MadaboutKitcars

So far so good!

Been busy doing the wiring.



Also set and painted the floor.



As the pedal box is now in place I'll start the copper clutch and brake lines next.

Finally completed the fitting of the driver side bulkhead including the pedals, servo and clutch cylinders.



Also fitted a radiator which will need a header tank.

Finally got to spend some time on the Jag today.

The inlet manifold Mk1.

Finally got to spend some time on the Jag project.

Made Mk1 manifold set-up.
It consists of a pair of Yamaha XS750 triple carbs, bridged together to make one bank of carbs which will be operated by twin throttle cables.



I'm calling it Mk1 as I'm not sure if the carbs will clear the bonnet and I can't check as the car is buried in the back of the workshop until the weekend.

Very interesting. Should sound great too.

Finally got around to trial fitting the first set of carbs.





They look good and do clear the bonnet but I have just realized these Yamaha XS750 carbs have a manual choke which will be a real pain to convert to a cable operated affair so maybe a re-think is needed.

Had a re-think on the bike carb set-up and think these will be better.





There Mikuni 38mm replacemnt jets are easy to get, they use a single throttle cable, single choke cable and have a TPS in case I need to fit a mega-jolt system.

They are also half the weight of the Yamaha carbs.

Finally got time to see how the new carb set-up fits on the engine.





They seem to fit much nicer and look much better than the Yamaha carbs.
The air filter choice will be critical to the final appearance.
Overall I'm very pleased with the up-grade.

Nice!

Should sound awesome too.

You could go seperate sock filters then with a metal shroud/cold air scoop covering those to keep it in keeping with the car?

This sort of thing ?

https://forums.hybridz.org/uploads/monthly_07_2014/post-29570-0-38332200-1405040722.jpg

Picture taken from this thread

https://forums.hybridz.org/topic/118751-air-box-design-webermikuni-whorns/

I like that idea as it will also keep the intakes in clean / dry air.

Possibly mr towed did the same in his Sammio?

Yes, pretty much. I needed the airbox to accommodate the methanol injection system -





I ran it like that for about three years before switching to bigger carbs, removing the methanol injection and running it with mesh trumpets -

Looks cool.
Have you still got the methanol system and did it work?

Also do you still want a Cordite/Spitfire fiberglass bulkhead?

The methanol/water injection system was something I'd always been keen to put together and try. I'd come across it in the RAF as it was fitted to the Harriers we used to take the Falklands back and I knew it had been fitted to the Supermarine Spitfires we sent for the Russians to use against Adolf, which meant they could run on the sub-standard, low octane fuel that was all the Russians had available.

Without going into too much detail about the why's and wherefores, it did work very well, mostly - the engine ran much smoother and economy improved by about 10mpg with it switched 'on', but the very fine nozzle needed for a 100hp motor kept clogging up despite the filters in the system.

I removed it and sold it on ebay, for about £110 as I recall, which was around double what I'd spent on the parts (don't pay a tuning specialist £200 for a 'water injection' pump, it's actually a £30 fish-pond pump put to better use).

If I fit another low powered car with Methanol/Water injection, which I probably will, I'll go with a gravity fed exhaust manifold/capillary system, which is obviously much simpler than the high pressure pump, solenoid and superfine nozzle I used last time.

I would definitely be interested in relieving you of a fibreglass bulkhead. PM me with the deal you'd consider (hopefully a simpler one than Brexit) and we'll sort something out.

Methanol-Wasser 50


As a bit of a WWII aircraft geek, I was immediately reminded of this:

https://en.wikipedia.org/wiki/MW_50

Regards, Mick

That's a great article, Mick, thanks for sharing it. It explains exactly why I fitted it - to allow the Vitesse engine, designed to take 100 octane (5-star) fuel, to run on 95 Octane modern unleaded without running in to detonation issues (pinking, for those old enough to remember that).

I tried various ratios of water to methanol and settled on a 10% methanol solution. The positive effects mostly come from the water anyway, so you could run 100% water injection, but some methanol still really needs to be added as it stops bacteria growing in the water and clogging up the pipes and nozzles.

The simplest form of water injection is just a water tank located above the exhaust downpipe but below the intake manifold, with a gravity fed copper capillary tube running from the water tank wound a dozen or so times around the exhaust downpipe. That is then connected to the air intake tract on the throttle side of any filters.

With the engine running, once the exhaust heats up, the water in the capillary that's wound round it boils. The steam created can't go back towards the tank because of the flow of cold water, so it exits the capillary into the intake tract, where it is sucked into the engine along with the incoming air.

As the wikipedia article explains, that has the effect of cooling the inlet charge and increasing its density, which can give around a 30% increase in power on a highly tuned engine (less so on a standard engine). Steam has been proven to have exactly the same effect as cold water in doing this, btw, and there are a host of side-benefits with no down-side.

My original plan on fitting it to my Spyder was to modify the engine, raising the compression ratio and fitting a wild cam to make best use of the benefits of water injection, but, in reality, around 100hp was quite enough to enjoy a very light car on the road anyway.

I can't say exactly how much extra power the system gave my mk1 Vitesse engine as the day I put it on the dyno to check was the day the system decided to clog itself up and stop working for the first time. That was ultimately down to the very fine nozzle needed on a low powered engine - I'd run the calculations to get the correct volume of water in the inlet charge and too much can cause a hydraulic lock in the engine which is likely to either bend the con rod, smash the crank out through the sump or blow the cylinder head off.

Anyway, that really sums up the joy of self-build cars - building and fitting a methanol/water injection system not because it needed it but just because I could.

Was that what Nubodi were selling?
Snake oil?

They were selling some kind of water injection system that gave greater mpg and performance.

A potential donor for someone in Scotland - https://www.ebay.co.uk/itm/303031515969

Ahh, okay, hadn't seen that. It does work, though.

As a matter of interest Mr Towed, where were you getting your methanol from and were you self-mixing?

I’ve just installed a system on my supercharged MGB Locost to reduce pinking. I’ve been put off self mixing a bit having read how nasty the stuff can be!

(If you are ex-RAF, then I’ll add....but not as nasty as AVPIN!)