Mr K
Posted a lot
Posts: 2,993
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Feb 23, 2006 20:35:35 GMT
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My new supercharger arrived today (thanks jonny69), looks perfect. Now you guys have all said that you cant run them off the fanbelt? but ive seen lots of pictures of this? For example. Also, how is the pulley held onto the eaton m45? and what is this plug (circled in red): Not much room behind it on the bulkhead, so will need to make a custom inlet (dom, can you make one with a 180 elbow?) I am also tempted to make some kind of chin spoler, in a simular design to this: (stolen from slaters post) Just a little less crude, and the ends tapering in rather than ranning out. Nick
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Feb 23, 2006 20:43:09 GMT
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isn't that a serpentine, multi rib belt? modern cars run everything off them (PAS, a/c, alternator,waterpump etc.), can't see why you couldn't run a 'charger as well as the other ancilleries on a single belt. alternator, water pump and 'charger, in your case
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Feb 23, 2006 21:02:07 GMT
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Is it advisable to run a charger off the ancillery belt though? I bet those things put a hell of a strain on belts, hence why they usually run their own that then goes to a pulley elsewhere.
Then again, I've seen big blown V8's that have single belts, but we're talking 2" deep belts ;D
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SidewaysGTM
Part of things
Spending my time at the Race track, Pub or in an Engine
Posts: 227
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Feb 23, 2006 21:36:40 GMT
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On my MUMS 1990 mustang when we ran a supercharger on that, the Vortech kit used a seperate serpertine belt and tensioner, a good reaons for this is if you running a lot of boost you will have to have a very tight belt to stop slipping, along with good pully wrap, which is easyier to achieve on a seperate belt, the extra loading on the belt may put too much load on the alternator bearings i guess if you used one belt for everything, just my thoughts, have a couple of good books at home about supercharging and one is excellant on things to consider such as bracket design etc think its called maximum boost or something like that
WEST
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Live life sideways, Honda Powered GTM Coupe, you better belive it GTM Coupe VTEC Constant progression and acceleration 67' Triumph Vitesse 2ltr [finally decided what to do with it, at the planning stage] 92' Mini nearly std [SOLD and Missed] GTM ownersclub forum
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Feb 23, 2006 22:02:29 GMT
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Right well it can be done, on a hillman imp the fan for the radiator takes 8bhp at around 8000rpm to spin. But the problem is that the belts WILL slip at higher load, as they slip they polish both the belt and the pulley, once this has started its a downhill slide. This is the power taken by the supercharger - I'm going to go for a ally toothed pulley and polyurethane belt reinforced with steel braiding, this can take 30Kw and 10000rpm. This def wont slip and can transmit all of the power from the engine, there wont be any boost fluctuations and so the engine will be totally predictable. The problem with a V belt in the lower gears is that the rapid rise in RPM means the inertia of the lobes in the supercharger will cause the belt to slip, and so the boost will drop, its kinda like a traction control! Try here for belts and pulleys fp.transdev.plus.com/index.htmThe pully on the front of the supercharger is temperature differential interferance fit, I.E. very difficult to remove. If you look at the pulley there is a weld about half way along, I'm going to carefully grind this weld back so that half the pully stays attached and the other half drops off. This will leave you with a flange to drill and mount you preffered pulley to. cheers J
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Mr K
Posted a lot
Posts: 2,993
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Feb 23, 2006 23:29:45 GMT
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I realise there will be higher load on the belt, and i had been looking at converting it to run on toothed pulleys and belts, as i already have a water pump like this and the rest would be easy, but i did not realise it was so hard to take the standard pulley off the blower. Doh. the problem is the water pump has a deep pulley with alot off ofset to it, which means it sticks out at the front just where i don't want it. i will look into whether or not i can get rid off, or atleast reduce it, otherwise i need a big step of about 1.5" atleast between the blower pulley and the aux pulley. Tomorow i will look and see if i can have the belt going around it or if it misses. How do i go about working out what size pulleys i need? i want effective engine power between about 3-5k, and red line at 7500k for safety reason (its should be good for 9k) Thanks for the site and advice... off to my drawing board now P.s. is BlownImp II going to be turbocharged and supercharger by any chance? thanks again, Nick
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Last Edit: Feb 24, 2006 0:12:08 GMT by Mr K
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Feb 24, 2006 12:01:27 GMT
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hehehhe yeah! T3 from a 2L monetego and a supercharger, the blower should spool it at around 3000rpm! h1.ripway.com/twincharged/TurboclaculatorIC-setupforreliant.xlsThis is an excel file that shows how much boost you will get at any RPM, realisticly it will boost from about 1500rpmish. All of the orange boxes can be changed and the outputs will automatically change. J
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Last Edit: Feb 24, 2006 12:01:51 GMT by Blown_Imp
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Feb 24, 2006 12:08:26 GMT
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Just had a look and the blower volume box is currently at 0.0005, change this to 0.00075 for the mini supercharger
cheers
J
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Mr K
Posted a lot
Posts: 2,993
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Feb 24, 2006 16:12:31 GMT
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Thanks mate, just amended it for the 748cc engine. h1.ripway.com/nickkeyser404/TurboclaculatorIC-setupforreliant-1.xlsthat look ok? or am i missing somthing? What should i use in the intercooler box? as I'm not using an intercooler, and i assume the engine effciency ect are just standard figuires? That looks perfect, my desired boost and power, hoever the blower rpm is abit on the low side, but it does spool at n he the desired 2500rpm to be on song for the 3-5 or 6 k power band that i wanted, and in not over the top by the 7500k red line. Blownimp II sounds awesome!! what power you expecting?nd hatbdy work plans have you got? Many thanks for the help. Nick
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Feb 24, 2006 16:44:48 GMT
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For the intercooler box use 1 if the final power is of concern, and zero if the outlet temperature is needed. The power figure is only a reference and not cast in stone!
The mini super chager is a 'roots' type supercharger, this means that it is positive displacement and moves a fixed volume of air per revolution. In the M45's case that volume is 750cc, this means that the supercharger dosent spool, its constantly on boost. As soon as the engine is spinning the supercharger is moveing more air into the engine than is natural and so it makes boost from idle.
Spooling is something that a turbocharger does, this is where the volume of exhaust gas is significant enough to spin the shaft, and so spin the compressor to move air. This is a centrifugal type of compressor, and needs to be moving at a fair rate to stop the air spilling back into the inlet again. At the point where is can move more air than the engine naturally takes in it starts to make boost.
On my car the supercharger will boost from idle, this means that the engine will be making more exhaust gas than it naturally would as more air is going into the engine. As there is more exhaust gas, i can spool a larger turbo earlier than without the supercharger. The engine will make 9psi boost up to around 3000rpm and 50bhp, then the turbo cuts in and the boost rises to 12psi and it makes around 120bhp at the red line.
One thing i would be cautious with is the race cam you have for this engine, do you know the specs of the cam? If it is a wild race cam the it will have a lot of overlap, this is where the inlet and exhaust valves are open at the same time to pormote better scavenging. The problem with this is that the supercharger will just blow through the inlet into the cylinder and then out of the exhaust, meaning less boost and running problems.
J
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Mr K
Posted a lot
Posts: 2,993
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Feb 24, 2006 16:59:52 GMT
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For the intercooler box use 1 if the final power is of concern, and zero if the outlet temperature is needed. The power figure is only a reference and not cast in stone! The mini super chager is a 'roots' type supercharger, this means that it is positive displacement and moves a fixed volume of air per revolution. In the M45's case that volume is 750cc, this means that the supercharger dosent spool, its constantly on boost. As soon as the engine is spinning the supercharger is moveing more air into the engine than is natural and so it makes boost from idle. Spooling is something that a turbocharger does, this is where the volume of exhaust gas is significant enough to spin the shaft, and so spin the compressor to move air. This is a centrifugal type of compressor, and needs to be moving at a fair rate to stop the air spilling back into the inlet again. At the point where is can move more air than the engine naturally takes in it starts to make boost. On my car the supercharger will boost from idle, this means that the engine will be making more exhaust gas than it naturally would as more air is going into the engine. As there is more exhaust gas, i can spool a larger turbo earlier than without the supercharger. The engine will make 9psi boost up to around 3000rpm and 50bhp, then the turbo cuts in and the boost rises to 12psi and it makes around 120bhp at the red line. One thing i would be cautious with is the race cam you have for this engine, do you know the specs of the cam? If it is a wild race cam the it will have a lot of overlap, this is where the inlet and exhaust valves are open at the same time to pormote better scavenging. The problem with this is that the supercharger will just blow through the inlet into the cylinder and then out of the exhaust, meaning less boost and running problems. J The cam is nothing too wild, and i have a good array of standard, mild, and this fast road / rally cam, until i get the block built i cant realy measure all this. a 37mm diameter pulley on the crank, and the 65mm pulley on the blower should give me what i want? right? Thanks again (sorry if i seem to be abit of a slow learner!) Nick
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Feb 24, 2006 17:09:18 GMT
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No you not a slow learner at all, its taken me years to get where i am now! That pulley ratio will give a smige over 7psi so should be absoutley fine And 70bhp woooot!!! I would go for the rally cam, this is the best compromise when it comes to supercharging. At the end of the day a long duration cam is only useful to get high rpm out of a normally aspirated engine by giving it lots of time to get the air in. The supercharger just forces it in so no need for the big cam!!! J
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Mr K
Posted a lot
Posts: 2,993
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Feb 25, 2006 12:54:41 GMT
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Woo 70hp, and 500kg!! cheers! No you not a slow learner at all, its taken me years to get where i am now! That pulley ratio will give a smige over 7psi so should be absoutley fine And 70bhp woooot!!! I would go for the rally cam, this is the best compromise when it comes to supercharging. At the end of the day a long duration cam is only useful to get high rpm out of a normally aspirated engine by giving it lots of time to get the air in. The supercharger just forces it in so no need for the big cam!!! J
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Feb 25, 2006 15:59:42 GMT
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You can buy a tool to get the pulley off, it clamps exactly around the old pulley and has a bolt that you tighten against the shaft to ease the thing off. It's just a very tight interference fit, not welded on or anything. I reckon a small hub puller would do the same job but probably damage the pulley.
By the way, your old blower was just what I was looking for - top swap! I'm going to strip it and change the bearings etc. Two questions if you know: does it need an oil feed? Any idea what car it came off?
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Mr K
Posted a lot
Posts: 2,993
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Feb 25, 2006 20:07:12 GMT
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Hi, its doesnt have an oil feed, you will find one of the bolts in the front at the top (i think) is a dipstick, it appears to be very simular to the toyota blowers of the 80s, however it is a nissan blower (was the sticker in the bottom of the box in a bag? if not it must be in my room and i will forward it onto u) and it appears to be the the same internals as that of the bigger strait six from the 80s (blowimp knows its name, 1U GZE or somthing) but i don't know exactly what it is from.
The two pipes are breathers for the bearings, and just need to go to the breather tank or carburettor, or even just to atmosphere.
What car are you going to put it on?
Glad your happy with it, give me a shout if you get stuck on anything about it.
Nick
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Mr K
Posted a lot
Posts: 2,993
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Feb 26, 2006 16:21:37 GMT
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AHHH! after seeing that fiat 500 using a reliant engine, i remembered that the fiat engine spins clockwise when looking at the front and the guy was still using the fiat gearbox, i thought i had best check my reliant engine span the same way as the blower.... Supercharger = anti clockwise when looking at the front (can someone confirm this) Engine = clockwise when looking at the front SH!T... i should have checked that sooner shouldnt I! plan B comes into action... (excuse paint, it was just a quick sketch) so if i spin the blower through 180degrees and stick it out front on some fancy mounts (probably a big bit of 8mm sheet metal and some supports welded on.)problem is solved, and i have definatly got room for Doms inlet, and the battery and bulkhead wont be in the way... just the radiator and front of the engine bay, but that can be all cut and removed.
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Last Edit: Feb 26, 2006 16:21:58 GMT by Mr K
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Feb 26, 2006 17:27:38 GMT
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Glad you're happy with my one! Any idea which end is 'in' and which is 'out'?
I've got two engines to play with. One is a 1660cc pre-crossflow, full race head etc and that's going in the car. I also have a 1760cc bottom end, but it's got the wrong pistons and the compression is only about 6:1 which would be ideal for the blower. I'll use the standard head and standard cam and toothed belts like you are thingking of doing. Will probably mount the blower on its side and have it suck through a 40 or 45 Weber. I'll mock it up on an engine stand first.
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Mr K
Posted a lot
Posts: 2,993
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Feb 26, 2006 17:44:02 GMT
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When you put on those peices of ducting, the inlet is the one with four bolts and a spacer (for a throttle body) and i beleive it will only go on one side.
Sounds perfect for what your doing, should be awesome!
Just looked and it should be fine to hang the blower out over the front, a plate on special nuts on the head studs, and thermostat housing, then also used as the outlet flange, holding the blower by the four bolts, and a leg to support the back.
should work perfect, just need to sort out a 37.7mm pulley, then i can get on and make the plate up.
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Feb 26, 2006 17:50:31 GMT
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Mr K
Posted a lot
Posts: 2,993
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Feb 26, 2006 18:11:00 GMT
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Ah so they do spin clockwise? I realy hope they do. just auto.howstuffworks.com/supercharger2.htm - i assumed the rotors would work in the direction shown here? How ever, have just played with it and as you say Dom, it feels like it works the other way around.... Is how stuff works wrong!?! Calling blownimp...
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Last Edit: Feb 26, 2006 19:07:28 GMT by Mr K
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