Fuel Economy For Small Block For Touring!

[Bilko]

I'm in the process of building an engine for my European rides. I've used a TS1230 an RT230 and both although good engines, extremely thirsty. Both at around 35mpg. This is my making my trips very expensive.

So, I've started building a small block engine. Iron for reusability on the road. I was considering the GT186. It seems to tick all the boxes, but I keep reading about the reeds breaking. This is not something I want to repair on the side of the road. I was also reading about the Gori kits. I stopped after some negatives about difficulty setting them up. The other option was HB's iron barrel work, but I know nothing about them.

I'm asking a lot. I want fuel economy and good torque for long rides pulling loads of gear ding 55-60. Does it exist?

[Scooterdude]

If you still have the RT 230 why not convert it to reed valve? Should increase power a bit and increase fuel economy as well. Yes i to have been following the reed valve GT thread on Facebook, doesn’t sound great but Darrell Taylor seems to have the answer to the problem and is offering an alternative set of petals to fix things.

At the risk of sounding like a long playing record; look at the RT 195 and again the idea of converting it to reed, should tick all the boxes.

For what it’s worth im getting around 90 miles to 7 litres of fuel on my RT 235 full MB touring tune reed on a long run.

[a.lo]

I am surprised by that RT fuel consumption, they are sold on the fact of good economy, it would put me off it as a replacement for my rapido which are not known for economy but still returns 45mpg + sometimes

[Storkfoot]

I have done several thousands of miles on a GT186 including Adria and Davos Euros. I have never doubled up on the reeds and never had one break. I do replace them quite regularly though and I don’t run an expansion pipe. I have an MB/bgm Clubman and a PHBH 30. When I have checked the mileage, I reckon I get 12 to 14 miles per litre with rally gear.


I’d say it ticks all the boxes but I have encountered one downside with the MB Clubman, the ubend of which does hang quite low. If you curb your ubend, the sacrificial part may end up being your exhaust flange on the cylinder as this is shaped in a manner to maximise cooling around the exhaust port.

[lozmondo]

I'll be following this with interest as I'm trying to decide between a GT and Qauttrini. Different beasts I know, but I run a standard 195 BGM on another scoot and though I cant fault performance, reliability and fuel economy I just want some thing different and to run an expansion pipe

[ULC Soulagent]

My reedvalve rt 200, 25 delly, bgm clubman does 104 miles b4 I go on 2lt reserve using a 11 lt tank
Well happy with that.
Oh it’s a Broady touring tune on it as well.
Currently building a rt230 version of it

[Solid Air]

I have the small-block GT Bilko and use it all year round, including for the Euro/C2C etc. In about 10k miles I haven't had any reed issues and they are doubled up.

I would advise checking that the casting allows the reeds to open fully though (I needed a manifold packer) and whether the manifold touches the frame (might need to use eccentric cones and/or fettle the manifold).

As for fuel, before Spain I would get 11-11.5 miles to a litre which works out to 49-51mpg for everyday use, a mix of A roads; town and motorway, and sitting at a steady 60mph would give me 46-48mpg. On motorways there's is pretty much always enough speed spare to pass the HGVs easily.

Set-up is 60/110 crank, 28mm Keihin PWK, BGM V4 clubby and an AF close ratio 4 speed box using 49/20 sprockets (4.9 FDR). This gearbox/sprocket set-up gives a touch more top speed, which I like, but does make pulling away up steep hills harder

During/since my Spain trip, fuel consumption has noticibly decreased though and ironically, I'm wondering if the reeds would affect this and so are ready to be replaced, but haven't had the time to investigate yet.

Would I recommend this kit for someone wanting to build up a small block engine for everyday/touring use and not costing the earth? Oh yeah

Lozmondo, if you've already got the RT definitely consider the M210 for the contrast. I've got one which I'm in the early stages of building and really looking forward to completing it

[lozmondo]

Ive got a heavily tuned 230 TS1, so i guess the Quattrini sits in the middle BHP wise but probably nearly top for torque..which is what interestd me. Iggy rates his and says the fuel consumption isnt bad either....I think Im convincing myself I need one

[Covboy]

I'm running a GT186 with a 30mm dellorto and a JL3 - during my recent Italy trip I was getting about 11 miles to the litre. It didn't miss a beat during the entire trip.
like Solid Air, I have the reeds doubled.

[Bilko]

If you still have the RT 230 why not convert it to reed valve? Should increase power a bit and increase fuel economy as well. Yes i to have been following the reed valve GT thread on Facebook, doesn’t sound great but Darrell Taylor seems to have the answer to the problem and is offering an alternative set of petals to fix things.

At the risk of sounding like a long playing record; look at the RT 195 and again the idea of converting it to reed, should tick all the boxes.

For what it’s worth im getting around 90 miles to 7 litres of fuel on my RT 235 full MB touring tune reed on a long run.

Thanks for the replies.

It's currently running a reed valve and it's matched to the barrel. Great performance, but I'm not sure I'd go for an RT with a reed valve again because of the costs when you include a reed valve and costs of matching them up. Although it does seem like RT kits have come down in price. Anyway, I'm hoping to get iron this time.

[Bilko]

My reedvalve rt 200, 25 delly, bgm clubman does 104 miles b4 I go on 2lt reserve using a 11 lt tank
Well happy with that.
Oh it’s a Broady touring tune on it as well.
Currently building a rt230 version of it

You're a lucky git Shane!

[Bilko]

I have done several thousands of miles on a GT186 including Adria and Davos Euros. I have never doubled up on the reeds and never had one break. I do replace them quite regularly though and I don’t run an expansion pipe. I have an MB/bgm Clubman and a PHBH 30. When I have checked the mileage, I reckon I get 12 to 14 miles per litre with rally gear.


I’d say it ticks all the boxes but I have encountered one downside with the MB Clubman, the ubend of which does hang quite low. If you curb your ubend, the sacrificial part may end up being your exhaust flange on the cylinder as this is shaped in a manner to maximise cooling around the exhaust port.

Thanks. I saw the issue regarding the exhaust flange. I'd need to be more observant riding through French & Belgium villages. (I raced through a couple this year and caught the u-bend of my CST3 on speed ramps). Scared the crap out of me, but nothing bad.

I have the small-block GT Bilko and use it all year round, including for the Euro/C2C etc. In about 10k miles I haven't had any reed issues and they are doubled up.

I would advise checking that the casting allows the reeds to open fully though (I needed a manifold packer) and whether the manifold touches the frame (might need to use eccentric cones and/or fettle the manifold).

As for fuel, before Spain I would get 11-11.5 miles to a litre which works out to 49-51mpg for everyday use, a mix of A roads; town and motorway, and sitting at a steady 60mph would give me 46-48mpg. On motorways there's is pretty much always enough speed spare to pass the HGVs easily.

Set-up is 60/110 crank, 28mm Keihin PWK, BGM V4 clubby and an AF close ratio 4 speed box using 49/20 sprockets (4.9 FDR). This gearbox/sprocket set-up gives a touch more top speed, which I like, but does make pulling away up steep hills harder

During/since my Spain trip, fuel consumption has noticibly decreased though and ironically, I'm wondering if the reeds would affect this and so are ready to be replaced, but haven't had the time to investigate yet.

Would I recommend this kit for someone wanting to build up a small block engine for everyday/touring use and not costing the earth? Oh yeah

Lozmondo, if you've already got the RT definitely consider the M210 for the contrast. I've got one which I'm in the early stages of building and really looking forward to completing it

Thanks mate,

I'm considering my TMX27 and a BGM V4.

If you've done 10k without replacing the reeds, now may be the time!

Great mileage which helps with my decision. Thanks again.

[Cgt75b]

Why don't you give Harry a ring at Pro porting I'm sure he'd be happy to chat you through it. His 175 cast barrels will sit at 55/60 all day long.

He's not called Harry big jets for nothing though so your economy on fuelling may go out the window.

Good luck in your decision making.

Cgt75b.

[HxPaul]

Its a pity that you wont consider nikasil lined alloy cylinders.In your first post you describe the Casa 185 to a tee.I have 2 Casa 185 kits and a casa 210 for the big block motor(big brother to the 185's.Out of production now)All three run through an undrilled airbox with a filter and a clubman exhaust,they also have 12v ignition and lighting.1 of the 185's and the 210 use a PHBl 25 carb,the other 185 uses a scootopia 22mil carb.The 185's do about 100 mpg(depending how there ridden)the 210 does about 70.As for speed,the top end is nothing to write home about,but they'll cruise about 55/60 mph all day.I've done thousands of miles so far and never had a problem.

[burnside]

I'm running the 186 and 200 GT kits, only reed break I had was early on and before I had doubled up, I have covered just over 13k miles with the 2 kits since doubling up and no reed issues. Did this year's Euro on the 186, 1300 faultless miles, economy was around 11 miles per litre but is running rich, especially mid-range, and not helped when riding at altitude. Really good kits, can't praise them enough.

[Scooterdude]

I just dont see why you would double up on the reeds, all you are achieving by doing this is “papering over the cracks” would it not be a better idea to relieve the areas of the casting were the reeds ar touching? Or fit a spacer to pull them back from touching the piston if this is what’s happening.

[Solid Air]

As I understand it, doubling up the reeds is not related to the barrel casting but because they were originally used in karting and the higher degree of flexibility required due to the higher engine rpm & characteristics which doesn't allow them to work too their optimum on a lambretta.

Happy to be corrected though.

Mark

[EddieStone]

I think you should decide what type of touring you're planning. If it's 'cover as many miles as possible' touring then a GT186 is probably the best bet. Fuel consumption is acceptable and I guess reeds don't take up much space. My concern would be more grounding the pipe as you don't really know what road conditions you'll be dealing with. Good kit, by all accounts.

If it was a more 'touring for the experience' type of tour where miles covered isn't such a big deal then I'd go for a more standard 175/185 tune, and aim for 60-70miles per gallon. (My 2.5litre car will return close to 40 mpg at 70mph and that has an 80 litre tank.) I don't really consider it practical to cover long distances with such a short range.

Another concern is oil. I'd prefer a 2% mix, 3% at a push. When you get to 4% you are going to have to deal with carrying a lot of oil, or gambling with what's available en route. A longer range engine with a lower consumption for oil would be my preference, at the expense of power and speed. Use smaller roads, see more, experience more. If you're touring by motorway and just getting from one place to another, then the GT186 is probably a better option.

[Scooterdude]

As I understand it, doubling up the reeds is not related to the barrel casting but because they were originally used in karting and the higher degree of flexibility required due to the higher engine rpm & characteristics which doesn't allow them to work too their optimum on a lambretta.

Happy to be corrected though.

Mark

I understand that the reeds are far more flexible than they should be for this application and see why people are doubling up in an attempt to create a more solid mass with less flex, ok i see this but the guy on Facebook with the split reed had witness marks were they had been contacting with the casting as well as the piston also.

Surely the makers should have addressed this issue by now? And started supplying a more suitable reed. When Darrell Taylor pointed all this out to the makers, instead of taking this on board he got all defensive and dismissive.

Darrell was saying on his builds using this kit he used his own reed without issue which he is now offering to the public.

[Solid Air]

Totally agree with you Scooterdude. When I first got the kit I contacted RT regarding a couple of issues which he said they were aware of but that he had other priorities. This obviously means we have to fettle parts to make them work optimally, which as we know is not unusual. He has been very helpful with other help and advise though and it is a good little kit despite the issues I encountered.