Hunter 701 fitting an inboard.

[Elefantman]

Hi,
I've recently purchased a hunter 701 which Im already in love with. I'm thinking it would be nice to fit an inboard engine... she seems to have the prop tube so I'm guessing she must have been designed to have one as an option... but I'm new to yachts so I'm keen for any advice before I even seriously start down the route... what parts are needed, anything to look for with regards space and fitting etc?
Total newbie questions I guess but I'd rather have the Mickey taken that spend a load of money I don't need to paying for work and advice.
Cheers Jim

 

[Tranona]

Really not practical or economical. A new Yanmar 1GM will cost you over £3k plus stern gear and prop and installation (electrics, fuel tank, exhaust, controls). With labour this would come to at least £5k depending on how much structural work is required such as beds, engine box etc. If you find a used one to the right spec you might be able to do it it for £2.5-3k. Suspect if an inboard were ever actually fitted it would have been something like a Vire 7hp 2 stroke petrol. However these are no longer made and are not particularly good anyway.

Best to stick to an outboard.

 

[Ceirwan]

I seem to recall in the PBO second hand review a while back that it mentioned that an inboard was an option.

Only you can decide if its worth it or not for however much it will cost so I'll stick to answering your actual question.

AFAIK the 1gm10 is probably the most compact unit you can get today, raw water cooled so no expansion tanks and heat exchangers. They come up second hand fairly often. Best to budget for some work done as people generally don't remove good engines.

Assuming your existing stern tube is useable you will need at a minimum.
- Engine + Gearbox
- Fuel Tank and associated pipes, fillers, fittings etc
- Morse controls and cables. + Stop cable
- Prop Shaft.
- Propeller.
- P-Bracket and cutlass bearing for outboard end of prop shaft.
- Stern gland to stop water coming up the stern tube.

That's just the engine and driveline parts.
You will also need:
- Enough room to fit it (drawings available online)
- To glass in engine bearers, normally with stainless plate inside them, drilled and tapped to accept the engine mounts. Obviously these need to be aligned with your existing stern tube.
- A decent enough battery and wiring to actually start the thing.
- An engine box to cover it all up.

I've probably forgotten something, but that's the gist.

If you do the work yourself, are a competent engineer and enjoy stuff like this then its doable, probably for around 2K if you don't mind waiting for the parts to come up second hand.

Is it worth it? Only you can decide.

 

[PeteCooper]

I wouldn't usually say this ... but you may be best contacting Seajet of these forums. According to his website the 701 in particular was very much the basis of the Andersons’ format so he may be able to help.
His website is here:
http://www.anderson22class.co.uk/

 

[langstonelayabout]

Before Seajet arrives I can confirm that, a few years ago, we viewed a rather nice looking A22 that had an inboard Yanmar 1GM10 fitted. It seemed to suit the boat well although access was under the companionway steps and through a hatch in the cockpit floor.

I nearly made an offer but in the end wanted something a little bigger. The 701 being very similar I'd say that it could well be done, just don't expect to recover anything near your investment when you come to sell.

 

[Ceirwan]

I think given that the OP has yet to return to this thread probably means he's been put off by the scope of work involved.

But if still interested. There is a article on installing a 1gm on a similar size boat.
https://corribee.org/technical/engines/inboard-engine/

 

[Seajet]

An inboard on a 701 might well be a good idea, subject to Langstonelayabout's correct comment one will not get the money from the materials or work back on resale; but some people just want a good boat, strange as it may seem !

The 701, unlike the Anderson 22 which was frankly a development from it, doesn't have an outboard well so means an awful transom hung outboard, ugly ineffiecient and unseaworthy as the prop will be pitched out of the water a lot of the time.

Somewhere on these forums there is - or was - a very experienced ocean sailor who'd had a big steel cruiser, then last I heard was making a big project of a fin keel 701 with an inboard and cooling plates on the lower hull / keel, he gave every impression of knowing what he was on about.

The Hunter 701 came with a choice of fixed fin or lifting keels, the latter was much the same shape as the A22 - which had lift keels as standard, only two fixed fins were made.

The 701 's lift keel was hydraulic, while the A22 keel is lifted by a Dutton-Lainson braked trailer winch.

If I can help in any way with Anderson 22 info please fire away or PM me.

Peter Poland of Hunter boats ( a friendly rival of Andersons when they were both attending boat shows ) did a series of articles in PBO a couple of years ago, mentioning both boats.

Peter Copley, editor of ' Small Boat ' magazine in the 1970's, sometimes mentioned his racing in his own 701.

The 701 is narrower at the stern than the Anderson, and what with the transom hung outboard and more fixed keels, seems less of a cruiser to me - but maybe a touch better to windward.

A few later A22's had inboards as well, the success depended entirely on the engine choice - one, specially fitted out for the then Lord Mayor of London, had a BMW inboard - susceptible to corrosion and last I heard on her fourth unit !

I see nothing wrong with a good lightweight inboard in a 701.

Edit; a Corribee is NOT a similar sized boat, it's a fraction the useful size or performance of a 701 or Anderson 22, putting an inboard in one of those might well put the tin hat on the already slow draggy performance and tiny amount of space available...

 

[Ceirwan]

Edit; a Corribee is NOT a similar sized boat, it's a fraction the useful size or performance of a 701 or Anderson 22, putting an inboard in one of those might well put the tin hat on the already slow draggy performance and tiny amount of space available...

I linked to the article not to give you a chance to espouse the virtues of your boat over others in its class, but to show how an engine was installed by an amateur into a similarly sized vessel. And an example of someone making a decent job of it.

 

[Seajet]

And I replied because the Corribee is tiny by any standards for a 21footer, so a meaningless comparison; if we can arrange it I'd be happy to put my A22 alongside a Corribee and put the pics on here.

The Corribee design has done some good trips despite the usual Robert Tucker design traits of high wetted area and frontal resistance drag, but I'd say that is down to some rather good sailors like Ellen McArthur having had the boats forced upon them early in their careers !

It is NOT ' a similarly sized vessel ' just as a Maori war canoe or prehistoric dugout of a similar length is not particularly akin to whatever boat you have

 

[DownWest]

In a case like this, I would look around until I found a really cheap yacht that had all the bits. Boat yards have many gathering mould.
Remove all the parts one needs, tidy up the damage and offload it. You would probably manage to get what you need for £1k or less. Then fit the booty to your 701. If you do not have the skills, then you need a skilled friend.
But, do bear in mind that older little Yanmars can have expensive problems. Heads are £700 and even the gasket is £60.
Good luck.
DW

Showing how an engine can be fitted to Corribee does not have any comparison to another design, just that it can be done, because someone wanted to do it.

Edit: when I said, 'offload' the old boat, that might involve chopping her up for the skip, but selling all the other bits on the bay. Sails, mast etc could get back quite a bit.

 

[Seajet]

In a case like this, I would look around until I found a really cheap yacht that had all the bits. Boat yards have many gathering mould.
Remove all the parts one needs, tidy up the damage and offload it. You would probably manage to get what you need for £1k or less. Then fit the booty to your 701. If you do not have the skills, then you need a skilled friend.
But, do bear in mind that older little Yanmars can have expensive problems. Heads are £700 and even the gasket is £60.
Good luck.
DW

Showing how an engine can be fitted to Corribee does not have any comparison to another design, just that it can be done, because someone wanted to do it.

Edit: when I said, 'offload' the old boat, that might involve chopping her up for the skip, but selling all the other bits on the bay. Sails, mast etc could get back quite a bit.

Agreed; this is where sailing clubs and boatyards come into their own - with a bit of luck more often than not there'll be someone around with the knowledge and will to help - you don't often get that in marinas.

 

[Seajet]

duplication.

 

[Ceirwan]

Showing how an engine can be fitted to Corribee does not have any comparison to another design, just that it can be done, because someone wanted to do it.

I gave the link as an example of what was involved in fitting a new engine of likely the type that the OP would go for, into a boat that while it may be a couple of foot shorter is not a million miles apart.

Obviously the OP isn't going to be able to extract specific dimensions from it, but I felt it was a helpful page to read. Much of the process will be the same.

In the case of the 701 a P-Bracket would no doubt be used and there would be no need to build a skeg.

Who knew that posting a helpful link would prove so controversial.

 

[lw395]

I had an Impala where a 1GM had been retrofitted (not by me!), which was common at the time.
It made it possible to motor much longer distances than with the outboards of the day, which suited people who wanted to JOG across channel and needed to get back for Monday morning.
However, being in a boat that size with an amateur-installed 1 GM is a bit like being in a concrete mixer.
I never motored for more than 25 minutes unless I really had to. To be fair, it was effective at punching tide. It was the first yacht I owned, so I didn't know what to expect. But it was shedloads better at sailing than motoring.

These days I would get a decent 4 stroke outboard, a couple of extra fuel tanks and spend the change on better sails.

To be fair, a smaller boat might make OK progress with a 1 GM at lower rpm?
And I'm sure it's possible to do better with noise reduction.
There are Impala owners on here who might be worth talking to. Maybe some can tell us about a 1GM retrofit that is somewhat better than mine was?

 

[Seajet]

The Impala was a much bigger, 28' wide hulled David Thomas era Hunter - pretty much race oriented and came with a swing-up ' aircraft undercarriage swing up door ' to close off the well; an idea worth a go in its time but it wouldn't suit the four stroke engines a lot of people are stuck with nowadays, due to both weight and lubrication oil going back into the combustion chamber.

A four stroke outboard ( when I investigated these at a boat show my feeling was ' what joker has nailed this to the floor then ?! ) on a transom bracket would almost cripple a narrow transom design like a 701 - even the much wider sterned Anderson 22 hates weight aft.

Until we get decent electric propulsion - ( which I also researched to quite a high level with German advice; not really suitable for these boats yet, better suited to a wineglass hull with the ballast consisting of batteries - a U- Boat ) a two stroke outboard or a relatively light inboard is the best option.

 

[VicS]

The Impala was a much bigger, 28' wide hulled David Thomas era Hunter - pretty much race oriented and came with a swing-up ' aircraft undercarriage swing up door ' to close off the well; an idea worth a go in its time but it wouldn't suit the four stroke engines a lot of people are stuck with nowadays, due to both weight and lubrication oil going back into the combustion chamber.

A four stroke outboard ( when I investigated these at a boat show my feeling was ' what joker has nailed this to the floor then ?! ) on a transom bracket would almost cripple a narrow transom design like a 701 - even the much wider sterned Anderson 22 hates weight aft.

Until we get decent electric propulsion - ( which I also researched to quite a high level with German advice; not really suitable for these boats yet, better suited to a wineglass hull with the ballast consisting of batteries - a U- Boat ) a two stroke outboard or a relatively light inboard is the best option.

You make these sweeping statements but to put the matter in perspective:

My 2 stroke 6hp Evinrude "Yachtwin" weighs 27.4 kg

If I was thinking of replacing it the modern 4 stroke with the same basic features, ie long shaft, high thrust prop and battery charging, that would be an obvious choice is the Tohatsu 6hp "SailPro"

The 4 stroke 6 hp Tohatsu "SailPro" weighs 26.1 kg

The arithmetic I use makes that lighter not heavier at all and IMHO it would make an excellent lightweight propulsion unit for a Hunter 701 for not much more than £1000

 

[Seajet]

Spiffing,

but how far have you gone in your Seawych ?

I'v'e motored across the Channel in flat calms a few times with a 4 hp Yamaha ( I now have a 5 hp Mariner which I reckon optimum on a good performing sailing boat of this size ).

My A22 has done 24 Channel crossings to date.

I''m trying not to be rude but the Seawych is not the sleekest most efficient design, with vertical keels designed foremost to pop out ouf the mould, without any thought to sailing ability.

Having such a heavy engine hung off the back of your boat must have crucified her sailing pefrormance.

 

[lw395]

The Impala was a much bigger, 28' wide hulled David Thomas era Hunter - pretty much race oriented and came with a swing-up ' aircraft undercarriage swing up door ' to close off the well; an idea worth a go in its time but it wouldn't suit the four stroke engines a lot of people are stuck with nowadays, due to both weight and lubrication oil going back into the combustion chamber.

A four stroke outboard ( when I investigated these at a boat show my feeling was ' what joker has nailed this to the floor then ?! ) on a transom bracket would almost cripple a narrow transom design like a 701 - even the much wider sterned Anderson 22 hates weight aft.

Until we get decent electric propulsion - ( which I also researched to quite a high level with German advice; not really suitable for these boats yet, better suited to a wineglass hull with the ballast consisting of batteries - a U- Boat ) a two stroke outboard or a relatively light inboard is the best option.

Some fair points in there, but doing much motoring with a 1GM installed as an afterthought in a small boat is still unlikely to be an experience I'd invest £4k or whatever in. Better to spend the money in the cafe waiting for a breeze IMHO. Or sell the kids and trade up to a boat with a 3cylinder motor.
Just my opinion of course!

 

[Tranona]

Some fair points in there, but doing much motoring with a 1GM installed as an afterthought in a small boat is still unlikely to be an experience I'd invest £4k or whatever in. Better to spend the money in the cafe waiting for a breeze IMHO. Or sell the kids and trade up to a boat with a 3cylinder motor.
Just my opinion of course!

A sensible alternative to a 1GM is a Beta/Nanni 10 or 14. I have just done that. Physically virtually the same bulk, but 2 cylinders and freshwater cooled. only penalty is weight - about 20kgs more. Infinitely better in a boat this size, not only quieter and smoother but up to 50% more power. However, another big step up in cost with the basic engine new about £800 more.

i know how you feel about the 1GM as i have motored across the channel 3 or 4 times. However after the Stuart Turner it replaced it was relative bliss knowing that it would actually run and only stop when you wanted it too. That and not sitting in the middle of 15 gallons of petrol in the tank and extra cans. The original owner carried 25 gallons in jerry cans for his annual cross channel trips. Just enough to get there and back. Those were the days.

 

[VicS]

Spiffing,

but how far have you gone in your Seawych ?

I'v'e motored across the Channel in flat calms a few times with a 4 hp Yamaha ( I now have a 5 hp Mariner which I reckon optimum on a good performing sailing boat of this size ).

My A22 has done 24 Channel crossings to date.

I''m trying not to be rude but the Seawych is not the sleekest most efficient design, with vertical keels designed foremost to pop out ouf the mould, without any thought to sailing ability.

Having such a heavy engine hung off the back of your boat must have crucified her sailing pefrormance.

All this is irrelevant bullshit!

You were trying to make out that 4 stroke outboards are so heavy that its impossible to lift them off the floor.

My point is that this is not necessarily so.