Testing Motorola 280 ECM

[rjdubiel]

I hope the other 5 are good! haha.

[LakeFever]

Yeah me too. It sucks going through this

[rjdubiel]

We pulled the motor down all the way Sunday and I have top pinned pistons already so that is good. I asked the piston what happened and he said the ring broke. Well he was lying as as you can see the Pinocchio Piston was heated and stuck. I am guessing my water pump kit I installed came with china impeller!!! I am pulling the lower tonight to find out.

Me: "What happened Pinocchio Piston?"

Pinocchio: "Ring Broke"


Me: "Looks like you got hot."

Pinocchio: (says nothing and looks away....)

[rjdubiel]

OK. Mr Pinocchio piston may not be lying as my water pump looks really good as it only had about 15 hours on it. I could not see any issues with the water pump and gaskets were all good and intact. Maybe there was a ring failure?

[racervboat]

It got hot and that caused the ring failure.Can't trust pinocchio he's been hittin the sauce.

[rjdubiel]

I am going to look in my heads and flush those to see if there is anything in there. Nothing wrong or stuck in my water pump, water tube, adaptor plate. I did find some small pcs of plastic or rubber in the water jackets but not enough to fry a cylinder from lack of water.

[Qshot1989]

it was a ring locator pin that caused the ring to hook on the intake port. Got very lucky to not stick under power and really do some damage. But Ignition Faults were as follows: IG1 - 6, IG2 - 0, IG3 - 1, IG4 - 0, IG5 - 5, IG6 - 2. So not many and nothing to worry about in my opinion. No Injector Faults. I was hoping the side pinned pistons would be ok for a hand full of 800 foot runs at high RPM but I was wrong.

Were these stock 280 pistons or aftermarket?

[rjdubiel]

Were these stock 280 pistons or aftermarket?

Top pinned merc.

[Qshot1989]

I was referring to the side pinned one that loosed up and grab the port causing it to almost stick in the 800ft. runs

[rjdubiel]

I was referring to the side pinned one that loosed up and grab the port causing it to almost stick in the 800ft. runs

I though they were side pinned merc pistons before we pulled the motor, but once we pulled the motor apart we saw it was a good merc top pinned set of pistons already in the motor. I think I am going to swap my water tube from 1/2 to 3/4 inch to get some added volume. Also I am going to send #4 injector out as Brucato just cleaned them that same week the piston burnt! I had about 6-7 800 foot runs turning 9K+ before this happened. All the previous 10-15 hours on this motor was max of 8200 with the ROS ECM. I just got the unlimited ECM the day before the race and tested, worked well and per the prop calculator it ran 9600 on Friday using 9% slip, 29P, 2:1 lower. Then Saturday morning I did a run right before my races started and it only did 9400 so it was hurt by my race already I think..

[Qshot1989]

You were running a 1/2 inch tube on a 1 piece adapter?

[Erine]

And what lower unit?

[rjdubiel]

You were running a 1/2 inch tube on a 1 piece adapter?

Yes, running a 1/2 inch tube all summer.

[rjdubiel]

And what lower unit?

coned big bearing 200 case.