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[Ramon]

Hi, I'm new to the forum and though not 'new' to model boats it is some thirty years since I built my last one. About 1970 I ventured from flying model aircraft into boats for a short period via encouragement from a new member to our club. (With no model boat club in the area 'Arthur' joined us aeromods). We soon became good friends and with his enthusiasm for the subject it was not long before he twisted my arm. Arthur worked for the local Ford agent and brought round this stunning poster of the (Ford) 1966 Round Great Britain Powerboat entries. We both got Aerokit Swordsman kits and we finished them as '707' (his) and '909'(mine). Both were powered by Merco 35s and ran extremely well. I later fitted a Merco 61 in mine but it was somewhat overpowered (!) and would roll over as the power and torque came on. An Aerokits PT boat followed with an OS 40 in and then interest turned to the Naviga 30 metre triangle timed event. Just before overseas work led to the (rapid) decline in activity I was running an OPS 60 in an ED produced glass hull which was far faster than my reactions would ever stay up with!
So here we are near forty years after that first foray and a recent chance encounter with an old aeromodelling friend led to me being asked if I could help to sell some marine engines for another, mutual, friend who had recently passed away.

It has to be said that when the engines arrived the (used) OPS 60 and HP61 among them re-kindled what I thought were long dormant interests so here I am second time round only this time with this wonderful medium by which to share and learn from.

I am about to start another Fairey boat, this time the Huntsman (which is actually the correct design for the '66 RGBPBR) from the Vic Smeed plan and again in conjunction with a good friend and though this is obviously a popular boat thought that it would be beneficial to some, yours included, if the build was shared.

Any thoughts or comments?

Regards - Ramon

PS This is the only pic I have of the original boats

[FullLeatherJacket]

Our prototype Modav (later Precedent) 1/8 scale Huntsman 31 was powered with the revolutionary Schneurle-ported HP61F R/C. It was the most powerful 2-stroke 10cc glow motor on the market at the time; 1 BHP. Now check the spec of the latest 0.65cu in OPS or similar.....scary!
FLJ

[GARY C]

WELCOME BACK    "another blast from the past" like me.

Love the tuned pipe  bet that was,nt below 80db.

Gary.

[pmdevlin]

hi Ramon,
 I have a Huntsman 28 being refurbed, its 40 odd inches long, I thought it was a 1/12 scale, are you sure your project is 1/8th? 
Its been a very long job, almost 2 years! between other projects. I have just finished the deck planking, so its coming along nicely now, really looking forward to getting it finished, its a superb looking boat.

[FullLeatherJacket]

Huntsman 28 = 28 feet long (more or less), so a 1/12 scale model would be 28 inches (1/12 is 1"=1'). 28' x 12 = 336" full size; 1/8 x 336" = 42" for the model.
Your model just got bigger!
FLJ

[andyn]

You say you have an HP61? Youll want to run it on straight castor oil fuel, because if you run it on a synthetic fuel, not even the throttle stick will stop it...

Welcome back to the hobby 

[BobF]

And of course, a lovely Starlet as well.

[Ramon]

Hi everyone thanks for the response.

I’ve been busy today setting up the keel and dry fitting the bulkheads.
I’m pleased to hear the HP61 is so highly rated, the example I have is the first one in many, many engines (mainly aero) owned over the years. It is in reasonable condition but will have to have a manifold attached for the exhaust system. As received it had a ‘strap on’ type sealed with a pound of silicone but doesn’t look as if it’s had much running so I’m hoping that that will not have influenced wearing the bore too much. I’d certainly like to hear more from anyone with experience of this engine
FLJ is quite correct about the scale, I had always thought that the ’66 RGB PBR boats were all Swordsman but since researching it this time it soon came to light that only one (606) was and the other three (707, 808, 909) were Huntsman 28’s. I had always believed that the Huntsman was only built with an aft cabin but now know that this was an updated version on the basic design – I think  that the Aerokits version was of this type which is probably the root of my confusion.

I’m hoping for a bit speedier build PMD but wish you luck in getting yours finished.
And yes that is a Starlet built by my work colleague Ken Akerman. Was that really thirty six years ago? Were db’s even invented?

Regards - Ramon

[Tester]

Hi Ramon

606 Seaspray in the 1969 Round Britain race was a Huntsman as were the other 3 you mention, the Swordsman was a larger boat at 33".

Lot of good info on the Fairey Owners Club site http://www.faireyownersclub.co.uk/default.asp

HTH
Richard

[FullLeatherJacket]

Ramon
That's the baby, except the carb doesn't look original Hirtenberg. We used the huge aero silencer simply as a manifold, and connected the outlet to a Ripmax Marine Silencer and thence to a transom-mounted outlet via a couple of miles of copper and silicon tube. Life was carefree when Ripmax were picking up the tab. 
FLJ

[Ramon]

Hi Guys,
Just popped in from the shed for a coffee and thought I'd check this.
I stand corrected Tester, you are of course quite right. I was quoting from memory (bad thing - quoting that is, but then the short term memory is not so bright either!) from an email I had received from the motor boat museum. Having just checked it I had completely misread it. Must be signs of my age!  It stated that all four boats were indeed Huntsman and that the safety boat was the Swordsman. My apologies for a misleading statement. Thanks for the link too though have been there before.

FLJ. The carb I believe is a Perry or Kavan. I have no experience of them and the guys at the local water say they can be quite difficult to set up on the idle. As you see the engine it's as received except for removal of the manifold. The internals however appear to be in very good order but I intend to strip and rebuild it as it is a bit gummed and add a permanent manifold - more later. I'm assuming the marine silencer was not a pipe - any details on this, nitro used, prop etc would be appreciated. (I shall be making the silencer to fit the aft bay)

In the meantime its back to the boatshed.

Regards Ramon

[FullLeatherJacket]

Nope - that carby isn't a Perry (because they had a black plastic body with a brass idle wheel at one end) nor a Kavan - they had a straight-through needle and spraybar. I think the old ED company had a stab at making RC carbs for a manufacturer called Red Shift, back in the 70's. This looks like one of those but I'm not certain. The Perry carbs were indeed a b1tch to set up and after a while the O-ring inside perished and was the very devil to get out and replace. The Kavan carb was a better-behaved beast, but I have no experience of the ED one (if that be what it is, my dear).

I can't find any reference to the Ripmax Marine Silencer in their present catalogue. This is not surprising, as it wasn't very quiet - certainly compared with a modern tuned pipe. The nearest one looks like the Irvine Marine Silencer, being a straight-through type but probably with a perforated tube and baffle plates inside. This only suits up to a .45 cu in engine, although these days even a modest "forty" will likely churn out more power and noise than the old HP61 did.

Ref fuel, we always used 80% methanol, 15% castor or synthetic oil, and 5% nitro. Went like stink and with a reliable idle, too - but the model got to smelling like a multi-storey car-park stairwell after a while............... 

Ah, sweet memories!

FLJ

[andyn]

Talking to Trevor at the club, I advise agaisnt using nitromethane at all, it just gets faster and faster and then sticks various parts through the crankcase that most definately shouldnt be through the crankcase.

Model Technics still do straight castor oil fuel, and on the plus side it's much cheaper than nitromethane fuels, £8.30 a gallon as opposed to £14 upwards

[FullLeatherJacket]

Talking to Trevor at the club, I advise agaisnt using nitromethane at all, it just gets faster and faster and then sticks various parts through the crankcase that most definately shouldnt be through the crankcase.

Model Technics still do straight castor oil fuel, and on the plus side it's much cheaper than nitromethane fuels, £8.30 a gallon as opposed to £14 upwards

Maybe so, old dear, but this is a 40 year old engine we're discussing. They do things differently with the metallurgy, ports, timings and such stuff these days; that's why the new motors are so much more powerful than the old ones.

My fault I'm getting old, I suppose................

FLJ

[andyn]

Indeed it is, I have two Merco .61's, one even older than this HP

A modern Novarossi or Picco .21 will probably chuck out the same power as a Merco, and a Picco or O.S .45 will chuck out about twice that of the HP

A HP will put out about 1 hp, the latest PIP A-45H is currently developing 3.5 hp. Same for rpm, about 20,000 for the HP, and 32,000+ for the PIP. I know which I would rather have in my Crusader...

[Ramon]

Hi guys,  its very interesting to read your input on the carb, silencer and merits of the venerable IC motor.
Firstly the carb. When these engines came my way both the OPS and HP are fitted with them. I took the OPS over to the local water. No one was sure on my thoughts (guess) of Perry or Kavan but FLJ, one of them also thought it might have been made by ED. I vaguely remember the Red Shift engines - weren't these aimed mainly at the R/C aerobatics and or scale aeromodelling fraternity? Apart from my short foray into boats in the seventies virtually all the engines I have been involved with were non R/C standard carb and used mostly for control line aerobatics, an event where throttles are not required and something I have concentrated on over the years.
I shall check out the Irvine, my thoughts are of an expansion chamber underneath the well deck built from ally tubing and JB welded together.

Regarding nitro I was interested in as much as - did the 1 bhp get produced using lots of it? I've used 5% in my engines for many years and am well used to it's properties at that level so I'm glad (relieved!) to hear I won't have to change anything greater.
Anyway, regarding power I thought it would be a good use of this (old) engine in a fairly bulky but reasonably fast and hopefully stable boat for my first venture back on the water. I do have other engines I could use but felt this to be an ideal use for this old warhorse.

Thanks again, this really is a great medium for discussion. I've had a good session in the workshop today and got all the bulkheads lightened, glued in and the first stringers in place. Roll on tomorrow. Ramon

[GARY C]

Hi,

Ref to the carb, Yes it is an E.D. carb, I used the same carb fitted onto the rear of my old OPS 40. SCREEEEEEEEEEEEEMED.
I got mine from Weston models back in the 70s, Alan Greenfield is still there, there may be spares for them in
his shop, collecting dust.

Gary.

[Ramon]

Hi Gary, That's cleared that up then. What's your opinion on the throttle setting characteristics ie idling.

Haven't got far on the hull today due to distraction - spent most of the day catching up with three modelling mates who happened to turn up one after the other just as I was getting ready to lay in the next stringer lamination! Ah well we did have a good old rabbit though.

In what spare time I did find between visits and waiting for the glue to grab I turned my thoughts to stripping the engine.  As i said before it's a bit gummed and the flywheel and cylinder head cooling jacket are quite solid. Before I get some heat on it to see if that will help and I'm sure it will can anyone remember how they actually fit? eg is the flywheel on a tapered collet? With the cylinder bolts out it appears that the head clamps the water jacket down on the cylinder and so into the crankcase. Any memories on this FLJ  or others?

that's it for now - back to the stringers! - yours - Ramon

[FullLeatherJacket]

Nope - I'm afraid I have trouble remembering what we just had for dinner, except for the occasional glimmer into the long past.

I do remember that Spray Gun Oil was the recommended stuff for keeping the motor working. It contains something that neutralises the nitro-methane and stops the corrosion caused by the resulting nitric acid. This was from a R/C car world champ called Dave Preston, who was a big mate of the guy who ran Pegasus Models in Nottingham in about 312BC........when I was 'Shop Assistant' there.

I never did strip down the HP61 - it belonged to Ripmax, and Len Hooley was very jealous of his engines!

FLJ

[Ramon]

Morning FLJ,
Looks like a step into the unknown then. I've stripped and rebuilt quite a few over the time but didn't want to dive in blind so to speak. I'm now off out to see an old ME friend but will get the heat gun out when I get back - will keep you posted - R

[andyn]

My second Merco .61 was completely gummed, would not move at all.

I got a sturdy plastic box (butter pot is fine, but not ice cream tub - they melt. Put the engine in flywheel upwards, fill with glow fuel up to the top of the carb. Leave for a couple of days (mine needed a week), the glow fuel will evaporate a bit, and it should turn over nicely. Remove the head and if you want, the back plate and turn over for a while to get the crud out, if needed, use an old toothbrush. While youre at it all the gunk you may have on the side of the engine will come off nicely. VERY VERY VERY IMPORTANT NOTE, Don't turn over the engine while its in the fuel, because as I learnt it squirts out the carb into your face. Glow fuel in the eyes is not at all good.

Please for your sake do this in the shed, on the floor, because it the pot does melt by the fuel SWMBO will kick you out and it's cold out there at the moment...

[Ramon]

Thanks for the tip Andy, especially about the kitchen floor, HI would be well impressed!

You know, I’ve stripped quite a few engines but have never given a thought to soaking them in fuel to loosen them off. Just never occurred!!! And you’re dead right about fuel in the eyes – very nasty indeed and something to be avoided at all costs.

I’ve normally found that heating with a hot air gun then a small drop of cellulose thinners through the port and intake will get things moving - it’s quick too but you mustn’t over do the thinners as this will soon take off the all the castor leaving a dry engine.  Cellulose won’t shift the baked on crud though but I found tonight that a soak in acetone has done a half reasonable job on the HP’s cylinder head.
Yep - I managed to get it off okay with some help with said heat gun - very easily in fact - to find that the water jacket is a separate entity that surrounds the liner. The liner itself was a little more difficult but came out okay with a bit more heat but the flywheel was an absolute ‘bugga’ due to a previously damaged/deformed collet and suffered slightly as a result!
Still it’s all apart now and the insides are looking very good indeed. Despite the crud around the exhaust it looks as if this motor had very little running. No evidence of the effects of nitro either. Very beefy crankshaft and some very impressive porting on the cylinder.

The carb came apart okay too but the post has been damaged by over tightening the clamp. The previous owner had ‘whanged’ a 4mm cap head right through the intake to keep the carb on so that will need renovating but apart from that and the collet it should be a straightforward clean and rebuild.



Now I know it’s a bit early in my build but I need some advice on couplings. All those years ago the only coupling that appeared to tolerate the forces involved on my OPS60 was one produced by Rip-Max. It had two bossed discs facing each other with a flat nylon(?) disc about 3mm thick between supported on two posts from each disc. The discs were chromed and the whole thing looked good and worked extremely well.
I have two ‘Huco’ couplings that were with some other bits and pieces with these engines and appear to be a 'variation on a theme'

Question is, are these couplings up to the HP 61 and if not what would others recommend. I’m using a standard straight 2BA shaft.

[pmdevlin]

Thanks FLJ! Great news, my boat is bigger than I thought!

re couplings, are these any good? The plastic things commonly used are really struggling in my Fireboat with the torque, and thats only electric, I was thinking of these

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=retrieveTfg&binCount=7&Ne=4294957561&Ntt=Set+screw+style+jaw+coupling&Ntk=I18NAll&Nr=AND%28avl%3auk%2csearchDiscon_uk%3aN%29&Ntx=mode%2bmatchallpartial&N=4294954315&Nty=1

Its a big link I know, but just tried it and it does work

Ramon, nice seeing the Hunts being built from scratch, mine was in a bit of a sorry state when I got it, its been taking ages,. the latest problem being this

http://www.modelboatmayhem.co.uk/forum/index.php?topic=14359.0

but very little info has come back, and its now a dead topic really

Here is a pic from the summer, and one more recent, its a lovely looking boat, keep us informed with progress. One regret, I took the cabin roof off, as the original had a big section that came off, and I didnt really like it. Whilst rebuilding, I decided to leave the removeable section, to access a sound unit and speaker in the future, sorry now I didnt just make a one piece roof

Sorry about grainy photos, they are from a phone

[Ramon]

Thanks for the link PMD. Couple of things from that - first they appear to be okay for the job in hand something FLJ confirms and very reasonably priced. Second was that I'd never given RS a thought since I finished work, we used them all the time then but I've been under the misapprehension that they were for trade only. That was the good bit the not so good was I then spent most of the morning looking through the online catalogue! Wonderful stuff!!

Good to see the pics of your boat. I’ve long been convinced that building a new one is near always easier than refurbing, renovating or major repairing so my hat is off to you, keep up the good work, you'll get there in the end. It’s interesting to see the different construction particularly in the cabin area, I’m not keen on that mid full bulkhead on the Smeed design and wished I’d given it a bit more thought. Still this is meant to be a standoff scale ‘get me back on the water’ build and once the cabin sides are on it will disappear.

FLJ Thanks for your PM's regarding the couplings. I've only just realised today that you run an electrics(tronics) business so your interest, input and offer of help on an IC matter is extremely appreciated.

Despite the lure of the RS catalogue I have had a good session today and managed to get the stringers all on along with the engine rails (dry fitted at the moment) etc. I don’t know if anyone else has tried it but I am using ‘Titebond lll’ PVA glue which, it is claimed, is waterproof. That remains to be seen but what is impressive is its extremely quick ‘grab’ time even on parts that are under stress eg on the stringer ‘pull’ in at the bows. I’ve used the standard Titebond before to good results but this is a definitely superior product and reasonably priced too.

Before I can get the bottom skins on I will need to get the engine rails drilled before I can fit them so that means turning to the engine and mount rails next. Here’s how it looks so far




Back soon - Ramon

[pmdevlin]

looks really nice

[Ramon]

Hi there,
I didn’t intend to post quite yet as not much progress has been made on the Huntsman but a friend called tonight and brought a couple of interesting items.
 
Firstly though,  the HP 61 is rebuilt and I’m very pleased with it. Despite it’s very gummed up and knocked about appearance as received I don’t believe this has had very much running at all. The fits on the parts are some of the best I’ve seen and it has gone back together extremely well. I can’t wait to see it running. I have been working on the engine mounting so that I can get the rails drilled before putting the lower skins on but a good dose of the seasonal ‘man flu’ (oh yes indeedy!) has kept me out of the workshop for a few days. Heres how it looks so far.


John, who had passed these engines to me in the first place had found the original box for the carb which confirms indeed that it was an ED product. (Not that that was in doubt GaryC).
Inside the box however yet another carb which is different again. I haven’t pulled it to bits yet but it appears to have two spray bars one inside the other, closing off the fuel outlet as it is closed. It also has some kind of valve arrangement at the base of the carb body which is closed (opened?) by a tapered faced extension to the throttle arm.


The other end to this valve has a conventional fuel tube nipple screwed into the body. At the moment this appears blocked. 


Despite the post having been ‘chewed’, probably to fit a smaller venturi apperture, the mechanical movement of this unit is exceptionally smooth – it certainly has a well made appearance about it. It's quite heavy though - over 2 1/2 ozs. - a bit on the heavy side for aircraft?

Any ideas anyone? Is it the original HP or OPS  both of which have been retro fitted with ED types (I don’t remember this from the OPS I ran in the ‘70’s) Is it worth renovating?

Regards and Xmas wishes to you all - Ramon

[andyn]

Oooh shiney....

I think, on balance, it would be best to use the first carb you had. If it doesn't work, I have a couple lying about the place you are welcome to.

You machine that manifold port? looks very nice.

[FullLeatherJacket]

I think that this  is a Kavan carby, chaps - although my memory isn't what it used to be. BTW that excellent fit was achieved because the manufacturers - Hirtenberg - were gun makers, too.
FLJ

[Ramon]

Hi Guys, thanks for the response.

Yes I did make the manifold Andy - skimmed the outside on the crankcase then machined the manifold to fit. It's 'glued' in position using 'JB Weld' with two 8ba screws through the ends.  I've used JB Weld before to make silencers and it stood up extremely well but these were for motors that revved much lower ergo not so much heat. It will be interesting to see how it stands up in this situation. Excellent product though.

FLJ - Interesting to hear that this is a Kavan carb. I've taken a better look at it this morning and the valve at the lower corner is nothing more than a schrader type valve which vents as the throttle is closed. I can only assume that this would be connected to the fuel tank to allow the tank pressure to dissipate as the throttle closes. Thinking about it a bit more it would probably help on starting too - in not allowing pressure to force fuel through and flood the engine.
Only very rarely have I used pressure feed on my control line engines, never with any success or benefit and consequently have little kowledge about it. These engines, always hand started, were mainly set up on 'Uniflo' tanks which give a very consistent run but they of course had small venturi's with very good suction.

I shall have a go at renovating it but will stick to Andy's advice and keep to the ED carbs initially at least

I'm now feeling much better and was hoping to get in the workshop and get going on those mounting bars but SWMBO has just kindly reminded me that its Xmas Eve today and Xmas Day tomorrow! Is it? Really? Why do they always notice these things?

Regards - Ramon

[andyn]

Its christmas??

News to me...

Having more bits on a carb means more bits to set up and ultimately more bits to go wrong...  I think you are wise to take my advise, and another point is as it's already on there, which usually means it works...

Andy

[Ramon]

Nuff said - if it ain't broke etc. springs to mind.

I shall press on regrundless

Have a good one - back soon ! - R

[Ramon]

Hi everyone, hope you all got what you wanted!!

Despite the Chrimble distractions have managed to escape here and there and make a bit of progress.

Got the engine mounted in it’s frame. This is the first time I‘ve installed an engine like this, last time it was a ‘paxolin’ plate bolted to two beech bearers P38’d into the hull! Wasn’t quite sure how to go about this at the outset – note the packing pieces! but the installation seems positive and in line. The prop tube is not finally installed as yet, that will be after the lower skins are on.

Rough planed the chine stringers down to the bulkheads on the bottom surface and planed and faired them in on the sides ready for the 1.5mm ply side skins which got fitted today. It’s beginning to look a bit like a boat now.

I intend to fit the bottom skins (also 1.5mm) as my early Swordsman and as shown to me at the time by my friend Arthur
This involves cutting the two panels as accurately as possible to  the ‘run’ of the keel and stem line and then drilling small holes along the (keel) edge and loosely ‘stitching’ together using copper wire. The holes get progressively closer at the turn of the keel to the stem. When the panels are opened up like a book they form a natural and symmetrical shape into which the hull frame work is ‘pushed’. Held in place the insides are then coated with resin – poly or epoxy which is allowed to flow filling any gaps. The result should be two stressed  skins uninfluenced by any bulkhead deviation.
Bear in mind this is a thirty year memory – I ‘remember’ it worked well on the Swordsman but it was along time ago. A couple of more days should see whether said memory is right!

Anyone any thoughts on this process? Any input would be valued.

Back later - Ramon

[FullLeatherJacket]

http://www.mecoa.com/acc/carbs/index.htm

Just as a matter of pride, really. See? I can  remember important things!! Thinking back, I'm sure that Kavan also made a "pressure" carb, which explains why there's a bleed valve on the lower corner. The R/C aerobatic boys used to use these carbys in the early 70's, with tank pressure from the engine crank-case to maintain an even mixture throughout the flight. This was in the days of the Webra 61, the OS 60 FRC, the HP61 and sundry indies like the Redshift. They also went like greased weasel pooh. Then someone invented the backplate-mounted fuel pump and the tuned exhaust and things were never quite the same again. I retired to 1/2A and Quarter Midget Pylon Racing for a quiet life.........

That model is looking pretty darned good from where I sit. I wish I had the time for building. 

FLJ

[Seaspray]

Nice clean tidy construction. 

I like the engine mount which cuts down viberation and noise, with plenty of room for the starting belt. Good solid looking glow engine with waterjacket on the head and well grooved flywheel.  Very strong coupling between engine and shaft. 

Seaspray

[andyn]

You might find that the rear rail bolts on that engine mount are a right b****** to get undone once everything is all sealed up, make sure you leave plenty of room for access and make sure before you put the deck on that you can get all the bolts undone, and once again when you put the deck on.

Looking great so far, whereabouts in the country are you?