1958 Evinrude 18hp piston part number cross reference

[levi_tsk]

Well I got to the tail end of a refresh on my new to me 1958 18hp fastwin and decided that since the head gasket looked original and the motor was 100% freshwater and the head bolts were free, I would swap the head gasket. Well I got an ugly surprise inside and it appears that a couple decades ago the head gasket was blown and a little water got in the cylinders and lightly pitted them.
Gonna have to overbore it but I can't seem to find any NOS pistons for the part number given in my OEM parts manual. I know that the 22 cubic inch motors shared internals for the better part of two decades but I don't know which pistons will work in my 1958.
Could someone help me with the part numbers that interchange for the .020" overbore pistons?

 

[racerone]

The 1966 pistons at 0.040" should work.------But look for a donor 18 HP block assembly.----Many low hr ones out there.------Place a free wanted ad on -----aomci-----website.------Save you a lot of beer tokens. ----Your location ?

 

[cc67]

Did it run good before you pulled the head? If so, replace the gasket and enjoy.

 

[levi_tsk]

Did it run good before you pulled the head? If so, replace the gasket and enjoy.

Compression was low (60psi on both ) pitting looks at least bad enough to need a rehone. Figured I'd go ahead and rebore it while I had it apart.

 

[levi_tsk]

The 1966 pistons at 0.040" should work.------But look for a donor 18 HP block assembly.----Many low hr ones out there.------Place a free wanted ad on -----aomci-----website.------Save you a lot of beer tokens. ----Your location ?

Jensen beach, Florida but I'm currently working in Northern Wisconsin

 

[racerone]

Cast iron is very porous.-----Corrosion goes in deeper than the eye can see.-----Easy to find a good used block and pistons.-----What does the crankshaft and bearings look like ???----Should be lots of donor motors in Wisconsin.

 

[levi_tsk]

Cast iron is very porous.-----Corrosion goes in deeper than the eye can see.-----Easy to find a good used block and pistons.-----What does the crankshaft and bearings look like ???----Should be lots of donor motors in Wisconsin.

Not sure? I just pulled the head Friday I am probably going to try to be home for labor day weekend and I was trying to locate everything before I head back.
Pretty sure that it hasn't been ran in a couple decades though the guy I got it from had it for 15 years he said and he got it from someone who hadn't ran it either.

 

[racerone]

A donor motor is what you need.-------Will save you a lot of beer tokens.----Place the wanted add and pick one up on the way home.

 

[tphoyt]

Racerone’s advice is worth’s its weight in gold. I to have heard that Wisconsin is a great place for good used outboard parts and that they plentiful.