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[glennb2006]

Mick,

can you not get hold of someone who will go with you to start and throw the boat into the water for you so you can at least see it running? I know of at least other model boater who lives on Canvey.
It must be killing you not being able to run the model.

The wood boat looks to be a work of art too by the way. And I am not a big fan of wood so there you go. Nice work.

Regards,


Glenn

[Patternmaker]

Glenn
You're  absolutely right, its driving me mad not being able to test the boat, I have a lot of patience building models but not when it comes to this. I cannot even drive at the moment, going to see the consultant tomorrow for scan results so fingers crossed, if all else fails I will have to find a volunteer test pilot.

Regards,
 
Mick

[knoby]

hi Mick, sorry to hear about your current predicament. I'm just up the road in Westcliff & would love to help you out if you like. I appreciate your priority is with your health, but would hate to think your sat there wishing there was away of getting to a lake to try out the boat. Let me know if i can be of  assistance. good luck with your back
cheers Glenn ( yes another 1)

[Patternmaker]

Hi Glenn, your offer of assistance is very much appreciated, I will see how I get on tomorrow and keep you informed. Since I joined Modelboatmayhem I have realised what a great bunch of people you all are, thanks again Glenn

Regards Mick

[martno1fan]

hi Mick, sorry to hear about your current predicament. I'm just up the road in Westcliff & would love to help you out if you like. I appreciate your priority is with your health, but would hate to think your sat there wishing there was away of getting to a lake to try out the boat. Let me know if i can be of  assistance. good luck with your back
cheers Glenn ( yes another 1)

See this is what this hobby (obsession) is all about,people helping one another out when they can nice one Glenn  .Good luck today Mick hope its good news.
Mart

[Patternmaker]

Thanks Mart, you comment is very much appreciated
Regards Mick

[Patternmaker]

Hi guys, not good news I'm afraid, been told to have complete rest for 2 months and I will be assessed again (keep taking the tablets) being told my age was against me did not help. Been given a back brace which limits your movements, I cant see me wearing this for long its very uncomfortable. The love of my life, my wife is my support even though I have got out of doing the household chores again.

I have had back problems since I was in my early 20s started when I was in the army 3rd battalion parachute regiment, 28 jumps in just in 2 years the base of your spine is stretched with the jerk when the chute opens at about 100mph and compressed when you land at about 14mph depending on how much kit your carrying.

I have found in my case over the years that resting is not the answer, if I keep on the move when possible and it gradually improves and becomes bearable, so only time will tell, one thing I do know it will not stop me building models when possible even if I cant run them. My son who lives in Cornwall will test my boat when he next visits, we used to race together in the 80s and 90                                                           One consolation I will be able to spend more time on MBM forum.

Thanks for all your support, and a special thanks to Glenn from Westcliff.

[martno1fan]

Sorry to hear your bad news Mick,just remember doctors don't know everything  .Keep your chin up mate and go build some new models for when you can get back out there.I hope your boat runs well when your son gives her a run.Also check out RC Universe theres lots on there to keep you occupied as well as whats on here.
Mart
http://www.rcuniverse.com/forum/default.asp?fh=1&forum=229

[Patternmaker]

Thank's Mart, you don't have to look very far to see people a lot worse off than yourself.
Mick

[Patternmaker]

Got my grandson to run the engine without velocity stack slight increase in RPM

[martno1fan]

Looks good Mick so come on what mods did you do to the motor how about a few pics of what you did for us dummies  .Might even have a bash at doing some minor mods to the one i have here,but i might keep it air cooled for now as i have a boat i can run open top ,this one will be for my son .
Mart

[glennb2006]

Hi Mick,

what is the current length from exhaust port flange face to the widest part of your tuned pipe?

Just working out a tuned length for you!

G

[Patternmaker]

Hi Glenn,

Its 380mm, the most I could gain with the present pipe is by shortening the header to clear the engine cowling is 12mm.

[Patternmaker]

Looks good Mick so come on what mods did you do to the motor how about a few pics of what you did for us dummies  .Might even have a bash at doing some minor mods to the one i have here,but i might keep it air cooled for now as i have a boat i can run open top ,this one will be for my son .
Mart

Mart,
Apart from water-cooling the head if you do not have a lathe anybody could do the mods I have done, porting; inlet open up the port as much as possible but NOT at the top because the port must not be above the piston at BDC, the exhaust port again open up as much as possible and polish both ports. Chamfer the edges of transfer ports, inlet and  exhaust inside the cylinder but NOT the top of inlet port, this will prolong the life of the engine when they are not chamfered they act as a scraper ring and take oil from bore.
Open up the carb insulator the same diameter as carb venturi, if you have one  fit walbro 257 I think this would be the best for this engine I am running with 644 which I had given to me.
I also rebalanced the flywheel, I notice some vibration when first run, easy to do remove flywheel fit on a shaft the same diameter as crankshaft fairly tight fit, set up 2 parallel bars rotate slowly if the flywheel stops in the same position without rotating its ok,  if it moves backwards or forwards before it stops it will rebalancing it will always rotate to bottom, the point of imbalance start with a small drill and remove a little at a time until you achieve correct balance.
I also use NGKCMR7H Spark Plug, hotter than the standard one
You can see what RPM I am getting, so there you go Mart, do you keep the original clutch, I dumped mine and fitted a flexishaft coupling which will screw straight on to crankshaft which also holds the flywheel.

Mick

[martno1fan]

Hi Mick thanks for that ill give it a go m8,ive kept the clutch still undecided on that yet as a clutch is a nice feature on a  play boat especially for kids.Good to know the threads are the same as the collets we use if i do decide to ditch the clutch though.The clutch is actually decent on these motors,seems to run ok.I never tried a different plug on my old one but might give it a go,you know if you remove the choke from your 644 and plug the holes you will basicly have a carb similar to a 257 and i actually prefer the 644 to the 257.The 644 is a lot cheaper to buy too   .I will then need to make an adapter for the header to bolt onto to to fit a tuned pipe.
Mart

[glennb2006]

Hi Glenn,

Its 380mm, the most I could gain with the present pipe is by shortening the header to clear the engine cowling is 12mm.

I did the calculation, but made an assumption that the pipe is tuned at 15000RPM, which we do not know as you have not run it and found where it is right now, but for arguments sake, if it is set at tuned length @15000RPm, then an increase in exhaust timing to 180 degrees, to aim for power @ 16000RPM would make your pipe tuned length longer @ 15.429". (391mm).

A few assumptions there mind Mick, but increasing the exhaust duration to a bit more might make the pipe easier to get tuned with the longer header you have.

I will email you the calculation if you want it Mick.

Glenn

[Patternmaker]

Thanks for the info Glenn, very interesting, I will wait until the boat has been run to see what the performance is like, I do not honestly think this engine will take many more revs unloaded. I have been trying to think of a way of loading the engine to simulate, I use a windscreen washer pump for cooling, thanks again for your trouble.

Mick

[Patternmaker]

Hi Mick thanks for that ill give it a go m8,ive kept the clutch still undecided on that yet as a clutch is a nice feature on a  play boat especially for kids.Good to know the threads are the same as the collets we use if i do decide to ditch the clutch though.The clutch is actually decent on these motors,seems to run ok.I never tried a different plug on my old one but might give it a go,you know if you remove the choke from your 644 and plug the holes you will basicly have a carb similar to a 257 and i actually prefer the 644 to the 257.The 644 is a lot cheaper to buy too   .I will then need to make an adapter for the header to bolt onto to to fit a tuned pipe.
Mart

Mart, The thread on the crankshaft is M8 so its collet would be for a CMB90 for 1/4 flexishaft, the choke has been removed from the 644, its a shame the exhaust port is mounting holes are offset, I had to make a watercooled flange to suit, incedentally I do not use a gasket on the flange and also loctite every bolt on the engine.

Mick

[martno1fan]

Thanks for the tip on the collet,yea its strange the bolts are as they are on the exhaust when the bolt spacings are exactly the same as the zens for  the carb,very inconsiderate lol.I was going to make a separate flange spacer to fit then tap it to accept the bolts for the header flange i have.Ive seen someone else do a similar thing on this motor and it seemed to work ok,a friend bought this one on ebay the other week.Your lucky you have access to the right machinery to custom make your own items.My expertise is with wood mainly not metal so just have to make do with what tools i have i suppose.
Mart

[glennb2006]

Thanks for the info Glenn, very interesting, I will wait until the boat has been run to see what the performance is like, I do not honestly think this engine will take many more revs unloaded. I have been trying to think of a way of loading the engine to simulate, I use a windscreen washer pump for cooling, thanks again for your trouble.

Mick

Probably right on the no load revs, if you can be bothereed make a bench mount and run it with an aero prop (a big one) as a brake.

Then you will be able to see where the power jumps up when the pipe hits a tuned length.

Glenn

[Patternmaker]

Thats a good idea Glenn, I will try it when I can.

Mick

[Patternmaker]

Thanks for the tip on the collet,yea its strange the bolts are as they are on the exhaust when the bolt spacings are exactly the same as the zens for  the carb,very inconsiderate lol.I was going to make a separate flange spacer to fit then tap it to accept the bolts for the header flange i have.Ive seen someone else do a similar thing on this motor and it seemed to work ok,a friend bought this one on ebay the other week.Your lucky you have access to the right machinery to custom make your own items.My expertise is with wood mainly not metal so just have to make do with what tools i have i suppose.
Mart

Looks good, whats the thickness of the front mount plate? It looks if the 1/4 flexishaft has be has been ground square to fit the original coupling?


Mick

[martno1fan]

Hi Mick im not sure as i havent seen the motor in person but i will be asking him,as regards the flex im not sure if its the stock one that came with them as a strimmer like my old one was or not.If i can get some more pics of it ill post them.I just test fitted the motor complete with shroud in one of my stepped vees i had to modify the hatch opening to get it in there but it fits,should be fine air cooled as theres a bit stuck above hatch to catch some air.Ill post a  pic later if you like.
Mart
by the way heres my old woody with the stock weedy,only change on it was the carb to the wa 167 carb.
http://www.youtube.com/watch?v=6DkwfMavcqQ&feature=channel_page

[gwa84]

martno1fan do you have the plans for that deep v bud looks like a nice boat for fun

[martno1fan]

Hi mate i dont but i can get you some,they print out as tiles so you just print onto A4 and tape the pices together.The hull runs very well,in fact with a zenoah its dam fast but can be a bit flighty so a little weight up front doesnt hurt when its choppy.Ill ask my m8 for a copy of the plans and get back to you.Pm me your email and ill send them.
Mart