Vitara piston on 4e block?

Skalabala

Member +
What do you think about the pistons Nissan GA15? 19mm pin.
QG15DE, Great piston. Light piston rings less drag in sleeve. Deck cylinder block by 0.8mm. Piston pin 19mm floating on piston.
Need to buy them in 20 or 40 though as std bore on them are 73.6mm
20 though might be a good option for people that do not want to rebore. Good hone job for 74.1mm
 
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MDCat

Member
QG15 has a thin place under the sample valve. Twice tried them. Burned. Not suitable for boost than two bar. Weak refractory zone. On GA15 is no such.
 
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Skalabala

Member +
That has nothing to do with the piston that is weak. That is detonation.
Did you polish the piston crown? And 2bar is a lot of boost bud. Not a lot of people on this site will even bother with that boost.
And almost none of them are into "out of the text book" mods :(
 
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MDCat

Member
It was just a little experiment) Detonation was not. Apparently slightly increased egt was fatal to the pistons (bad gasoline). I think that GA15 pistons must be tested this summer. 1.6 bar for QD15 normal boost. Suzuki pistons on our Starlet ride 2.4-2.6 bar. Pistons are not polished. I do not think that was necessary. The surface free from voids and irregularities.
 

Skalabala

Member +
It was just a little experiment) Detonation was not. Apparently slightly increased egt was fatal to the pistons (bad gasoline). I think that GA15 pistons must be tested this summer. 1.6 bar for QD15 normal boost. Suzuki pistons on our Starlet ride 2.4-2.6 bar. Pistons are not polished. I do not think that was necessary. The surface free from voids and irregularities.
I do not know of a QD15 piston? But the QG15DE piston will take 1.6bar no problem.
What fuel did you use on the blown QG15DE pistons? To high EGT? Mapping wrong.
 
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MDCat

Member
Oops. Of course I mean QG15DE. Translator fun with me. To configure use regular gasoline at a gas station. 95 octane. Maybe the problem is the mapping.
 

Skalabala

Member +
Oops. Of course I mean QG15DE. Translator fun with me. To configure use regular gasoline at a gas station. 95 octane. Maybe the problem is the mapping.
1.6bar is dangerous for sure! Remember that the compression ratio of the QG piston is much higher than the Vitara piston.
 

trimmata

Fresh Recruit
The pistons to be used are 2NZ-FE :)
The vitara pistons gives a CR of 6.4:1
Skalabala is a well-known person for his knowledge in *FTE's.
What he says is correct!
He helped me in the past, when i prepared my own H-beam-custom length "Vitara" pistons setup for 4E/5E-FTE engine

Thanks mate in public :kiss:

Get a video with, what i use the last 30.000km
[video]https://www.youtube.com/watch?v=e-1U6TdX_Tc[/video]
 

Skalabala

Member +
Skalabala is a well-known person for his knowledge in *FTE's.
What he says is correct!
He helped me in the past, when i prepared my own H-beam-custom length "Vitara" pistons setup for 4E/5E-FTE engine

Thanks mate in public :kiss:

Get a video with, what i use the last 30.000km
[video]https://www.youtube.com/watch?v=e-1U6TdX_Tc[/video]
Hey bud. Nice to see you are well :) And glad the engine is doing good.
 

faiscamix

Fresh Recruit
Flood the engine, he is running to lean . Cut maybe 5 º - 10 º on timming and balance it before assembly . That hole near the wall of the chamber on my humble opinion means one of 2 things, or you have bad mixture air/fuel that come in from inlet , or it was a crack on piston that evolved to a hole. Remember , at high boost he must to f@rt fire to maintain the chamber cold (just like old school group b). See ya ...
 

Skalabala

Member +
I am also not to sure what he is trying to say :D But it maybe comes down to that when on full boost you want black smoke out of the exhaust to keep the combustion temperature down :p
 
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