Coolie ignition timing

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NaughtyBits
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Re: Coolie ignition timing

Postby NaughtyBits » Sun Oct 01, 2017 12:26 am

There was a lot of confusion about the race getting cut short or cancelled mid way through due to increasing winds, so no winners as such. This being the 1st year for 40's to join in, they were allowed to leave with the wooden dinghy/old motor class.

Certainly the fibreglass dinghy/40+ you're remembering pulled way out in front very, very quickly. Next year, we're hoping that dinghy/40+ combo records a time that would put it near the top 5 fastest finishing times for dinghies.

But yes, there were 4 or 5 identical dinghies last year and I think the one with the 40 looked to be the second fastest, behind #38 - judging by the class starts and good ole unscientific eyeballing.

headdownarseup
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Re: Coolie ignition timing

Postby headdownarseup » Sun Oct 01, 2017 12:17 pm

Charles
How low are we talking on compression with 40's? Going back a bit here if we compare Keith's FVP and my FV, Keith's has 45 psi and my FV has 71 psi.Both engines apparently run well enough. Both engines have never been apart before so apart from worn cylinders or rings the only other variable in all this is probably going to be the proximity of the head to piston crown measurement. I'm confident that Jeremy will have similar data to support this.
A screw-in compression gauge is all i ever use to measure this, although i believe from talking to Jeremy about this that with some of the earlier 55cc 40 series engines the gap between piston and head (what i termed wrongly as "squish" before) can vary quite a bit with some of them.
Without going to the lengths of completely stripping down a powerhead the other easier way to get an idea of what's going on is to use plasticine (like Jeremy) down the plug hole and turn the engine through past TDC and measure the squashed plasticine to see how big that gap really is.
As i've said, with some of them this gap can be small and in others fairly big and the difference in compression when measured via a compression gauge can be seen clearly.
When it comes to ignition timing if this compression is found to be on the low(ish) side i think for most of them after a hard life could benefit from a little tweak to reduce the advance a little bit and help with starting. Jeremy has already done this with a few of his.
I tried asking the question earlier about how much is enough? How much compression does a seagull REALLY need to be reliable and easy starting, and as you've seen this varies a lot now. As long as the ignition side of things is strong and healthy, whatever compression an engine can make these days is down to how worn a cylinder or rings are, BUT is there a minimum amount we should be wary of before things go belly up?
102's on the other hand generally work out to have a bit less (sometimes a LOT less) in the way of compression,not always because they're knackered but because of design and as we know have an integrated combustion chamber. Not much can be done here in the way of increasing compression apart from new rings and plenty of oil in the fuel. Again timing issues will occur with some of them and of course there will be limitations with the dimple or not. 40 something degrees of advance may or may not be helping here when it comes to starting the poor old thing. I try to tweak mine to around 30 (ish) degrees and so far no problems, but there again the compression isn't what it was.

Depending on the state of how good or bad a coil is these days, i think it's fair to assume that a lot will be tired by now. Pot luck with a lot of them.
Any news yet on coil re-winding? I'm sure there will be plenty of customers queuing up for this by now. (as long as it's affordable)

Jon

Gannet
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Re: Coolie ignition timing

Postby Gannet » Sun Oct 01, 2017 5:05 pm

Hi Jon,
I have dug out some figures for compression values:-

FV1786--- 48psi (Not been stripped for at least 50 years)
FV1867T--- 65psi
FV2682 --- 65psi
FV2821--- 65psi
FV3048--- 63psi
FV6353--- 60psi

Jeremy

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Charles uk
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Re: Coolie ignition timing

Postby Charles uk » Sun Oct 01, 2017 7:05 pm

Therein lies the problem Jon.

There are no component parts for these coils other than the wire & the paper separation material.

So all the coils must be stripped so the paper case tube, brass HT button, mica sheet square, primary coil, core lamination & Bakelite end piece can be re-used , the points connection will have to be desoldered & the internal grub screw that connects the primary winding to the secondary loosened.

I will also have to drive to Northampton to measure up the coil winding machine which I believe will wind 5 at a time, & design & manufacture all the components required to turn 5 cores into 1 shaft that is suitable for the winding machine.


These coils will only be close to economic viability if the owners stip them themselves.
The cost of their share of the required fixtures & fittings will have to be added to each coil.
Make it idiot proof and someone will make a better idiot.

headdownarseup
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Re: Coolie ignition timing

Postby headdownarseup » Mon Oct 02, 2017 6:43 pm

That's interesting Jeremy.
If we were to take an average of say 60psi for something that is still in adequate running condition, then we can assume (according to Keith's FVP with 45psi that still runs well) these 55cc gulls will tolerate a bit less compression and still manage to run well enough provided the ignition passes muster.


Charles
That sounds like an awful lot of work to be entrusted into an owners hands that doesn't know what they're doing. Perhaps when you get a bit nearer to this operation you can give us some detailed photo's of what you need doing and how we can do this prior to rewinding a coil.
There must be quite a few dead gulls waiting to come back to life again because of this.
Ballpark what are we talking pound notes to re-do a coil?

Jon

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Charles uk
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Re: Coolie ignition timing

Postby Charles uk » Mon Oct 02, 2017 7:09 pm

I think you should ignore Keith's 45 lbs figure, using a push in gauge held in one hand & with the other pulling the starter rope, might not be the best way for an accurate figure. It felt better than that to me!
I haven't got an ignition in bits at the moment or one that needs stripping, if you've got one that needs doing Jon, could you count the turns in each layer, diameter of that layer & the number of layers, it would help provide an a more accurate average, as these were wound one at at time by women at Villiers & can differ quite a lot, these numbers could enable a more educated guess of how they were designed, turns & layers or length of wire.

No idea of the cost as we need to write the recipe first, & have no idea of the fixtures & fitting cost.
Make it idiot proof and someone will make a better idiot.

headdownarseup
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Re: Coolie ignition timing

Postby headdownarseup » Mon Oct 02, 2017 7:59 pm

Firstly, yes i have a coil or two that are dead.
Secondly i/we need some careful instruction in how to take it apart.
Thirdly what exactly am i counting?

I have one with a damaged outer paper tube that i don't mind taking to bits for the cause if it helps get things started. Not so keen on stripping one down from a baseplate unless there's clear instruction beforehand.

Jon

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seagull101
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Re: Coolie ignition timing

Postby seagull101 » Mon Oct 02, 2017 8:12 pm

I have a few dead flattop MK1 coils that i could strip down and photo if it helps, i also have a coolie one with a damaged paper tube.

Jacob

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Charles uk
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Re: Coolie ignition timing

Postby Charles uk » Mon Oct 02, 2017 9:28 pm

Thanks Jacob, don't need to rewind mk1s as you can get eastern replacements.

"could you count the turns in each layer, diameter of that layer & the number of layers,"

Oh & the thickness of the wire with insulation removed.
Make it idiot proof and someone will make a better idiot.

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seagull101
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Re: Coolie ignition timing

Postby seagull101 » Mon Oct 02, 2017 9:47 pm

Charles uk wrote:Thanks Jacob, don't need to rewind mk1s as you can get eastern replacements.

"could you count the turns in each layer, diameter of that layer & the number of layers,"

Oh & the thickness of the wire with insulation removed.


I know but it would give a rough idea of what to do, just trying to help.

Jacob

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Charles uk
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Re: Coolie ignition timing

Postby Charles uk » Mon Oct 02, 2017 10:11 pm

Good point, all you'll need is a soldering iron, solder sucker & some methylated spirits.
Make it idiot proof and someone will make a better idiot.

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seagull101
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Re: Coolie ignition timing

Postby seagull101 » Tue Oct 03, 2017 5:45 pm

I will try to buy some methylated spirits.

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Charles uk
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Re: Coolie ignition timing

Postby Charles uk » Tue Oct 03, 2017 6:34 pm

One litre should be enough & a glass jam jar & lid.
Make it idiot proof and someone will make a better idiot.


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