Supercharged Predator 212

Status
Not open for further replies.
B

BoostedBaja

New member
Messages
19
Reaction score
1
Location
Corbin, KY
I currently have a baja heat with a predator 212 engine. It is currently stock, but I plan on supercharging it with a belt driven smog pump I've found. I will use this thread for questions I have and for advice from you guys, as opposed to making several threads.

For anyone who has actually used a smog pump in this way, should I place the pump before or after the carburetor? I would like to keep away from pressurizing things ( placing the pump before the carb), but I am also worried about possible issues with fuel running through the pump, and causing damage( placing it after the carb). What do you guys think? Also, I am going to try to stay away from EFI, or anything else electric, if possible.
 
machinist@large

machinist@large

Active member
Messages
2,865
Reaction score
33
Location
West Michigan, 49331
BoostedBaja said:
I currently have a baja heat with a predator 212 engine. It is currently stock, but I plan on supercharging it with a belt driven smog pump I've found. I will use this thread for questions I have and for advice from you guys, as opposed to making several threads.

For anyone who has actually used a smog pump in this way, should I place the pump before or after the carburetor? I would like to keep away from pressurizing things ( placing the pump before the carb), but I am also worried about possible issues with fuel running through the pump, and causing damage( placing it after the carb). What do you guys think? Also, I am going to try to stay away from EFI, or anything else electric, if possible.
Click to expand...

Unless you have a smog pump rated for an over the road semi, you won't have the displacement to keep the engine running at full load at it's rated power, let alone boost your output.

You need to understand, a smog pump is designed to deliver a fixed amount of air strictly for aiding the burning of the tail end of the fuel/air charge as it's existing the combustion chamber. That's a small amount of air. They're also not designed to generate much pressure: basically just enough to overcome any back pressure in the vehicles exhaust system. That means that if you want to match the boost pressures of automotive aftermarket units, it'll most likely die a short and painful end. And as the one's I'm personally familiar with are vane style pump's, I can confirm that they like to run slow. Upping the RPM of the unit will just kill it that more quickly....

Try it if you want, but don't be disappointed when reality sets in.....
 
itsid

itsid

Moderator
Staff member
Messages
11,563
Reaction score
248
Location
Ruhrpott [Germany]
Just a heads up on numbers...

don't forget that you need to deliver at the very least 1800 * 212 ccm of air per minute
to NOT RESTRICT the engine.
that's 381,6 liter (~13 ft³) per minute
for a 3600rpm governed engine that is,
so if the pump cannot move 780 ft³ of air per hour it'll not help at all.

for 5000 rpm you need ~19 ft³ per minute or 1140 ft³ per hour
and.. that's at atmospheric pressure

to powerbreath the engine even slightly, that number must be bigger ;)

'sid
 
B

BoostedBaja

New member
Messages
19
Reaction score
1
Location
Corbin, KY
Thanks for the replies. That video is what actually got me interested in this, but as opposed to a 68 vw pump, I'm going to try to use one off of a 93 mustang. So would I need to run more RPM in order to power the pump, or is it strictly a displacement issue?
 
itsid

itsid

Moderator
Staff member
Messages
11,563
Reaction score
248
Location
Ruhrpott [Germany]
Joe-405 said:
This is one case i actually disagree......................

And this video proves it..........
Click to expand...

With whom?

That video is nice, one thing I can't help but notice...
of course it's a garage video, and that rear wheel is not allowed to move freely (although that's easy to do in ANY garage)

Anyways, the throttle is released as soon as the clutch want's to engage,
assumingly 1800 rpm...
soo 900 *212 , 190.8 liter... (~6.5 ft³) per minute
or about 390 ft³ per hour.

Now, an analogue pressure gauge on a single cylinder engine is
maybe not the best idea
since the reading is only accurate when the intake valve is open,
that by design is no more than a quarter of the time;
only the carb and the tube is pressurised,
I can't tell what volume that has, but I doubt it's large enough to give an accurate reading at all.

So the gauge.. nice bling; actually telling.. I doubt (But IDK)

But I must clarify..
All I'm doing is playing with numbers;

I don't know shirt about that pump,
I can't tell if it'll withstand the rpms where "we" need them (say 6000)
I can't tell it's internal volume (uhm rotor displacement... whatyoucallit? it's delivery rate at any given rpm !)
Or the max flowrate it's capable of before it's intake will restrict enough to have the rotors leak.

Looks plausible, but frankly...
if it doesn't move the required volume of air, it won't help.

'sid

PS dang, now I want such thing to do some measurements...
addictive nerdism... :eek:
 
Joe-405

Joe-405

Enjoying New Projects
Messages
2,673
Reaction score
97
Location
U.S.A.
BoostedBaja said:
Thanks for the replies. That video is what actually got me interested in this, but as opposed to a 68 vw pump, I'm going to try to use one off of a 93 mustang. So would I need to run more RPM in order to power the pump, or is it strictly a displacement issue?
Click to expand...

It has to be the one this guy is using. I have talked to him before. He had it for sale for $2k and I was gonna buy it.


And I was referring to it in general for supercharging is a bad idea. Nobody in particular. Anything can work with alot of patience and know how. P
 
itsid

itsid

Moderator
Staff member
Messages
11,563
Reaction score
248
Location
Ruhrpott [Germany]
Ah.. I see..
yes supercharging works of course, even for small engines..
it's the technology that's at least worth a closer inspection.

As Pat said, smog pumps are usually NOT intended for bigger volumes of air;
that one in particular might use the same layout as a conventional supercharger, but it's NOT a supercharger (not designed to be used as such)
if it's capable; I can't tell without at least having it's specs.

the patent sheet isn't telling since it's only talking about the design, not that particular size or model ;)

Ah well.. maybe one day such thing drops from the sky and I can play with it..
until then I'll just sit and watch ;)

'sid

PS the numbers though should be rather solid ;)
 
machinist@large

machinist@large

Active member
Messages
2,865
Reaction score
33
Location
West Michigan, 49331
Just watched the video; the pump he used is not what you'll find as a smog pump in anything built in the last 30 year's or so.

That one does appear to be an actual twin rotor Roots type compressor, which can move a lot of air. The most common type of smog pump I'm personally familiar with look's a lot like an automotive alternator in size and shape, with a pully diameter the same as the crank pully, or down to 3/4 or 5/8 that diameter.

All of the one's I'm familiar with are vane style pump's, using graphite vane blades. That's to make them maintenance free for the life of the pump. Looks great on paper. In reality, they run until the graphite blades are so worn out and fragile that they shatter, thereby locking up the pump at what ever RPM it was running at. And while they are rebuildabale, the price just doesn't justify it.

They're not designed for real pressure loads or volumes. That being said, I think the video (of a totally different style of air pump) may very well be the root of the urban legend that a smog pump can be used as a supercharger.... Outlier rules.....
 
Last edited:
rushking19

rushking19

Active member
Messages
1,045
Reaction score
2
Location
Richmond Virginia
Fabroman said:
According to a youtube vid, you can unlock a car door with a tennis ball with a hole in it but, we all know, that's not possible...
Click to expand...

I'm just saying that ive seen videos were they built boost and look like they make more power but anyways he can always try a turbo instead
 
D

Denny

Canned Monster
Messages
11,966
Reaction score
8,468
Location
Mayberry, Indiana
Well I played with a vane type smog pump as a supercharger back in the early 80's and you all are right. ;) Yes you can build about 5 psi of boost with it (1970's 5 hp Briggs). Yes you do have to overdrive the crap out of it to do so. I injected MMO to help it live longer (the second Ford 460 smog pump). Yes the vanes turn into little bits and pieces and wreck a perfectly good engine. I got the idea from a magazine article one of my older (70 years old) neighbor gave me. In it was a article about a new vane type supercharger for Crosleys and Volkswagons. They also injected the MMO to help it live longer. Man to be 14 again. I never got to run it in anything so I can't tell you about power increase. But it sure looked cool, it was a draw through carburetor design. It did work better than my bolt a squirrel cage fan to the flywheel and duct the air to the carb design. you should have seen when that finally exploded. It took out the rf fender of my dad's new Oldsmobile. :oops: Ask me some other time about running my Honda ct70 on nitro.

Denny
:feedtroll:
 
B

BoostedBaja

New member
Messages
19
Reaction score
1
Location
Corbin, KY
Thanks for the help guys. Probably isn't a good idea to try something that might screw up my only motor. That turbo is interesting though. If only it wasn't 300$.
 
rushking19

rushking19

Active member
Messages
1,045
Reaction score
2
Location
Richmond Virginia
You can do it just have to find that exact or similar roots type smog pump which are kinda hard to find , and make sure your not putting to much boost in the motor
 
Poboy kartman

Poboy kartman

Senior Moments Member
Messages
12,461
Reaction score
69
Location
White Settlement Texas
Awwww....It's that time again....when I must rely on my fellow members to post a link for me: YouTube: 'You can't Cook; How to slice an onion'.

Just have never figured out to link on this phone.:surrender:
 
Status
Not open for further replies.
Top