My 2.4 Six Engine, Manufacturing prototype intake adapters. Options

[McMark]

I picked up this 2.4 six awhile back and I'm gonna use this thread as I develop the engine which will eventually go in my gold car.

I'm starting a little out of order, but too bad. (IMG:style_emoticons/default/tongue.gif)

So I have this aluminum flywheel. No manufacturer stamps or numbers on it whatsoever. I'm thinking that it might be too light for a street car, so I may not use it. It's about 3lbs by itself. I've got a 914 clutch adapter (basically a cut down 914/4 flywheel that bolts to the outer edge) and that brings the total flywheel weight to about 10lbs.

I want a streetable car, is this thing too light?

[ConeDodger]

Try it...

[BKLA]

(IMG:style_emoticons/default/agree.gif)

I have a lightened Patrick Motorsports flywheel on a 2.4 that I'm building. Its not aluminum and weighs 7.00 lbs. If yours is not less than 5 lbs, it should be fine, depending on cams.

I'm using e cams based on Dempseys book.

I am, by far, no expert tho. (IMG:style_emoticons/default/biggrin.gif)

[sixnotfour]

your right at a stock 2.0 6 cylinder flywheel weight.. do you have an aluminum pressure plate the would be great, unless its for a LIMO, Then get a cast iron anchor..

[brant]

old and new flywheels

of course we don't have the torque of a 2.4
and we use an F first gear

[sixnotfour]

oh Brant that aluminum one is real vintage alright (IMG:style_emoticons/default/lol-2.gif)

[brant]

its Frank Becks toss off.....
he went to a 4.5 diameter clutch to save weight

[pcar916]

I've had a 6.75lb Patrick Motorsports aluminum flywheel and a push-type clutch on this 993 engine since 1999. No problems. Clutch/pressure plate/flywheel assembly weighs in at about 18#.

Good luck

[biosurfer1]

Too light? I think you just killed a little part of Ury with that comment (IMG:style_emoticons/default/biggrin.gif)

[get off my lawn]

how light is your flywheel?

I'd say it's somewhere between a medium silver and light gray, about the same color as yours. Not dark at all.

[Chris Pincetich]

My daily driver 914 turned cafe racer AX weekend warrior turned semi-daily driver has a lightened flywheel. It's 12 lbs I recall, behind a stock 1.7 TIV. When the engine is cold, it dies more often than it should. When warm, usually no problem. If you rev up in neutral, the drop back down can sometimes cause the engine to die. It just doesn't have that rotating mass to keep it smooth. I am really good at re-starting the engine no matter where/what. I like that my 914 is so sensitive to driver inputs w the light flywheel, turbo tie rods etc etc (IMG:style_emoticons/default/biggrin.gif)

Go for it (IMG:style_emoticons/default/beerchug.gif)

[GeorgeRud]

Figure that the heavy outer starter ring is at the perimeter, I think this should work fine. Just don't put a 'puck' type clutch disc in the car if it's going to be a street driven car!

[McMark]

Cool. Sounds like this flywheel will be fine. I can always swap it out later if need be.

On to the next subject! (IMG:style_emoticons/default/biggrin.gif)

These are the throttle bodies I will be using. They are from a Polaris 650. They line up perfectly with the intake ports, but I'll need to make adapters to make them fit. They're fairly large at 46mm, but I think they'll work okay.

I need to transition from the intake port size (36mm I think) to the TB size (46mm). There are two options I can think of that I like. Have a flange cut from 1/2" aluminum and taper the inside. The other is to have longer transitions, but this would mean CNC milling.

So there's the question: longer smoother transition intake, or short quick transition?

(IMG:http://www.914world.com/bbs2/uploads/post-419-1368374534.jpg)

(IMG:http://www.914world.com/bbs2/uploads/post-419-1368374542.jpg)

(IMG:http://www.914world.com/bbs2/uploads/post-419-1368374550.jpg)

[JmuRiz]

With a 2.4 I'd go with longer to get a smidge more torque....

Those throttle bodies look really cool, can't wait to see what you do, and if you want to make another set...let me know.

[BKLA]

(IMG:style_emoticons/default/agree.gif)

Love the polaris TB's! Great Idea!

[scotty b]

What cams are you using ? (IMG:style_emoticons/default/confused24.gif)

[Dave_Darling]

Remember that the factory went to high-butterfly throttles in some of their race motors. I bet that was to allow them nice longer transitions in diameter, plus a longer distance after the injector squirted the fuel into the air stream for it to mix and vaporize.

I think you should go for the longer intakes. Can you do the machining yourself, or do you have to farm it out?

--DD

[Mike Bellis]

Longer runners will give you better low end torque. Shorter will move the torque curve higher typically.

What is your goal?

Make sliding adjustable runners with O rings. Then tie a linear actuator to them. Control the actuator with an rpm counter to raise and lower as you drive... EASY! (IMG:style_emoticons/default/blink.gif)

Mazda did this on racing engines. a NA 4 rotor did over 750hp. The RX-8 has multiple runners that are rpm/load controlled valves to lengthen and shorten the runners.

[McMark]

Street engine. I like torque.

[r_towle]

2 flanges cut.
Two pieces of tubing, cut stretched, welded.
Then tig it all together...


As I was thinking about it, you should be able to hammer a tube to get 10 mm out of one end....
I would think a bit of time on the sharp end of an anvil, with some patience, you could make the tube cone shaped..

Just a thought.

Also, aren't the Ida carbs 46 mm?
What kind of parts can you find using that stuff?

Might want to contact Eurometrics, he specializes in the old carbs...