supercharger set ups

[panel]

I thought I posted this already but couldn't find it so I'll re-post.

http://www.porvwoo.fi/Project-Eaton-M45.php

[a1953mdl]

What do ya'll think about the superchargers on the Seadoos? Would they work okay?

http://cgi.ebay.com/ebaymotors/05-SEA-D ... ftQ5fParts

IIRC the engines are 4 stroke and either 1300 or 1500cc and 185-215 hp.

Size wise they would be much easier to mount.
Just thinking, don't really know much on supercharger sizing.

Lee

[my_medusa]

i will bring that up gain and will add a plus to small supercharger again but this time with demonstrate.
now i drive my daily driver far over 10000km and over 1,5 years. alot full throttle and fist 1/8 mile racing this summer.
the engine is a 36hp 1192cc engine, stock heads , stock manifold. heads have 29,6mm intake valve, 28mm exhaust.
manifold has a diameter of 21mm so very restrictive.

original it put out:
30 din ps at 3400rpm
75,5nm at 2000rpm

my setup is with the most tiny seriall supercharger (aisin amr300)
good 6v ignition box and boost retard via saab pressure tin.
my best 1/8 mile RIGHT ( last 150feet without fuel in the carb...stock fuel pump tiny bowl..fixed that after that)

next year i try to get close to 10sec...btw
here the dyneresult with way to fat lambda (about 0,65) because i did a mistake one day before the dynoday.

70hp at 3910rpm
close to 150nm!!! at 2010rpm.

but what i want to say...this is at 12500 rpm blowerspeed and 14psi. aisin say this blower can handle 20psi and 16000rpm(18000rpm) .
i try to port the heads next, build 1,2:1 ratio rockers because at the moment 8mm valvelift and bigger manifold + carb.i try to get peak at 4500 than it should have about 85hp and this is also only at 14400rpm blowerspeed.
up to 90hp i would not use a bigger one. i also use the amr500 on a 1192cc 36 with about 100hp at the moment.
for sure with goals over 100hp i would go a step higher(amr500 ore simmilar) but small superchargers are not like small turbos they mostly can handle more boost and more rpm in compare th the same design in bigger.

wishes
christian

[Alexander_Monday]

My how time flies since I posted back on page 1.

Seems I hope to have mine done "this spring" ...... again!

Money and time are in short supply, especially when I constantly change things.

740303.jpg

[chickensoup]

Hi guys, so im building this 1385cc 40hp, and have a crazy idea. the bottom end will be mostly stock but the rods and pistons will be balanced, it will have a cb2236 cam, ported 40hp heads, solid rocker shafts and 1.1 rockers, shortened 1600 push rods, lightened 6v flywheel, NOS german 83mm pistons with 22mm wrist pin, modified Japanese ISS forged rods with toyota 22mm wrist pin bushings, tight deck height, lowerish compression, SS exhaust valves(i will be having larger valves resized on the lathe, 4 or 5 angle seat grind, stock exhaust with heater boxes, TWO AMR 300 or 500 draw through, and on top of all that, TWO 32 PDSIT carbs with auto chokes and vacuum advance.

My question is, what AMR should I use? the 300 or 500? I saw a chart recommending that the 300 be used on 600cc-1000cc engines but if I could use the 300 vs the 500 it would save space and weight. redline will be at 4500 rpm.

thanks!

edit- ok, I just did some math, and it looks like if I run the AMR300's at roughly 15 psi boost or one bar, the supercharger displacement will work out great. I think...

15(desired boost) / 14.7(atmospheric preassure at sea level) x 84.5(CID of 1385cc) = 86.22 CID (the supercharger)

when we convert 86 CI to CC we get roughly 1400cc or 1.4L

So using a 1:1 ratio, the AMR300 will work right?

[grelland]

Hmmm, I dont get this to add up.

Are you talking about TWO AMR300's? If so, it will displace 600cc per revolution. Your engine is a 4-stroke, so it displaces 692cc per revolution. According to my simple calculations, you will need a drive ratio of about 2,2:1 in order to achieve 15 psi boost. with a 1:1 ratio you will not make any boost at all.

[panel]

I think he's wonder if the 300 or the 500 either/or would be better.

[meloni]

Hello Everyone,

I'm Daniele from Italy and I would like to ask you some wuestion about the use of superchargers on aircooled engines. In my case, I'm planning to use a supercharger (probably AMR300) on a modified Fiat model 110 engine.

That engine is the type used on the classic Fiat 500 from the 1960's, and it's an aircooled parallel tween (499cc) but my engine has already been modified

Forged 82.5mm pistons (750cc)
H beam roads
Stronger crankshaft (stock 70mm stroke)
All massess balanced
Bigger IN-EX valves, compression 10:1
Race exhoust
38mm throttle body with full EFI system
Custom made cam with relatively aggressive timing (still a street cam btw...)
6 liters oil pan with oil cooler (never seen more than 120-123 celsius even during hot summer..).

It pulls well from 2500 up to 6500rpm (currently the limiter is set to 6500rpm but it can do 6800-7000 safely)

At this point the performances are already good, but I was wondering if I could do something better with a supercharger.

Any suggestion and more important, is there any risk about running with 10:1 compression ratio?

Thanks in advance for any suggestion

[madmike]

You must drop the compression or you will get cracked pistons Cheers,Mike

[meloni]

Hello Mike, thanks for the answer…. And yes, I will probably need to drop the compression and use a way more stock camshaft… I will get some numbers.

Probably another good idea might be to build a specific motor with smaller displacement (77-80mm bore, 650 to 700cc) and use a specific camshaft (maybe even a stock one since will give the best low end torque)

At this point i can also drop the compression down to 7:1 or so in order to be safe with boost….

For an engine that size will the amr300 be sufficient?

[Clonebug]

Blowers are well known for heating the air whether at cruise or on boost. It's not uncommon to see cruise IAT's of 160* F. using a blower unless a good intercooler or aftercooler is used.
Manage your IAT's and you will have a nice responsive engine.........if not it will blow itself to kingdom come..........
Make sure you have a quality programmable ignition system.

My experience with turbo is 130* F. is a critical temp.....anything higher and you will be fighting detonation no matter the boost level........

[my_medusa]

Hello Everyone,

I'm Daniele from Italy and I would like to ask you some wuestion about the use of superchargers on aircooled engines. In my case, I'm planning to use a supercharger (probably AMR300) on a modified Fiat model 110 engine.

That engine is the type used on the classic Fiat 500 from the 1960's, and it's an aircooled parallel tween (499cc) but my engine has already been modified

Forged 82.5mm pistons (750cc)
H beam roads
Stronger crankshaft (stock 70mm stroke)
All massess balanced
Bigger IN-EX valves, compression 10:1
Race exhoust
38mm throttle body with full EFI system
Custom made cam with relatively aggressive timing (still a street cam btw...)
6 liters oil pan with oil cooler (never seen more than 120-123 celsius even during hot summer..).

It pulls well from 2500 up to 6500rpm (currently the limiter is set to 6500rpm but it can do 6800-7000 safely)

At this point the performances are already good, but I was wondering if I could do something better with a supercharger.

Any suggestion and more important, is there any risk about running with 10:1 compression ratio?

Thanks in advance for any suggestion

In that setup I definitely would use a turbocharger. No idea how strong your transmission is, but with a positiv supercharger you will have torque 1:1 rise with throttle position that can break parts at low rpm. I used a Amr300 on a 36hp for years with 1,2 bar all day long also a amr500 an a 36hp with 14psi and up to 8200rpm shift points, if you want that high torque from idle go for it. Compression as low as your torque/ power/ boost goal will need it. But with efi and that cylinder head I definitely would use a turbocharger. Easier to build/adapt and way more power and at the same time more reliable and saver to your transmission and parts also easier to intercool if you want. I also would think about a traction bar, these engine and transmission mounted 2 zylinder are very shaggy, that also is to make the transmission saver. I once turbocharged a nsu prinz 4 engine that is kinda close to yours (598cc, 2 cylinder parallel twin, aircooled 7.5:1 compression, 30hp at 5600rpm) without intercooler and draw through we almost double the hp with 14psi and it was pusching up to 7000 rpm without any changing at the engine. Than it startet flexing the axle's every here and now.
https://youtu.be/iECPxF3SzEE
In compare turbo to supercharger, the supercharger will bring more heat into the intake and more stress to the belt system and transmission, the higher rpm and boost you will put into it, the harder will the supercharger be to your parts. With low boost both systems are kinda equal.
So, what is your goal in performance with that build? If you are clear here it's easy to make a recommendation about compression and stuff.

If blower, the Amr300 is the way to go, it's a nice small, package and better than the amr500, I used put apart and repaired both and definitely liked the Amr300 more. The Amr300 can be pushed to pump air to make abit oder 100 hp. Up to 90 hp I would always use the Amr300. Doesn't matter what your displacement is. Your hp goal is important to chose blower size. Displacement per revolution and max. rpm and also capable boost limit of the blower in relation to your engine.

Whishes chris

[meloni]

Hello Everyone,

I'm Daniele from Italy and I would like to ask you some wuestion about the use of superchargers on aircooled engines. In my case, I'm planning to use a supercharger (probably AMR300) on a modified Fiat model 110 engine.

That engine is the type used on the classic Fiat 500 from the 1960's, and it's an aircooled parallel tween (499cc) but my engine has already been modified

Forged 82.5mm pistons (750cc)
H beam roads
Stronger crankshaft (stock 70mm stroke)
All massess balanced
Bigger IN-EX valves, compression 10:1
Race exhoust
38mm throttle body with full EFI system
Custom made cam with relatively aggressive timing (still a street cam btw...)
6 liters oil pan with oil cooler (never seen more than 120-123 celsius even during hot summer..).

It pulls well from 2500 up to 6500rpm (currently the limiter is set to 6500rpm but it can do 6800-7000 safely)

At this point the performances are already good, but I was wondering if I could do something better with a supercharger.

Any suggestion and more important, is there any risk about running with 10:1 compression ratio?

Thanks in advance for any suggestion

In that setup I definitely would use a turbocharger. No idea how strong your transmission is, but with a positiv supercharger you will have torque 1:1 rise with throttle position that can break parts at low rpm. I used a Amr300 on a 36hp for years with 1,2 bar all day long also a amr500 an a 36hp with 14psi and up to 8200rpm shift points, if you want that high torque from idle go for it. Compression as low as your torque/ power/ boost goal will need it. But with efi and that cylinder head I definitely would use a turbocharger. Easier to build/adapt and way more power and at the same time more reliable and saver to your transmission and parts also easier to intercool if you want. I also would think about a traction bar, these engine and transmission mounted 2 zylinder are very shaggy, that also is to make the transmission saver. I once turbocharged a nsu prinz 4 engine that is kinda close to yours (598cc, 2 cylinder parallel twin, aircooled 7.5:1 compression, 30hp at 5600rpm) without intercooler and draw through we almost double the hp with 14psi and it was pusching up to 7000 rpm without any changing at the engine. Than it startet flexing the axle's every here and now.
https://youtu.be/iECPxF3SzEE
In compare turbo to supercharger, the supercharger will bring more heat into the intake and more stress to the belt system and transmission, the higher rpm and boost you will put into it, the harder will the supercharger be to your parts. With low boost both systems are kinda equal.
So, what is your goal in performance with that build? If you are clear here it's easy to make a recommendation about compression and stuff.

If blower, the Amr300 is the way to go, it's a nice small, package and better than the amr500, I used put apart and repaired both and definitely liked the Amr300 more. The Amr300 can be pushed to pump air to make abit oder 100 hp. Up to 90 hp I would always use the Amr300. Doesn't matter what your displacement is. Your hp goal is important to chose blower size. Displacement per revolution and max. rpm and also capable boost limit of the blower in relation to your engine.

Whishes chris

Hello Chris,

Let's say the transmission is normally reasonably reliable (in my case a nice overhauled but stock 4 speed non synchro xmsn with additional 5th gear fitted). It's holding up well but lets say if you start kicking hard it might let go.
Let's say up to 50-55hp I don't see many issues, and I'm also not planning to start doing drag races with it.

My tuned 500 is also my daily so I need some reliability.

At the moment, i don't think i will ever use any kind of hard boost since those engines have severe limitations (the crankshaft has only 2 supports, in the attachments some picture of the building of my 750cc).

Let's say about 10PSI will be the max boost.

[my_medusa]

most 2 zylinders have just 2 main bearings. No idea what others say about those engine when they fail but looks like alot of potential for that kind it is.
10psi of boost with supercharger I would stay in the 8 or very low 8:1 compression ratio. Depends on your camshaft. But those straight rotor roots blower bring alot of heat. And about the transmission. Hp is not important, torque brake stuff, I would talk to people that have done that way with that engine/transmission combo. And how much is your 750cc making. Should that not be in the 50hp range? Those heads look good and has big valves in there. And for boost, you habe 4 head studs per cylinder. That is very nice.
Enjoy building it

[meloni]

most 2 zylinders have just 2 main bearings. No idea what others say about those engine when they fail but looks like alot of potential for that kind it is.
10psi of boost with supercharger I would stay in the 8 or very low 8:1 compression ratio. Depends on your camshaft. But those straight rotor roots blower bring alot of heat. And about the transmission. Hp is not important, torque brake stuff, I would talk to people that have done that way with that engine/transmission combo. And how much is your 750cc making. Should that not be in the 50hp range? Those heads look good and has big valves in there. And for boost, you habe 4 head studs per cylinder. That is very nice.
Enjoy building it

You are 100% correct: most automotive parallel twins use only 2 main bearing, since they are usually rotate very slowly and produce little HP's.

The transmission have been used even in some 100cc big bic bore and stroker engine, with mega torque and the XMSN survived.... of course joints are the weak part but unless you do burnouts every day it shouls survive

About the compression, it make sense, and at this point I will probably go for another build specific for the use of supercharger.

Maybe it will be even better if I keep the bore a little lower (80mm, 700cc total..) so I willhave ticker cyl wall and more meat on the crankcase..

In order to keep a decent reliability the big cooled oil pan will be mandatory) like the H beam rods.

The "supercharged" engine" might have the same components of bottom end of my actual 750cc, but a slighty smaller displacement (700 or even 650cc..) and a compression of abput 8:1 (maybe a air less...).

The idea is to avoid the use of an intercooler to keep the things as easy as possible.

Otherwise, what turbo can be used in such a small displacement? (ofcourse in case of turbo the intercooler will be mandatory..).