Brian Taylor FW190 build.

[Eric Robson]

If you mount the engine with the head in the bulge you will have issues with the tank position. When making the new bulkhead don't put the tank hole in till you have established the engine and tank position, I often just drill 3 holes for the fuel tubes. 

[Declan]

On 07/11/2024 at 10:31, Jon H said:

A 90 4 stroke will be plenty. My 63 inch hurricane is 9.5lbs and like a missile if I run it's laser 80 flat out. A 90fs with 14x7 prop would be my vote for power plant. Just make.sure the engine to tank alignment is good. Brian often arranged things where they would fit rather than where they needed to go and Th is can cause issues. I would expect a side mounted engine to be the best way to go

Jon, yes the 90 seems to be the plan.  I'll need to purchase it I think to have a play around with the positioning as I said to Nigel on a previous post.   The fuel tank will also need to be moved back accordingly.  

[Declan]

So I treated myself and ordered the OS FS-95V from Just Engines.  I've always liked the look and feel of OS engines and they do seem to be well engineered.  The running in instructions seemed quite straightforward compared to the Saito and the SC.  Only thing I'm not sure of is the need for an electric starter.  I've not got one at the moment and tbh I preferred doing it manually with a chicken stick.  Will this be an issue with this engine cowled and will I ultimately need an electric starter?  And on that subject I've seen starters connected to lipo batteries as opposed to my memories of heavy leisure batteries?

 

Finished the horizontal stabiliser and elevators.

 

[Chris Walby]

I am sure there will be a few different suggestions, but for me (having never used a chicken stick) I would go with a on board starter and save marking what will be an expensive spinner if I had the option.

 

My hand starter uses an old 4S3300 mAh lipo, but check your starter can handle the extra Voltage/ current or the contacts might weld up (mine has a few times). Its more an inconvenience taking it apart and dressing the contacts as it does it at the most awkward time! 

 

PS Its not like its weight critical at the front anyway.

Edited November 12, 2024 by Chris Walby

[Declan]

Chris, thanks for the reply.  The chicken stick was also freindly to the spinner.   I like the idea of an on board starter.  What are the implications on weight and on board battery required.  I know nothing about on board starters.  The model is 3.8kg on the plan but maybe a little wriggle room up to 4.5kg. 

[Chris Walby]

Hi, Part of the equation is total weight, but more importantly its where the weight is located to achieve C of G.

 

Example I have is a Mosquito that is mostly fibre glass construction and has a well made tail section. Its AUW is about 17 Kg without measuring C of G, but because its got a heavy tail its going to need 2.7 Kg of ballast to achieve the correct C of G. It will fly at 20 Kg, but would be so much better at 17 Kg! 

 

Glow engines are light compared with petrol (once you include all the other bits and pieces!) so even if your model comes out light or target weight you will probably need to add some lead to achieve the correct C of G. You can use lead or you could use a on board glow driver and battery (assuming its in the same place as the lead!). On the off change you don't need any lead up front you could locate the glow driver/battery on the C of G area.

 

PS I have a couple of models that have not required lead up front to achieve C of G however all of my warbirds have lead or a substitute of some sort (like brass prop nut).

 

[Declan]

Chris, maybe I'm missing something here.  My interpretation of an on board starter system is one that negates the need for a starter motor to be applied to the spinner.  This would be a built in starter motor as in a car?  Is this what you are talking about and what are these commonly known as to buy one? 

The energising of the glow plug is a straightforward issue.  Not sure if having an electronic solution to this is preferable to me.  At least if my recharghable glow charger is disconnected I know the glow plug isn't energised from a simplicity point of view.  

[Jon H]

I would use an external glow and a normal electric starter. If the spinner is aluminium, and i suspect it will be, the worst thing you will do is scuff up the paint a bit and you can always touch it up from time to time if needed. I have numerous ali spinners with some starter burn on the paint and i just hand brush new paint over the top. As the spinner gets more and more worn and chipped all over the paint repairs blend in for a nice weathered effect. 

 

With all that said, the OS should have start with ease if you can prime it. Old OS's used to have chokes and you might find that an ASP or SC 90 choke could be fitted. 

 

I wouldnt recommend adding any additional stuff onto the model in the interest of saving weight. I would rather have a horse shoe of lead just behind the front of the cowl than twice that weight in stuff but no lead. 

[Declan]

[Declan]

Not posted anything for a couple of weeks and I've started a new build alongside this one.  

Weston Cougar for electric power kit.  I've completed the main basic wing structure today.  Maybe I'll start a new thread for this one.

[Declan]

Recent purchase of an OS FS95V for the build.  A really lovely bit of Japanese engineering.  Seems a shame to run it and get it dirty.  I'll need to set up a test bench to run it in and set the mixture. 

[Jon H]

Dont loose too much sleep worrying about running in and hold fire until you are ready to put it in the model. To be honest, i would just put it in the model and not really bother with the bench. In either case, when you do come to run it, make sure you get the thing hot as its no good if its stone cold. Running it slobbering rich at 4000rpm will do the engine no good at all and it will simply go rusty once you are done as it will be full of methanol. Just fire it up on a 14x7apc on 5 nitro 15 synth oil fuel. Leave it at 5000rpm for a few minutes to warm up, then full power and tune it for about 95% of maximum performance (this tuning should take less than 10 second) i would expect to see 8800-9200rpm which is fine, just check the revs after you tune it. Dont use a tach to tune. Set the slow run needle, double check top end...done. Should take about 5 minutes from first start to get all that done. Once set just play with the engine up and down the rev range with a few blasts (5 seconds or so) at full power, some hard accelerations from idle etc. When another 5 or so minutes of this exercise have gone by give it a good 10 second blast at full power and pinch the fuel to stop it.

 

With that done let it cool, refuel, check tune, fly using full power only in short bursts as before. After 2 or 3 flights go for peak tune....extend the full throttle allowance a bit...and you are done. 

 

There is so much hysteria about running in engines. Its a non event, just tune it up and get on with it, just dont try and run it flat out all day and it will be fine. A maiden flight is stressful enough without also having to worry about an engine that is coughing a wheezing as its miles rich so just tune it up and go for gold using slightly less throttle. If you feel so inclined you could shoot some 2 stroke oil into the crankcase and rockers before you start, but OS are normally pretty good at this. If it were an ASP then it would need some lube for sure. 

 

 

 

 

[Declan]

Jon, that may well be what I choose to do.  However, I'm keen to play with the engine in the meantime...  We'll see.

Interestingly no-one ever thinks about running in petrol lawnmowers or hedge strimmers so I do agree with you in the main.  I'm a motorbiker for many years and the Japanese engines are pretty much bulletproof as long as they have oil in them.