SoCal Jet Boats
Discussion => The No Wake Zone => Topic started by: enginedoctor on May 01, 2010, 06:37:18 PM
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IMHO ...Please dont :thumbdown:
Ask me WHY >:D
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I'll be interested to see the do's and and do nots but I'm not asking why
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I'll be interested to see the do's and and do nots but I'm not asking why
Nordie....I just told you why...let's see what the others say 8)
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detonation kills >:D and if you are not the mr good wrench chances are you wont even hear it happening.
ive said it many times before CHEAP AINT GOOD AND GOOD AINT CHEAP.
read my sig line ;D
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Calling on all engine experts to chime in here....Opinions wanted ;D
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in this operation ralph no one is trying to cut corners we'll just leave it at that! just perspective like dave is saying
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Ya but ya be talking chebbie I am guessing :thumbdown: :thumbdown: :thumbdown:
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in this operation ralph no one is trying to cut corners we'll just leave it at that! just perspective like dave is saying
this is not a debate....matter of fact.....lets see what other's say...just curious, ;D
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Ya but ya be talking chebbie I am guessing :thumbdown: :thumbdown: :thumbdown:
Mr. 76... you are joking right...after everything I have taught you :sly:
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Mr. 76... you are joking right...after everything I have taught you :sly:
OK shorty don't get your panties in a bunch, I was just fruckin around :screwy:
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OK shorty don't get your panties in a bunch, I was just fruckin around :screwy:
You mean my G-string ???
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You mean my G-string ???
Oh dude that is disgusting..or shall I say a major party foul :thumbdown: OK back to the thread at hand :thumbup:
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Oh dude that is disgusting..or shall I say a major party foul :thumbdown: OK back to the thread at hand :thumbup:
Ya.. but Desiree and Tara never complained.....Back to thread :thumbup:
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Oh dude that is disgusting..or shall I say a major party foul :thumbdown: OK back to the thread at hand :thumbup:
X2 TMI
Ya.. but Desiree and Tara never complained.....Back to thread :thumbup:
Laughing too hard to comment... ;D
When a Hyper piston (non heat treated) is used in a slight over bored application for marine stuff, accelerated ring land wear and a pretty substantial piston slap can occur due to the rocking of the slug...Coated Hypers could "give up" their silicone or ceramic coatings and contaminate the oil charge with the added skirt wear..They also have an insulating property making them more prone to a cold shock issue (way out on a limb)...
Detonation is another story, a good quality polished dome forged piston can withstand twice the abuse of a Hyper IMHO.....
Hyper pistons have their positives, but really need to be built to OEM specs to really shine. They also seem to really work well with really low cylinder pressures and high cylinder temperatures....
Heat treated T6 Hyper pistons are an excellent middle of the road performance piston, but are close to the same cost of the forgies....
GT
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GT... on a coated piston skirt ...You cannot get your piston /to wall...unless you scotch bright the sht off the skirts.
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I'm by no means an expert when it come to Marine Applications, But I'll chime in because I'm bored.
My experience with street engines showed me how Forged pistons expanded a tad more at temp than cast ones did, being much denser, forcing a slight overhone to compensate and cold piston slap was pretty normal. Didn't have the "Hyper" dealios back in those days, so not even real sure what they even are. My best guess is a form of heat treating and coating a cast piston to simulate true forged pistons and a lesser cost. I just use forged, and will continue to do so regardless of application.
Given our marine applications, save for closed systems, but for our sake, we NEVER see "Normal" operating temperatures, which would throw the normal equations for street use out the window. So I think, maybe, where Dave is headed is on the expansion characteristics of cast aluminum vs. forged aluminum, and how the "Hypers" inadvertently hinder themselves trying to be one but made from another. I have a metalurgical explanation in my lil brain, but it'd take me an hour to explain it.
Ray
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GT... on a coated piston skirt ...You cannot get your piston /to wall...unless you scotch bright the sht off the skirts.
I read somewhere that you run Speed Pro coated pistons at a tighter tolerance than stock...wouldn't that mean you could stay tighter in a marine deal?...I have a set of coated Hyper Speed Pros here and they are not round at all (wide at the skirts) they are still in the box and they will stay there..LOL
They measure like an outboard piston (Oblong), does this mean the coating makes the piston bigger on purpose?...
GT
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here is a good thread about them over on PB.
http://www.performanceboats.com/html/forums/showthread.php?t=17399
the consensus says do not run them in a marine application.
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Good info brad :thumbup:
GT..........I can give you at least 3 reasons why you should not use Hyp. Pistons for marine :
1. Piston to wall rec. clear @ .001.too tight IMO....if you open up the clear...they simply wont work, IMO.
2. Issues with funky ring end gaps, causing piston breakage @ top ring land. (Wrong gaps will cause rings to butt)
3. That ridiculous skirt coating...prevents you to establish the desired wall/to piston clear..manufacturer simply
gives you a size to finish the bores to ...printed on the box :thumbdown: The coating does more harm than good.
Shit , you may as well graphite coat the whole engine assy, try establishing clearances then :thumbdown:
4. Hyp. pistons as you said GT, have too much "Cam", plus are not impact friendly, anything contacts the piston
it will EXPLODE...same result if ring end gaps are not exact....Just MHO....Not to say I dont like these pistons :sly:
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heres some pics of what happens to hypers when in a marine application....
[attachimg=1]
[attachimg=2]
[attachimg=3]
[attachimg=4]
[attachimg=5]
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wow...im going to take a guess and say the top ring was in there a little tight
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wow...im going to take a guess and say the top ring was in there a little tight
Thats the problem nordie....Guesswork :thumbdown: