Hi, first time posting on the forums, lots of great info.

I finally ran out of searches and resources on the issues I have so im going to ask and see what everyone thinks.

I built an engine for my boat and have a few issues with how its running.

The engine is a rebuilt 350 bored .030 with ~270dur 0.49lift hyd roller cam, flat top pistons, roller rockers, vortec heads, vortec alum intake and TBI setup stock tune.

Its using stock OMC water jacket headders so Im unable to use O2 sensors without having them machined, and I dont know if thats possible even.

My issues start there because I would like to tune the engine using either someone elses similar setup or try to use EBL_Flash. However, ebl uses a learn procedure to build some of the tables, and that utilizes the O2 sensor from what I understand. So will I be able to achieve a decent tune without the sensor and just run the engine in open loop?

Thanks
Bryan

 

Not that much of a boat guy, but you can't mount the O2 sensors further down the exhaust then the header? But sure you can tune open loop without the 02 sensor, just takes a little more work. Same as tuning a carbureted vehicle. Read the plugs, do some performance testing. Make some small changes, test again. Procedure's not that much different, just a little less info fed back to you.

 

Cool, now I just have to buy the parts and take the time to do it.


The problem with the O2 sensor mounting lies in the cooling system. The water comes out of the manifold, through the exhaust headers and into the exhaust. So the only place the sensors wouldnt get wet would be in the header, which is jacketed. Im sure with some careful drilling you could get through the inner and outer shell. Maybe two different sized holes and a thick weld would seal it.

 

I have an EFI MPFI Vortec engine in my boat. I suspect it is a closed loop system with NB02 sensor. I would have to look. I am certain coolant is fresh lake water. Some engines use a contained coolant system I read. Another option is run OL with WB02 sensor assistance. Possibly your headers disallow any feedback options .