Merc 140 motor/470 outdrive?

[Tycer]

Hi all,
Didn’t find anything under advanced search on this.
We put a down payment today to have Aristocraft restore one of their Nineteens for us. The hull we chose is a ‘79 and has the 140hp/181cid engine and a 470 outdrive. As I write this I realize I should have Scott take pictures of the plates on both before asking this. I’ll add those #s asap.

Anything wrong with with this combo? Any suggestions on props? They have plenty of factory Merc aluminum props to be able to make a choice. Day cruise fuel economy is prolly most important.

Kind regards,
Tycer

 

[Scott Danforth]

Welcome aboard

On the 470......Its the platypus of motors. Ford 460 iron head and pistons, GM flywheel and damper, Mercury outboard parts.....some peyote and acid for lunch, then after lunch design an aluminum block with floating bores

Spend a few hours googling 470 repairs and problems

 

[Tycer]

Correct. Which is why the boat we chose has the 140. Both Bill and Scott said the 470 would be a poor choice for our needs. I think one of them called the 470 the spawn of the devil. Or it was someone on this forum.

 

[Bondo]

Anything wrong with with this combo?

Ayuh,...... Welcome Aboard,...... The 470 drive won't work well with the 140 hp motor,..... Wrong gear ratio,....

The 140 hp should have a 1.98:1,......

The 470 is 1:84:1,.....

 

[TunaFish389]

The 470 will run about the same as an alpha one with a 1p lower pitch. IE alpha one 17p to 470 16p. It will work but need to dial prop to 4200 to 4600 wot rpms.

 

[achris]

The only differences between any of the drives in a particular series (MC1/R/MR/Alpha One/Alpha One-Gen II) are the ratio and the little sticker on the back of the drive which designates the ENGINE that drive was originally install behind.

Even if the sticker said 260, the drive (apart from the gears in the top housing) is exactly the same as a '120'.....

The fact that is says '470' on the drive and it's behind a 140 engine is neither here nor there. The ratio will be 7.6% lower, so you need to reduce the propeller pitch accordingly. As long as the engine reaches maximum recommended revs at WOT (wide open throttle) with a 'normal' load (4200-4600rpm), then you are 'good to go'...

My preference is to prop right to the top. Even a hundred revs over isn't going to be a problem unless you plan on spending all day at WOT. My own boat is propped to the rev limiter (4950) and the wear on the engine and drive is significantly reduced because of it. The boat 'drives' better and is easier to hold at a particular speed. It also means I can load up on fish and still be in the engine's 'happy place'....

Chris.......

 

[Tycer]

Thank you everyone! Scott said he’ll make sure it’s a 1.98:1. He said that at least the upper has been rebuilt and it may have been done to change the gears. Can’t speak highly enough of the Turners. If y’all are ever near Dawsonville, GA go see the Aristocraft museum and shop. I think it’s pretty amazing they still have all the tools, molds and parts to restore these Nineteens.

The motor is serial #6920118.

 

[GA_Boater]

Welcome aboard, Tycer.

Sounds like the A/C folks are taking care of the drive train for you.

Are you going to visit the shop as they do the resto or get progress photos from them.? Maybe you can start up a resto thread showing before and after - In our Resto section or the Aristocraft section.

 

[Tycer]

Welcome aboard, Tycer.

Sounds like the A/C folks are taking care of the drive train for you.

Are you going to visit the shop as they do the resto or get progress photos from them.? Maybe you can start up a resto thread showing before and after - In our Resto section or the Aristocraft section.

I think my wife (her boat) wants to just see the finished product. I’ll email Scott and ask him to keep a picture record and post it. With their current workload we’re expecting 8/20 to be the pick up date.

 

[QBhoy]

Hi.
Last year a friend eventually replaced his 470 (after another 470 and also a rebuild of the original)...with a brand new 3.0 tks.
We were worried he would need to change the prop or drive ratio.
It was totally fine. The 3.0 didn’t have the same initial punch as the 470...but was only 200 rpm off the wot of the 470 and with the same drive and prop. Was totally ok.