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Supercharger on an AMC six cylinder |
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Rambler Mexicano
AMC Addicted Joined: Mar/05/2011 Location: Guadalajara Status: Offline Points: 976 |
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Posted: Jan/25/2020 at 3:52pm |
Has anyone here ever installed a supercharger on an AMC six cylinder engine or know anything on making such a move?
I am not looking forward to making that with my current car (1981 VAM Rally GT with a 282 inline six cylinder) since it already has a notably higher than average compression ratio (around 10.5:1) after I put in the flat pistons and shaved the head 0.050 inches. However, if I happen to buy another VAM car with the 282 six and the stock compression ratio (ranging from 8.0:1 to 8.5:1) I might consider installing a supercharger for more engine boost. Does anyone know what would be highest compression ratio possible to be used in an AMC six cylinder with a supercharger for normal use? Also, what possible percentage increase I would obtain in regards to overall performance? Mainly regarding acceleration and engine performance? Thanks in advance.
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Mauricio Jordán
Cuando no se es una empresa famosa se deben hacer mejores automóviles. - Vehículos Automotores Mexicanos S. A. de C. V. |
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6880 |
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Jeep people do it all the time. Here is the rather expensive kit:
Go on Jeep forums to see how they perform. The DIY on this for the Jeep crowd comes in multiple flavors, but the end results seem to be in favor of a high performance build is cheaper and just as good as the supercharger. There is also this option:
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676 |
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A turbo is relatively easy to mount also. Use the stock exhaust manifold and mount the turbo on the RIGHT side of the engine, with a crossover pipe running under engine to turbo. How much boost you can run depends on compression and fuel. In essence, boosting is like running high compression. When you get much over 11:1 you start having detonation issues with pump premium fuel. You can run a bit more if running E85, up to 12:1. This chart says up to 12:1 boost, so that might be more like it. With 12:1 and 8.5:1 compression engine can run 6 psi of boost, only 4 psi if you stick with the 11:1 number (actually 10.8). If you use a good intercooler you can run much more boost though, roughly double. Boost is essentially free power for a turbo, which uses waste exhaust power. It would be more efficient to build a 7:1 compression engine and run 8 pounds of boost than to build an 11:1 engine.
Edited by farna - Jan/27/2020 at 8:22am |
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Frank Swygert
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g-man
AMC Addicted Joined: Jul/05/2007 Location: Cal Coast Status: Offline Points: 703 |
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Mauricio,
I have not supercharged a 6cyl yet...as I am currently recovering from some very serious health issues (and I am not able to go to work yet). But when I recover, I want to supercharge an AMC 6. I would like to use a ProCharger (or Paxton) type centrifugal supercharger. I looked at the BoostTech blower...and I don't like it. I've seen other blowers like that before. Just don't like them for the 6. I know that turbochargers are much easier and less expensive, and that it uses free energy to produce boost, but I like the idea of having that instant boost of a mechanical supercharger...especially to take advantage of the 6cyl's low rpm torque. I have a 258 in a Gremlin that I want to put a 4.0 head on, and then put a centrifugal charger on. But I think that it will probably be a completely homemade effort to mount it. Let me know if you come up with something easier. Thanks, g-man
Edited by g-man - Jan/27/2020 at 9:53pm |
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AMC only daily driver
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676 |
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Here's a link to one such project, using a Ford T-Bird supercharger. Never finished as far as I know, but some pics of the intake he made... |
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Frank Swygert
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g-man
AMC Addicted Joined: Jul/05/2007 Location: Cal Coast Status: Offline Points: 703 |
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Frank, I had actually forgotten about that project. Did he ever finish it?? The story just kind of fades off...with no updates in a few years. I was really impressed with what he made...however...I still think that a centrifugal blower would work better for the 6cyl than a roots type blower. You can hang a centrifugal blower off the front side of the motor in a similar style to how you would hang a turbo, and just have your power tube go across the top of the motor to blow thru the carb or injection inlet. And also...is he even going to have room in the engine bay for that blower/intake assembly?? Just wondering if he accounted for the available space. g-man PS: Just went back and looked again...no updates on that post in 9 years!!!
Edited by g-man - Jan/28/2020 at 5:51pm |
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AMC only daily driver
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tomj
AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7544 |
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I was given by a generous forum-er a Toyota Previa supercharger. It's a roots type, but modern, low profile, sized for a 2.5L engine, for 160 HP out. It was used for 6 psi boost, with intercooler. He'd got it to put in a 195.6 flathead.
I don't know how likely I am to do this, to be honest. I don't have a car, or plans for one, that it would suit. I toyed with the idea of a scratch-built hotrod using all (or very many) rambler parts, who knows. I think Frank did calcs on boosting the flathead, and worked out that 4, 5, 6 psi or whatever it was would be good for 130 hp, or about what the OHV produces. But it would be SUPERCHARGED!! Its a pretty thing. 2"-ish flat grooved drivebelt. There's a lot of junkyard boost options today. I wish instead there were junkyard EFI options. |
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1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676 |
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I don't know that he ever finished it, or is even on the forum anymore. He was putting it in a 63-64 Classic, IIRC, so he had a little room. Wouldn't be much in an American or Javelin, would have to be a big body car. The only issue with a belt driven centrifugal supercharger is having room in front. If you don't have or plan on having AC it shouldn't be a problem though. You can squeeze a Sanden style compressor up there too, but space and brackets get to be an issue. Tom, I'd still like to bolt a blow-through turbo directly to the L-head, with a throttle body between head and scroll ... like a hair drier sticking out of the hood! Would look cool, but as noted, with only a 20-30 hp increase you're looking at 110-120 hp... the 196 OHV is rated 125 hp with the 1V, 135 with the 2V... hop that up like you did and you're looking at 170-175 hp without a power adder. Or better yet use a suck through system to look even cooler... with the scroll bolted directly into the head and the rest indexed over... To recap what I said before... Ttheoretically you get a 50% increase with around 7.5 psi (half atmospheric pressure, which is what... 14.7 psi?)... bump that up to about 9 psi to make up for inherent losses. That would still only be 45 hp on the L-head with 8.0:1 compression -- and 8-9 psi would make it equivalent to 11.9:1 or so compression (according to chart in previous post link -- 8 psi = 11.4:1, 10 psi = 12.4:1). Too much for pump gas. Running about 5 psi would be a 25% increase -- 113 hp -- and be equivalent to 10.7:1 or so compression... doable on premium with some tuning and maybe some type of spark control. Would be cool, but easier to swap in a modern four with trans and get 150 hp or so.
Edited by farna - Jan/29/2020 at 6:38am |
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Frank Swygert
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tomj
AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7544 |
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Yeah, but if "power" is the only criteria, crate motor from Summit etc is the answer. It's 2020, horsepower isn't a mystery like it was when we were all in high school. A flathead with blower would be weird-cool for sure, but it's driving characteristics would be very fun -- torque torque torque. Sure, a couple hundred ft lbs max, but it would be at crazy low speeds. I still have to adjust to the 199, after the 195.6 ohv. the 199 has more power by some slight margin, much nicer revving, but that old six, aroudn town and "low speed fun" -- where admit it! most fun driving is! -- it grunts at 800 - 1600 rpm and a total pleasure to drive. The *character* of a motor is more interesting to me. A 4.0L or a 360 is "better" by numbers. Or just a dumb old (sic) 258. I agree with you, a blown-thru EFI is the way to go. Grille intercooler would be tough in an early american. |
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1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676 |
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With an intercooler it just wouldn't be as cool looking as a "hair dryer" stuck on the head! So it limits you to 3-4 psi... as you said, it's all cool factor more than anything! There is some precedent here... Kaiser used a Paxton centrifugal super charger on the Continental 226 L-head six in the early 50s because they didn't have a V-8. From a Kaiser site (http://vs57.y-block.info/kaiser.htm): "For 1954 Kaiser
addressed the power
problems of the Kaiser and it’s possible impact on sales by utilizing
the McCulloch
VS57 Supercharger on the 1954 Kaiser Manhattan. This raised the
horsepower of
the 226 cid L head engine from 118 hp to 140 hp reducing the 0-60
times from
17.5 seconds to 15.0 seconds for the manual transmission (19.5 seconds
to 15.4
seconds for the hydra-drive transmission units)....
The ONLY internal changes were high pressure bearings, both mains and
rods. (big snip) ... All
Kaiser supercharger
installations utilized the VS57B unit (Kaiser no: 215706) which was
preset to
four pounds boost and featured a 6 volt solenoid. The VS57B unit was
only ever
used on the Kaisers and not all of them were supplied with Kaiser
badges. The
use of a low boost level for the VS57B in conjunction with the
modifications
made to the engine by Kaiser pretty much guaranteed low stress levels
for the
engine, resulting in long engine life and high reliability. Most
failures that
occurred tended to be supercharger failure, and the majority of these
were attributable
directly to lack of regular oil changes to the supercharger. The
supercharger
itself was also relatively unstressed due to it’s low boost output
setting and
the low airflow demands of the engine." I like driving a car with lots of low end grunt too. Pulling out of the curves quick is easier, and more fun than a drag race down the straights. A fellow running a Spirit at Road Americas in Atlanta was having issues, always finishing near the end instead of the middle of the pack like he wanted to do -- at least! He had driven a little bug-eye Sprite in SCCA before, and is sounded like he was driving the 258 the same way. I recommended he not rev the engine so much and maybe gear down a bit (five speed, had to run a stock rear axle ratio) -- don't drive it like a windy little four, use the higher low speed torque to out pull cars like Mazda RX7s and some of the high rev fours coming out of the curves. It worked! He even won a couple races! Edited by farna - Jan/30/2020 at 6:48am |
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Frank Swygert
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