Sleds
Active member
How much is it to rebuild a 800 etec
I am curious why someone would think it would need to be rebuilt after a season with a turbo vs. non-turbo.
How sure are you the crank suffers?
Is it spinning any faster? Does the crank know the output of the motor has increased because of forced air?
With a turbo system that uses secondary injection not possibly last longer?
There are a few different ideas one could consider. With the etec fuel no longer is sprayed into the block and higher case and crank temps were expected to reduce crank life. With a turbo system that uses secondary injectors does the fuel now help keep the case and crank cooler? If it does would that not promote crank life?
Or does the added fuel wash down the lubricant that has been allowed to maintain lubrication?
Have you check runout and play in the bearings prior to replacement? Are the replacement cranks trued prior to install?
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How sure are you the crank suffers?
Is it spinning any faster? Does the crank know the output of the motor has increased because of forced air?
With a turbo system that uses secondary injection not possibly last longer?
There are a few different ideas one could consider. With the etec fuel no longer is sprayed into the block and higher case and crank temps were expected to reduce crank life. With a turbo system that uses secondary injectors does the fuel now help keep the case and crank cooler? If it does would that not promote crank life?
Or does the added fuel wash down the lubricant that has been allowed to maintain lubrication?
Have you check runout and play in the bearings prior to replacement? Are the replacement cranks trued prior to install?
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The motor is producing MORE HP AND TORQUE... This extra force is exerted on your crank.....
You think it doesnt matter to the life of yer light wieght crank if it makes 150lbs of torque vs 100lbs? lol
F#ck it then up the boost to 30lbs and ripper up....haha
Did I say it doesn't matter? You just assume from my post that I am saying it doesn't matter.
What I am adding though that with extra fuel could crank life actually benefit in some ways.
This appears to be a sensitive topic for you.
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How sure are you the crank suffers?
Does the crank know the output of the motor has increased because of forced air?
Did you put single ring pistons back in?
Was it a 11 or 12? Premixed, so you deleted the oil injection?
The thick ring on the stock pistons works well in rich conditions. Most doos are richer than they need to be from the factory. Single ring pistons can be less prone to detonation failures as well.
But start running the sled leaner and the single ring heats up quicker. The single rings also flutter more at high rpm. The powertek made peak power at 8150 rpm. The etec was first recommended to run 8000, then 7900 rpm. Is 7900 peak performance? Or due to single ring piston failures was the peak rpm brought down to compensate for failures and improve reliability? Without the ability to change the stock injection it is difficult to tell.
On boosted etecs do you maintain a max 7900 rpm?
I am not trying to argue with anyone but answer some of my own questions.
There is no disputing the top ends on these sleds do not last forever. For my own piece of mind 2500-3000 kmis a max for mountain use. The cranks in recent sleds have benefited from the clutches being indexed for better vibration control, but lost out on fuel cooling. The auxiliary fuelers on the turbo kits may or may not be helping this.
I know the turbos use a thicker reed peddle. But are the chipping and cracking like a stock etec?
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It would be interesting to see what your reeds look like after a year running the turbo. Especially stock reeds. The reeds in the etec are prone to chipping and flaking. At most I have seen 1200-1300 miles on a set. Many people never check their reeds though. One of my theories is that they are drying out due to no fuel passing over them. A secondary fueling system might cure this. If it does the stronger my assumption becomes.
Crank life in the etec by all reports has been good. Yes there is higher temps in the case, but no fuel is washing away the oil that is being injected. So, with that, is it better to have direct injection and good lubrication even though higher temps, or is adding fuel with the chance of washing away lube.
The cranks life is subject to more than just lube, temps and forced induction. Components like clutch balance, bearing seals and so on can reduce the overall picture.
A over bore etec setup pulls over 100 ft lbs of torque throughout most of the rpm range yet there isn't anymore concern about cranks in them. Personally my feeling is if the cranks are true, everything else is maintained like clutch components and run out is checked periodically, a turbo crank should last just as long as a stock etec crank.
For a turbo build I would likely pull the motor before it has any miles, have the crank trued and run dual ring pistons. I am not saying that it wouldnt lead to a failure but it would give me greater peace of mind.
If someone else's idea is to rebuild the motor every year so be it. I just would like to believe there are easier and more cost effective ways.
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