Lee's Monaco utility build

Designs for inboard or outboard power

Moderator: BruceDow

User avatar
kens
Posts: 5273
Joined: Wed Nov 12, 2003 5:25 pm
Location: Coastal Georgia

Re: Lee's Monaco utility build

Post by kens »

Bill Edmundson wrote:
Mon Apr 12, 2021 9:10 pm
Lee

I think you have that backwards. If the helm is on the right/starboard it's clockwise. If it's on the left/port then CCW. Most gears can be set up either way. Some you just make a small change in the shifter. Some have small plate that you reverse.

Bill
Bill, the down angle trannys get reverse rotation at the shifter, they only use automotive rotation engines. (CCW)
The inline 71/72 series Velvet's, they change rotation by counter-rotation engine, and, change the little pump housing
Oak..........the juice ain't worth the squeeze :D :shock: :o :)

User avatar
Roberta
Posts: 7201
Joined: Tue Jul 31, 2007 5:23 pm
Location: East Troy, Wisconsin

Re: Lee's Monaco utility build

Post by Roberta »

The velvet drive liberty A is down angle and can be run CW or CCW at full speed. Other velvet drive transmissions can be only be run at full speed in the direction of the motor rotation. The liberty A may not lower your motor as the transmission does protrude lower than a 71c making the motor set up higher in the rear. Depending on the motor, things like coolant heat exchangers or flame arrestor may still protrude into decking structure. This was the reason for the hood scoop on the Torpedo. I have a liberty A and crusader 5.7 engine in the Torpedo. I run 1:1 ratio, 1" shaft and 13x13 four blade OJ prop. About 50+ mph WOT. My engine is standard rotation (ccw), helm is starboard, prop is turning CW. I run the transmission in full speed reverse.

The advantage to the down angle transmission is to place the engine in more level attitude. Raising the back of the motor to level it more and allow necessary clearance for the bottom of the transmission did raise the heat exchanger up enough to interfere with the deck structure. The Torpedo decking slopes more downward than most other boats, so this interference may not be an issue in other boats. The Torpedo was designed for a normal engine installation with a 7lc transmission.

Ken is correct that down angle transmissions are reversible by just changing the shift direction. Many helm motor controls can be reversed to accommodate this keeping the direction of throttle travel correct.

Just something to watch for.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

User avatar
kens
Posts: 5273
Joined: Wed Nov 12, 2003 5:25 pm
Location: Coastal Georgia

Re: Lee's Monaco utility build

Post by kens »

I just had to look it up.
Inboard motor installations book by Witt & Hankinson. page 119 and I quote:

........."the so-called torque reaction sometimes (but not always) caused by the propeller"...........
.........""boats, especially those with deeper vees in the bottom".........
.........."helmsman can amount to a considerable percentage of the weight of the loaded boat, especially on smaller boats".....

So my take on Lee's L/H prop with R/H helm is this,
that only applies sometimes but not always
only on boats with deeper vees. Vee bottoms are Ok just not the deeper ones
only on really really small boats with a really really big helmsman

The Monaco I don't think is a deep vee, it is not real small, and Lee is not real fat.

edit: if the port/starboard helm actually was a big deal, then everybody that picks up 1 passenger would run with a list.
with 1 passenger, the boat becomes neutral and the torque would then show it's list,,,but no, that don't happen
Oak..........the juice ain't worth the squeeze :D :shock: :o :)

Hercdrvr
Posts: 1525
Joined: Mon May 11, 2015 12:52 pm
Location: McKinney TX

Re: Lee's Monaco utility build

Post by Hercdrvr »

Another option that worked for me recently, build your own SBC or SBF engine from a marine long block. Total cost to build a raw water engine from scratch would be about $5,000 with all the marine accessories. I went with a 285 hp built by ATK marine and sold thru Summit Racing for $2,400, it’s turning a 1:23-1 transmission for a Barrelback. Haven’t gotten it wet yet so standby for performance numbers but I built it to have a great hole shot and run out about 45 mph. More speed than that in these wood runabouts is unusable. It takes gobs of hp and trim tabs hanging off the transom to hold her steady for another 5 mph.
If you can build a boat you can build long block carbureted engine.
View from my angle,
Matt Biehunko
Attachments
D690C2F3-DC34-46DF-9581-A15C6469AE12.jpeg

User avatar
Roberta
Posts: 7201
Joined: Tue Jul 31, 2007 5:23 pm
Location: East Troy, Wisconsin

Re: Lee's Monaco utility build

Post by Roberta »

Here is a link to the engine install on the Torpedo showing the lower output shaft on a Liberty A transmission necessitating the higher engine install and items that interfered with the deck framing. I left about 1" of clearance between the bottom of the transmission and the keel.

https://www.glen-l.com/phpBB2/viewtopic ... start=1020

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

denbrlr
Posts: 735
Joined: Sat Sep 18, 2010 10:06 am
Location: Peoria, IL

Re: Lee's Monaco utility build

Post by denbrlr »

Thank you everyone for the additional comments.

Bill, what I meant to say (and was not very clear :) ) was that the motor installations book said with a starboard helm, it is recommended to use a CW prop rotation. This is to counteract the torque from the prop but like kens said, this might not really matter with a Monaco.

kens, your comments make me feel more comfortable about the prop rotation in relation to the helm location.

Matt, thank you for your thoughts but I guess I am not daring enough to build my own engine :shock:

Roberta, thank you for your comments about your setup and the height related issues. I am building a utility and will have a motor box. I would really like to to keep the motor as low as possible. I was wondering if tipping the motor (with an inline trans) would require it to be raised a little due to the oil pan. I know that was not exactly what you dealt with but it is similar.

After all of this discussion I think I have decided to switch to a 1 1/8 prop shaft so if I end up going with a non-1:1 trans, I will feel more comfortable with a little more robust shaft. Now I need to figure out which motor and trans to go with. Thank you all again. It is good to get more expert opinions than my "barely know enough to be dangerous" opinion :lol:

Lee
YouTube channel: Boat Builder Lee
Monaco build YouTube playlist: https://www.youtube.com/channel/UCP4Edb ... /playlists

User avatar
Roberta
Posts: 7201
Joined: Tue Jul 31, 2007 5:23 pm
Location: East Troy, Wisconsin

Re: Lee's Monaco utility build

Post by Roberta »

Tipping the motor with an inline setup will actually raise the oil pan as the transmission output flange still needs to be somewhat above the keel in order to provide clearance for the prop shaft flange, shaft packing, and the angle of the shaft as it exits the shaft log. The motor bellhousing is typically about the same level as the oil pan.

You can find examples of typical installations in the Glen L Inboard Motor Installations book or Crusader and Mercruiser. Also, Glen L typically shows basic engine installations for each design on plan sheets. Heights and other pertinent datum planes can also be found to assist is planning your installation.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

User avatar
Roberta
Posts: 7201
Joined: Tue Jul 31, 2007 5:23 pm
Location: East Troy, Wisconsin

Re: Lee's Monaco utility build

Post by Roberta »

This is a link to numerous drawings for Mecruiser installations with various transmissions. Click on a link to see how motors are oriented and various dimensions.

https://www.mercurymarine.com/en/us/doc ... -drawings/

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

User avatar
Roberta
Posts: 7201
Joined: Tue Jul 31, 2007 5:23 pm
Location: East Troy, Wisconsin

Re: Lee's Monaco utility build

Post by Roberta »

Here is a link to Crusader engine installation drawings.

https://www.crusaderengines.com/wp-cont ... 510023.pdf

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

User avatar
kens
Posts: 5273
Joined: Wed Nov 12, 2003 5:25 pm
Location: Coastal Georgia

Re: Lee's Monaco utility build

Post by kens »

question,
what are both you talking about 'tipping' the motor? what tipping?
whats is this? "shaft packing, and the angle of the shaft as it exits the shaft log"

there is no tipping, you align the engine to mate with the shaft, the shaft is fixed in place no alignment nor adjustment of the shaft
you make the engine come to the shaft as it is installed

if you go to 1 1/8" shaft you might run into more available props at 15" diameter vs 13 or 14"(do you have tip clearance for that)?
perhaps no 13" at all. just something to follow up on is tip clearance

kinda funny that the lowest install on the mercruiser list was the one called Scorpion and it had the 71C, the lowest in stall height.
Oak..........the juice ain't worth the squeeze :D :shock: :o :)

User avatar
Roberta
Posts: 7201
Joined: Tue Jul 31, 2007 5:23 pm
Location: East Troy, Wisconsin

Re: Lee's Monaco utility build

Post by Roberta »

Just talking about the angle the motor is tipped to meet the angle and alignment of the prop shaft. Sorry if we confused you.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

denbrlr
Posts: 735
Joined: Sat Sep 18, 2010 10:06 am
Location: Peoria, IL

Re: Lee's Monaco utility build

Post by denbrlr »

So now I have a question about the strut. I want to use one for a 1 1/8 inch shaft, 16 degree, and 7.5 inch drop. I found a supplier that has one with only a 7 inch drop. What strut drop have you all used for the Monaco, Riviera, Torpedo, etc.? Will a 7 inch cause problems because the prop will be a little closer to the hull?

Roberta, thank you for the info. I would like to look at it now but I am still at work (from home) :). Any thoughts on a Crusader engine supplier?

Please let me know. Thank you.

Lee
YouTube channel: Boat Builder Lee
Monaco build YouTube playlist: https://www.youtube.com/channel/UCP4Edb ... /playlists

User avatar
Roberta
Posts: 7201
Joined: Tue Jul 31, 2007 5:23 pm
Location: East Troy, Wisconsin

Re: Lee's Monaco utility build

Post by Roberta »

I used Marysville Marine in Sun Prairie, WI. Talk to Brian. He can set you up with either new or rebuilt equipment. They were very accommodating. I rented a trailer from Home Depot to pick it up.

I would stick with the recommended running gear in the plans. If you go with 1:1 ratio transmissions, stay with 1" shaft. If you use gear reduction, go with the 1-1/8" because you will need to swing a bigger prop. If you haven't purchased anything yet stick, with 1:1 ratio.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

User avatar
kens
Posts: 5273
Joined: Wed Nov 12, 2003 5:25 pm
Location: Coastal Georgia

Re: Lee's Monaco utility build

Post by kens »

Lee, if you already been looking at the michiganmotorz webpage, have you noticed this:?

5.7L inboard ski boat engine
MPSKI57, it is available in reverse rotation for $1100

ZF 45c tranny 752100
this is the ZF answer to the BorgWarner VelvetDrive 71c.
$1700.

notice that the ZF 45c tranny lets you get reverse rotation engine for the same money as the down angle
thus, you can keep your 1" shaft, keep your current strut, keep everything you got thus far.
you get your R/H prop, R/H helm, all that and a bag o' chips.

So, the ZF 45c is less expensive by the same amount as the premium to pay for the down-angle. (+reverse rotation)
Oak..........the juice ain't worth the squeeze :D :shock: :o :)

denbrlr
Posts: 735
Joined: Sat Sep 18, 2010 10:06 am
Location: Peoria, IL

Re: Lee's Monaco utility build

Post by denbrlr »

Roberta, thank you for the comments. I will definitely check out Marysville Marine. You also reminded me that the inboard hardware details are in the plans :oops: and what do you know, they call for a 1" shaft and a strut with a 7.5 inch drop. The only thing the plans don't address is the trans ratio. You mention that I would need to swing a larger prop if I go with gear reduction. Would that be true if the reduction is about 1.2:1? Would that mean a 13 inch prop? Please let me know. Thank you.

kens, thank you for the ideas. No, I didn't notice that engine and I figured out why. I am wanting an MPI engine and that one is carbureted. Bummer...

Lee
YouTube channel: Boat Builder Lee
Monaco build YouTube playlist: https://www.youtube.com/channel/UCP4Edb ... /playlists

Post Reply

Return to “Power Boats”