Hemi 426-Monster Motor (Need opinions)

Well Im stuck with that stupid 1/6 Hemi 426. I was thinking of building just a monster motor, no car for it to go in. What do you all think of motor build ups? A lot of people build models with out motors, so what about building a motor with out car?

Next question deals with the setup. I love superchargers...and I love blowers. I also love twin turbo set ups because of the amazing power they produce. I cant decide whether I want to do a twin turbo set up, or supercharger. I love blowers, I think they look great. I love twin turbo set ups because they look great, and they produce tons of power. Now I propose the question; can I have a twin turbo set up with a supercharger and blower?

I'm not as much an engine guru as I am a metal worker, so bare with me. I want the motor to be realistic. Im thinking that running a supercharger with twin turbos is probably impossible due to the immense compression pressure. So, in real life, would it even be possible to run twin turbos with a super charger and blower?

If I cant have twin turbos and a supercharger, could I have twin turbos and a monstrous blower?

Sorry for the verbose question. I know its a little technical too, but please express your opinions!

Thanks!

Erm, is it just me, or are superchargers and blowers the same thing? I always just kind of assumed that they were since I've only ever seen people talking about superchargers when they say blowers - perhaps you are calling centrifugal type superchargers "superchargers" and the roots type superchargers (that sit on top of the motor) "blowers." For the rest of this post I will consider them to be interchangeable.

I have seen a turbo + supercharger set up, and have heard of a few others that I beleive (internet = Liarville USA). These are immensely rare subjects, and for that would make interesting models. Me personally would not do something so exotic, since their usage is so limited that it loses a lot of its appeal to me. Call me nuts.

Supercharged (blower) Hemis are fairly common, really, there are tons of American V8s with a blower dropped on top to make some power, and while pretty, that would be too common for me for an engine-out-of-the car model.

Centrifugal superchargers just look goofy to me.

The twin turbo set up, now, there's something that exists in fair numbers but you don't really see that many of. Plus, where a blower just bolts on top of your manifold, under your carbs (or on or under the EFI) and you pretty much run with it, a twin turbo set up would require fairly complex exhaust manifold work, intake charge tubing (plus intercooler(s)) and oil routing. And, with as hot as turbos get, you would have plenty of opportunity to heat-stain pipes and do all sorts of fun painting effects. This would be a much more involved project than would a blower on top, and would be the one I would choose.

And you asked if engine but no car models are cool. Well, you bought two kits of just engines, with no cars. My bet is that these weren't intended for folks who want to scrathcbuild an entire car around them, what do you think?

I have always wanted to do just an engine from one of the top fuel dragsters. I would think that this would make a great base for this type of subject. Also I would think that references should be easy to find as the engine is usually out in the open for the rail type dragster. :2cents:

I don't know the story but why are you stuck with this engine. :dunno:

I think people think that superchargers are little like 6-71 or 8-71 and blowers are 14-71 something you would see on a funny car or a tope fuel car. Yes you can have a twin turbo and a blower. If you were going to do that I would use a smaller blower like a 6-71. Then your regular twin turbo. Whatever you choose good luck.

I have always wanted to do just an engine from one of the top fuel dragsters. I would think that this would make a great base for this type of subject. Also I would think that references should be easy to find as the engine is usually out in the open for the rail type dragster. :2cents:

I don't know the story but why are you stuck with this engine. :dunno:

Believe it or not, quality reference pics of a twin turbo V8 are hard to find. Im stuck with it because I've opened it. I dont really want it, so I figured I'd make the best of it I guess.

http://www.bankspower.com/Twin-Turbo-images/TTurbo-frontleftquarte-lg.jpg

http://www.bankspower.com/Twin-Turbo-images/TwinTurbo-offsideLeft-lg.jpg Small block chevy may help?

Dave thanks! I had been looking for large pics of the Banks. All I had found were miniscule pics.


Where do the wastegates come into play? I see them but cant figure out what exactly is leading into/out of them.

its kind of hard to see but dont the waste gates have to do with the exhaust? i beleive the rear most portion of the gate is attached to the exhaust manifold, and the pipe coming off of the side is wher ethe exhaust exits...

Here's a small primer and I'll do my best not to bore anyone. There is much much more than this, I'm merely presenting the basics. You could write a book on how differently a centrifugal supercharger, roots blower, and turbocharger increase engine power in a high-performance (HP) application. The easy answer is no, they can not be realistically combined.

Roots blowers were originally used to pump air into mine shafts and furnaces, i.e. to "blow" air, hence the term "blowers". For HP use, they are useful as they are positive displacement air movers, which means instant boost. The faster you spin them, the boost rises proportionally with RPM. If you want, say, 8# (# being P.S.I.) of boost at 6000 RPM, that's around the only time it'll get 8#. At lower RPMs you will have less boost because the rotor speed is coupled to the crank. Roots blowers are known for near-instant boost. The caveat is you get boost no matter what, even when you don't need it. Also when you do need it, you have to wait until the RPMs go up for max boost. You could overdrive it to get boost at lower RPMs, at a cost of limiting max engine RPM.

Turbos as we most know run off the exhaust. They are more "on-demand" and run off engine load and exhaust heat. A non-loaded turbo engine (lets say on the freeway while grandma borrows your 15# twin-turbo Mustang to the store) at 2000rpm will have no boost, but a non-loaded roots engine at 2000rpm probably already makes ~3#, depending on the pulley. Hit the throttle and your turbo, depending on many variables, plus the fact that it doesn't rely on engine RPM to create boost, will probably hit full boost by 3500RPM. Hold on, granny! Easy boost adjustment via a few knobs or buttons and this is clearly the choice of many engine builders. Plumbing, complexity, packaging and cost are some of the downsides.

Centrifugal superchargers are a cross between roots and turbos. They run off the crank, have larger turbo-like compressors, but have a parabolic boost curve. That is, low engine speeds will usually have low or near-zero boost but as RPM goes up the boost will rise up in a curve to reach full boost at an earlier RPM. It sounds like the best of both worlds, but the downside is that you still have a curve to worry about. 12# at 6000 RPM still means probably half that at 3000. So far, these are the easiest forms of boost anyone can bolt on to their engine, and that's a plus for many people.

The only real-world applications that commonly uses roots blowers together with a turbo are buses and various other 2-stroke diesel machinery. Reason for this is the blower is just that, a blower, and not a supercharger. It doesn't exactly add boost, but it's there to help move the fresh intake charge into the chamber and push the old air out. The turbocharger is what's used to create the added boost, if needed.

Other than that, you only see roots/turbo hybrid engines on show cars. There's a reason you don't see the stuff mixed together in a HP application - it just doesn't work.

I've seen some nice engine-only builds at NNL West, most of them large scale. Plus you get to make a nice, realistic, weathered engine stand. I'd say forget the car and go for it, whatever you decide on.

Back in the 80's Rick Doberton (may not have that last name spelled right) built a Pontiac J2000 prostreet car that was blown and turboed. Before that he built an old Chevy II that had a big block Chevy that had a GMC 671 and 2 turbo's it was one of the colest engines I have evr seen. Do a search on his name you'll find some pics. As said before, not real practical ,but seeing turbo's and blower's on the same engine looks wild.

Thanks Privateer, that was wonderful.

Mike - the wastegate is as white97ex says, an exhust device, not to be confused with a blow off valve. The wastegate lets air out of the exhaust manifold at a certain PSI to make sure the exhaust turbine and manifold and valves are not faced with too much pressure. The "bottom" of the wastegate attaches to the exhaust manifold, and there is a sliding spring loaded valve (the valve is in the part of the wastegate with the heat disappating fins)(the spring is in the chrome hat just forward of it) that lets the overpressurized air out the side (the S curving narrow pipe) so that the air bypasses the turbo. In cars that are driven on the street that have to meet emissions, the gasses that go through the wastegate go back into the downpipe after the turbo, on race applications it may just empty into the atmosphere.

A blow off valve is similar but on the intake side. There is a very similar spring-loaded valve that attaches to the intake tubing (between the turbo and the intake manifold) but it always just vents out to the atmosphere. This helps to prevent too much boost from building up and prevents one from "blowing the welds" on ones intake manifold. I don't see it on the Banks motor, it is probably integrated into the intake manifold.

Man I feel stupid and embarassed. I can engineer a car, rebuild an engine, but couldnt figure out how exactly I should set it up.

The waste gate is between the header (motorside) and the turbo, right?

Now, does anybody have any suggestions for a good project name?

You can use both! I have one or two pics of twinturbo supercharged car. Wait a moment.

Here you go. So far i have found couple of small pics of this car.

Note: Not my picture. But had to resize.
http://files.automotiveforums.com/gallery/watermark.php?file=/503/851231024x780-12-med.jpg

Try building this setup. I will try this someday, on 1/24.

i have a pic of an RB26DETT with a blitz supercharger as well as the two turbos, when my laptop's fixed i'll post them

The waste gate is between the header (motorside) and the turbo, right?


The wastegate straddles the turbo.

If I remember correctly the s shape tube can go where ever on some street machines it goes back into the exaust. A name hmm Im not sure. How old are you mike? If you dont mind.

If I remember correctly the s shape tube can go where ever on some street machines it goes back into the exaust. A name hmm Im not sure. How old are you mike? If you dont mind.

16 Years old.

I figured out the configuration for the waste gate. Thanks!

16 !?!!??!!?

i thought you'd be late 20's - early 30's


and i remember reading that "turbo-super-charging" is very difficult to get correct on real engines, and the money you spend, you could get the same power from twin turbo's.


but i'd say, do it, for exactly that reason. it's so rare that it would make a great conversation piece.




(:evillol: make a 1/6 bicycle to put it in :evillol:)

Hey maybe you should build a hilborn injected hemi? That would be really cool.