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DIY supercharger option - with EFI!!!

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Yankeedriver Avatar
Yankeedriver Platinum AdvertiserAdvertiser Joel Young
Albuquerque, NM, USA   USA
So, I've completed what I am satisfied is essentially exhaustive research (though I would welcome cheaper sources, obviously!), and can't find a better deal than this outfit on the professionally rebuilt M45 used in this conversion: https://www.buyautoparts.com/buynow/40-10018_R They want $550, plus a $300 core charge--which is ridiculous. Obviously, the thing to do is either get one from a wrecking yard for $50~60 and if not up to snuff or if one is uncomfortable rebuilding it one's self as I did, send it in and walk away with a professionaly rebuilt, warranted unit (1 year unlimited mileage). I may consider offering rebuild services, but having done the work, I have to say $550~560 including core is pretty hard to beat.

*Note: their weight is way off. These things weigh nothing like 35 lbs. If I recall, something like half that amount. Also, their listed dimensions are wrong, as Adrian and I have discussed in earlier posts.

I think I may have misstated the year/model range in an earlier post, and these guys appear to have it right based on subsequent research. This Eaton supercharger model no. 207018 was used on the 1999-2004 Mercedes Benz SLK230 Kompressor (without electric clutch) and only two years of the Mercedes Benz C230, 1999-2000 (without electric clutch).

I will lose light here pretty soon but should finish up the mounts and pulleys this weekend. The lawnmower bushes came in and they are much higher quality than the image in the page I linked to earlier suggests: apparently Grade 8 or equivalent. You have to put them on a 3/8" bolt inserted into your drill motor and kiss them with a piece of sandpaper or flat file for about 10~20 seconds so they'll slip into the idler pulley's inner bearing race. But I much prefer that to a slightly sloppy fit.

The CS121D internal fan alternator should be here in a couple of days, so I'll post photos of both alternator choices next weekend. Well, actually, I will get the CS130-style Saturn most of us are familiar with featuring the $10 bi-directional fan mounted today or tomorrow and will post pics.

Finally - I got bumped by a big government labs order at the machine shop which is tying up the CNC lathe for a week or so, but the 5-rib crank pulley will be available in the not-too-distant future... and we'll be off to the races!

Joel



Edited 1 time(s). Last edit at 2018-01-20 04:28 PM by Yankeedriver.


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Yankeedriver Platinum AdvertiserAdvertiser Joel Young
Albuquerque, NM, USA   USA
The thing I love about engineering performance upgrades for old British sports cars, is that it combines problem-solving with creativity and serendipity.

Today, I mounted the $10 bi-directional fan on the CS130-style Saturn alternator--which merely required: (i) swapping the thick Grade 8 spacer that was behind the OEM clockwise fan for two, thinner Grade 8 spacer-washers I had lying around (and which you can get at any hardware/home improvement store or the web), and (ii) putting a few more between the fan and stock Saturn pulley--which is dished on both sides--to get the fan j-u-s-t grazing the pulley while not pressing on and distorting the fan. Mine was ever so slightly bent, so once on the alternator, I just trued it with a pry bar--but a big flat-blade screwdriver would work fine.

I like using a big monkey wrench more than an impact driver, because it makes me nervous grabbing the fan and hitting the trigger (gulp). You grab it by the edges, not the inner grooves, and that way don't damage a thing.

Then, I just tapped the flange bushing flush to afford more fore-aft adjustment, and experimented with washers behind the alternator's forward mounting ear to align the pulleys.

Finally, I bent a gentle 'S' curve into the OEM alternator adjustment strap so it wouldn't bind, while still allowing me to use the long thermo housing stud to replace the lower 5/16" fine thread bolt as discussed earlier. As you can see, the pulleys line up to within a few thousandths--more than accurate enough for true belt tracking.

**Note: the neat thing about this uber-simple rear mount design--which facilitates that ultra-accurate belt alignment--is that the size of the radius for the bend you make in a vise as the first step in fabricating it is totally unimportant to the end result. All you have to do is make sure you drill the holes forming the terminus of the adjustment slots nearest the forward side of the mount, so that their edge is right around 1" from the plane formed by the leading or forward edge (see second micrometer shot). If you are short a bit, as I was, all you do is use a round file to extend the slots a bit... and bada-bing. Plenty of adjustment to align the blower pulley just right.

I then hung the belt and realized there was not enough slack with the idler mounted to the hole where the OEM alternator/generator adjustment bolt went. So, I simply moved it up to the angle iron mount. The end result--as I ran out of light and it started getting cold in the shop--was that my first impulse turned out to be the most straightforward: a sliding, screw-driven adjuster, such as fitted to my '98 Subaru and worked for 270K miles without a hiccup (and many other cars).

However, the optimum configuration for the Spridget might never have occurred to me, but for the front mount iterations I went through, etc. This final solution will be extremely strong, dead simple to adjust--since it will sit right on top and directly in front when you open the bonnet--and very easy to make with a vise and drill, or drill press, if you have one.

In short, the Spridget-specific adjuster will be a long bolt or all-thread passed through two 'L' brackets fashioned from leftover angle iron and bolted to the front mount. Then, a leftover piece of the aluminum bar used for the rear mount will be drilled and tapped left-right for the bolt or all-thread, and drilled and tapped fore-aft to receive a bolt, or more all-thread, for the idler pulley. You'll simply rotate the long bolt, or two nuts locked together at one end of the all-thread, to move the block holding the idler to the right in the photo, dialing-in the perfect belt tension. It'll use a simple clamping setup to lock down the adjustment. Voila.

Can't wait to finish it up next weekend--then I'm done with this project for now, and shifting over to fire up the EFI project! Then, I'll rebuild the motor and shift back here to hook up the blower!

Joel



Edited 4 time(s). Last edit at 2018-01-21 07:09 PM by Yankeedriver.


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Yankeedriver Avatar
Yankeedriver Platinum AdvertiserAdvertiser Joel Young
Albuquerque, NM, USA   USA
Oops - forgot to show the method for shaving the bushing to reduce the $11.00 Dorman idler pulley to a 3/8" bolt or all-thread. The bushing costs $1.29 at Lawnmower Parts World, and as you can see below is much higher quality than what their image depicts: https://www.lawnmowerpartsworld.com/lawn-mower-parts/pulleys/bushing-idler-pulley-375-id/

Although, come to think of it, I bought 11 of these bushings, so I'll just throw one in the box with each of the M45 blower adapters.

This job took about 60 seconds, machining for a few seconds, slipping on the pulley, rinse & repeat, etc. You want a nice, tight finger-press fit.

I thought I'd show a method for folks who lack a drill press. Most people have a drill motor, and if you're going to work on an MG, a vise is one of the best tools you'll ever buy!

Joel



Edited 2 time(s). Last edit at 2018-01-21 09:56 PM by Yankeedriver.


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Yankeedriver Avatar
Yankeedriver Platinum AdvertiserAdvertiser Joel Young
Albuquerque, NM, USA   USA
This post has more alternator research and information--pretty much the last bit, I think.

I got the CS121D, pre-clocked by Adam, and mounting-wise, it looks to be a one-for-one replacement for the CS130-style Saturn alternator. I'll double-check this weekend that it's a viable alternative from this standpoint.

Now, the much more open housing clearly shows the two internal fans, both of which are clearly oriented for clockwise rotation. We knew that, of course, but Adam's invoice acknowledges it was sold 'for reverse rotation,' or words to that effect, and he is a warranty center, and will honor it.

HOWEVER, an obvious, final alternative occurred to me: running the CCW alternator from the same VW Beetle, Passat, et al., that donated the 5-rib, double-sided belt. It's mounting ears are fine (no clocking required), and I think from scoping the pictures that the clutched pulley would put the forward mounting ear behind, rather than in front of the A-series water pump mounting lug.

Now, the VW alternator sports a whopping 140 amp output. That's more than I'll use with no A/C or power windows. However, I do run an electric fan, Hella halogens, dual horns, and with the EFI or supercharger, two electric fuel pumps, plus the heater fan and wipers on a cold, drizzly day... and with EFI, the ECU, injector, the idle air control servo, and several sensors (though their draw is quite small).

My understand is that an alternator's power output is current times voltage. So, if one were to draw the Beetle unit's full output, that would be 14V at 140 amps, which is 1.9 kW. kW and HP are both measures of power; much as meters and feet are both measures of length. They can be converted from one to the other by a simple conversion factor. The conversion factor from kW to hp is about 746 W to 1 hp. So the output of the alt at max output is about 2.6 hp. Since it's not 100% efficient, the drag on the engine might be around 3 hp.

That's noticeable on a 65 hp engine, but of course that would be consuming 140 amps--something my car will never do. Also, the supercharged motor will be producing 90+ hp.

The final consideration is the greater rotational mass of the heavier-duty internals. But this alternator has one of those nifty 'overrunning' alternators discussed here http://www.onlinetechhelp.com/TechTips/Clutch%20Pulleys%20on%20Late%20Model%20Alternators.pdf ...and here... https://www.gatestechzone.com/en/problem-diagnosis/accessory-drive-system/oap-function-tests

In short, together with the fact that a more powerful alternator doesn't mean more drag on the engine unless you use [x] additional output, you don't get any additional wear on your belts and pulleys, water pump, etc. from the greater rotational mass. Pretty neat!

Also, these pulleys are dead simple to remove, as you just pry off the plastic cover, and the 'special tool' required is just a splined socket that costs <$10 (see picture).

Anyway, I'm going to borrow one from my friend who runs a local Autozone and see if it's another viable alternative to the two Saturn models, as an alternator that requires no clocking, has the correct 5-rib pulley, and has internal fans oriented for CCW rotation, might not be a bad option.

Joel


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Denis Avatar
Denis Denis Hill
Bearii, Nth Victoria, Australia   AUS
Progressing well and looks very professional, however I would still like to see all the ancillaries, except the water pump, on the slack side of the belt. It will work as is but I recon it would be better with a spring tensioner. Denis



68 B roadster, Daffodil yellow, supercharger, Burgess SC head, SC cam, Mikuni HSR 48 carburetor and engine built for supercharging.

73 BGT V8 conversion starting with a bare shell. Built the engine early in 2016 with high comp pistons and a few other nice bits. Started on the body late 2016 and found Its a lot of work and expense starting from scratch. Did the work myself, mechanical, body. paint etc all except the interior trim.
Finished and going well, great to drive and quick. Future mods, maybe an increase in gearing but not for a while.

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Yankeedriver Avatar
Yankeedriver Platinum AdvertiserAdvertiser Joel Young
Albuquerque, NM, USA   USA
In reply to # 3668133 by Denis Progressing well and looks very professional, however I would still like to see all the ancillaries, except the water pump, on the slack side of the belt. It will work as is but I recon it would be better with a spring tensioner. Denis

Denis,

Thank you. Yes, I think the belt routing will work just fine. Sliding tensioners are proven and, in the Subaru application, last hundreds of thousands of miles without a hiccup.

There is no way that I can see to run the belt as you suggest, so as to put the alternator before the supercharger and add a spring tensioner immediately after the crank pulley. If you can see a way to accomplish that, please do share it with us. I'm happy to give it a try.

Joel


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pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
Better belt wrap... but I'm not sure about tensioning the belt outwards. Or the V grooves not engaging the alternator pulley.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.



Edited 1 time(s). Last edit at 2018-01-25 09:30 AM by pinkyponk.


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trevorwj Avatar
trevorwj Trevor Jessie
Louisville, KY, USA   USA
In Adrians drawing the tensioner is on the slack side. Where I would expect to see it. In your current configuration the tensioner is on the load side. One issue with it being on the load side is that it must be VERY rigid to stay in the same plan as the other pulleys and the bearings will have a much higher load than if the tensioner pulley was on the slack side. This may not be an issue for this application, but I know it makes a difference in high HP applications.



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trevorwj Avatar
trevorwj Trevor Jessie
Louisville, KY, USA   USA
Forgot to say that On Adrian's sketch I would tension the belt inwards if you could move the alternator up a bit.



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pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
In reply to # 3668301 by trevorwj Forgot to say that On Adrian's sketch I would tension the belt inwards if you could move the alternator up a bit.

thumbs up

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
Could be done with an idler below the alternator... if room exists for any of these suggestions...

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.


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pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
Just popping out ideas which may or may not have any merit... in the hope they inspire a solution.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

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Denis Avatar
Denis Denis Hill
Bearii, Nth Victoria, Australia   AUS
This is the way I would try for. The top idler may not be necessary, as there should be enough belt wrap. I know its easy for me just sitting here but different when you have to fit it all together.

Denis



68 B roadster, Daffodil yellow, supercharger, Burgess SC head, SC cam, Mikuni HSR 48 carburetor and engine built for supercharging.

73 BGT V8 conversion starting with a bare shell. Built the engine early in 2016 with high comp pistons and a few other nice bits. Started on the body late 2016 and found Its a lot of work and expense starting from scratch. Did the work myself, mechanical, body. paint etc all except the interior trim.
Finished and going well, great to drive and quick. Future mods, maybe an increase in gearing but not for a while.


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Yankeedriver Avatar
Yankeedriver Platinum AdvertiserAdvertiser Joel Young
Albuquerque, NM, USA   USA
Adrian, Trevor, and Denis,

These are thought-provoking - thank you!

Denis, thank you for your sketch (immediately above). That was the first thing I tried with the Avalanche tensioner (there are earlier pictures--I know it's been a while, who can keep track?!) and two other tensioners. Unfortunately, the alternator doesn't sit that far outboard; it's much closer in, if you look at Adrian's reposting of my recent photo in post #461. That really complicates putting a tensioner that low and close to the crank pulley.

But this back-and-forth is really helpful. I am looking forward to playing with these suggestions--and eliminating the topside idler/slide tensioner also makes it easier to get the snorkel headed down toward the facia on the right-hand side, for those who want an intercooler.

Also, I note that numerous cars use outward tensioners right after the crank, so although I had a similar impulse to Trevor's--go for an inward tensioner--so long as there's sufficient contact with the crank pulley, there's nothing wrong with Adrian's first suggestion, in theory.

Cool, I'll let you know what develops!

Joel


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Denis Avatar
Denis Denis Hill
Bearii, Nth Victoria, Australia   AUS
You can get the tensioner into a pretty small place by swinging it off the alternator bracket. Looks like enough room in your pic but maybe not. The sprung idler pulley can run very close to the crank .and give an even better wrap. I used to have a lot of A series once and going from memory but that was many years ago. Denis



68 B roadster, Daffodil yellow, supercharger, Burgess SC head, SC cam, Mikuni HSR 48 carburetor and engine built for supercharging.

73 BGT V8 conversion starting with a bare shell. Built the engine early in 2016 with high comp pistons and a few other nice bits. Started on the body late 2016 and found Its a lot of work and expense starting from scratch. Did the work myself, mechanical, body. paint etc all except the interior trim.
Finished and going well, great to drive and quick. Future mods, maybe an increase in gearing but not for a while.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <

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