Baja 190 Sport I4 to 350 swap

ElwoodB

Recruit
Joined
Dec 12, 2009
Messages
2
Hi guys, first time here.
I'm one of those guys can't leave ANYTHING alone. Bought a 89 Baja 190 Sport in great condition with a bad 4 cylinder and an Alpha Gen1. Going to drop in a 350 mag I have for a little excitement on the water. Not sure if I have missed something, wanted to see if anyone has done something similar. I know the drive is the wrong ratio, have a 1.5. Think I have to change the from dash harness (existing is a 8 pin), thru hull solves exhaust problem. Plenty of room in engine bay. My concern is the motor mounts. Have not measured but stringers appear to be in correct location to mount motor mounts but I'm not sure. (they came with a 4.3 v6 as well).
Anyone ever done something similar?
Appreciate it.
 

joey maneri

Petty Officer 3rd Class
Joined
Nov 4, 2009
Messages
92
Re: Baja 190 Sport I4 to 350 swap

If they put a 4.3 in the boat the stringers should not be a problem cause its the same width as the 350. As far as the wrong gear ratio, you should be able to change the prop to make up the differance but it might be a little hard on the drive.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Baja 190 Sport I4 to 350 swap

In a 14' boat ????? It will probably be so squirrelly at speed that it will be down right dangerous. I would also bet that with even using thru-hull exhaust that you may have water problems due to how low the boat will set in the water with the extra weight of the engine. Your exhaust could still be in the water.
The electrical plug should work fine if the 350 has the round plug.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Baja 190 Sport I4 to 350 swap

Don: That is I4 (inline), not 14 like 14', I think it is a 19 foot boat. Yeah my eyes are getting old too.:D

Doh. Baja 190 should have been my clue. Oh Well, some days you win, some you don't .

One thing I do know for sure, is changing props to cure a wrong gear ratio wil not work worth a darn.
If it would work, the manufactures wouldn't have all those different gear ratios for different engines. It won't be hard on the drive, it just won't work very well.
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Baja 190 Sport I4 to 350 swap

You may want to post on the Baja bulletin boards. What you're talking about is apparently a pretty common swap over there:

http://www.teambajamarine.com/

Don, he also states that he has a 1.5 ratio drive available to put on the boat:
I know the drive is the wrong ratio, have a 1.5
 

AZSenza

Chief Petty Officer
Joined
Mar 11, 2008
Messages
521
Re: Baja 190 Sport I4 to 350 swap

That drive should be fine for a V8. I ran a 1.98 in my conversion from a L4 to 5.7. It ran for years before I sold it and the drive was in great shape. I ALMOST want to say the 1.5 is supposed to be behind a V8 right?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,116
Re: Baja 190 Sport I4 to 350 swap

That drive should be fine for a V8. I ran a 1.98 in my conversion from a L4 to 5.7. It ran for years before I sold it and the drive was in great shape. I ALMOST want to say the 1.5 is supposed to be behind a V8 right?

Ayuh,.... With what Prop,..??
 

wca_tim

Lieutenant Commander
Joined
May 28, 2007
Messages
1,708
Re: Baja 190 Sport I4 to 350 swap

in a light boat like that you would probably be fastest with a 1.84 gear ratio - I would be surprised if you will be able to find good props that you won't blow out on take off running a 1.98. Or that if you do, they'll be way to much blade area and leave a lot of performance on the table.

I've run my 18 foot / small block boat which is even lighter than yours with 1.32, 1.5, 1.65 and 1.84 gear ratio outdrives behind the same engine and gone through prop selection for each.

Note that if you really increase power a lot beyond a stock 350, you have to worry aobut the drive holding up and in general, the higher the gear ratio (ie 1.84), the more likely you are to break the upper gear set. sooo.... faster with more gear reduction, but if you go over say 300 horsepower, the more likely you are to break it if you're not careful.

at 1.84 gear you should be able to run 23-27 inch props depending on how much power your engine makes and how fast it is with that hull (probably in the lower 60's ?). merc laser 2 props are a great place to start. If you blow those out, start looking at hydromotive or merc bravo props. Just my experience / opinion, hopefully helpful, but may be worthwhat you paid for it. ;)

With a 1.5 gear you're probably looking at turning 19-21 ish inch props and will give up a few mph on the tope end (with the same caveat as above regarding the engine you put in it).

ps. the baja boards mentioned above have good info on them as do the donzi boards (regarding set up of "overpowered" shorter i/o boats)
 
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