compedgemarine

since I was the first to question the ring end gap and possible butting of the rings I would like to say one thing. thank you to everyone on this thread. most of these end up in some stupid pissing match about nothing but this thread has stayed on topic with lots of great info and helpful tips that everyone can and has learned from. this is what these threads are supposed to be like. I am not a master engine builder but I do build some and any time I can help and learn benefits all of us. thanks to everyone that has been civil and informative.

Keith Atlanta

LOL Thats because most conventional engine guys on OSO either hate or dont know anything about 496/8.1

So here we are, the redheaded stepchildren.

compedgemarine

you think the 8.1 is a redheaded stepchild? I restore cars so there is no telling what I end up rebuilding. I have done all the chevy and ford stuff which is pretty basic but when you get to the rambler or flatheads or packard or worse, some with multiple carbs, well you want to talk about odd ball. that is why I like threads like this that stay on track. things I learn here I can apply to others. and yes I hate some of these odd engines and I am pretty sure the engines hate me some days but I still have to figure out how to fix them.

donzi matt

I prefer being referred to as the white elephants lol.

This 555 ECM is really a killer. It has some really nice capabilities, but it is either uncrackable or nobody is willing to do it. Nothing against Whipple, but it is pretty impractical to try to dyno tune a motor by shipping off an ECM for each adjustment.

I am just an idiot with a toolbox, but is there really no way to crack the programming on this thing so changes can be made by the end user? I would love to hear what you guys who have spent years massaging these motors have learned about this obstacle of an ECM.

thirdchildhood

Should re-title this thread "Red Headed Step-Children & White Elephants". lol It's all good. Probably all engines can be made to perform but some are just easier than others. Take the big block Fords for example. Has anyone been able to get big power from a 460 Ford? Has anyone even tried?

hogie roll

Not exactly 460s

http://www.offshoreonly.com/forums/v...-upgrades.html

buck35

You can add "and the 555pcm blues too", there, now its very patriotic . lol
wouldn't it be easier and more cost effective to sell the stock unit and buy an aftermarket self learning unit?

thirdchildhood

It would sure make life easier if they could figure out how to make an O2 sensor work with wet exhaust and run a closed loop EFI like cars do.

MILD THUNDER

Its often done. Lots of Jet/V drive guys use the big block ford.

bobl

Just need a good exhaust to run an 02 sensor. I've done it on quite a few boats. You need to get a good tune, then remove the sensor. The Holley system is really nice. Run the boat under as many conditions as you can, upload the learn table and remove the sensor once you're satisfied. If you have a significant altitude change you might need to reinstall the sensor and let it learn again. FWIW, many cars only run closed loop at idle and cruise (mainly for emissions purposes). They will go into open loop at wot and run 12.5 - 13 AFR.