1500xs

[Droll-l6]

something "special" about the '73 model year 150 Merc that made it desirable over the other years. Remember anything?

Didn't the short shafted 73 1500 blocks have a more aggressive porting than the long shaft engines, also known as the "J" block, same ( or close ) porting as the later 1500XS ??.

Arne Kjetil

[Bill Gohr]

Just the opposite, the 73' long shaft motors were what we called square ports. Back in the SJ, JP days that was the motor to have, the exhaust ports were squared from the factory and if you had one of those by serial number it was legal to race. If you see one it looks madified. Most people believed it made more power than a J block, it was definately quicker than the J block.

[switzerbullet]

Was it only the long shaft or the early 73 motors? My other 1500 short shaft is a 1973. Maybe I should check the exhaust ports.

[Bruster]

Just the opposite, the 73' long shaft motors were what we called square ports. Back in the SJ, JP days that was the motor to have, the exhaust ports were squared from the factory and if you had one of those by serial number it was legal to race. If you see one it looks madified. Most people believed it made more power than a J block, it was definately quicker than the J block.

Then I guess I had a good weekend. I picked up a long '73 150 remembering something like this.

[Bill Gohr]

Well I don't remember if the block was marked in any way, but what I do know is if it was an early production 73' 1500 long, it had the 2 fuel pumps mounted on the block and the exhaust cover was smooth, not ribbed, it was a square port.

[Bill Gohr]

The best way to tell is just look in the cylinder with a bendo light. The exhaust ports are squared. The middle one is the easiest to see, it looks like when they cut the ports, they went in with a smaller tool and did the corners.

[Bruster]

Thanks for the info.

[TomAprilsSwitzers]

Believe me even Ralph will ask Tony how to do certain things nowadays when it comes to Mercs Tony is the man...and i am an OMC guy saying this.

[Bill Gohr]

Nope Ralph is still the I6 man, the only problem is the "man" is getting old and so is his memory.................LOL

[yamonster]

Switzer, Hows the lil Alli doing now?, give us some progress.