Mercury 2.4 litre mod-vp cowl conversion

[greatwhite85]

So I had a crazy idea and I'm going for It. I'm attempting to turn a 1995 mercury 175 black max Cowl into an 86-93 2.4 litre mod-vp cowl. At first I thought that all I had to do was make a bottom pan, A few body mods and boom, Showtime!!! I purchased a Cowl on eBay for a good price and after observing it much closer and comparing it to pictures from Google images, i'm starting to think the black max Cowl is a little fatter. But I really want to be sure before I chop it.
So if anyone out there who has a 2.4 L mod VP can take a few measurements for me I'd really appreciate it. I just need the width front and back from the top corners.

[greatwhite85]

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[greatwhite85]

Okay, so this thread is really boring right now but I will post updates and pictures as it moves along. The black max Cowl looks eerily similar to the Bridgeport cowl b340162ut a little wider. I will figure out the exact width before I cut and narrow it . So far I've managed to rig a plate to engine for the bottom pan, where there were three vent holes on the top now have five. In the middle of it there are two raise portions that I need to grind down and flatten out. After that I can cut the front vent wing in. I'm trying to make this as close to the real thing as possible but It will have a few subtle differences. Hoping to have this wrapped up by June, but my time is limited it may take longer.

[greatwhite85]

Next i had to flatten the raised portion in the middle. I used an angle grinder to take it down then block sanded it to make it all flat. I will have to skim coat with glazing putty and block sand it again to fill in the few low spots.340223340224340225340226340227

[greatwhite85]

... And then I had to build up the 2 inch section towards the front where the vent wing will be cut out. Just used standard fiberglass with polyester resin and blended in with and blended in with light weight filler.

[STV_Keith]

Do you still need measurements? I can take some tonight when I get home. Which ones?

Seems like a lot of work to keep from buying a $300 cowl/pan.

[greatwhite85]

Yes thank you Keith. I just need the top two measurements on the front and back corners similar to the ones shown on my first post. If I had it my way I would have bought one by now but they are hard to find and I don't always have $300 ready to go. I have had this idea rolling in my head for a few years now and at this point I am determined to finish just to see if I can do it. These are the kind of projects I love to do. Those two measurements would be gold to me that way I can at least get the dimensions right so it doesn't look out of proportion. The rest the measurements I have been able to scale with a photo.

[STV_Keith]

I'll get those for you tonight.

[STV_Keith]

Here they are. Same order as your pics...

[greatwhite85]

Keith, I can't thank you enough. That is perfect:thumbsup:.So the black max cowl i'm working with is about 16 inches at the rear and about 11 1/2 at the front. And from what I can see your Bridgeport cowl is 14 3/4 of an inch at the rear and 10 inches on the front. So I'm looking at 1 1/4" to 1 1/2" difference. In my head I was thinking it was closer to just 1 inch but I'm not too far off. I'll probably just split the difference and cut 1 3/8". Project moving forward...

[greatwhite85]

...ok so i've cut the vent wings out. Was planning on leaving the front attached and then bending it in but that piece had too much of a curve to it, so I ended up just cutting the whole thing out in anyway. 340835So filling in the entire two and section toward the rear was a waste of time. I could have just filled the upper and lower corners just a little.
So after cutting them out I made pieces for the inside section by molding it from the inside of the cowl ( still curved but not so dramatic will look more precise).340836340837l340839 for the outside edge and center piece i'll just use balsa wood.

[greatwhite85]

Shaping the vent wings have been a tedious process. Trying to get all the lines to roll smoothly. This part is the signature detail so it must look right. I finally got one side done and now I get to do it all over again on the other side. 341553341554341555

[David - WI]

I don't know how many different versions of that cowl there were, but mine doesn't look quite like that... what you're calling the "wings" I guess, are divided down the middle.

[greatwhite85]

Yes, I will add that later. It makes it easier to shape the outer walls with that removed. I guess the names i use for the details are a little misleading, i call it a "vent wing" even though they aren't functioning vents but they sort of resemble a wing.

[STV_Keith]

Technically, I think it was modeled after a NACA duct, but there is no hole, so it's just for aesthetics.

[greatwhite85]

Another detail i forgot to mention, at the top rear I need to cut out a false vent and fill in smooth...

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For this I just covered the back with masking tape, layed down a sheet of fiberglass and leveled it with filler.

[rgsauger]

Great thread! Keep 'em coming!!

[greatwhite85]

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Cut out false vent and smooth out. Check. When I get around to narrowing it 1 3/8" I will cut out the center divider and toss it. It is too tall, about 1/4 of an inch tall on this blackmax cowl and i'm pretty sure it is closer to 1/8 of an inch on the bridgeport cowl.
So I set my dial calipers to .6875 ( the decimal of half of 1 3/8) and dragged it along the existing center divider scratching strait line all around the cowl. This line represents where the edges of the new center divider will be after narrowing it.
As of now I'm assuming the center divider is the same width on both cowls which is 2 1/4 inch wide. Can anyone confirm this for me??

[David - WI]

Yes, 2.20 to 2.25 depending on where I measure it.

[greatwhite85]

Yes, 2.20 to 2.25 depending on where I measure it.
Awesome, thank you David.

[PARKER RABE]

what a cool thread! love the pics of the progress! great job!

[greatwhite85]

This is so cool. At first I thought it was just me having a conversation with myself and I, but now I feel the love. Thanks everyone!!!�� I have been busy block sanding all week, all 44 faces. These Mercs have more cuts than a diamond. 342542342543342548

[greatwhite85]

I don't know why some pictures turn out right and others are grouped together in a box marked attached thumbnail.

So I used a 1/8"x1/2" aluminum flat stock and epoxied it's along the lines that were scratched in. The aluminum is now the outside edge of the new center divider.
342554342555And now the pics are coming out sideways,WTF!!!
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Why aluminum?
Because after it's narrow road I will fill the space in between With a sheet of fiberglass to bridge the gap and then blocks and it perfectly flat until it's even with the outside edge of the aluminum rails. That should give it a laser straight edge and make it easier to keep the height perfectly even all around.

[greatwhite85]

I finally get to split this thing in half...

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cutting out the "old" center divider I left four small tabs and then cut exactly 1 3/8" out in the middle. That way when gluing back together all I had to do was set it on as flat a surface as I could find, then line up the tabs, check measurements, adjust, check measurements, adjust... Until it was just right, then epoxy the tabs.

[greatwhite85]

... And then bridge the gap with fiberglass
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[David - WI]

I gotta say, you're ability to plan out your moves makes me jealous; but for this much effort you should be making a mold to produce dozens of these to sell! :cheers:

[greatwhite85]

I gotta say, you're ability to plan out your moves makes me jealous; but for this much effort you should be making a mold to produce dozens of these to sell! :cheers:

Hmm!!!🤔 That's not a bad idea. I would have to sharpen my mold making skills first, i have molded small stuff in the past with amateur results. If this cowl turns out good i just might give it a shot.

[greatwhite85]

OK time to rant. I am definitely a "newb" at posting on a thread. But every time I login with my username to scream and fly and then type out all the updates and add pictures and then post. It tells me that I need to refresh the page and login again. Usually I can scroll back to find everything I typed out and then post it. But sometimes I lose everything I wrote out and have to start all over again. This has happened a few times since I started this. Could this be something I can fix in my settings or do I just have to deal with it? Oh well I will work around it and try again tomorrow

[greatwhite85]

Now that the top Cowl is mostly rough sanded into shape, i've decided to take a break from body shaping and start fabricating the pan . I already had a 1/8 inch aluminum plate rigged to the engine. I made it a two-piece so I can install and remove it without removing the powered head. 343186

I used a 3/4 inch plywood that will be screwed and Epoxied to the aluminum plate then added a 1/4 inch lip around the outside that will allow the top cowl to line up centered to fit snug.
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After I screw and Epoxy The aluminum plate to the plywood I am going to use a "bar top" epoxy to seal the entire pan. That stuff is super thick and self levels nicely so I shouldn't have to block Sand much before priming.
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[rock]

When I first started following this thread I kinda thought you were nuts. I would have just bought one. Your process has been pretty well thought out and your final product is looking like the target. Still think you might be a little nuts but I admire your perseverance. Looking forward to seeing the final product painted with decals. Good job.

Rock

[STV_Keith]

Are you planning to support the top of the cowl with the bracket/pin/spring pin that is used on the hi-perf cowls? If not, remember that your pan is supporting the full weight of the cowl and it's oscillations due to boat movement. Stiffer is better. The stock pan is stainless sandwiched between the powerhead and adapter.

[transomstand]

When I first started following this thread I kinda thought you were nuts. I would have just bought one. Your process has been pretty well thought out and your final product is looking like the target. Still think you might be a little nuts but I admire your perseverance. Looking forward to seeing the final product painted with decals. Good job.

Rock:iagree:


He IS nuts, but that thing is coming out really nice.

[transomstand]

OK time to rant. I am definitely a "newb" at posting on a thread. But every time I login with my username to scream and fly and then type out all the updates and add pictures and then post. It tells me that I need to refresh the page and login again. Usually I can scroll back to find everything I typed out and then post it. But sometimes I lose everything I wrote out and have to start all over again. This has happened a few times since I started this. Could this be something I can fix in my settings or do I just have to deal with it? Oh well I will work around it and try again tomorrow

It's not you. The site is undergoing some upgrades so it's a little goofy, and some functions are temporarily disabled like "auto save"

[greatwhite85]

Are you planning to support the top of the cowl with the bracket/pin/spring pin that is used on the hi-perf cowls? If not, remember that your pan is supporting the full weight of the cowl and it's oscillations due to boat movement. Stiffer is better. The stock pan is stainless sandwiched between the powerhead and adapter.

I wasn't planning on it, but now that you mention it I will think about it. I certainly wouldn't want this thing to start "tweaking"on me. Perhaps maybe some "pads" underneath for it to rest on. I'm not opposed to the spring and pin method. I always apply a little over-kill cause it helps me sleep at night.

[David - WI]

The other thing I've wondering is... how much does this thing weigh? I can weigh mine if I can get it down without emptying the building first.

[greatwhite85]

The other thing I've wondering is... how much does this thing weigh? I can weigh mine if I can get it down without emptying the building first.
I weighed it before I started working on it and it was at 16 lbs. but that's not counting the pan which I won't know until it's finished. I would have to guess around 20pounds when it's finished.

[greatwhite85]

When I first started following this thread I kinda thought you were nuts. I would have just bought one. Your process has been pretty well thought out and your final product is looking like the target. Still think you might be a little nuts but I admire your perseverance. Looking forward to seeing the final product painted with decals. Good job.

Rock
lol. I'm definitely nuts no doubt about it. The worst part about it is that I am strapping this on a whopping 150. Yeah, thats right a 2.0 liter stock ass 150 that is bolted to a 1972 16 foot challenger ski boat. So I had to break one of my own rules to have a 100 mile-per-hour looking boat that currently can't break 60 mph. I will be exposed the first time I get smoked by a Jetski. That's OK I've made my peace with that. I feel the work I will put into achieving that look will mean i've earned it and by next season I plan on buying a 200 powerhead to justify the look. Until then ill be "that guy"

[STV_Keith]

I weighed it before I started working on it and it was at 16 lbs. but that's not counting the pan which I won't know until it's finished. I would have to guess around 20pounds when it's finished.

To my point about the pan supporting the cowl...I haven't weighed mine, but I'd bet the lift off cowl is only about 6-7#.

[greatwhite85]

To my point about the pan supporting the cowl...I haven't weighed mine, but I'd bet the lift off cowl is only about 6-7#.
Wow, That is certainly as light weight as it gets. I will definitely add more support. I knew it wasn't going to be as light weight as the real thing. But it will still be lighter than the cowl that I am replacing it with. The clamshell Cowl weighs 25 pounds when you include the aluminum bracket that bolts to the back for the hinges.
Just one question I read somewhere that these Bridgeport Cowls are made of plastic. Is that true ?

[transomstand]

Just one question I read somewhere that these Bridgeport Cowls are made of plastic. Is that true ?

Yes..

[greatwhite85]

Sooner or later i will have to make a front cover, So I am again in need of measurements. I was going to guesstimate based on the dimensions of the decals I have for It, but if someone could send me the measurements i'd really appreciate it. Here's a sketch of which ones I need which are pretty much the whole thing.343257 ... And of course the picture came out sideways again.

[David - WI]

Mine weighs 15# including the pan/tray... 8.5# for the upper alone.

Approximate dimensions:

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[David - WI]

Also, those five openings at the top are more like "louvers" punched in, opening to the front, than holes.

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The thing really looks more to me like it was heat/vacuum formed from two sheets than injection-molded; but I really don't know. The openings in the louvers look they were hacked out with die grinder or small axe. LOL

[greatwhite85]

Mine weighs 15# including the pan/tray... 8.5# for the upper alone.

Approximate dimensions:

343263
Thank you David. Perfect, you even included measurements I didn't even think about like thickness and distance off the Cowl. I'm thinking I will make it out of plywood and "bar-top" Epoxy coat it before primer and paint. Perhaps I could hollow the inside with a router To lighten it up a bit.

[greatwhite85]

Also, those five openings at the top are more like "louvers" punched in, opening to the front, than holes.

343264343265

The thing really looks more to me like it was heat/vacuum formed from two sheets than injection-molded; but I really don't know. The openings in the louvers look they were hacked out with die grinder or small axe. LOL
Yes this part will be one of the most noticeable of the subtle differences. I will add a piece that will be glued to the inside that will act as louvers similar to what's on the real thing. After adding the two vent holes I noticed they are slightly larger on this black Max. On the Bridgeport cowl The five louvers stretch across to about halfway between the very top line and on mine it goes about 1/2" or so beyond that. This is a difference that I can live with, it doesn't look that bad to me and Little extra airflow shouldn't hurt.

[greatwhite85]

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[PARKER RABE]

looks killer great job!

[greatwhite85]

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...and the first mock up.343518

[greatwhite85]

Not much happening lately, just fine tuning everything again. I finish sanding all the original paint off, and block sanded all the facets with 150. Still have a few spots to touch up. I made a front cover (�� David) with plywood and mounted it with four screws
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I will seal the wood with a coat of "bar-top" epoxy before primer and paint.
All that's left to do for bodywork is to make the centerpiece for the false NACA ducts, or as I have been calling it "the vent wings. I will cut it out of 1/4 inch poplar and probably cut it with Epoxy or filler before I have my buddy "JB" "weld" it in, and because I like overkill I'll throw in a few screws from the inside. Once I blend the corners in it will be ready for the first coat of epoxy primer.

[greatwhite85]

Was supposed to be a :cheers: Symbol for you David.

[greatwhite85]

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I set a 1/4" ss bolt on the top rear of the engine ( in the bolthole that used to hold the bracket for the old cowl, dabbed a little epoxy on the headof it then set the new cowl in place. After which i braced the bolt with an aluminum bracket and epoxid the crap out of that. Now I have a rigid firm "pin" that lines up perfectly at the top. There is about a quarter inch gap between the base of the "pin" setup. A few rubber washers Will allow the Cowl to slightly rest on it taking a load off the bottom pan. I think that should be enough support for this. I don't know, maybe I'll set the front side the same way to

[greatwhite85]

Made The center pieces for the "vent wings" with 1/4 inch poplar and shaped it before I epoxied it into place. Although Epoxy itself is probably more than strong enough I went ahead and drilled holes along both sides to allow the epoxy to seep into ( I know, it's ridiculous) and of course I'll throw in a few small screws underneath it to further overkill on top of my overkill just in case some fool tries to use it as a handle and snaps it off I want to know it's not because I didn't bond it good enough.

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[David - WI]

I went ahead and drilled holes along both sides to allow the epoxy to seep into ( I know, it's ridiculous) and of course I'll throw in a few small screws underneath it to further overkill on top of my overkill

They have medicine for that now. :D:D:D

[greatwhite85]

So I guess I lied... About the 5 intake vent holes on the top. At first I didn't mind (that they were bigger) but the more I looked at it the more it bugged the sh!t out of me. :cool: The way it looked stretched across too far ( was more like 1" than 1/2") seemed to throw off the dimensions and I know i'm the only one who would think that. Maybe I really am crazy! But it wasn't very hard to fill a couple of holes in. It took about 10 minutes of work with 20 minutes of wait time. So now I have four vents holes instead of five and I'm glad I did it. In looks much better to me, and the engine was still breathe just fine. I've seen earlier models of these Cowls with 3,4 and 5 vents.
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Epoxy primer is next!!!

[greatwhite85]

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[David - WI]

Very cool... I was kind of doubting it would be possible (that you would end up with just a pile of jigsaw pieces) when you started - but it looks awesome. :D

[rock]

So now that you have one under your belt I would like to send you maybe 15 or 20 old clamshell cowls to convert. You OK with that?

Rock

BTW It looks really good.

[PARKER RABE]

god damm looks killer, u might want to start a little side business ,im speechless ! GREAT JOB BUDDY!

[rock]

Been wondering what it weighs. Have you had a chance to check it?

Rock

[greatwhite85]

[QUOTE=rock;2860306]Been wondering what it weighs. Have you had a chance to check it?

Rock[/QUOTE

Top cowl-15 lbs
pan-7 lbs
front cover-1.6 lbs
so altogether it is just shy of 24 pounds. Certainly not a lightweight version, I just can't compete with molded plastic. But it's almost 1 1/2 pounds lighter than the old cowl I'm replacing it with and if my calculations are correct that equates to 100 h.p. :icon_bs:

[greatwhite85]

So there won't be much left to post until the paint is down. It's going to be a bit of a long grueling process of sand, prime, sand, prime, sand, PAINT, then sand again and buff that b!tch out!!! I want this thing to have a perfect finish since I have taken it this far I might as well go for "gold", Plus This obsession I have with a "mirror quality finish". This is the part that stresses me out the most. Like most amateurs I have a problem with knowing when to stop. Something that has so many faces to cover I most likely going to have a problem burning through an edge when color sanding. I managed to pull off A decent job on the last project i painted but that was white. This will be jet black and we all know how black paint will highlight every flaw, but when it's done right nothing looks better.

[greatwhite85]

Well i wanted to show the complete finished product with decals on but I ran out of paint and had to order more. So far i've shot the pan, front cover, hardware and one side of the cowl. Here is where i'm at right now.
345381345382345383345384345385345386 Almost there!!!

[David - WI]

That's a mean-ass looking cowl... I love it!

[greatwhite85]

Another teaser!
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[greatwhite85]

...and the results are in!!!
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[greatwhite85]

So am I happy with the finished product? **** Yeah, I think I nailed it!!! I certainly tried my ass off to get a flawless result, but there are a few flaws in the paint, they are very minor and hard to find though. It's nothing I can't fix later. Usually I never give myself a deadline but I really wanted this finished before my trip to the river. This is no doubt the best result I have every achieved. So again thanks to Stv_Keith and David-Wi for all the measurements, I would have been way off without those. I'll post more pictures when I get this boat in the water and in the sunlight.

[motexas]

Awesome Work, that is a piece of art work.

MO

[STV_Keith]

Man, that came out great! Congrats. It is my favorite Merc cowl still, and what I have on my STV.

[greatwhite85]

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[PARKER RABE]

amazing job! why didnt you wrap the decals around the back?

[David - WI]

Outstanding! Dude, I'm exhausted just from cheering for you. :cool:

[greatwhite85]

I kept going back-and-forth on whether or not to keep them all original or make a few slight changes, i wanted to put my own touch to it. Personally I like the way it looks on the back with the 2.4 decal by itself. I also cut out the fine white stripes around the decals. Originally I planned on not using the 2.4 decal because it would be a false advertisement ( underneath is a 2.0) but it just looks so damn good with it on.

[greatwhite85]

Thank you David, you got me thinking:cool: about making a mold. I have this strange feeling that eventually I'm going to just go for it. There's lots of great info on the Internet. It may be a while if I do. I can practice on the original coun I can practice on the old cowl till I get it right

[David - WI]

Thank you David, you got me thinking:cool: about making a mold. I have this strange feeling that eventually I'm going to just go for it. There's lots of great info on the Internet. It may be a while if I do. I can practice on the original coun I can practice on the old cowl till I get it right

Lay up carbon fiber... or vacuum mold polycarbonate? Mine is crappy (bought it here) but you can borrow it if it's not on a boat by then. :cheers:

[greatwhite85]

Lay up carbon fiber... or vacuum mold polycarbonate? Mine is crappy (bought it here) but you can borrow it if it's not on a boat by then. :cheers:

The ultimate goal would be carbon fiber version. I Watched a couple videos on pre-preg carbon fiber and that would be awesome. But I going to start with polyester resin and fiberglass, already ordered orange tooling gel, resin, veil on fiberglast.com. Got to put myself through a test of trial and error on something that's not that important first.