guillermof

does any one have any experiance with holley fuel injection. I am looking at using this system and procharging hp500.
why does no one use O2 sensor in the marine aplication.

Tinkerer

There isn't a good place to mount the O'2 senser. Does that unit have a max HP rating of 500? If it does it wont work on your motor. I had one of the older style units on a small block ford that put out over 500 HP. I tried everything to get more fuel flow-

Mr Gadgets

guillermof
I have not used the commander 950. I do know that using an O2 sensor can be touchy. They say that the sensor cant handle any water at all. I have mounted them in Stock Merc manifolds and in CMI headers and have monitored readings from them. But I have never relied on one for control of air fuel ratio.
Do a search in Tech Q&A about fuel injection. Dustin from Whipple made some interesting comments about air fuel ratio on a boat motor. Needs to be richer than 14.7:1. If you look at the output voltage curve on a regular O2 sensor it is not linear and only accurate at 14.7:1. So it isnt that usefull at richer mixtures. I have been running a Cutler setup for several years and have not had any major problems with it. I was able to make 690 hp with this setup. Holley now owns that system and uses a lot of the pieces from the Cutler system. I do have lots of spare parts if you are interested in building your own setup.
Proper sizing of injectors and fuel deliver system is crucial to max horsepower and has a definite effect on idle quality.

Let me know if I can be of any help.

Dick

guillermof

mr gagets:
the holley system is updated from the cutler system. it is capable of going to 800hp and with the race software you can set fuel are mixture to 14.7 to lean if you wish. my only fear is that the o2 sensor gets water on it.i am ussing gil wet offshore so the water is mixed late in the process.
i think what he is taking about on running a marine engine rich is because there is no good way of monitering that on long wot situations the engine is not going to lean out so for safety they are run them rich.

thank you very much for the response.

Mbam

I put a Merc 502 manifold & injectors on the 496 in my truck, used the 950 commander. Works great but I did have one fail after about 1000 miles, had to get towed home. The replacement seems ok so far. I would nix the O2 sensor in the marine environment, run it open loop. However I think it would be best if you map the fuel curve on a dyno using a wideand O2 for reference.