jp
Enthusiast
Just curios to know if this is normal wear, the small scratches in the cylinder wall...or is it just nitrous abuse?
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Scratches in cylinder walls
- Thread starter jp
- Start date
HP
Enthusiast
It definitely wouldn't be normal to have the vertical scrape
marks that you have - pulling the piston - you would probably
find galling on that side of the piston.
Usually scuffing on only one thrust surface occurs from inadequate supply of oil - or high piston loading (i.e. nitrous). It also looks like your motor was never broken in
completely - the honing looks too new. How many miles do
you have on it?
Next rebuild add an oil accumulator and NOS window switch
and make sure to break the motor in good before racing.
And on real cold days - make sure to warm the motor before stressing it. I'm sure some of the techs can give more details on your motor - I'm just pulling from my memory files.
marks that you have - pulling the piston - you would probably
find galling on that side of the piston.
Usually scuffing on only one thrust surface occurs from inadequate supply of oil - or high piston loading (i.e. nitrous). It also looks like your motor was never broken in
completely - the honing looks too new. How many miles do
you have on it?
Next rebuild add an oil accumulator and NOS window switch
and make sure to break the motor in good before racing.
And on real cold days - make sure to warm the motor before stressing it. I'm sure some of the techs can give more details on your motor - I'm just pulling from my memory files.
MES
Enthusiast
When I changed my heads, mine had no scratches as shown in your pic. That was after 30K miles and twenty 15 lb bottles. My cylinder honing also looked like yours, like new (I would attribute that to Mobile 1 oil)
IMUO (in my un-educated opinion
) Looks like your piston overheated, causing the skirt to expand and scuffed the cylinder. Are all the cylinders like that?
IMUO (in my un-educated opinion
HP
Enthusiast
I think thermal expansion galling is more widespread and is
not limited to the thrust surface. Break-in should be done
with NON-synthetic oil.
not limited to the thrust surface. Break-in should be done
with NON-synthetic oil.
jp
Enthusiast
7 of 10 cylinders look more or less like that, the picture is from the worst cylinder.
The Nitrous was added after 16000 miles. The amount of Nitrous used on the strip is equal to .95 sec and 10Mph faster then without.
My theory is that the Nitrous have been engaged at to low rpm when I missed shifts...gone from 2nd to 5th a couple of times, and I did not lift of the trottle.
The system is a Propane(gasol)/Nitrous system.
Anyway, it's not a problem, I just wanted to show that Viper engines can be hurt by Nitrous abuse.
The Nitrous was added after 16000 miles. The amount of Nitrous used on the strip is equal to .95 sec and 10Mph faster then without.
My theory is that the Nitrous have been engaged at to low rpm when I missed shifts...gone from 2nd to 5th a couple of times, and I did not lift of the trottle.
The system is a Propane(gasol)/Nitrous system.
Anyway, it's not a problem, I just wanted to show that Viper engines can be hurt by Nitrous abuse.
FRANK
Enthusiast
It doesn't look good to me...shame you didn't do a leakdown test on it before you ripped it apart...
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