EFI Conversion on a 76 PCM 351W

lets see some pics, you wouldnt happpen to work for professional products would you?

Pretty cool idea, I think the problem with the Holley system is that these motors are at or above the HP levels that it will support. I don't see a thing on your site about anything being marine rated so, good luck with your testing, hope you don't blow yourself up.

the HP rating is up to 500 Hp with the fuel pressure set at 45 psi. You could increase the fuel presure and go beyond that. The base system i am using is far above the HP rating of a 351W.

The marine version which doesnt exist would consist of a marine spark arrester which I am using from my old carb. Its a Professional Products 70026 Powerjection, not a Holley Pro-Injection sorry I messed up the name in my earlier post.

The oxygen sensor mount is a neat design, you drill a larger hole in the outside wall, then a smaller one inside.

I will uploadsome pics

How much does the kit cost?

Location of the o2 sensor is always an issue because any moisture and it's toast. I think you should be ok there but time will tell, please keep this thread going after you get it running and report back with results/issues.

I played around with making an adapter for an o2 sensor a while ago so I could hook up an air/fuel meter for engine tuning, that was a semi success because it worked for a while but I killed 2 sensors from moisture as the final sensor placement on my log manifolds was too close to the water entry. I don't think it takes much to ruin an 02 sensor.

This first picture is an adapter I made for PCM manifolds which I never installed but think it should work. The later is the one for my logs which again worked long enough for tuning but failed later. Both versions install between the manifold and elbow.





Good luck with your project, sounds like fun.

How's it working out?

I couldnt be more happy, took about 5 hours to install, time was spent plumbing the return line. I would have replaced my fuel gauge sender with one that was plumbed for a return already so I didn't have to drill a hole in my tank. A alot of the time was also spent running a whole new fuel supply just because I had so much braided line.

Yeah, definitely keep us posted. I looked on their site and there are returnless versions too.

Price? If you don't mind.

Yes, $2000 when all said and done, I'm sure.

skfitz wrote: That is a sweet O2 adapter! Do they sell it alone? 81nautique's are slick too. I've run a Megasquirt TBI system on my 1975 351w for about 18 months. However, it runs open loop only (so you have to dial it in a little more precisely). I'd love to let it autotune with O2 feedback. My system cost me a total of about 600$ (and a pretty steep learning curve). It was definitely not a drop-in "kit". All fuel lines, connectors and wiring are marine. The throttle body -- from a GM truck -- temp sensors, fuel pump, computer (w/ map sensor) and home-made relay board are not.

pictures of that setup are welcome!!!

How is it runing performance wise? how you fuel consumption?

The mount was purchased from Howell Engine Developments at http://howellefi.com/ . I didn't establish a base line for fuel consumption, wasn't really paying attention to it, my problems were rooted in going to a different elevation lake each time and never having the carb adjusted right for any of them. I really like the easy of the tuning, just tell it what displacement it was, start it up idled ruff for about ten seconds and it smoothed out and then run it around on the lake and it self tuned. the returnless system was my first choice but was back orderd for 4 months so I changed to order to the return style when I found out the return computer controll part of the kit was what was holding it up and they could ship the next day if I go tthe return style and it was $300 cheaper. I got it for $1600 but that was ordered before the price change.

tedwarde wrote: On your Powerjection install, did you use their fuel pump or did you use a USCG approved marine fuel pump instead? If you used theirs, any problems with the fact that it was not a marine unit? I've heard that automotive pumps do not perform well in boats.

A VERY excellent point!!! Why "upgrade" if it's not marine rated??? So, you create a bomb under the dog house?? Real nice!!!!

Not given,
Please fill us in before you potentially misdirect someone else.

QUOTE]
A VERY excellent point!!! Why "upgrade" if it's not marine rated??? So, you create a bomb under the dog house?? Real nice!!!!
Not given,
Please fill us in before you potentially misdirect someone else.[/QUOTE]

As said before...
Gee Ward aren’t you being a little rough on the beav'