OK I found the job sheet for the latest pistons, all the same other than the fact that each piston lost a further 2gms due to the custom machining options.
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Sorry btu i dont get it right what are the positive or negative effects about Lateral gas ports?
What other specs-coatings should the pistons have? My goal is a reliable piston that maybe would not be the best thing but also dont have any thoughts about coatings going bad.
Can you give me some advice here?
I am going for Diesel Block and crank and 158mm 23mm rods.Go Holset or Go RS4
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Originally posted by Billman View PostSorry btu i dont get it right what are the positive or negative effects about Lateral gas ports?
What other specs-coatings should the pistons have? My goal is a reliable piston that maybe would not be the best thing but also dont have any thoughts about coatings going bad.
Can you give me some advice here?
I am going for Diesel Block and crank and 158mm 23mm rods.
Piston gas ports come in two flavours vertical or lateral, vertical are used in drag race applications as these engines are usually rebuilt often and carbon doesn't get a chance to block the ports significantly between builds. Lateral ports are usually used in circle track motors.
I am experimenting in using these and so far I am happy with them, although to be fair my lack of time and progress with other areas of the car have prevented me from really giving them some stick.......so far.
Edit
Here is something cut and pasted from the Wiseco site:
Vertical gas ports are primarily used in drag race applications. Lateral gas ports are more often used in circle-track and road-race applications where carbon build up can occur. When gas ports are used, pressure is directed to build up behind the compression ring and seal it against the cylinder wall. This helps prevent ring flutter and extends the power curve upward in the RPM range. Vertical gas ports have the holes drilled from the deck of the piston into the top ring groove and behind the ring. Lateral gas ports are drilled through the bottom side of the top land and extend to the back wall of the ring groove.
And something from JE showing them with other custom piston machining options
http://www.racetep.com/carpics/jeoptions.jpg
HTH cheers
P.S.
My pistons are not coatedMark - Modded
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@MArk - you know too much !
SO jealous of that build of yours - but I'm so glad you are blazing a derisked trail for others less brave to follow. Brilliant thread this.
PaulPaul Nugent
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1994 S2 Coupe ABY - aka Project Lazarus
2001 A6 allroad 2.5TDi - family tank
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Originally posted by Mark Halligan View PostI'd like to know how S4quattro got on with his problem too.
My problem with the engine had nothing too with the TS pistonrings. The pistons was totaly destoyed by knock and detonations.
So it was my own fault the engine "died", trying too run it on a map that wasent suited for that engine. Had MTM 420 map and fuel delivery , but that wasent good enough.
I took me almost 10 months too get new pistons, so in the meanwhile i run the car with the "standard" MTM 420 kit that the car had from new.
Will try too rebuild that engine again (2,5L project) this winter.
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Originally posted by Mark Halligan View PostThanks
Good point - I forgot to mention that the subframe needed modding to clear the sump which is 10mm lower, I did this a long time ago when I knew I would probably use the girdle. Modding the sump is another option too.
Reason for the Zetec headstuds is for the extra length needed with the girdle.
Paint is Blue smooth Hammerite
Cheers
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