Needing Air

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Can anyone suggest a thin coating product that is impervious to immersion in petrol (no ethanol mixed).
Ta.
 
I use a car type PCV valve. I suspect it only works effectively at idle speed.
 
Kenny Dreer sold Krank PCV ~$100 for Peel to fit ahead of oil tank but a bit longer thinner version so laid nice and close to frame with just hose supports. Trixie Combat inherited it. Works as advertised but does not lower pressure much or any below ambient like the reeds of course for a few extra hi rpm hp.
 
Re: Needing Mechanicals

The bottom end is still waiting for con rod nuts so I spent a few hours fitting rings to pistons, pistons to bore, machining for a captive magnet, flushing oilways, checking end float, fitting seals, etc. The magnet is a 10mm x 3mm neodymium that is adjacent to the crankcase oil pick-up (if it had been fitted earlier it would have caught the ferrous particle that went through the oil pump return gears).
Ta.
 
Jumps out of airplanes reveals relationships of attitude, temperature and humidity on speed, with high humidity and higher temperature noticed more than height c/t, displacing N2 & O2 molecules, at least to 10,000 ft. in land speed and sprints the early birds catch more records in cool morning air. I pay attention to my climb out power entering steep hwy (with traffic already at speed appearing out of blinds) to like slight humidity above freezing vs below freezing dry air. Play with these to juggle mixtures to suit.
https://www.google.com/?gws_rd=ssl#q=at ... gine+power
 
Re: Needing Air Mechanicals

A couple of new arrivals in my shed so far today.
Sturdy little buggas with a 43.5% weight increase but I reckon they will fix the 'dropping skirt' problem.
The front skirt is machined flat on the aftermarket parts.
Ta.
 
Bores also get beaten and worn to flukes textures d/t to intake pulse backwash pounding so more slides mass should extend bore life and prevent slides from tending not to drop down immedicately.
 
Re: Needing Air but not in fuel

Hi.
I read about the BSA mod to AMAL float bowls for full throttle flow rate on this forum and thought the flow constraint is always the float needle seat orifice (not the needle clearance) at maximum flow.
As the upper lip of the seat bush is above the fuel height due to carby tilt angle on Commandos, the fuel will be aerated and frothing as it 'erupts' vertically into the fuel bowl. The mod makes more sense as a way to flow fuel horizontally into the bowl at, or below, fuel level.
Old parts modified for example. Black line is near my standard fuel level.
Ta.
 
I was shown the BSA fuel slot by NOC/UK members 15 yr ago and shared here. Nicer slicing shown than my crude slot. Peel would run out of flow on new 932 AMALS after a some seconds of WOT till I slotted bowls but still did not power as well as unmodified single 34 mm Miki carb. Amals would respond and pull better to upper 3000 rpm then the 34mm Miki beat the snot out of standard dual Amals. So the Amals were better on Peel in my 1/2 mile driveway steeple chase but disappointing beyond that so put them on my all factory Trixie Combat that is about slowest worse handling cycle out there but deliciously smooth and responsive -safe within legal-ish useage.
 
Re: Needing Air & Fuel Flow

While waiting for parts, I refined a few tweaks on my engine.
The inlet rocker caps new T-peice connects viton tube to the vacuum bluetooth sensor and to the catchcan oil extractor solenoid.
The carby inlets are interconnected and link directly to the tank taps. Banjos begone.
Bulkhead fittings replace bowl plugs for quick drain plus offers deep sump for detritis to settle away from the main jet orifice.
Ta.
 
Re: Needing Air Gap at Rotor/Stator

I set the gap for my rotor and stator using wrappings of paper so the stator only just eases over the rotor.
Tighten the capscrews, ease the paper out then double check with a brass feeler gauge (to be sure, to be sure).
Ta.
Sorry for the dark photo.
 
Re: Needing Air & Fuel Flow

needing said:
the vacuum bluetooth sensor
Click to expand...

What does this look like when its at home ?
How does it get on with +ve earth lectrics, or remind us this has -ve earth conversion. ?
What sort of vacuum would we expect to see inside the inlet rocker cap ?

How/why are the vacuum pipe attachments for the manifolds pointing UPWARDS on your manifolds there ??

Some rusty looking fasteners in some shots there, they don't get a spruce up. ?
 
Bike is on the road again.
Ball valve in Combat breather tower now in use, 4-petal reed valve removed from catchcan.
Low pressure/high flow filter fitted to clean oil on way back to tank from cases via catchcan (filter lead courtesy of comnoz in another thread).
Rubber glove shown in picture is after 10 minutes after engine shutdown.
Compression shown is with hot engine, wide open throttle and 3 strong kicks.
Ta.
 
IMpressive compression test values so highly suggest starting with slightly retarded initial timing and creep up to hints of back fire then on your own to adv any past that point and not expect to be painfully surprised kicking off. Oh is will run a bit better on enough octane if can tolerate risk to out kick the back fire but not worth it to me anymore.
 
It seems to me that 200 psi cylinder pressure would indicate something wrong like stretched rods or a cam or ca timing issue.

This may be a desirable figure for some applications, but a bit high for street use.
 
hobot said:
IMpressive compression test values so highly suggest starting with slightly retarded initial timing and creep up to hints of back fire then on your own to adv any past that point and not expect to be painfully surprised kicking off. Oh is will run a bit better on enough octane if can tolerate risk to out kick the back fire but not worth it to me anymore.
Click to expand...

Hi hobot.
I have a dyno booked for after I clock up a few more kms on these rings (Total seal) to set a new baseline and assess some other tweaks I have made. I will look at ignition timing then but in the meantime I am running off Tri-spark static setup which starts just fine.
Ta.
 
Re: Needing Air and Oil separation

Nater_Potater said:
Please expound on the rubber glove. Is it on the breather outlet? If this is 10 minutes after shutdown, what is filling it?
Very interested in your experiments!
Nathan
Click to expand...

Hi Nathan.
You are correct, I haven't explained the glove very well.
I ran a 4-petal reed valve in the catch can (this can caught all the oil from the Combat breather tower). This system burst a party balloon when it was attached to the catch can air outlet.
I removed the reed valve from the catch can and fitted a $1 13gram steel ball to the Combat breather tower to function as a one-way ball and seat valve (see earlier post in this thread).
A piston ring replacement bottom end teardown came to fruition yesterday so a 37 km ring bedding-in ride resulted.
Upon return home, I removed the breather hose from the tower and fitted a elbow hose with a latex glove cable-tied to the other end. I started and ran the engine up to 3500 rpm and the glove inflated but did not burst.
I shut the engine off so as not to 'cook' the rings and left the glove in situ. Ten minutes later, it was still inflated as you can see from the photo so confirming that the steel ball seats well in the breather tower.
When dismantling the glove, hot engine oil had contaminated the inside of the glove (see photo) and compromised the latex integrity - if I had then restarted the engine, I am confident the glove would have then burst.
My modified Combat breather system now has:
- ball valving at the crankcases
- oil/air separation at the catch can
- vacuum extraction of catch can oil via a 'proper' low pressure/high flow filter (was a fuel pump filter) to the oil tank
- vacuum extraction supplied one-way by engine at inlet rocker cover and activated by the catch can float switch
- vacuum operates at 3 to 5 inHg [delete mmHg] (to be confirmed now that rings are renewed)
- vacuum extraction duration is controlled by a time-delay relay
- air venting to atmosphere via base of air cleaner box
- partial recirculation of blow-by gases to carburettor air intake (optimum volume to be determined at dyno re response to hobot)
The momentary push-on switch mounted near the ignition switch is for manual activation of the t-d relay.
Ta.
 
Re: Needing Air and Oil separation

needing said:
- vacuum operates at 3 to 5 mmHg (to be confirmed now that rings are renewed)
Click to expand...

3 to 5 mm of hg isn't much of a vacuum - thats so close to atmospheric it may as well be called atmospheric.

Is that an AVERAGE of the internal pressure though - it should swing between being pressurized (at least a little) on the piston downstrokes,
and pulling a fair vacuum on the piston upstrokes. (??).
 
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