bad dyno day

[rotayt]

hey people my 13b bridge port with ida was getting dyno tuned yesterday got all set up on the dyno, set the timing with the iming light and locked the dizzy,

done a first run and found the ida needed to be modifyd took it apart and was jetted out to suit and took out a wall in side the ida for more fuel.

assembled the ida an put it back on and started the next run checking the air fuel ratio an all.

it got opend out to 8000 rpm and it sounded like it rev limited and he picked up sumthng on the knock sensor

as it came down to idol it sounded like like a 6 cylinder

turned it off and he checked a few things out at first he thort he broke a tip on the spark plugs

culdnt find anythng and then we did a compresion test ,the thing he picked up on the knock sensor was a breaking apex seal

and the front rotor was down on compresion aswell , but it had definatly broken a rear apex seal

the motor is roughly 600km old from a brand new re build new housings carbon, apex seals,new bearings with extra windows



im so gutterd about this as i have been building this rx7 up for 3 years.



i am going to talk to my engine builder and try find out why it has done it and hopefully come to an agreement.

as the engine is warranted for the engine build

iv always warmed it up befor i drove it never thrashed the crap out of it always run premix


any help on why you think it has done this will be greatly apreciated, is it the dyno tuners fault?? or the build i dont know

i did get a kw reading    194 kw atw

[Kentetsu]

Dude, that totally sucks.  But at least with carbon apex seals, you might get away without too much damage.  Keep us posted.
Who did the build?  And who was running the dyno?
Good luck....

[rotayt]

wat a day!!!!!

went to tauranga to see what was gunna happen got told i could take motor out an take it to engine builder sooo i went bk to waihi picked ute an trailor up thanks heaps to ma mates for borrowin it to me, went to dyno power pickd rx7 up took it bk to dads shed got down to it an took the motor out..................

was just in time to drop it off in tauranga hahaha so it will be getting taken apart an assed by the builder.

i had a look at the apex seals through the exhaust, clearly broken on the ends on a couple in the front an bak

sooooo i need to find out why that would happen i heard of poor clearance??

and i heard from some one if you use the round middle corner seals they can break the carbon apex ends???

i dunna but it was not dry in there,, the middle of the apex seals lookd good aswell

any help would be great

[Kentetsu]

You might want to head over to the Engine Building section at www.nopistons.com

They've got about the best building section of any forum that I've come across so far.

[orion84gsl]

With only 600kms on it before taking it for a hard dyno run I have to guess that it wasn't properly broken in. From what I've read you need to give it some time with gradual rpm increases before going full throttle to make sure all the seal's get seated and whatnot. Good luck, let us know what you turn up.