Building/ freshening up my 175 big bore crossflow

[keefallan]

OK guys. I am right in the beginning stages of my build. There have been numerous postings by me already about various aspects of this engine. Originally, I was just going to run it, because the guy I got it from said it was in good shape......as was good compression when he checked it a year ago. The motor is all original with good compression. My lowest cylinder I think was 105? My highest was 112....and these were with the stock bathtub heads. I was just going to put on my set of high compression heads I got off EBAY, jet it up a size , if needed, and let 'er eat. But I wanted to look in the inspection covers to see how things looked from the side.......4 of the 6 looked great. I couldn't get cylinders 4 and 6 's inspection covers off because of the starter's mounting boss. But as soon as I opened a cover up, I remembered the factory fangs hanging down in the intake ports. ANd I cant leave that alone There's also casting flash all through the intake tract that needs to be removed. I also obtained a set of 2+2 reeds from Chris Carson. So this was my original intent.......clean up the intake run, mild port clean-up, new reeds and go enjoy.

I finally was able to tear the motor down today. I was a little disappointed to see that piston number 4 has contacted the bore. Its a pretty good scar in two spots.....yet no ring scoring in the sleeve or on the rings themselves. So, I need to obtain a new piston.

I am going to try and post some pics. I do not any pics of the scored piston...yet. I have pics, so far, of the cages started, the cowling being repaired so I can cut louvers in it, the old dirty motor itself, my heads, and a little more.

Pics to come........I hope

[keefallan]

I have pics of the before and during.....no afters yet. Pic #3 was the image of the busted corner. I removed all the badging front and back. The inside has 2oz surfboard glass on the inside to back all those little holes. I used bondo glass for the front filling. The busted corner was backed with 3 layers of 6oz cloth to support the corner. Before the resin hardened, I jammed some resin and pieces of cut glass to build it up.....so I didn't have to use a lot of bondo or bondo glass. It worked. I sanded it today and there are only 3 small divots to fill and then skim with a fairing compound. I still need to get the stickers off anyways. They come off with a heat gun pretty easily.

More on this later...........

OH yeah, the gasket is the biggest pain-in-the-butt to clean up. It's black when it should be white. I soaked it in smoking hot bleach water....didn't do much. The only thing I have found that works is a scrub pad with acetone!! Its horrible

[keefallan]

This is to show what I started with and what the end product will be. I blended all the edges and left no sharp corners or edges where the air leaves the cage.

Sorry the cages are backwards............the before is on the right.............my reed petals look like the left cage. Now to do 5 more. I had a learning curve as far as time goes. I learned at the very end how to cut them and not take forever. It should only take me about a 1/2 hour each cage from here on out. I still have to lap them thought. I am just going to take it down to 320.

I think they will flow a lot more than the stock reeds. I wanted to go this route because I saw on the loopers how much larger the reed cages are for them. I said,"i want too." So, this is me making the cages larger.

[mrichartz]

Going to use emblems or decals on cowl? Or nothing
List of mods you plan in doing?

[Merc 2.5]

Well 1st thing I notice in all that was u least need buy 1 piston? So u plan on reusing everything but rings and 1 piston? Measure ,measure and measure again. Bores that is , I'd go 15 over and new slugs for a good reliable motor , can b done but measure measure again! Haven't had gud luck just tryin to rering , best of luck. But again mrchartz has couple strong rudes , maybe the "SLOMC" has thicker more forgiving cyl. Sorry I couldn't resist.. plz 4give me hahahahah

[keefallan]

Going to use emblems or decals on cowl? Or nothing
List of mods you plan in doing?

I am not sure about emblems or decals yet. I did go to a website..........outboard decals.com.........I think, And I may get a set of the 175 gt stickers. Undecided. I will paint the motor white. I forgot to mention that only thing usable off this motor was the powerhead and trim pump and lower. Tge mid was not salvageable because I couldn't get it undone............salt and galvanic reaction between stainless and aluminum. It cost me the adapter, mid, and steering head. But I have a 20" motor sitting on a stand with a 200 powerhead that is in perfect condition, but needs helicoils put in on some heads bolts............nothing worse than torqueing them down to twenty and it keeps on spinning..........doh!!

My List of mods are this:

1)reeds cages cut/blended for new petals

2)intake tract completely removed/blended of all the flashing. I was looking today where the scalloping normally takes place, I will blend that lower ridge down to a smooth transition......it will make more space for incoming air as well as remove turbulence

3) I will remove all the fangs in the ports both intake and exhaust...........both sides have them. I will also blend the intake ports instead of straight walls........it can only help...I know it can't hurt. I may open up the center port in both the intake and exhaust side.........center only....not all three.

4) open up the adapter..........it has some nasty straight line blocks...............need to remove the corners and blend it into smooth tapers

5) open up the filler blocks for cylinder # 3 and 4. The upper and lower cylinders have this huge amount of space. But the mid cylinders look like they are the red headed step child.........kinda an after thought......very narrow and short. I actually would like some advise on what to do about this.

6) the intake manifold........I am really thinking about removing 1/8-1/4 material between the 2 barrels. I would mirror the top cut (where the choke machining is) at the bottom and cut that all the way from top to bottom.....knife edge the center divider that remained. The intake manifold has a lot of casting that needs to be removed/smoothed too. I just need advising about the cutting/milling. will that hurt performance or help.....lose bottom end only to make it peaky? dunno..............I don't want that. SO, I will hold off and continue moving on other stuff first.

7)repairing of the cowl and cutting louvers for looks and make sure it has enough air to support the engines needs.

8) I have velocity stacks coming.............always wanted a set..............finally got 'em. If it don't help performance, at least it will look good...instead of the old plate design.

9) powder coating chrome of various pieces to make it look nice............water jacket covers, t-stat covers, stacks, etc.

10) re-jetting so as to not blow my engine up..............LOL!!

[keefallan]

Well 1st thing I notice in all that was u least need buy 1 piston? So u plan on reusing everything but rings and 1 piston? Measure ,measure and measure again. Bores that is , I'd go 15 over and new slugs for a good reliable motor , can b done but measure measure again! Haven't had gud luck just tryin to rering , best of luck. But again mrchartz has couple strong rudes , maybe the "SLOMC" has thicker more forgiving cyl. Sorry I couldn't resist.. plz 4give me hahahahah

I do plan on measuring since I have things apart. But no, I am reusing the rings in in the good pistons......don't need to change them. Where I install a new piston, I will install new rings and hone cylinder too. But I will measure top and bottom of bore to see taper....etc. and bore if necessary and then bore everything I guess. But seriously, theres no scarring in the sleeve.........the ring never made contact, or at least I cant see evidence of it. But I just cracked it open today. No measuring done yet.

I did forget to mention that this engine has spent most of its life sitting on a trailer. If had more use than that, there is no way I would have been able to open this motor up because of salt and time. I am amzed I got the exhaust open.........scared to try and take it off.......come to find out, I only broke one bolt at the bottom.

[mrichartz]

I might have Evinrude emblems to donate if you want
Might need to piece one it's a clean crack and can't see when put together.. clean and paint.
What year 200 crossflow I assume..Time-serts work better.
What's the motor going on?

[keefallan]

I might have Evinrude emblems to donate if you want
Might need to piece one it's a clean crack and can't see when put together.. clean and paint.
What year 200 crossflow I assume..Time-serts work better.
What's the motor going on?

I'll take the emblems..........might give me more ideas for paint design etc. Unsure of the year of the 200. I got it as a reman 150gt powerhead about 7 years ago. They didn't know what they gave me. I only found out because I decided to find out why their p-head kept leaking oil down the mid when I took it out of the water.......used bearings, forged and cast pistons, both styles of bearings for the rods.....a 2700dollar hodge podge of rebuilt mess............oh yeah.........broken sealing ring on the crank...........the oil leak. It was then I saw the ports were as big as a 235's ports..........especially the exhaust, where a 150 has puny ports on the exhaust side. So, I got a 200 block out of the mess. But I have to fix the head bolt threads.....2 I think. As a matter of fact, the ports on my visitor page is that engine.

[keefallan]

pics. I only removed the fang in the middle. I compared these to a bad 150gt block I have........these are huge. Is been sitting for 3-4 years now, run for 2 minutes since I put it back together........and only 10 hours run time b4 that.

[mrichartz]

I'll take the emblems..........might give me more ideas for paint design etc. Unsure of the year of the 200. I got it as a reman 150gt powerhead about 7 years ago. They didn't know what they gave me. I only found out because I decided to find out why their p-head kept leaking oil down the mid when I took it out of the water.......used bearings, forged and cast pistons, both styles of bearings for the rods.....a 2700dollar hodge podge of rebuilt mess............oh yeah.........broken sealing ring on the crank...........the oil leak. It was then I saw the ports were as big as a 235's ports..........especially the exhaust, where a 150 has puny ports on the exhaust side. So, I got a 200 block out of the mess. But I have to fix the head bolt threads.....2 I think. As a matter of fact, the ports on my visitor page is that engine.

Ah damn could have gotten them in the other box too but it went out already

[BOATMANBLUES]

back in the 80s I got a CCC evinrude... I used the block as a template to build a bunch of other motors to CCC type specs...blend,scallop,port ,boost ports etc,etc,....they ran good...the CCC had 6 two barrel carbs, so I figured i needed more air for the clones, so I tried cross drilling the intake...this pretty much sucked ...the motors became almost untunable at anything less than WOT...would only idle so high rpm that I would just lock the shifter and crank it up in gear so I wouldn't break anything when it shifted...then went to L&S big bore carbs..mill the 2 bbls out to 1.5" ..they worked pretty well...so, in my opinion ...don't mess with the intake...it will make your motor a bitch for very minimal rpm gain up top..

[powerabout]

anyone tried to put mid bore looper carbs on a custom intake?
They are slightly bigger then 1 3/8 but I would guess with port and stb separate you end up with a better shot at the reeds

[keefallan]

Boatman, that's the kind of info I was looking for..........so I will stick to just cleaning and blending the holes themselves.......there's enough work in there. I know that will help by itself. Every single runner has that sharp edge on the way to the reeds and the barrel opening is not consistently smooth.....power to be had

[keefallan]

I didn't get much work done on the motor today. I spent some time using my t handles and mic to check the bores in the cylinders. I am not done yet. I have a bore gauge........but my battery was dead. So, I will get a new battery and check again. But it all looks promising. If it checks out, I am going to install new pistons across the board. I found a good deal on some WSM's and will put new slugs in.

I ordered a new hone. I got the Lisle 15000 and a set 280 stones and a set of 500 stones. I finally got a rigid hone....

I did however finish cutting out the reed cages........not complete.........but at least the cut-off wheel work is done. Now I just have to file everything flat(didn't cut it right on the money because of fear of making a whoops!), and then blending the new edges down. The cutting took me about 1.5 hours.........I used the cheap flimsy dremel wheels instead of the fiber ones.......just wanted to use them up.
Then lastly, lap them on my plate and install new reeds. That'll be one part done off my checklist.

I looked again at the intake manifold(on the inside). Man. there is a lot of room for improvement......nuff said.

Pics tomorrow I hope.

Fergot.......motor is completely disassembled now.........all the way down to the water deflectors. I plan on soda blasting the block to get it to bare aluminum. I am gonna need about 20lbs soda( its heading my way). but its worth it. The block comes out beautiful and clean............with no damage to anything. I highly recommend it. You can blast aluminum all day long......it don't hurt it. It gets those ring lands spotless too. The cheapest place I've found for soda............Harbor Freight.........its Arm and Hammer too....not some no name product.

Keith