Repowering a 41 Attack with BBC Motors
 

A friend is looking at a 41 Cig Attack with no motors. Had Cat diesels in it. Number 3 drives and borg trans. He has a couple of blown 468 BBC motors sitting in his garage looking for a new home.
Has anyone done this? Are there any serious concerns with it?
My concern is will the lack of weight in the rear create handling issues? Unbalance the boat basically?
Also what gears are in the #3's??
What ratio trans came in these?

I'm thinking a diesel motor that has a mak rpm about 3k vs a gas motor with a rpm range over 6k. Where did they make up the difference in prop rpm?

Thanks

Do you have any pics of the CIGARETTE ATTACK ???

I do but they're on my phone.

3's come in several ratios from 1.3 up to 1.6x if I remember correctly. How wide is the boat? Weight?

9'9" I believe is the beam. Dry weight I was told was 13,500. Diesels weighed a total of 4klbs that were pulled from it.

What the hell is a cigarette attack?

Cig's 41' express cruiser made back in 1980 to 82'ish. Maybe a dozen were produced, equipped with Cat diesels. One of these boats, actually the one off the 1980 Miami Boat show floor has been on Grand it's whole life, less a few years in Mexico. I would have bought the one one Grand a few years ago if I could have been able to house the whale at my dock.

Very cool old boats!

There's one in my local harbor. There's pics of it somewhere on here.

They look basically as if cary and magnum had a baby.

They're a big azz beast of an 80's resign bucket. I'd say they weight 13-15 with out power all day long. I don't think a set of bbc's would get one onto plane!!

What colors the one you're looking at and where's it located??


Almost positive this is the one from my local harbor.

http://www.boats4sale.pro/detail/us/...at-Diesel-Cali

They had 1:1 SSMIII's, Velvet Drive 72C's, 1:1, -In order to keep prop shaft speeds up. Cool old very heavy beasts

Interesting - I googled them. Not a bad looking boat.....

So the drives are 1:1 and the trans is 1:1? So are the props huge then?
I not a math guy, but I was figuring a BBC spinning 6k rpm through a 1.5 drive is spinning a prop 4500 rpm. Depending on HP, torque, and weight will determine the pitch of the prop. Lets just say it's spinning a 23p prop to achieve 60mph. These Cigs typically max out at 55-60 from what I've read. So with a disel running max rpm through a 1:1 drive and trans they are spinning their prop at only 2500-3000 rpm. Am I figuring this right??

Thisisstank - that black and red one is the boat we're looking at.

The weight of the diesels is half of a BBC. So we're cutting about 2000 lbs out of the ass end of this thing. Is this gonna work or bad idea??

Not going to work with 1:1 drives. Will need 1.6's to get a 468 to push that boat.

I'm almost positive the owner of that boat is a member on OSO.

I don't think pulling the weight out of the stern will really affect the CG that much because they're just so damn heavy!!

You in the Ventura /so cal area? I'm 5 miles from where that boat is sitting. Just saw it's still in Ventura.

Not because of gear ratio.

Going from a 1.5 to a 1.0 (no other changes) would require a much smaller pitch prop.

This is why many very fast I/O's change from 1.5 to 1.36" . They need more pitch but can't get it or fit it, so they drop the gear ratio so they can run a more available (able to fit) smaller pitch.

Reducing the ratio gives you more prop speed. Pitch x prop shaft rpm (per engine rpm) = how far you go per shaft revolution.

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Use cars for example. 3:08's vs 4:11's. Say 1:1 trans final ratio for easy understanding.

If you drive at 6000 engine rpm with the 3:08's. And then same rpm with the 4:11's, which is going to have a much higher mph ? The 3:08's will cause a much higher mph. The higher mph of course has faster wheel speed.

SB thanks for clearing that up for me. I actually had it backwards in my head.

Did they have 3208s originally?

https://marine.cat.com/cda/files/101...Propulsion.pdf

Supercharged 468s would get the job done with 1.5s.

250s on 468s would work well and not cost a fortune to build.

Well that was a bust. Drove 7 hours with a trailer and a fist full of dough to find the boat was not really as expected. So we made the best of Long Beach and came home with an empty trailer.

Sorry to hear that. Boats now in long beach eh?

What was the issues with it?

The front deck has deep stress cracks in every 90°angle the entire length. There were signs in the cabin that there had been standing water in for awhile. Bulk head between anchor locker and vbirth was rotting, wet mud was in there too. Every interior panel in the cabin was starting to come unglued from all the moisture. It had potential, but not what we were looking for. Basically rub rail up would need crack repair and paint. All new interior below. Props were wasted. All the wires in the engine compartment were cut to remove engines. To be honest the space layout for a 41' boat with almost a 10' beam left some to be desired. Oh and a huge crack in fiberglass wall separating the cabin to the head. Toilet was busted and not hooked up. I could keep going. Is advertised as drop your motors in and go. I suppose you could.

Yeeeeeeea. Looks like that dash hardware is worth more than he whole boat!! Too bad.

Understand on the layout of the 41's. But, in 1980, an express cruiser was still a new concept. :)

If you are still hunting an Attack. You might consider calling Shangi La Marina in Afton, Oklahoma and ask if 'Come on America' is still for sale.

The dash was seriously the nicest part of the boat. Previous owner dumped $10k on it.