Building/ freshening up my 175 big bore crossflow

**powerabout** · 05-12-2019, 07:25 PM

CCC factory said 265hp I think, racers go them higher? I remember factory team saying at 295 the sleeves move so the head gaskets blow hence you know your close.
CC 110 or something, the later 31M was like 120+

**keefallan** · 05-12-2019, 07:46 PM

Pretty cool. What about the years available?

**powerabout** · 05-13-2019, 04:54 AM

Originally Posted by keefallan

Pretty cool. What about the years available?

70's
the F3 31m was sold in 80's mainly to Europe and OZ, was a custom engine

**keefallan** · 05-13-2019, 06:52 AM

Based on the color scheme..............my guess was gonna be around 79-82 because I don't remember any motors like that when I started getting into evinrudes as a kid. My grandfather and father both had them. My grandfather had a 79 200 and my dad bought an 84 rude for his boat when the Chrysler that was on it burned up.

**keefallan** · 05-13-2019, 02:13 PM

I took 2 pics of the flanges where I blended the 2 case halves.

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In both pictures, the flange line that runs from 11 to 4 is where the mess was. In the lower left of the pics you can see the bottom of the cylinder taper....and intake ports in the left image. So the front half is on the the back half with the image shooting inward like the airflow. So, on the flange area, there was a lip of at least 1/8" sometimes as much as a heavy 3/16". All intake runners were typical of these two runners.

**keefallan** · 05-13-2019, 02:29 PM

I got some work done on the cover at work today. THe body work was done already, but I cut in for the louvers. So, what you see from 1st to last is beginning of the cover to where it stands now. I have the smaller louvers as well, but it didn't look right with these, so I don't think I will be putting them on. However, I would put on a small single louver on the front to feed air directly to the carbs. I would epoxy screen to the inside of the cover to keep the air clean.

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The louvers are just sitting in there. I will paint them individually. Everything gets white epoxy primer....then primer and base/clear.

**FMP** · 05-13-2019, 02:45 PM

The transfers, the outside ports. The outside port edge has a bit of distance from the perimeter wall which makes up the tranfer area from the case. Could a bit of epoxy and shaping help the corners and sides?
How's the transfer bypass cover with gasket for fit on the roof of that whole transfer bypass area?

**keefallan** · 05-13-2019, 03:22 PM

I am unsure of what the inspection cover will let me do with adding epoxy in that area.

**FMP** · 05-13-2019, 03:46 PM

So other ideas, tighten down the cover area buy lowering the mounting area.
Earlier covers.
https://www.screamandfly.com/showthr...transfer+cover

**keefallan** · 05-13-2019, 04:49 PM

Originally Posted by FMP

So other ideas, tighten down the cover area buy lowering the mounting area.
Earlier covers.
https://www.screamandfly.com/showthr...transfer+cover

Very interesting read indeed. I knew about the other covers, When I looked for them 4-5 years ago, I couldn't find em. So, I gave up on it. But, I did like when one of them said that they milled the face down on the inspection flange to bring the cover closer to the port. The drill press/mill I have access to can make that happen. That's just more free hp with no tradeoffs there.

I need to put a cover on and see if I can figure just how much to mill off. I'm thinking that if I miil it down to where the cover just touches inside there(no gasket), then when I put the gasket on...........the right height.

**FMP** · 05-13-2019, 05:39 PM

Yes and maybe stuff a little epoxy in places and shape.

**Dave S** · 05-13-2019, 06:26 PM

Be careful when milling the block that you don't weaken the gasket clamp up front. JMO.

**keefallan** · 05-13-2019, 08:05 PM

Originally Posted by Dave S

Be careful when milling the block that you don't weaken the gasket clamp up front. JMO.

Can you explain more Dave?

**keefallan** · 05-14-2019, 03:14 AM

Never mind, I know what you are saying, I just pictured it. I think I will just try and locate some new(older) covers.....I see that milling will make the bridge(s) too thin for my liking. Not willing to weaken any of the structure.....that is so critical.

Anyone have a set of the older inspection covers they want to part ways with?

**keefallan** · 05-14-2019, 02:27 PM

Not much done today. But I did get the intake reassembled......throttle linkage, shift linkage etc...........cleaned up and powder coated. All the check valves were checked.......lol.......then cleaned up and re-installed. I expected to have bad one or two, but they were all good. So, that's one thing off the check list of things to do......