My 13B ported engine blew while tuning, running 13 degrees and 11.4A/F at 1.1kg/mm with a TO4S.

On strip down of the engine the rear rotor was trashed ie housing scored, all apex seals broke and side seals stuck in on one side, then I noticed that the diffuser for the rear primary injector had broke, so must of gone through the engine I thought this maybe the problem, the rear stationary bearing also has alot of copper showing. When I took the front apart everything is intact apart from a side seal being cracked, but the rotor housing has three gouges in it under the exhaust port exactly the same width as a side seal, also it seems the rotor was lightly touching the housing opposite the spark plugs, the secondary ports both seem to a small gouge on the top egde nearest the o-ring.

I have checked the compressor wheel and that is intact.

Does anyone have any idea what could have happened?

I will try and get some pics.



Regards



Jason

Did you reuse housing/plates for you rebuild? If the stationary gears were new they shouldn't have shown that much wear. What was knock? There are so many things that it could be, from the rebuild to a tuning error. Something wasn't set right! You said 13 degress timing, was that leading or trailing. What was your spilt at full boost?

The engine was built by a "rx specialist" it had new housings, the exhaust ports were ported but with no bevel on the edge, the engine had covered 2500 miles.

The plates were lapped and ported.

The timing is for the leading with a 11 degree split at full boost.

I don't know if the bearings were new, the wear is on the exhaust side of the bearing.

How where they tuning it? Wideband on dyno or road tune? Knock reading?

We were tuning it on the road with a wideband, the cars knock sensor was not working.

Do you think tuning would cause all the problems in the engine

ie gouged front housing and nothing broke and the rear primary injector diffuser broke?

First what ecu are you using? . PFC doesn't retard timing, only monitors it. I am not sure about haltec. The diffuser should cause that much damage, it is plastic. But then again ingesting anything is bad. I have seen people blow seals and have no scraches/marks on the housings, or turbos. Just lucky maybe. Pictures would help me and who ever else decides to help you. There are almost to may variablies to tell you extactly what went wrong.

The car has a pfc, we were going to fix the knock sensor but knew it is only for moniting.

I could understand if it detonated and blew the rear rotor, or the diffuser blew it as it seems coincidental to be broke on the rear, but the deep scraches on the front housing when nothing has broke???

It sounds like you have quite a bit of damage for just a tuning mistake...

sounds like a really really hard knock/pre-detonation, i've seen piston motors get totally rooted because of simple tuning mistakes.



Tuning/Fuel mapping should be done with all sensors working correctly

>sounds like a really really hard knock/pre-detonation, i've seen piston motors get >totally rooted because of simple tuning mistakes.



>Tuning/Fuel mapping should be done with all sensors working correctly



The only sensor not working was the knock sensor, this makes no difference to the pfc and cannot be relied upon anyway.

What would cause the front rotor housing to be scored and no apex seals broke?