350 vs 383?

[dwna1a]

Would a 383 fit into my 1988 weekender? Also what would the difference in horsepower be?

 

[cfd95]

Yes its still a small block chevy.
It's a 350 with a 400 crank.
HP depends on how it's built .
Mercruiser is selling 377 small block as a replacement for big blocks.

 

[hughespat57]

But keep in mind it's just a long stroked 350 SB.
That Merc 377MPI is pushing anywhere from 320-350 HP from the same block you have right now.
And has a 9:1 compression ratio without the computer that would be premium fuel to keep it from knocking.
If yours is like mine it's rated 260HP, anytime they squeeze more power from the same block you give up longevity.

Now to be fair Merc makes there own blocks now, so not a GM. Maybe their new blocks they are comfortable pushing that hard. When they were using GM block they gave up on squeezing to much from a SB and started offer the BB in those HP ranges.


ps the alphas are only rated to 300HP

 

[HawkX66]

Would a 383 fit into my 1988 weekender? Also what would the difference in horsepower be?

Yes. It's what's considered a stroker motor. It's a .030" over 350 (355ci) in addition to the crank and rods differences which makes it 383ci. The power difference"should" be significant, but it all depends on who built the motor and what they did to it. A 383 has a lot more torque which is what you want for a boat. Also, you want to make sure it's a 4 bolt main. The only differences are internal. Otherwise it's identical to a 350.

 

[dwna1a]

Hawk I’m going to look in Jasper for a reman. If you could recommend other companies I’d be very thankful

 

[HawkX66]

Hawk I’m going to look in Jasper for a reman. If you could recommend other companies I’d be very thankful

You could look at Summit. I've never been disappointed with anything from them. Another option is getting a local builder to build you one. It's an extremely easy motor to build.
I'd go local for the simple fact that I've often heard reman engines don't always get all new parts. They only replace what's out of spec. I don't have first hand experience with that though.

 

[HawkX66]

Here is one option that looks ok from Summit.

https://www.summitracing.com/parts/hpe-hp90#overview

 

[SCORPIO]

Look at Michiganmotorz.com. Many of the higher horespower rated small blocks are rated at much higher rpm. IE, the 260 is rated at 4200 to 4600 rpm. My 325hp roller cam Vorteks are rated at 6000 rpm.

 

[northern]

Question: Is the fuel burn of a 383 similar to a 350.

 

[HawkX66]

Question: Is the fuel burn of a 383 similar to a 350.

Depends on a few things. An underpowered engine uses more fuel because it's working harder. A 383 has a lot more torque, so it doesn't have to work as hard as the 350.

 

[spikedaddy99]

ps the alphas are only rated to 300HP

He doesn't have outdrives.