Max Engine RPM

On a 1980 Mercruiser v-8 228 w

On a 1980 Mercruiser v-8 228 which is a 350 5.7 liter. What is max running RPM's??cant find that info anywhere??

"Per SELOC:

228 V-8 Mercrui

"Per SELOC:

228 V-8 Mercruiser

WOT: 4200 - 4600 RPMs

It's a 305 5.0 Liter, not a 350 5.7 Liter."

really i was under the assumpt

really i was under the assumption it was a 5.7 liter. thanks guy. good info thanks a bunch

the 228's were 305's b

the 228's were 305's based on what data i have.

Shoot for 4200-4600 for WOT

ok thanks owner told me it was

ok thanks owner told me it was a 5.7 but it says 228 on the motor but WOT was around 6200!!way under propped it must be!!thanks again guys

Unless the engine was replaced

Unless the engine was replaced with a 5.7L

What prop do you have on it now ?

Its not my boat YET!! Still lo

Its not my boat YET!! Still looking into buying it..Its a 3 blade stainless. Im not sure what size and pitch i think its a 19 pitch but not 100% sure.

I still believe its the original engine in it. It says 228 in red along with thunderbolt ignition. Is there any way to tell a diff. between the 305 and 350 in appearance??

"The only outside appearance,

"The only outside appearance, is the numbers on the block, IE, Serial Number on the pad just below and in front of the Starbord(RH) Cylinder Head. (unless the engine block has been milled), and or Stampings on the side of the block or back where the Distributor is.

Any Tags or stickers can be swapped from engine to engine. (look for a Mercruiser Serial # Tag) at the back of the engine, just above the Starter. (not typically replaced)"

"If the owner did replace the

"If the owner did replace the engine with a 5.7 then the high RPM problem lies with your outdrive gearing. The 305 typically came with 1.62:1 where the 5.7L came with a 1.50:1. You will have the same problem even with the biggest prop you can fit on your outdrive but if you keep the RPMS to the max range you shouldn't have any problems except for people passing you. Also rent a remote laser tach to make sure your boat's tachometer is reading correctly.

The reason I bring this up is because I'm going through this myself. I now believe that someone replced the outdrive on my 3.7L with an Alpha 1 made for the typical 4 banger such as, 1.98:1 where my 3.7L is supposed to have a 1.84:1. I have the biggest prop I can fit and I can still reach way too high of RPMs than what is good for my engine. But at my RPM max range I'm only doing about 30+ when by all rights I should be able to do 40+ with my set up. Afetr inspecting my outdrive I'm pretty sure it's not the original, the decals don't match! never noticed before. BUT the good side is I've put many hours on my boat with no troubles as long as I keep the RPMs down. It just takes longer to get where I'm going.

BTW can anybody tell JCH and myself how to check the ratio in the outdrive? IS the lower gears a 1:1?"

"well, my current volvo you ca

"well, my current volvo you can check the ratio by removing the prop and zinc ring. underneith that it is stamped right on the gearcase itself. not sure if Mercruiser does it the same way??

or you can also turn the crankshaft on the engine and see how many times the prop rotates per engine crank"