Converting a Astro 4.3 to semi marine

Technorunner

Petty Officer 3rd Class
Joined
Oct 1, 2010
Messages
95
HI all
i have searched and googled myself blue with this.
A little background: my friend bought a funlinear 195 fantastic with a mercruiser 130 and a alpha one gen1 1998 y/m
he had had it in water only 2 seasons second season he found water in the oil.
he took the engine out and took it a part , the cyl.head gasket was in bad shape so he hoped he found the problem. But to be sure he pressure tested the cyl.head and the exhaustmanifold. and they found no leakage.
so he changed all bearings and rings and so on when he had it a part.
he put it together and started it no water in the oil.
he took it down into the water and after like 5 min there where water in the oil again. so he took it up and let it be for like 4 years then i ?bought it cheep from him.

with the 130 hp engine it took forever to get it up in plane
so either the prop is way to big or the drive has the wrong gear ratio. and there is no label on the sterndrive left to tell what ratio.
so i bought a 95 astro vortec engine complete with engine cable to ecm and the ecm with it. Its a CPI engine and have 195 KW in the car.
so i have bought a manuell 168teeth flywhell.

i have had the ECM reprogramed in swedens best tunning company.
and they removed the O2 sensors and fault codes related, EGR and faultcodes. reprogramed to manuell so it skips transmissionsignals and removed VSS signal.
he also made som small adjustment to timing and fuel.
But if i want to run it in closed loop he toold me to take a preheated O2 sensor and make a thredded adapter to fit the EGR valvehole and put a O2 sensor in there and make a pipe from the O2 sensor bung to the cow horn.
It only needs to be like 8mm in diam to have a little flow. because your always (almost at least) in same throttellevel. And in the ECM GM had made 1 nice mode called highwaymode. If you have the same throttelpossition for a little longer time it uses the O2 sensor to leanout the engine. And thats the only reason im thinking of maybe program back the O2 sensors.

i have a friend making the wet manifolds in stainlesssteel for me
but in most it will remain a car engine since i got pretty much Hp over.
but it has the same WOT rpm as the 130.
So this will be a CPI boat engine. with alot less vapours from the gas in the engine compartment a little better fuel consumption
and better coldstarts.

please feel free too leave a comment.
And i know my English isent the best :)
And my background with engines is 12 years as a truck engine mechanic in R&D at Scania here in sweden
 

Danny Mc

Seaman
Joined
Jul 18, 2010
Messages
71
Re: Converting a Astro 4.3 to semi marine

Someone has already invented the wheel.
 

paultjohnson

Lieutenant Commander
Joined
Jul 29, 2010
Messages
1,560
Re: Converting a Astro 4.3 to semi marine

thats easy--- Eleventeen squared. with umptifrump reverse backlash.. two cookies and a dead frog. lets go to Spain where 6 is 9 but !! How many pancakes does it take to mend a helicopter blade ? None! Cuz ice cream comes in cartons.,. So using my wristwatch as a tennis racket , I knocked the needle thru the eye of a pork chop, as I was riding down the street in my canoe
 

Technorunner

Petty Officer 3rd Class
Joined
Oct 1, 2010
Messages
95
Re: Converting a Astro 4.3 to semi marine

I might have been a little unclear with that sorry.
My thought was to get feedback of thins i might have overlooked.
Since i havent find anything from google about CPI vortec engine in a boat. Just think it strange ppl dont use em since you have knocksensors on it and a injected engine is almost to prefer over a carbed engine.
 

adeneo

Petty Officer 2nd Class
Joined
Jul 7, 2010
Messages
107
Re: Converting a Astro 4.3 to semi marine

It all sounds lovely and wonderful, and at some point even mycket underbart.
Now make sure all the electronics are marine proof, so you don't blow yourself or your boat up.

Also, more electronics is'nt always a good thing in a boat, but if you can make it work, I'm sure it will be riktigt skoj :eek:
 

ewenm

Petty Officer 2nd Class
Joined
Mar 30, 2005
Messages
187
Re: Converting a Astro 4.3 to semi marine

yep plenty of vortec engines in boats, i have two 4.3 EFI,s (throtle body injection)

previously had a VP 4.3gxi a multi point injected vortec engine

plenty around from at least 1999
 

LAC_STS

Master Chief Petty Officer
Joined
Jul 1, 2010
Messages
895
Re: Converting a Astro 4.3 to semi marine

thats easy--- Eleventeen squared. with umptifrump reverse backlash.. two cookies and a dead frog. lets go to Spain where 6 is 9 but !! How many pancakes does it take to mend a helicopter blade ? None! Cuz ice cream comes in cartons.,. So using my wristwatch as a tennis racket , I knocked the needle thru the eye of a pork chop, as I was riding down the street in my canoe

LMAO!!!

Go tell someone in public that i bet youll find some people think your actually asking them a question and will give you an answer.
 

scrdanis

Cadet
Joined
May 12, 2003
Messages
23
Re: Converting a Astro 4.3 to semi marine

I'll second LAC STS! That was too funny. Sounds like a valiant effort but don't know enough about engines to help you out. Wish you luck.
 

Technorunner

Petty Officer 3rd Class
Joined
Oct 1, 2010
Messages
95
Re: Converting a Astro 4.3 to semi marine

The Ecm is going to be in an seperate airtightbox with solderd connection on the inside and snapon oringed connectors on the outside. My only consern there is how hot the ECM vill be if i need to make a colling system for the ecm or if its ok anyway.
The airtightbox are ? times bigger then the ECM so it has a little space around it.

Regarding Vortec Engines in boats i only found the MPI injected (way to much money for me) and the Carbed Vortec.
I did suspect that ppl had converted these engines as well but dident find any good info about it.
 

Hogger

Petty Officer 1st Class
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Jul 15, 2008
Messages
214
Re: Converting a Astro 4.3 to semi marine

hats easy--- Eleventeen squared. with umptifrump reverse backlash.. two cookies and a dead frog. lets go to Spain where 6 is 9 but !! How many pancakes does it take to mend a helicopter blade ? None! Cuz ice cream comes in cartons.,. So using my wristwatch as a tennis racket , I knocked the needle thru the eye of a pork chop, as I was riding down the street in my canoe

Hahaha. Cliff Clavin on crack.
 

Tail_Gunner

Admiral
Joined
Jan 13, 2006
Messages
6,237
Re: Converting a Astro 4.3 to semi marine

It sounds like your doing the FI right. But i believe your going to run into some problems with mating the engine to the drive..Watch for Bondo or Don if they post.

Just using conventional carbs would be much eaiser..But if your really do have acess to good tuners you will be ahead..For your own information here in the states tuning or reprogramming marine efi motors is expensive and very hard to find someone who has the ability to do it.

Big project good luck

Guys the poster is putting a old CPI motor in a boat..It is being customed tuned or programed..He also has someone building a custom stainless exhaust system...
 

adeneo

Petty Officer 2nd Class
Joined
Jul 7, 2010
Messages
107
Re: Converting a Astro 4.3 to semi marine

I did this a few years ago, or atleast something similar.
Bought a boat with a Penta GXI with cracked block and both heads from freezing, and pulled a CPI from a Astro van to replace it.
I used all the auxiliaries and camshaft from the Penta though, so never had any real problems making it work.
Still runs like a charm 3 years later.
 

Utahboatnut

Senior Chief Petty Officer
Joined
Jan 15, 2009
Messages
785
Re: Converting a Astro 4.3 to semi marine

Unless the drive was changed at some point it is probably a Gen 2 not a Gen one as stated in the orig post.
 

Technorunner

Petty Officer 3rd Class
Joined
Oct 1, 2010
Messages
95
Re: Converting a Astro 4.3 to semi marine

It sounds like your doing the FI right. But i believe your going to run into some problems with mating the engine to the drive..Watch for Bondo or Don if they post.

Just using conventional carbs would be much eaiser..But if your really do have acess to good tuners you will be ahead..For your own information here in the states tuning or reprogramming marine efi motors is expensive and very hard to find someone who has the ability to do it.

Big project good luck

Guys the poster is putting a old CPI motor in a boat..It is being customed tuned or programed..He also has someone building a custom stainless exhaust system...

That problem against drive sounds interesting. What is the problem going to be as you see it ?? This is why i posted here always great with more thoughts, always thinking of things that may have been overlooked.

i payed roughly 130$ for the basic tuning and reprograming.
if i want it really tuned to perfection while running it in water he will charge about another 200$. I also got his permition to copy the EPROM and sell it so if any one else is doing the same thing il gladly sell a copy. BUT this is with standard Astro camshaft not the Marine so if you doiong this and have a Marin camshaft you need to tune it your self but its a good start to work from.

I was thinking about carb, but it would roughly cost me the same to carb convert it as reprogram the software so felt better with the CPI.
I also took the gastank (console?)complete with fuelpump and fuellevelsensor.
Im also making a narrow compartment in the tank that fuel can get in but not out so it wont pump air if the sea is rough!
 

Technorunner

Petty Officer 3rd Class
Joined
Oct 1, 2010
Messages
95
Re: Converting a Astro 4.3 to semi marine

Unless the drive was changed at some point it is probably a Gen 2 not a Gen one as stated in the orig post.

I also thought it was a gen 2 untill i compared the picture of the 2 and the only thing i saw directly was that gen 2 have a little bit from the tilt cyl mounting sqrews to the centrumbolt above the prop, while the generation 1 the mounting screws from the tilt cyl and that centrum bolt coming from above are almost on the same place, and that is how my drive looks.
 

Technorunner

Petty Officer 3rd Class
Joined
Oct 1, 2010
Messages
95
Re: Converting a Astro 4.3 to semi marine

I did this a few years ago, or atleast something similar.
Bought a boat with a Penta GXI with cracked block and both heads from freezing, and pulled a CPI from a Astro van to replace it.
I used all the auxiliaries and camshaft from the Penta though, so never had any real problems making it work.
Still runs like a charm 3 years later.

Nice to here it runs good then i have something to look forward to ( hopefully)
Are you running it in closed or open loop?
how did you mate it up with the boats harness or did you build a new one?
 

Tail_Gunner

Admiral
Joined
Jan 13, 2006
Messages
6,237
Re: Converting a Astro 4.3 to semi marine

Marine FI uses open loop systems..primarily because of the oxygen sensor issues...You cant place one in a factory riser..They tend to get wet...:)...Marine motors run about 160 degrees..Ox sensors need to be 300 degree's or better for a good reading...Now there are heated sensors..but again they dont like water..

6582263-0-display.jpg



You need to get by that outer jacket to get the os sensor in the exhasut flow close enough to the exhuast ports that it will be hot enough...That would have to right at that 100 point and as you can see it has a water jacket 360 degree's around it..;)
 

Technorunner

Petty Officer 3rd Class
Joined
Oct 1, 2010
Messages
95
Re: Converting a Astro 4.3 to semi marine

Marine FI uses open loop systems..primarily because of the oxygen sensor issues...You cant place one in a factory riser..They tend to get wet...:)...Marine motors run about 160 degrees..Ox sensors need to be 300 degree's or better for a good reading...Now there are heated sensors..but again they dont like water..

6582263-0-display.jpg



You need to get by that outer jacket to get the os sensor in the exhasut flow close enough to the exhuast ports that it will be hot enough...That would have to right at that 100 point and as you can see it has a water jacket 360 degree's around it..;)

If im gonna do closed loop im not sure yet. Im going to use a heated O2 sensor and use the EGR output in the intake and take a small pipe like 8mm from the O2 sensor and let it go back to the U exhaust pipe just to get a little flow on it. And that pipe is going to be without a waterjacket just a heatsinking cover on it.

But the ECM are today programed to open loop but for like 10$ i can get it back to closed loop so we will have to se how il do it :)
 
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