3x Times The Same Problem Hole In The Piston Rb25det Why? Please Help

[VB-]

what was your A:F ratio and timing in the top end on each?

your profile says your in adelaide but you say the car ran the nurburgring (or is that a copy cat in SA called nuerburgring?) what fuel was is tuned on and was it constantly getting the same fuel? or have you jumped countries and changed fuel without the tune to suit? is it possible all 3 cars got a dodgy batch of fuel from the same servo/area?

did you tune the cars on dyno or road?

i wouldnt focus too heavily on it always being cylender 6, as i personally think its just motor design. just get rid of the problem

[discopotato03]

Yes very interesting . Has anyone ever set up crank pulley and flywheel position sensors to see how much variation there is along the length of the crankshaft at various engine speeds and power loads ?

Cheers A .

[JapanDyno.com]

here a pic i didnt had time yet to open the block now

all block and head upgrades are done in engine builders factorys

[JapanDyno.com]

  VB- said:

what was your A:F ratio and timing in the top end on each?

your profile says your in adelaide but you say the car ran the nurburgring (or is that a copy cat in SA called nuerburgring?) what fuel was is tuned on and was it constantly getting the same fuel? or have you jumped countries and changed fuel without the tune to suit? is it possible all 3 cars got a dodgy batch of fuel from the same servo/area?

did you tune the cars on dyno or road?

i wouldnt focus too heavily on it always being cylender 6, as i personally think its just motor design. just get rid of the problem

was a few years in adelaide thats why

here pics from 13.07.2008 =)

PS yesterday on the NÜR the piston rings are gone

Edited July 14, 2008 by JapanDyno.com

[GeeTR]

^ hope the skyline mashed that pesky Porsche

[STATUS]

give your tuner the right nine

how old is the A/F gear your using?

[JapanDyno.com]

  URAS said:

give your tuner the right nine

how old is the A/F gear your using?

no idea how old the gear is i changed the tuner twice,

About fuel pump

the R34 had a Nismo pump and the engine is abit white inside was running too lean understand easy

but the R33 also had a GTR pump and

alot people say here its too lean right ?

so the problem here is again the A/F ?

now are 3 engines to rebuild 1 Neo and 2x Series 2 Rb25

if anyone can tell me some good tips to take care of please let me know

thanks for any help

im just sick of spending money to rebuilt them and then soon or later something happens

dino

Edited July 15, 2008 by JapanDyno.com

[rob82]

  discopotato03 said:

Yes very interesting . Has anyone ever set up crank pulley and flywheel position sensors to see how much variation there is along the length of the crankshaft at various engine speeds and power loads ?

Cheers A .

Havn't seen this issue in the XR6T's and thats up to about 700rwhp at 5500rpm on the standard crank and I'm pretty sure there would be alot more torque in a tough XR6T than most tough skylines. And as for over advanced ignition timing being the only thing to cause engine failure thats a crock.

[unique1]

slightly off topic but from my personal experience on my rb26 and a mates one as well with totally different setups (both over 500rwhp) we both run individual egts in each runner and they show 5 and 6 the hottest off boost and cruising but on boost 3 and 4 are hottest by a fair amount, even with 4% more fuel in 4 mine is still getting 20-30 degrees hotter than all the other cylinders. We both have had our injectors tested and they are spot on as well, im interested to see proof of no 6 cylinder running the hottest on boost as everyone seems to say?

[rob82]

  unique1 said:

slightly off topic but from my personal experience on my rb26 and a mates one as well with totally different setups (both over 500rwhp) we both run individual egts in each runner and they show 5 and 6 the hottest off boost and cruising but on boost 3 and 4 are hottest by a fair amount, even with 4% more fuel in 4 mine is still getting 20-30 degrees hotter than all the other cylinders. We both have had our injectors tested and they are spot on as well, im interested to see proof of no 6 cylinder running the hottest on boost as everyone seems to say?

Did you calibrate the thermocouple's in the operating range as alot of K and J type thermo's are quite inaccurate from sensor to sensor.

[unique1]

  rob82 said:

Did you calibrate the thermocouple's in the operating range as alot of K and J type thermo's are quite inaccurate from sensor to sensor.

they are innovate dataloggers (tc4's) and RTD thermocouples, it says nothing in the instructions about having to calibrate them, how would u go about doing that? put them under the same temp condition and measure the temp readings i assume? whats the best thing to use to calibrate them then.

[rb26s13]

  unique1 said:

they are innovate dataloggers (tc4's) and RTD thermocouples, it says nothing in the instructions about having to calibrate them, how would u go about doing that? put them under the same temp condition and measure the temp readings i assume? whats the best thing to use to calibrate them then.

perhaps to test them yourself is go for a drive.. data log it.. than change the sensors around.. than go for another drive and compare the logs to see if the differences between each cyclinder change much at all

[The Dan]

  rb26s13 said:

perhaps to test them yourself is go for a drive.. data log it.. than change the sensors around.. than go for another drive and compare the logs to see if the differences between each cyclinder change much at all

Smart cookie

[Adriano]

Or attach them all to the one port, and datalog that

[unique1]

ill have to give it a try, i think it would be abit of luck that both mine and mates run hot in the same cylinders and the whole time clyinder 6 runs the hottest except on full boost, thanks for the info

[GeeTR]

  unique1 said:

...on boost 3 and 4 are hottest by a fair amount, even with 4% more fuel in 4 mine is still getting 20-30 degrees hotter than all the other cylinders.

Have you guys come up with any idea's as to why this occurs on 3 & 4...?

... maybe its the reason CRD and others are big on multi point, head coolant relief setups.