you run out of fuel there what do you think happens to that piston....BOOM!


Posted by: motorhead

i am thinking of going with the top shot system where the nitrous and fuel mount on the carb stud. anyone have any experience with one of these. im into keeping the engine as stock as possable, ya know street races


Posted by: Mykdiver

Quote:
Originally posted by LS1 Mopar Turbo
Right you are anthony, that explains how someone like myself can run large amounts of boost in a Turbo Dodge even with cast pistons. If you have enough fuel for what you are doing you should be fine. 100 Shot to 150 wet shot on LS1 and LT1 motors are fine. I have seen LT1s with 140,000 plus miles on them that have had Nitrous on them since about 20,000 to 30,000 miles of course having forged helps but if you run out of fuel there what do you think happens to that piston....BOOM!



Yeah, like my motor did, with 100 shot! There were probably other resons also.


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