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-   -   Fabricating Aluminum Intake Manifold, need help (http://www.hotrodders.com/forum/fabricating-aluminum-intake-manifold-need-help-227743.html)

ryankalel 12-30-2012 12:55 PM

Fabricating Aluminum Intake Manifold, need help
 
Hello all and Happy Holidays.

I have a stroked Volvo B20 engine that I am building and will be turbocharging and I am looking into fabbing a new intake manifold out of aluminum, yes I do weld aluminum.

My question is about tuned port, pressure waves, runner size to name a few. A cursory search found this article, http://mysite.verizon.net/vzezeqah/s...ionsystems.pdf

Volvo does have a Fuel Injection manifold that I can use, but space will probably be an issue, hence the idea of creating a new intake manifold to make more room for the turbo.

This article points to pressure waves and equations for, as far as I can tell a NA engine. Do the same principles hold true for a Forced Induction?

Any help or direction is appreciated.

vinniekq2 12-30-2012 01:29 PM

do you think it will make much difference in the end?

ryankalel 12-30-2012 02:02 PM

Thank you for the replies.

Because the intake and the exhaust are on the same side I have been wondering about throttle body and plenum on the other side of the engine with the runners going over the top of the valve cover and then doing a 180° to the intake valve. I am a little leary about the 180° turn.

Here is the stock intake look. With a turbo in there it will be tight. http://www.1800philes.com/images/rebuild/side.jpg

This is from another forum, but the basic design of what I am thinking about. http://i22.photobucket.com/albums/b3...28etIntake.jpg

techinspector1 12-30-2012 02:55 PM

In my opinion, tuned port, pressure waves and runner size can be tossed out the window when you go from naturally-aspirated to turbocharger-aspirated. All you will need is a plan to deliver the proper air/fuel ratio to the motor and a way to keep the charge cool. In your case, using FI simplifies keeping the A/F ratio in line. I like your "over the top" runners, same as the intake system on my old '91 Ford 300 six cylinder motor, but I think if I were doing it, I would fabricate an intercooler to fit in that space also.

I understand that you have little room on the driver's side for the turbo unit, but weigh making room there by doing a little surgery on the existing parts against running exhaust tubing to the other side of the motor to run the turbine. I have made the comment many times that with a cutting torch, a Sawzall, a MIG and a good hand grinder, you can make anything fit anything.

I think if I were doing your project, I'd mount everything on the driver's side by doing some surgery, then I might mount an air-air intercooler down low in front of the car.

I'm certainly not the forced induction guru on this board, just presenting a few thoughts......good luck.....:thumbup:

ryankalel 12-30-2012 03:27 PM

Quote:

Originally Posted by techinspector1 (Post 1628749)
In my opinion, tuned port, pressure waves and runner size can be tossed out the window when you go from naturally-aspirated to turbocharger-aspirated. All you will need is a plan to deliver the proper air/fuel ratio to the motor and a way to keep the charge cool. In your case, using FI simplifies keeping the A/F ratio in line. I like your "over the top" runners, same as the intake system on my old '91 Ford 300 six cylinder motor, but I think if I were doing it, I would fabricate an intercooler to fit in that space also.

That is what I needed to hear, I did not think that the pressure waves, length, etc, etc held that much importance when going to forced induction.

My CR is going to be right around 9:1, with a turbo I know that is higher than recommended. Can I place knock sensors on the engine to prevent detonation? If so, where on a loud and noisy 4 cylinder would be the best place?

Thanks

techinspector1 12-30-2012 04:12 PM

Quote:

Originally Posted by ryankalel (Post 1628753)
That is what I needed to hear, I did not think that the pressure waves, length, etc, etc held that much importance when going to forced induction.

My CR is going to be right around 9:1, with a turbo I know that is higher than recommended. Can I place knock sensors on the engine to prevent detonation? If so, where on a loud and noisy 4 cylinder would be the best place?

Thanks

With all things forced induction, I tend to lean on the information from Blower Drive Service. They've been in business long enough to have done most everything there is to do with pressurizing air. Their chart shows that with 9.0:1 static compression ratio, you can run up to 6 lbs. of boost on pump gas.
Blower Drive Service: We Deliver Horse Power! - Blower Drive Systems, Blower Kits, Blower Cams, Custom Carb Service
Now, this is with hot air. I'm thinkin' that with an intercooler, you could use more boost without detonation.

I have little experience with knock sensors, being from the old school and reading spark plugs to get the tune right. I'm sure that most of the high-tech world has passed me by though. A little surfing on the web found this offering that may interest you.....
J&S Electronics SafeGuard Indivdual Cylinder Knock Control

As far as reading plugs, buy a 10X lighted exam tool, chop the ignition and coast to a stop after a power run and examine the plugs.
How to Read Spark Plugs
Reading Spark Plugs
Spark plug reading
Reading Spark Plugs Correctly
Wallace Racing - Spark Plug Reading

B&B's Spark Plug Magnifiers
Spark Plug Reading Light - Twin Cam® Cam Change Kits - Cam Chest and Oil Pump Gasket Sets - Gaskets and Gasket Kits - All Products
Comp Cams 5326 Pro 10x Spark Plug Viewer
Nitrous Express » Next Generation Nitrous Oxide Systems » Spark Plug Magnifying Glass w/Light

timothale 12-30-2012 06:09 PM

long time ago.
 
50 years ago my engineering college project was designing a tuned injected manifold, as I remember tuned length was calculated using temperature , density and cam and rpm for max horspower. to get the numbers right. But I needed more money to finish college and sold my roadster. but I did get an A on the design project.

ryankalel 12-31-2012 11:46 AM

Quote:

Originally Posted by hcompton (Post 1628929)
I would copy the stock intake out of larger 1/4 thick wall alumiunum tubing.

Do you mean copy the inside diameter of the stock intake manifold? The original engine size is 2.0, I am stroking it to a 2.3. Will this make a difference in tubing size? I was thinking that 1/8th of an inch for the intake runners would be thick enough?? No? :confused:

I am also planning on reinforcing the runners by welding some 1/8th inch between the runners, like webbing. The flange I agree needs to be at least 3/8 inch.

Inside the intake/plenum should I run air horns or just smooth it down with the same idea of the air horn?

Thanks again for the input!!

Esprit Aviation 01-03-2013 07:21 AM

IMO I would keep inside diameter the same and go fairly thin on the tubing especially with gusseting; no sense in adding weight. The tubing gauge from the early 90's Geo Prizm/Toyota Corrolla intake should be fine. You may want to look up some photos of these manifolds as it could be an alternative to the over the top (which is a GREAT design and will yield good low end torque prior to boost).

The engine will be used for low end accelleration/cruise, not just boost and a good normally aspirated design should be adhered to for optimization over the entire range. Log style exhaust manifolds should be avoided as well.

Project89 01-05-2013 02:02 PM

what cam/s do u have in the engine and what size turbo charger
whats the engines redline and were do u want it to make the most power

on my 2.8L turbocharged v6 engine i picked up 28hp and 35ftlbs at the rear tires with a manifold i made for it

i shortened the runners 3 inches and and increased plenum volume almost 2.5 times over stock

the plenum volume increase helped it pick up power uptop but made off boost,low rpm driving responce a tad sluggish

Project89 01-05-2013 02:12 PM

here one o fthe ones i built . i reused the stock lower and middle section but did a whole new top

heres the cutup stocker
http://i76.photobucket.com/albums/j3...i/100_0896.jpg
and what i made
http://i76.photobucket.com/albums/j3...i/100_0858.jpg
http://i76.photobucket.com/albums/j3...i/100_0869.jpg
http://i76.photobucket.com/albums/j3...i/100_0871.jpg
http://i76.photobucket.com/albums/j3...i/100_0874.jpg
http://i76.photobucket.com/albums/j3...i/100_0875.jpg
http://i76.photobucket.com/albums/j3...i/100_0876.jpg
http://i76.photobucket.com/albums/j3...i/100_0880.jpg
http://i76.photobucket.com/albums/j3...i/100_0887.jpg
http://i76.photobucket.com/albums/j3...i/100_0881.jpg

urs will be much simpler to make over what i made for my car

for the plenum u want a flat bootom were the runners meet it, and u want all entrys bellmouthed , then use a half round plenum , u can tune runner lenght a lil bit to fine tune the intake

what i would do is make the plenum bolt to the runners , so u can make 2-3 diff sets of diff lenght runners and see what works best


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