All moda 2.4L (what would YOU do?)

What would you do if you had a chance to build an all motor 2.4L.

engine work, tranny work, engine management?

must be intelligent. No nitrous, no turbo, no supercharger.

MUST use 2.4L block. If head swap must state what you are doing to tame the compression changes that will come about.

There is no money limit, but you can't say you're strapping JATO rockets to the car either.

Spy's all moda monsta.

basics.
2.4L block
2.4L head

moving onward we'll go from intake, to head, to block, to exhaust, to fuel system.

intake!
45mm individual throttle bodies.

Crower valvetrain (retainer, oversized valves, springs) that induction-dynamics has under lock and key
bronze guides
mantapart hydraulic cam followers 33mm
ported polished head biased for all moda power
RSM cams (yeh they look quite tasty)
Mantapart cam gears (yeh I'll be more than happy to drain the oil, take off the timing cover, adjust and do it all over again till I find the sweet spot!!!)
11:1 compression (stock bore) JE pistons w/ a slight dish to them
Eagle rods (love economy rods)
Crank polished/lightened knifedged & 2.3 oil pump gear
fully balanced rotating assembly
balance shaft delete
block guard *no more balance shafts to act as one apparently*
modified oil pan w/ windage tray
custom 4-2-1 header w/ 2.5inch collector going into 2.5inches of catless love
370cc injectors (if I need bigger than I will go bigger)
a/c delete pulley
Fluidyne radiator (find a design they have that will closely match to what will fit and order it custom style)
replace the stock fans for somethign sleeker and more "hardcore" flex-a-lite


(IF the intake that manta offers can somehow work on the stock pcm than I'll go the route outlined below, if not than I will be using an Electromotive TEC3 engine management)
Apexi S-AFC II
Wideband 02 sensor
MSD DIS-II

weight reduction, essential to any all moda car:
carbon fiber hood (rsm and MFX offers one)
road race engineering (have them make me a carbon fiber glove box to fit my pretty S-AFC and non essential gauges, carbon fiber center console piece)
Bride racing seats (carbon fiber shell)
Headliner replaced with thin solid molded sheet of carbon fiber w/ a thin sheet of insulation
carpet delete, tar mat delete (gunmetal repaint for the floor)
trunk hatch (cut off support structure underneath trunk, delete brake light)
Lexan rear quarter windows
Passanger airbag delete
driver wheel replace with thing Sparco unit
side mirrors delete and replace w/ thin carbon fiber mirrors
wheels (something 16inches something less than 12lbs)
big battery - batcat battery less than 12lbs!? wtf!?
a/c delete
carpet trunk delete


Still streetable

Naturally aspirated 4-cylinders don't high make HP, good streetable engines (Unless ~200-250HP is high for you).

But if for some reason money was no object, I'd get the ported 2.4 head from I.D as well as their intake, bore the block out as much as possible, probably .040" or .060" if it sonic checks ok.

Manta has a "2.5L Billet crank" for the 2.3L block, I'd probably try to machine the journals for the 2.4 block, if that wasnt possible, a custom lightweight stroker billet crank from SCAT or somebody would be in order, there's still no replacement for displacement... titanium connecting rods as well to keep the rotating mass down, and 11.5:1 or so lightweight forged pistons, with total seal gapless rings, whatever compression you figure I can get away with on crappy canadian 91 octane premium fuel.

Also the 3-stage dry sump oiling system from manta, since that allows high RPMs and high cornering G's..

Other parts include a lightweight aluminum flywheel, a 65MM TB, and manta parts' "competition" camshafts and their higher quality hydraulic followers, since no cam blanks seem to be available for the 2.4, those should be plentty aggressive and put the torque curve peak somewhere over 6000RPMs, coupled with all the other lightweight parts and high compression, should make for quite a rev-happy engine with a power peak around 7500RPMs, and a shift point around 8000RPMs

This would have to run off something like a TEC2 or TEC3, BTW...

But with the added displacement (somewhere between 2.5 and 2.6L) and the power band way up in the 7000RPM range, it'd definately be up in the 250+HP range, but a very rough and harsh engine, and and no power below like 2500-3000RPMs

interesting twist. 250hp would seem plenty to have fun w/.

I went the way I did because I did not want to increase displacement. Just doing things differently.

Well increasing displacement is definately the best way to make power.. I don't know what people have against doing that. "NOoooo I'm going to make tons of power from the smallest engine I can find! You'll see! Just wait!" Ok whatever.. it's both easier with more displacement, and it gives you a larger, more usable/streetable power band, you'll often hear people say they don't care if it's very streetable, but they're liars and don't enjoy it once they start driving it on the street...

got any more cool pics

I donno of these are "good"... just found them trolling the j-body.org forums, some dude building up his 2.4...






In the last pic you can really see how tall the 2.4 TC is, with the cam tower sticking way up there, because the cams sit up fairly high over the valves with the followers on top of the valvesprings, and the cams directly above the followers (or lifters for you OHV V8 guys)... it's sort of an antiquated design now, if you look at the ecotec, the cams sit sorta beside the valvesprings for a much more compact design, everything fits right inside the cylinder head, there's no need for lifter bores and cam covers up over the head...

Hopefully this is easier to visualize than the last paragraph :P :

Originally posted by Final-Reality@Dec 17 2003, 12:35 AM
Well increasing displacement is definately the best way to make power.. I don't know what people have against doing that. "NOoooo I'm going to make tons of power from the smallest engine I can find! You'll see! Just wait!" Ok whatever.. it's both easier with more displacement, and it gives you a larger, more usable/streetable power band, you'll often hear people say they don't care if it's very streetable, but they're liars and don't enjoy it once they start driving it on the street...

I'll agree, but I like my idea. It'd be fun to build that motor, and see what happens. Definitely not daily driver.

The weight reduction I listed will help out

Man if only I had cash to figure out how to throw that into a Civic Hatchback, than I'd be rollin around making honda boys cry foul...


mwahhahhhaha.

drinkie drinkie spy drinkie drinkie

Originally posted by Spy@Dec 17 2003, 04:00 AM
It'd be fun to build that motor, and see what happens. Definitely not daily driver.

The weight reduction I listed will help out

It'd be fun to build whether you bore it & stroke it or leave the displacement stock... and it'd be FUNNER to see what happens then too because it'd make more power.... I wanna see what a bored & stroked, completely done up 2.4TC can do spy... if you're going to tear down the engine anyways it's too damn easy NOT to bore and/or stroke it... DOOO IT!!!

Also, I just re-read your first post (fully this time) and with more radical cams, no S-AFC or DIS system will properly modify your stock ECU to work with them...

Originally posted by Final-Reality+Dec 17 2003, 04:39 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Final-Reality @ Dec 17 2003, 04:39 AM)</td></tr><tr><td id='QUOTE'><!--QuoteBegin-Spy@Dec 17 2003, 04:00 AM
It'd be fun to build that motor, and see what happens.Â;-) Definitely not daily driver.Â;-)

The weight reduction I listed will help out

It'd be fun to build whether you bore it & stroke it or leave the displacement stock... and it'd be FUNNER to see what happens then too because it'd make more power.... I wanna see what a bored & stroked, completely done up 2.4TC can do spy... if you're going to tear down the engine anyways it's too damn easy NOT to bore and/or stroke it... DOOO IT!!!

Also, I just re-read your first post (fully this time) and with more radical cams, no S-AFC or DIS system will properly modify your stock ECU to work with them...[/b][/quote]
this is just what I heard from emailing RSM, and they said it works w/ the stock pcm.

I'm just going by what THEY said.

and I'm also going by what the APEX documentation for the S-AFC is.

"The second-generation S-AFC is a fuel computer that adjusts fuel/air ratio by modifying the air-flow meter/MAP sensor signal. The S-AFC features a user-definable, eight-point, adjustable fuel curve that can be set in 500 RPM increments. The range of fuel adjustment is +/- 50% at each of the user-defined setting points. On hot-wire vehicles, the Deceleration Air Flow Correction function is capable of curing the erratic idle and stall problems associated with open-atmosphere blow-off valves on hot-wire air-flow meter systems. The S-AFC is capable of monitoring and replaying the following data channels in Numerical, Analog Meter and Graph displays: Intake Manifold Vacuum/Boost Pressure, Air Flow Capacity, Intake Manifold Pressure Karmann Frequency, Engine RPM, Throttle Position, and Air Flow Correction %. "


Either way, if I did that setup I know I would try every option available to me just to see if it could potentially or not work. Than I woudl tell you all my findings. mwahhaahh..

TEC3 would seem and I'm goign to say is the best way to go about that setup. Goddammit it's sooo tempting to try.

*BUT! I must hold out and order my injectors and mapsensor next week, and drop some cash to build my manifold... :-x goddammit I said something secret. *

Why do people keep this stuff secret? Who cares? If I was doing a buildup I'd probably post pics and specs of what I plan on doing... :P

Originally posted by Final-Reality@Dec 17 2003, 09:10 PM
Why do people keep this stuff secret? Who cares? If I was doing a buildup I'd probably post pics and specs of what I plan on doing... :P

well I have pics of everything it's just I have a problem at going to the 1-hour photo. I have 4 rolls full of SEMA pictures, buildup pictures, random pictures, etc.

Why is it a secret now? Well, cuz I'm still gatherin' my parts together.

[Oldsman]

i wouldn't stroke out a 2.4 this will hinder RPM's. 4 cyl are known for low end. Best thing would be to set it for mid to high end hp and put 6 speed race tranny behind it and balance the motor for 8000 to 9000 rpm.

i would say i would do this
bore block
forged steel rods
cryo treat crank
spot peen, cross drill crank
balance motor for 9000 rpm
10-11:1 compression pistons
extrude hone head
larger valves
stiffer springs
w-41 cams
custom mandle equal length header
weber setup
6-speed race manual tranny ( there is one out there but expensive)
remove balance shafts
2.3 oil pump
external oil cooler
remove a/c

then
remove about everything out of car and do
alum floor
alum dash
alum door panels
basically gut whole inside and trunk
lexan windows

The valvetrain is the biggest offender to high RPMs, stroking it a few MM doesnt mean it won't rev to 8000RPMs with a lightweight valvetrain (and the proper cams of course)... we have fairly heavy cars, torque is a good thing...

Originally posted by Final-Reality@Dec 18 2003, 07:12 AM
The valvetrain is the biggest offender to high RPMs, stroking it a few MM doesnt mean it won't rev to 8000RPMs with a lightweight valvetrain (and the proper cams of course)... we have fairly heavy cars, torque is a good thing...

my car weighs in at 2800lbs currently..

And I still need someone to help fund my carbon hood purchase, interior work, drum-disc conversion, fender purchase, and seat purchase..



the goal = less than 2800lbs w/ me in the car. I'm shooting for a goal weight of 185lbs, instead of my current 205lbs. No more going to the gym for me no more eating either..

arent drums heavier than discs?

Also.. why are you doing this to your car? What class of racing are you planning on running it in?

Originally posted by Final-Reality@Dec 19 2003, 12:22 AM
arent drums heavier than discs?

Also.. why are you doing this to your car? What class of racing are you planning on running it in?

in a totally uneducated response. I think discs look prettier.

Also I just want a stupid crazy street car. It's all in good fun mang.

It keeps me busy, and is more fun than taking an AUTO 101 class which I really should take.

heheh I guess... you should really look into autocrossing the car so you can see how it does though... I have no idea what class you'd run in with it stripped and whatnot but you'd probably have some stiff competition... make sure your suspension and chassis can keep up with the engine... light weight is a start but definately there's more to do

Originally posted by Final-Reality@Dec 19 2003, 03:45 AM
heheh I guess... you should really look into autocrossing the car so you can see how it does though... I have no idea what class you'd run in with it stripped and whatnot but you'd probably have some stiff competition... make sure your suspension and chassis can keep up with the engine... light weight is a start but definately there's more to do

It'd be interesting..

but well I'm going to have to raid pfyc.com for all their suspension goodies, and raid rsm for their polyurethane goodies.. and cross my fingers hope for the best.

Mantapart are definately the suspension experts... they have all sorts of braces and anti-rollbars and include polyurethane bushings with everything

Originally posted by Final-Reality@Dec 17 2003, 01:57 AM
In the last pic you can really see how tall the 2.4 TC is, with the cam tower sticking way up there, because the cams sit up fairly high over the valves with the followers on top of the valvesprings, and the cams directly above the followers (or lifters for you OHV V8 guys)... it's sort of an antiquated design now, if you look at the ecotec, the cams sit sorta beside the valvesprings for a much more compact design, everything fits right inside the cylinder head, there's no need for lifter bores and cam covers up over the head...

Hopefully this is easier to visualize than the last paragraph :P :

Just to let you know, those pics are from the 2.4 "Ecotec" LE5 engine GM is throwing in the new Cobalt. The LD9 does not have rockers as shown in the pics but rather a single lifter between each valve and camshaft lobe.