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the Deck height of the sst60 is lower than the standard 56 c u in fishing motor, but by how much is this decked too ?
if raising the ports of a standard block to sst60 specs it would be way off unless this was taken into account .
the top of the exhaust port height would be higher up the bore in a standard block.

for example if the sst60 is decked by 1 mm then measuring 1.450" from the top of a fishing motor and using these specs
it would put this point exactly 1mm higher up than the sst60 !!!

I have only put 1mm as a extreme example, but whatever the difference is, then that's what needs to be taken into consideration if porting a fishing motor surely. ?

I cant find what the actual difference in deck height is, I know they do this as the sst60 piston at tdc are above the deck
and on a standard motor they are not.

so does anyone know the height difference ?

Ok I will ask the same thing differently.
what is the EXACT height of just the short block if laying on a table to top of cylinder where the head gasket would sit.
This needs to be the lost foam later blocks, not the older 56 sand casted block. (dont know if they would be different )

the sst60 in standard form is between 6.363 inches and 6.387 inches. ( according to apba rules)

well after measuring the total deck height from base to top the measurement is 6.300 inches !!!
that makes it the same as sst60 , BUT the pistons on the oval port DO NOT protrude above the deck !!

Both My standard oval port56.1 cu in blocks are both the same measurement as in deck height of 6.300 inches
( will be measuring this again to make 100% sure with different gauge)....

ive took a pic of the internals of the ports, they realy do need a clean up big time.
the exhaust port measured from the top of deck is exactly 1.500 inches and could be taken to 1.450 by grinding the sleeves.
to my surprise the oval port sleeves are already chamfered on the top and bottom of the port in the middle as in picture below.
this would need to be put back if port is raised to stop any snagging of the rings. ( I think ).
I did hear of someone putting in a chamfer on his oval port engine so I dont know if they are all like this.



the transfer ports and boost ports are real bad inside, the glue lines are very thick and deep causing a lot of un-wanted turbulence of fuel/air flow. with these cleaned up performance must be a tiny bit better.
here is a pic of the foam glue lines inside the ports ,




now if the ports are raised and the chamfers put back in and angled upwards and inlets cleaned up and head shaved to
sst60 spec what sort of power gain over the existing standard amount of hp could this roughly achieve ?
( I know its not going to be exact but a rough estimate would be good).
I dont want to be touching anything if some real big gains are not going to be seen.
I would want atleast in the region of a 10hp gain for it to be worth stripping everything down and rebuilding an otherwise
perfectly normal engine.
ALSO more to the point, would this cause any detriment to the life expectancy of the engine /
it would never be pushed above 6700 rpm.

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