Cam belt drive

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Re: Cam belt drive

Postby Hans Efde » Thu Nov 01, 2012 12:13 am

I don't think there is much to win in fuel consumption if you compare fuel injection with a proper adjusted SU carb. SU carbs are still amazing in how they perform. But setting up by grinding the needles is something I am a bit fed up with. Also with a tuned engine it is sometimes impossible to get it right through the whole rev. range. And you have to choose for power or for efficiency, you can't have both.
That's why I got the multimap Emerald ECU. I hope to get it quiet, smooth and fuel efficient for the long hauls and when switched on to an other map to be a complete hooligan for the circuit or on a nice piece of curving road. I got a three way switch for on the dashboard when I bought the computer. It seems the third map is usually used for a pop'n bang setup. Nice for a crackling exhaust note when driving through a tunnel or in the mountains. Can't wait to get it running and play endlessly with it on the laptop.
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Re: Cam belt drive

Postby max midas » Thu Nov 01, 2012 12:04 pm

It's the proper setting up of the SU that bugs me, have rolling roaded a couple of times, and hoping to slim down exactly the part of the needle that corresponds to the rev range you're looking for without making either side of that range too rich is too difficult/costly. My Midas is currently only achieving 35mpg on a long haul, I'd have thought that's not really good enough for a 1293 with a 266 cam.
I'd like to give the engine the correct a/f ratio throughout the rev range except around 3250-3500 where it'd be a bit leaner for motorway cruising, is that possible or even good for the engine?
I do like the three way switch idea for optional hooliganism :D , maybe I could sort out a Bluetooth link with phone to switch the megasquirt map, though may not be as simple as that.
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Re: Cam belt drive

Postby Hans Efde » Thu Nov 01, 2012 12:34 pm

max midas wrote:It's the proper setting up of the SU that bugs me, have rolling roaded a couple of times, and hoping to slim down exactly the part of the needle that corresponds to the rev range you're looking for without making either side of that range too rich is too difficult/costly. My Midas is currently only achieving 35mpg on a long haul, I'd have thought that's not really good enough for a 1293 with a 266 cam.
I'd like to give the engine the correct a/f ratio throughout the rev range except around 3250-3500 where it'd be a bit leaner for motorway cruising, is that possible or even good for the engine?
I do like the three way switch idea for optional hooliganism :D , maybe I could sort out a Bluetooth link with phone to switch the megasquirt map, though may not be as simple as that.


I am not sure it works that way with the Megasquirt. The Emerald has it built in. But it is always possible to fool the ECU. My engine builder also races a standard injection Mini. But by flipping a switch under the dash the value of the lambda probe is changed so the ECU thinks the engine is running lean and pumps out more fuel. After the race it is switched back and the car is road legal again with proper emissions.
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Re: Cam belt drive

Postby Rich » Thu Nov 01, 2012 2:03 pm

max midas wrote:It's the proper setting up of the SU that bugs me, have rolling roaded a couple of times, and hoping to slim down exactly the part of the needle that corresponds to the rev range you're looking for without making either side of that range too rich is too difficult/costly. My Midas is currently only achieving 35mpg on a long haul, I'd have thought that's not really good enough for a 1293 with a 266 cam.
I'd like to give the engine the correct a/f ratio throughout the rev range except around 3250-3500 where it'd be a bit leaner for motorway cruising, is that possible or even good for the engine?
I do like the three way switch idea for optional hooliganism :D , maybe I could sort out a Bluetooth link with phone to switch the megasquirt map, though may not be as simple as that.


I'm running a ported 1330 with a 266 and a HIF 44 carb, on a run I see 55mpg and that's with an electronic speedo/odometer that is dead on. The only thing that's any different is I'm also running Megajolt.
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Re: Cam belt drive

Postby max midas » Thu Nov 01, 2012 11:24 pm

So if I at least get the spark at the right time, I should get better mpg. The right fuel as well and my Midas will be well cheap to run :D
Speaking of petrol costs, I'm considering going over to LPG for our Campervan, does anyone have any experience in these matters, companies to recommend or stay well clear of?
Thinking about it, a well sorted Midas on LPG must be one of the cheapest forms of motoring possible!
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Re: Cam belt drive

Postby manifold » Fri Nov 02, 2012 11:43 am

Yes you will get better MPG as you will be able to map the spark to suit your engine. It also works on the wasted spark principle sparking at the bottom of the stroke as well as the top. Lots of Maps around to suit your engine. I bet Rich's map will be a good starting point too if he's getting 55MPG. Another advantage of the Megasquirt/Megajolt and Probably other Systems like Emerald (I dont have much info on that one but Hans does) is that you can drive at Water Puddles and heavy without fear that you will have spark missfire as the systems are pretty well water resistant as long as you keep the ECU somewhere dry, (like inside the car, although in a Midas that is debateable).

I fitted an LPG kit in an E Class Mercedes about 4 years or so ago. I installed it over several days fitting a bit at a time. My wife used the car daily to get to work while I did it. I found that I didnt notice any reduction in power at all.I had to changethe plugs more often thats all. Main thing was to remember to let the car warm up before switching over to LPG as the solenoid can freeze without having the water system heating up the vapouriser..causing the air filer housing to 'pop'. The saving on fuel was great. I could buy LPG for 45p a litre at the local garage when at that time unleaded was about 95p a litre. My wife was commuting 65 miles each way (so 130 miles a day) and it was costing £50 a week in fuel. I consider that pretty good and the kit paid for itself in no time at all. Kit was about £450 back then. I just bought it from one of the LPG suppliers. WTV I think it was. http://www.lpg-kits.com/. Theres others like the LandRover people at http://www.tinleytech.co.uk although I dont know what they are like. The Merc used a toroidal tank (the more expensive one) which just fitted in the spare wheel well so you didnt notice it was there.

LPG burns very clean. Fascinatingly the oil that I took out at the oil change interval looked the same colour as it went in. There was no black death colour present. Some people reckon you can increase your mileage intervals for oil change because of this, although I didnt.

I have a spare LPG kit with sausage tank in the garage for an A series engine...using the SU intake. Just never got round to fitting it yet.

You can get pumps for pumping out from those 47KG propane bottles too (LPG is basically Propane/Butane). So you could even get your fuel delivered at your house if you have the storage. Cheap if you buy in bulk.

All the best,

David
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Re: Cam belt drive

Postby Hans Efde » Fri Nov 02, 2012 1:15 pm

What I also like from computer ignition is that you can have a start map and when the engine gets above a certain rpm, the ECU switches to the running map. This is the reason why modern cars start so much quicker than engines with distributors.
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Re: Cam belt drive

Postby max midas » Sat Nov 10, 2012 11:20 pm

:shock: WARNING!! :o
If you're going to put a timing wheel on your crankshaft pulley so you can install megajolt/squirt/Emerald/Canems/etc,
DON'T fix the trigger wheel before you've decided the most sensible place for the VR pick up.
I did :roll: and it's taken ages trying to make a bracket that has the VR sensor in the right place, but doesn't foul the water pump/alternator belt.
Perhaps the pictures show better than my words:
http://i1273.photobucket.com/albums/y40 ... ELARCH.jpg

I've made this rather complicated bracket to hold the sensor in the right place (pensil hanging over the side gives correct diameter of trigger wheel)
http://i1273.photobucket.com/albums/y40 ... 012229.jpg

hopefully the belt won't catch, and the VR sensor is supported in two dimensions so it shouldn't vibrate and break.
http://i1273.photobucket.com/albums/y40 ... 012232.jpg

Any comments or suggestions?
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Re: Cam belt drive

Postby manifold » Sat Nov 10, 2012 11:36 pm

Looks generally to be in the right place to me. Similar to mine.
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Re: Cam belt drive

Postby max midas » Sat Nov 10, 2012 11:39 pm

If I did it again, I'd put the gap at the zenith of the trigger wheel so the VR pick up would be a little lower, so the bracket would clear the fan belt more easily.

Right, get it painted and installed. :D
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