EFI Conversion on a 76 PCM 351W

Hey Alpha,

I am having my 99 GT40 rebuilt as we speak. I am turning the engine to a 408 with a holley dominator efi system and reusing the original gt40 intake for aesthetics.

In regard to the Howell EFI 02 adapter, do these adapters fit standard PCM ford exhaust manifolds? It would be awesome if they do so I dont have to machine a set.

Thanks!

EDIT- I just realized these are only bungs, not adapter plates.

AlfaDon wrote: I can't believe it's been 3 days and I haven't responded to the thread yet. I have a hard time logging in from my phone and so have to wait until I'm at home. Peter, I appreciate what you're doing and I'm going down much the same road except that it's taking me forever to get it done. I am using the Howell EFI O2 adapter with a wideband A/F sensor in one of my manifolds It's worked great for 2 seasons now and it's nice to have just to monitor the mixture. I built a new HP motor and wanted to make sure I didn't go lean.   I also use a cheap anti-fouling elbow that I got on ebay. I believe it helps to keep the O2 sensor out of the steam stream. The idea of sequential spark sounds great although I've heard that batch fire is nearly as effective I also have the coil near plug set up using a modded Cam sensor from a Ford 4.3, as it's the same dist shaft diameter as the 351 dist. I had a friend weld up the sensor top to an old 351 dist base. There's also a guy online that makes them up just for this purpose. I struggled with the Microsquirt. I have a MS2 that I never used because of the fear of explosions. I also heard that they can be difficult to tune. I ended up going with a Holley HP ECU. This article says that they're marine approved but other components in an EFI system might not be. (https://www.efisystempro.com/efi-pro-hangout/custom-efi-configurations/converting-marine-engines-to-efi). I'm hoping the HP ECU's self tuning feature will take care if it. It's a potted ECU which takes care of sparks. If you're using all of the mechanical fuel lines and hardware from the GT40 setup I think you should be fine. I just bought the PCM Fuel Control Cell from Nautique parts on their Black Friday sale. One of the problems with the Fuel pump issues is that the fuel line from the tank can't be pressurized. It has to be a vacuum from a mechanical or electric fuel pump that needs to be within 12" of the motor. I believe with the FCC, I can return the extra fuel to the FCC, although if I have to run a return to the tank it will have already been done already by PCM, and I'm just following what has been CG approved. The benefit of the return line to the tank is that it cools the fuel much better than returning it to the FCC Don

Hi McFadin

The Howell adapters aren't bungs the way we typically think about them.
They're designed to thread into the inner wall of the riser, and seal against the outer wall with an O-ring. Mine have worked great for 2 seasons now. At the time I bought them, the sandwich type wasn't available off the shelf like they are for the Mercruisers.

DHMcFadin wrote: Hey Alpha, I am having my 99 GT40 rebuilt as we speak. I am turning the engine to a 408 with a holley dominator efi system and reusing the original gt40 intake for aesthetics. In regard to the Howell EFI 02 adapter, do these adapters fit standard PCM ford exhaust manifolds? It would be awesome if they do so I dont have to machine a set. Thanks! EDIT- I just realized these are only bungs, not adapter plates. AlfaDon wrote: I can't believe it's been 3 days and I haven't responded to the thread yet. I have a hard time logging in from my phone and so have to wait until I'm at home. Peter, I appreciate what you're doing and I'm going down much the same road except that it's taking me forever to get it done. I am using the Howell EFI O2 adapter with a wideband A/F sensor in one of my manifolds It's worked great for 2 seasons now and it's nice to have just to monitor the mixture. I built a new HP motor and wanted to make sure I didn't go lean.   I also use a cheap anti-fouling elbow that I got on ebay. I believe it helps to keep the O2 sensor out of the steam stream. The idea of sequential spark sounds great although I've heard that batch fire is nearly as effective I also have the coil near plug set up using a modded Cam sensor from a Ford 4.3, as it's the same dist shaft diameter as the 351 dist. I had a friend weld up the sensor top to an old 351 dist base. There's also a guy online that makes them up just for this purpose. I struggled with the Microsquirt. I have a MS2 that I never used because of the fear of explosions. I also heard that they can be difficult to tune. I ended up going with a Holley HP ECU. This article says that they're marine approved but other components in an EFI system might not be. (https://www.efisystempro.com/efi-pro-hangout/custom-efi-configurations/converting-marine-engines-to-efi). I'm hoping the HP ECU's self tuning feature will take care if it. It's a potted ECU which takes care of sparks. If you're using all of the mechanical fuel lines and hardware from the GT40 setup I think you should be fine. I just bought the PCM Fuel Control Cell from Nautique parts on their Black Friday sale. One of the problems with the Fuel pump issues is that the fuel line from the tank can't be pressurized. It has to be a vacuum from a mechanical or electric fuel pump that needs to be within 12" of the motor. I believe with the FCC, I can return the extra fuel to the FCC, although if I have to run a return to the tank it will have already been done already by PCM, and I'm just following what has been CG approved. The benefit of the return line to the tank is that it cools the fuel much better than returning it to the FCC Don

Hello Real Internal Combustion (on water) Engineers!


I have yet to convert to EFI but want to.
I can handle a wrench and yank a 454 and put the right bearings back in it..
I have taken the electical step to install electronic ignition as I hate (points, plugs condenser) etc even back to my 1970 VW Beetle!!!

However I am worn out with holley 4160 issues. (yes I know that ethanol plays a part) Have paid a carb guy every 4 or 5 years to get me back there. Hey I wanna pull 4 barefooters without needing step off skis. My buddy with AN efi malibu can pull 5!!! OUCH!

Anybody out there put EFI on a vintage 454???

Heck I don't know how you cover the mechanical fuel pump mounting hole??

Have googled and found for Marine... Holley EFI, Summit Racing, Mega Squirt, Affordable Fuel Injection,

"Where Do I Begin"

Any EFI system is far superior to any carburetor why do you think pretty much every car and boat on the planet is now?? Sure a carburetor may make ever so slight amount of more power but it is really small number in comparision to how many times your going to rebuild that unit over time, cold starts ,   Its not that difficult once you get it tuned and know the pitfalls your going to encounter to begin with .   Most people are scared of it really because of the unknown or scared of change or maybe still own T- shirt from 1970 that still fits.   
Really the best option for the $ right now is the Holley sniper EFI it meets the coast guard standard and with the master kit you get everything you need with exception of plumbing a return (hardin marine has one for fill hose) and where your going to plumb 02 sensor. FAST efi is still an option but its pricey and requires more tuning and has alot less support than the Holley EFI systems. Having tuned on most of them out there I have seen the good bad and ugly.   Sure Quickfuel is another option but your back in the same boat probably a few years down the road. Time to say goodby to cold starts and hesitation. I am tired of sitting at the dock waiting for 454 to warm up as well and I certainly don't have fuel quality issue and 351 was also most same way with a brand new holley carburetor.

I'm with rosconole I converted to MS3X 4 years ago from ford fuel inj. on a GT40 and had many carburetor's before, I never go back I choose the Ms3X because it offered the most options for tuning and control but it also requires more programming the Holley system is more plug and play.
I think the EPA emission standards are good and protect us from unnecessary smog, And for sure not the only reason for fuel injection.
Peter

Unless you’re running 6,000 ft in the morning and sea level in the evening I see no reason to convert to EFI. Yeah I have trouble with carbs every 4-5 years so I just replace with a new one and before my coffee gets cold I’m back to running. A new $750 Holley 4160 “calibrated” for SBF from Summit works out to $187 a year, I feel that’s reasonable enough. I’ve never been a fan of rebuilding carb’s. A properly tuned carb starts is as easy as using toilet paper so I’m confused as to where they’re “hard to start”. And EFI or not I wouldn’t plan on pulling up a skier until temps 160 which usually happens by the time we get the vest on.

I find bolting up a new carb and having the engine run well extremely satisfying We have had few issues with good running carbs unless they sucked up water or debris. We bought a new boat in 2003 with a carb and I don't regret not getting efi at all.

I think some finally discard their pos fram cartridge filter and install something that actualy functions and clean their tank and replace the hoses and say see, efi fixed it

Pete, Sorry for the long time to answer. Covid 19 gonna give me some time to dig into these issues Ive been battling. Looked for my dwell meter but then I remembered tossing it likely 2007 when I put EI on the BFN and owned no cars without EI.

I have never traded a car and with the exception of exhaust work (I'm an ugly welder) have never paid a $$ on auto service fees. Drive em' till they are uneconomic to fix. Like donateing them to a charity for the tax value. Less haggling when buying a car. Did clutches, ball joints, half shafts, brakes etc etc.

Bought my BFN (my first inboard) in 2004.(skied rather shallow lakes B4 1996 so wanted an outboard with power trim) Early on after buying it I had to crank extensively when cold but determined that choke plate was getting hung up on underside of flame arrestor. Now when cold I remove arrestor to confirm plate is fully closed to start. By 2007 was having long cranking required for starting when warm after shutting it off a few minutes between skiers. A good ski nautique friend told me he had a stars and stripes mastercraft with a holley 4 barrel and he had issues like mine. He told me he bought a 2nd carb and replaced and rebuilt his every season after that and never had another problem. In 2007 I took the carb to a seasoned auto mechanic (am not good with TINY parts and can't live with a boat not available) and a skiDim rebuild kit and it started with a few cranks warm and cold intil 2016. From 2016 to 2019 I'd dump a can of sea foam every other week when long cranking starting returned and no issues (frequency increasing as the months went by). Again late summer 2019 I had issues starting it when warm (but not when cold) Took carb back to my rebuilder and problem again solved.

I have experimented with gas from a turnpike vacinity high volume convenience store to the local small convenience store that is closest to home. Can't say I see a difference. Have changed fuel filters 3 times. Replaced all fuel lines with ethanol friendly hosing somewhere in that time period.

It has rarely "instant started" like a fuel injected engine (or like any car I have owned carbureted or FI).

Hence my slight dismay. I'm always able to start it but my wife "will not take the boat out by herself". My adult son would not take it out without me first starting it this past summer.

Am sure a dwell meter can be found on ebay!! What do I do with it??? Since I have EI.

John

Gary S wrote: rosconole wrote: Any EFI system is far superior to any carburetor why do you think pretty much every car and boat on the planet is now?? Twist it any way you want the only reason for fuel injection is simple - EPA and California mandated air quality standards

Gary, I have done some EFI googling and did find some info that emissions are the big benefit, and that HP or low end torque is not really improved.

However "instant starting" for me and anyone running my boat would be reassuring.

John

Oooh

John I encourage you to reconsider your apprehensions to rippems and let that thing spin.
You are leaving a lot of performance on the table and as far as longevity and efficiency it can be argued your setup is counterproductive to that as well
Hang with us and we should get all your issues addressed

I just finished my conversion (Holley Sniper EFI.) The first day on the lake was 6/3/2020 will keep everyone posted. The hardest part was the O2 sensor. I found this on eBay and was able to redrill all holes with 3/8 and make it fit perfectly.

https://www.ebay.com/i/222482543306

EFI installed
https://photos.app.goo.gl/bRgMZNWoRFMbyMre7

I have to remove the manual fuel pump this week (left as a backup plan just in case the EFI install failed). I purchased as a marine kit from Holley but never got an answer back about the fuel pump being USCG approved. That is the only outstanding item of the install. If I find out unapproved I will buy a USCG pump.

BTW runs way better than a carb but mine was in need of replacement ($735 vs $1235). Next up is DUI distributor but that is another season.

1986 CC Martinique (351W RH)

Interested in how it runs under 160 degrees where the learn mode open /closed loop starts typically Have you had it under load on lake yet?   Pretty much any drop in efi walbro style pump will be USCG cert. the in line probably should be , Probably depends on where you mount it really. Glad to see it running!

nubf14 wrote: Good day on the lake (6/4/2020) and 160 is hard in my boat. I have to run about 3400 for 10 mins to get 160 or greater

I don’t understand this. Why??

Would have to be I would think if it’s even in there.