1974 351 ford questions(in a century ski fury)

I recently acquired a 1974 Century Ski Fury with a merc 255 hp(stated on a sticker) I have read the posts about the windsor/cleveland I believe its a Cleveland but I have not confirmed the numbers.
The carb was wasted ,I sprayed pb in all the cylinders got it to move and am tearing it down . 1 Can I replace the carb with a new one from summit racing ? If so any suggestions ? 2:Can I do anything simple to juice up the motor while I have it apart ? 3oes anyone know what cam might be in it ?
I have a friend who recently went thru hell and back working on a four winns ford 351 trying to diagnose water in the oil only to finally find that he had a hole in the( ?riser?) part of the exaust manifold ,so I will be pressure testing the manifolds ect any other suggestions? thanks ..harley .

harley's boats said:

2: Can I do anything simple to juice up the motor while I have it apart ?

Click to expand...

This is most likely the Windsor version.
The 5.8L Windsor incorporates a wedge style combustion chamber..... very similar to the SBC cylinder head.
(see image below)

This combustion chamber lends itself to a quench surface or squish area. You can take advantage of this by being proactive with regard to quench dimension.
This isn't necessarily a HP modification, as much as it is for Marine Engine Load Detonation control.
Ignition lead can become greater, allowing our LPCP to occur a few degrees earlier....... more in line as to where it should be.
With a good quench dimension, typically the static C/R can also be increased some and without concern for detonation.


Piston deck height + compressed head gasket thickness = your quench dimension.
For this bore and stroke, you're probably looking at/near .038" to .042" quench for Marine use.
(see this thread starting at post #7 re; the SBC....... much will cross over to your 5.8L Ford engine)


Piston A is the silly "full dished" piston that GM uses in their Marine builds.
This piston lowers C/R for use with the 64cc chamber heads, but can't possibly create a "quench"!

Piston B is one profile that Ford uses as a dished piston in some 5.8L's.
This piston is lacking a quench surface.

Piston C is what a correctly built SBC Marine would use. (the piston industry may offer something very similar for the 5.8L Ford)
This piston offers a well designed quench surface, and the dish volume controls our desired static C/R.
(the piston shown is for the SBC Vortec cylinder heads)

Lastly.... find a good machine shop who won't give you that "Deer-in-the-head-lights-look", when you mention "Quench Effect" to them.
If they do, find another machine shop!
This is nothing new......... people have been doing this style build for years and years. The Small Block Chevy boys.... the Chrysler Wedge Head boys, and several more.
Street use or Marine..... and of particular importance for a good Marine build.

harley's boats said:

I recently acquired a 1974 Century Ski Fury with a merc 255 hp(stated on a sticker) I have read the posts about the windsor/cleveland I believe its a Cleveland but I have not confirmed the numbers.
The carb was wasted ,I sprayed pb in all the cylinders got it to move and am tearing it down . 1 Can I replace the carb with a new one from summit racing ? If so any suggestions ? 2:Can I do anything simple to juice up the motor while I have it apart ? 3oes anyone know what cam might be in it ?
I have a friend who recently went thru hell and back working on a four winns ford 351 trying to diagnose water in the oil only to finally find that he had a hole in the( ?riser?) part of the exaust manifold ,so I will be pressure testing the manifolds ect any other suggestions? thanks ..harley .

Click to expand...

Ayuh,... The Clevelands have Never been used in boats,... You've got a Windor, or a cob job,...

Summit sells Marine carbs, which 1 is yer choice, but make Sure it's a Marine rated carb,...

A friend suggested putting a high lift cam to make it sound better be a little more mean do same rules apply with cams in marine? I have a feeling she is going to sound mean all ready with the headers anybody have any suggestions? ....thanks for the great info.. I am new to all of the engine building and not too proud to ask for help ..my wallet can't handle me learning the hard way. Am I wasting my time and fuel hopping it up? I would imagine the prop eventually cavitates with too much horse? Do I even need to worry about this? A
Harley ..74 century ski fury ,

Harley, my first and foremost suggestion would be to completely steer clear of the Automotive guys for your Marine Engine build.
They may be great at automotive, but unless they possess true Marine Engine experience, I'd steer clear.
Not so much for the actual machine work and assembly work........ but more so for the build specs.

Find a machine shop who understands and appreciates the Quench Effect..... not one who gives you the "Deer in the headlights" stare.
If the term "hop it up" is important to you....., the best thing that you can do, would be to take measures against the dreaded Marine Engine load "detonation" potential.
This is where the Quench come into play for the Marine Engine build.
The detonation potential is completely different to that which the Auto engine undergoes.
Apples/Oranges!
Once your known build specs have been decided upon, a good piston supplier can set you up with the correct piston profile.

High lift camshafts, unless equipped with roller tip rockers, may prematurely wear valve stem and valve guides.

Also, camshaft duration and lobe separation angle are very important for wet exhaust systems.
Duration will also have an effect on dynamic C/R.

Talk with a camshaft expert.... perhaps call Comp Cams, or any one of the major camshaft companies.
With your proposed build specs, they will know exactly which profile camshaft to recommend.

As for my wallet can't handle me learning the hard way..... good call.
Do it once, and do it correctly!


.

harley's boats said:

A friend suggested putting a high lift cam to make it sound better be a little more mean do same rules apply with cams in marine? I have a feeling she is going to sound mean all ready with the headers anybody have any suggestions? ....thanks for the great info.. I am new to all of the engine building and not too proud to ask for help ..my wallet can't handle me learning the hard way. Am I wasting my time and fuel hopping it up? I would imagine the prop eventually cavitates with too much horse? Do I even need to worry about this? A
Harley ..74 century ski fury ,

Click to expand...

Nope, the rules are Very different in boat motors,....

Think RV cam, Truck cam, Boat cam,...

Torque, down low, redline at 4800 rpms,.. Power from Idle, to 4800,....

Any taller, 'n it'll never get outa the hole,...
'n like Rick says, reversion will kill a motor,...