1969 Chris Craft Roamer 46 Refit: Muffler Platforms

I’d hoped to get the V-berth head (AKA the Throne Room) done by the end of April, but now it looks like it won’t be done by the end of May. My Boatamalan* painter is very busy at work, and he hasn’t even been able to spray ICA on the final wall panels over the last week. But there are plenty of other things going on, and even more on the honey-do list of things I need to do before we can splash (hopefully, later this year). So I installed the new platforms for the water lift mufflers that are painted and awaiting installation. The side exhaust outlets are already installed. Once the mufflers are in, I can begin making the exhaust risers.

* Boatamalan: Noun. Joking portmanteau referring to the Central American origin of the fairing and paint crew (boat + Guatamalan). In fact, the Boatamalans are from Honduras, but Boatduras doesn’t roll off the tongue like Boatamalan does.

Under-side of the muffler platform

For the muffler platforms, I welded some 3/16″ 5052 plate leftovers from the aft deck enclosure and side decks to some angle that was leftover from the galley floor supports. Once the platforms are installed there will be no access to the bottom side, so I rolled and brushed on a couple coats of Devoe 235 epoxy primer.

Upright angles will hook onto existing engine room floor frames

Ready to light up

The uprights “capture” the original ER floor frames

Since these platforms will be subjected to quite a bit of vibration, I didn’t want to rely strictly on my welds to hold them in place. So I cut a slot in the uprights so the original engine room floor frames slide into the upright. These things aren’t going anywhere.

Dirty aluminum puts a bit of carbon in the weld

Chris Craft used Bitumastic, a tar-like substance, as the insulation on their metal hulls. It’s not bad stuff, but removing it is a real pain. The aluminum looked clean and I wiped it with acetone before welding, but there must have been some residue remaining (maybe embedded in the aluminum).

Port muffler platform is welded in

Not bad for a vertical weld done up-side down

These vertical welds were hard. I was looking straight down at the joint and had the torch angled slightly upward, to keep the weld area covered in argon. I pulled the torch toward me as I added filler. It doesn’t look like a stack o’ dimes, but the penetration is good and the weld is clean.

Starboard muffler platform is clamped and ready to weld

First tack looks good

Better looking vertical weld

It’s more like a pile o’ dimes than a stack, but the penetration is good. I’m sure it will be fine.

Coated with Devoe 235 epoxy

Done!

Next up in our 1969 Chris Craft Roamer 46 Refit: Rub Rails

1969 Chris Craft Roamer 46 Refit: Reinforcing the Exhaust Parts

I’m juggling many different things on the Roamer refit right now, but all of them are essential must-do items if I’m going to splash later this year. Getting the Cummins 6CTA Diamonds attached to the exhaust system, fuel lines, and raw water are three of those things. Some exhaust parts arrived a while back, so it’s time to reinforce the fiberglass tubes where the clamps squeeze the hose. Without reinforcement, the clamps can cause the fiberglass to crack.

400 hours on the turbos, which both look good inside

New exhaust anti-crush sleeves and clamps

First, use a grinder to rough up the exterior of the clamp sleeves

Next, a die grinder roughs up the inside of the exhaust tubes

High temp epoxy bonds the sleeve to the elbow

One down, one to go

Muffler will need crush sleeves, too

In the pic above, the muffler is sitting on a tray I made using scrap aluminum sheet from the aft deck enclosure and 6063 aluminum angle. Because I’m using Centek waterlift mufflers, I wanted to position the muffler as low as possible so the spill-over point from the muffler to the exhaust outlet is lower than the spill-over point of the dry portion of the exhaust riser. That will make the exhaust system inherently safe by making it virtually impossible for sea water to back up into the dry part of the exhaust. I’ll be welding that muffler tray in soon.

The stick shows the direction the exhaust hose will have to take to meet the riser

While the epoxy cures for the crush sleeves in the exhaust elbows and outlets, I’m wrapping up fitting the muffler trays. But there’s other stuff going on, too.

Next up in our 1969 Chris Craft Roamer 46 Refit: Relocating the Fuel Tank Fills

1969 Chris Craft Roamer 46 Refit: Turbocators!

In order to splash the boat in 2016, I need to make the exterior waterproof and get the engines operational. After making an expensive mistake(/valuable lesson) on a set of exhaust risers, I decided to make a custom set myself. I ordered all of the stainless tubing and the exhaust flanges, which have already arrived, but I’m still waiting for my new TIG welding machine to get here. I could have gotten a TIG gun, a pedal, and just used my Miller Trailblazer 280, but the Onan two-cylinder air-cooled engine in that beast is noisy. It’s fine for working in the yard, where there’s not enough power to weld thick aluminum. But I’ll be welding these risers on a bench in my garage, so a welding machine powered by a 220v wall outlet will be nice and quiet. I figure any excuse to buy a new welder is a good one. 🙂

While I’m waiting for the new machine to show up, I also ordered Isspro Turbocator gauges from Seaboard Marine. The Turbocator gauges indicate boost and exhaust temp, both of which are very useful in determining if a turbo-diesel boat is propped right. There isn’t room in the Roamer instrument panel to add more gauges, but I’ve got an idea that might be kind of cool.

Isspro Turbocator with 3″ stainless bezel

Shortly after the Turbocators were delivered, I learned about Westach boost and EGT combo gauges that also come in the 3″ bezel size.

I think the Westach gauges look more era-appropriate

That Westach gauge is more attractive than the Isspro ones I bought, I think, but there’s no going back now. The 3″ diameter is crucial for the plan I’m kicking around.

Original Chris Craft gauges on my Roamer, rechromed, installed, and coated with wax

A 3″ bezel gauge will fit inside the chromed bezels used on Chris Craft gauges.

Ratty gauges bought on ebay might look good with Turbocators installed

Or maybe bigger-diameter tachometer bezels would be the way to go

I’m leaning toward retrofitting the Turbocators to the smaller Chris Craft gauge bezels and housings. Then I’ll use foam to model a housing for both that would fit between and take styling cues from the two original tachometer pods on the boat. I’d fiberglass the exterior of the foam model and paint the Turbocator pod to match the tachometers.

Something kinda like this, but twinned together

Well, that’s the plan. I’ve got all the parts now, I just need to get busy with the foam and fiberglass. But since this isn’t exactly mission critical, I’m going to keep pondering how to pull it off while I keep working on other things.

Next up on our 1969 Chris Craft Roamer Refit: Cleaning Up Cummins Parts

1969 Chris Craft Roamer 46 Refit: New Exhaust Risers

The original Cummins exhaust risers that came with my Cummins 6CTAs take a 90° turn after exiting the turbo, but there is no way to safely point the exhaust toward toward my waterlift mufflers. The turbo would end up being on the low side of the system, and that’s bad news for wet marine exhaust–you don’t want water flowing back into the turbo and engine. So two years ago, I checked with several marine exhaust manufacturers about having custom exhaust risers made, with the dry section going as high in the engine room as possible before turning down with the showerhead pointing toward the waterlift mufflers. The estimates that came back were quite high–they averaged $5300 for both sides. So I held off on ordering a set until they were absolutely necessary. Well…we’ve reached that point now.

Oh, and those original, low hour Cummins risers are listed on my  For Sale page.

While I was waiting, I found some brand new DeAngelo hard shell marine exhausts on ebay. They were advertized as being made for Cummins 8.3 engines, which is what I’ve got, and the price was right. So for the last two years I’ve toyed around with the idea of buying those and modifying them to fit my application. Over the holidays, a friendly commenter mentioned the ones on ebay, so I pulled the trigger and bought them. The thing is, while I’d been aware of them for two years and thought about how I’d modify them, I never really investigated the parts themselves. Turns out that was an expensive lesson in why it’s important not to make rash decisions just because somebody double-dog dares you.

The box took a bit of a beating

Hard shell insulation coating is cracked and the turbo flange is bent

While it was unfortunate that one of the risers arrived damaged, I wasn’t really concerned about the hard shell being damaged since I would have to cut it off to modify the riser anyway. The flange was a bigger concern. I contacted the ebay seller and let him know about the damage on the one riser.

But the biggest problem of all was that on both risers the showerhead and raw water inlets were too big. The original Cummins risers for these engines have a 6″ diameter outlet, and the raw water inlet is 1-1/2″. These risers had an 8″ outlet and a 2″ water inlet. Without thinking it through very much, I figured I could just use a reducer between the showerhead and the muffler. So while the return was being processed on the damaged riser, I got to work dismantling the good one.

Good looking riser, but it’s too big

Like removing a cast after a broken bone has mended

Hard shell insulation removed

Intuitively, I like the fact that these risers quickly increase in diameter after leaving the turbo. It steps from 3-1/2″ at the flange to 4″, then immediately up to 4-1/2″ where it enters the insulated zone and then up to 5″. After the 5″ 45° turn, it goes up to 6″ the rest of the way. It makes a very complicated part, but that big pipe must be good for lowering back pressure. Since my port riser will be longer and have more bends than the starboard, I was thinking that maybe the fat pipe will compensate for the additional back pressure.

Cut-off wheel sliced through a welded joint where the 6″ pipe begins

Inside the pipe looks good

The whole time I was dismantling the riser, I was focused on the task and not really thinking about next steps. After I had it cut up, I started looking into the parts it would take to make this riser work. It turns out there are reducers, but they’re somewhat expensive. Then I remembered I’d have to buy two stainless anti-crush rings that go inside the fiberglass reducers. Then I’d still have to buy the materials to modify the riser and pay somebody to weld them up. I’ve had bad luck with fabricators in this area, so there’s that, too. I was looking at no less than $600 more to make each riser which, when added to the purchase price, is getting close to the cost of just having a set of risers custom made.

It was around this time that I really started kicking myself for buying these risers. The ebay ad was misleading, but I should have contacted the seller to verify the dimensions. When I realized they were too big, I should have just sent them both back. But then, with my new-found understanding of how these risers are made, I started thinking about just buying all of the materials and making a set myself…

Next up in our 1969 Chris Craft Roamer 46 Refit: New Riser Materials

1969 Chris Craft Roamer 46 Refit: Exhaust V

When last I was messing with the exhaust system, I had made the fiberglass outlets that exit the hull near the aft bulkhead in the engine room. Since those will fill up two big holes near the waterline, I need to get them installed and the exhaust systems assembled so we can splash later this year.

The exhaust outlets went off to the paint shop to have the blue stripe applied

Slathered with Sikaflex 291 LOT

Bolted in place

Cleaned up and looking good

After installing the outlet on other side, that’s two more holes on the exterior that are filled. But to finish up the exhaust system I need to replace the original Cummins exhaust elbows with something better. The original elbows are listed on the For Sale page for Refit Parts, Tools, Supplies & Leftovers, along with a bunch of other stuff. Two years ago, I checked with several marine exhaust manufacturers about having custom dry exhausts made, with the wet showerhead pointing toward my waterlift mufflers. The estimates that came back were quite high–they averaged $5300 for both sides. So I held off on ordering a set until they were absolutely necessary. Well…we’ve reached that point now.

Next up in our 1969 Chris Craft Roamer 46 Refit: New Exhaust Risers