Thinking about doing a repower. 3.7 to small block Ford

[Bri7070]

I have an 87 Searay 190br with the 3.7 and it is due a rebuild. I also have a 66 289 small block ford. I was wondering,
1) What would it take to repower?

2) With the engine size being close would i need to regear the outdrive?

Thank You
Brian

 

[matt167]

Re: Thinking about doing a repower. 3.7 to small block Ford

Your going to need a bigger hammer.. Fords were never used with the Alpha drives, and they changed things a bit when the Alpha's came out tho some parts still fit like you can put an Alpha leg on the older transom assemblies.. You would need an older transom assembly from 1983 or older and the right parts to fit an 888 ( Ford 302 ) Mercruiser to make it work, and you don't have manifolds, or ignition for the Ford most likely..

You have a '87 so you can put a 4.3L bobtail engine in without much trouble. Just need the Y pipe. The ratio is good for the 4.3L also

 

[haulnazz15]

Re: Thinking about doing a repower. 3.7 to small block Ford

Well, the 3.7L was an inline-engine, so you'd need a new set of motor mounts for the front, the transom plate wouldn't likely fit, either. I don't recall that the 289 was ever used in a marine application, at least not by Mercruiser, so finding a coupler might be difficult as well as exhaust manifolds and exhaust y-pipe. The gearing would be the least of the problems you'd encounter.

As much as I like my Fords, it's not really an easy swap unless you want to source a lot of NLA parts and do custom fabbing of your own. Either refresh the 3.7L, or find a junk boat with a good engine and swap all of the parts off of it.

 

[Maclin]

Re: Thinking about doing a repower. 3.7 to small block Ford

Bri7070, it is not so much Ford vs. GM performance capability as it is parts availability and sustainability. GM "won" the engine package supplier "wars" so best to go the GM route if you want to go boating more than parts hunting/trying/failing

 

[500dollar744ti]

Re: Thinking about doing a repower. 3.7 to small block Ford

Swap to 4.3 V6, don't waste your time doing anything else unless it's fixing the current motor.

 

[haulnazz15]

Re: Thinking about doing a repower. 3.7 to small block Ford

You would need an older transom assembly from 1983 or older and the right parts to fit an 888 ( Ford 302 ) Mercruiser to make it work, and you don't have manifolds, or ignition for the Ford most likely..

Don't forget about the Mercruiser 233 (Ford 351w). That's the real gem from the 1975-1977 era. :happy: Parts are relatively easy to find, but nothing that will necessarily fit a 289 without modification.

 

[thumpar]

Re: Thinking about doing a repower. 3.7 to small block Ford

I agree with the others that say go to 4.3l. The drive ratio will be correct and all parts to make it work are available. The 4.3l was used in the astro/safari vans and some of the trucks so they are a dime a dozen.

 

[500dollar744ti]

Re: Thinking about doing a repower. 3.7 to small block Ford

If you go 4.3, get the one with the Vortec heads and find a 4bbl intake and carb for it.

 

[stonyloam]

Re: Thinking about doing a repower. 3.7 to small block Ford

Geez you have a really desirable engine there, 3.7 with the 4 barrel Rochester right? Lots of guys would want that engine, so my vote is don't screw around, rebuild it over the winter. Slap a OEM head gasket on it, Hardened exhaust seats, rings and bearings, redo the cam seals and it should be good for another 25 years or so. With the 190 you will gain almost nothing by going to a 4.3 except the PITA to swap and an extra 200 pounds in the stern. Just IMHO

 

[achris]

Re: Thinking about doing a repower. 3.7 to small block Ford

Geez you have a really desirable engine there, 3.7 with the 4 barrel Rochester right? Lots of guys would want that engine, so my vote is don't screw around, rebuild it over the winter. Slap a OEM head gasket on it, Hardened exhaust seats, rings and bearings, redo the cam seals and it should be good for another 25 years or so. With the 190 you will gain almost nothing by going to a 4.3 except the PITA to swap and an extra 200 pounds in the stern. Just IMHO

Ah, the voice of reason. Good call Terry....

 

[HT32BSX115]

Re: Thinking about doing a repower. 3.7 to small block Ford

Geez you have a really desirable engine there, 3.7 with the 4 barrel Rochester right? Lots of guys would want that engine,

And since that is true, you could also part it out to those guys that want the engine and then find yourself the parts to switch to the 4.3L V-6. It wouldn't be all that hard since it's still in production and has been for a great many years........... and then you'd have an engine that is still "cheaply", fully and easily supported.

 

[dan t.]

Re: Thinking about doing a repower. 3.7 to small block Ford

Just a few more things you should know about a 66 289;

10.5 compression ratio, hope you like to buy premium fuel.

soft exhaust seats, big bucks at the machine shop for hardened seats ,or lead subsitute added to the premiun fuel

302 marine components will fit but try to find them

take the good advice that has been given, rebuild what you have

 

[Bri7070]

Re: Thinking about doing a repower. 3.7 to small block Ford

Just a few more things you should know about a 66 289;

10.5 compression ratio, hope you like to buy premium fuel.

soft exhaust seats, big bucks at the machine shop for hardened seats ,or lead subsitute added to the premiun fuel

302 marine components will fit but try to find them

take the good advice that has been given, rebuild what you have

Well a stock 66 289 might have had 10.5:1 compression but this 66 89 was rebuilt to have 9:1 compression and harden seats installed. this motor was in my mom mustang and dad decieded to put in a 5.0 with and AOD. There is less then 10000 miles on the motor and dad used quality parts thru out the motor. All fastners are ARP Full comp cams valvetrain
ECT. I was just hoping to be able to use this motor as I know the full history.

Looks Like a rebuild on the 3.7 is in order.

 

[thumpar]

Re: Thinking about doing a repower. 3.7 to small block Ford

The cam in the 289 might cause problems in a boat. Boat cams are close to truck cams not hot rodded car motors. They can cause reversion with overlap. Best bet would be the rebuild.