It's How I Roll

[Big T]

'99 Burb with Blackman 20 Center Console, Volvo Diesel with DP290 drive. Grabbing munchies before a day of fishing threshers off Laguna Beach.

Released a thresher pushing 200 lbs after 1 hour on 16# tournament line. Released a thresher on Saturday for a buddy that went about 150 lbs on 16# tournament line. Just in case you wondered why I'm Big T...hresher.

It's how I roll.....

 

[gnel]

Nice boat! I have a 19 ft. Mako and would love to have an inboard diesel. No Thresher pics?

 

[chris4521]

Very nice boat indeed
any shots of the engine ? How much power does she put out. I love larger center consoles. I own an 84 Mako 224 CC myself

 

[vail426]

Very nice boat indeed
any shots of the engine ? How much power does she put out. I love larger center consoles. I own an 84 Mako 224 CC myself

Does that mean you have a 470 Mercruiser engine?

 

[chris4521]

Does that mean you have a 470 Mercruiser engine?

Nope my boat has an outboard on it
transom was re-done, closed, and a bracket put on- holding 200hp 2 stroke merc v6 wish i had twins

 

[Big T]

Nice boat! I have a 19 ft. Mako and would love to have an inboard diesel. No Thresher pics?

Pics are a luxury when you're solo fishing threshers, even with two aboard. It's all focus.

My wife has the IGFA Women's 8# (95.0 lbs) and 6# (46.0 lbs) line class records for Threshers. But for her spinal stenosis and slipped vertebrae, she'd have many more records. Lots of experience on these fine game fish. My holy grail is to get one on IGFA Spec fly gear and tippet. No one has ever done it, NEVER, EVER!

 

[Big T]

Very nice boat indeed
any shots of the engine ? How much power does she put out. I love larger center consoles. I own an 84 Mako 224 CC myself

I have shots of the engine. Will have to dig them up. It's an AQAD 31A with DP 290 drive. Puts out 130 hp. It cruises at 18 to 20 knots and gets 4 to 5 nmpg with an 80 gallon tank. When people ask what's the range?, I tell them it's more than your body can tolerate.

PIC of the starboard side of the engine, oil cooler in place and heat exchanger pulled for cleaning:

 

[chris4521]

Nice engine. is yours the duo-prop or the single outdrive? How is that boat in waves?

 

[Big T]

DP 290 = Duo Prop 290 dirve. The boat is heavy and plows through stuff. Then again, it's not a rocket ship.

 

[chris4521]

yeah but you gain that in mileage! thats insane. my boat will drink about 200L in a day if you really want to, top speed 45Mph or so. I bet that volvo will last a lifetime. Watercooled turbine ...MMMmmmm you ever think of doing any power upgrades to it?

 

[Big T]

The AQAD31A is a 146 cu inch (2.4 litre) displacement 4 cylinder with non wastegated turbo charger and air to raw water aftercooler. Compression is 17:1 and sustained boost at cruise speed (3300 to 3400 rpm, or 90% of Wide Open Throttle of 3800 to 3900 rpm) is 25 psi. Coolant temp at cruise is 190 to 195 with T-stats fully open at 194. I do not have a pyrometer on it. Wish I did but would have to tap into the exhaust manifold and I don't want to go there due to the pricey Volvo parts.

This same engine was pushed to 170 hp in the KAD32 series, which came with both a supercharger and a turbo, plus the aftercooler. The supercharger is engaged up to 2500 rpm where a switch passes it off to the turbo. The turbo really kicks on at 2600 rpm on mine. Not sure if they had to improve the cooling on the KAD32, but they did have to go with coated pistons to deal with the increased heat. Early KAD series without the piston coating crapped out about 2000 hours. Would love to bump the power on mine, but don't know how to do it safely. These were purpose built engines and there are no aftermarket parts or easy mods. The Volvo parts are very spendy. Very few people I know tweak their marine engines to get more power. Just not like the road engine marker with all the driveway wrenches working on them. Recreational marine engines are run hard for sustained period pushing heavy loads through or over drag creating water. If you tweak the engine and the heat gets out of whack, the engine will grenade. It's not like you can simply pull over and get a tow. Also, the marine engine market is much smaller so the parts are very expensive. I imagine it's the same with airplane engines: no one tweaks them for power beyond their original design.

Mercruiser has a 1.4 litre diesel I/O package based on a 4 cylinder Isuzu engine that puts out 120 hp. I know of two of these that have grenaded in less than 500 hours. One was installed as a repower in a 24' Skipjack and it was arguably too small of an engine and the owner pushed it waay too hard. The other was in a new boat package for a 21' Angler and I think poor maintenance came into play to expedite it's demise.

I bought mine used in '96 with 700 hours on it and now have 2400 hours on it. That said like any saltwater boat, I've done my share of work on it to keep it running right, including new injectors (twice), new water pumps (twice), new turbo (once), new exhaust elbow (twice), etc, etc, etc. That's just part of owning a saltwater boat. This engine taught me diesel work, then I bought my trucks to really keep me busy. Thank god for the Honda commute car .