Formula Atlantic

[xero]

you coming up for WTAC again man? i will definately be able to take you for spin this time

[pen15]

the n2 cars do not use the formula Atlantic motors they use built 16v and 20v motors but hardly formula Atlantic spec

[Kenex05]

Im not trolling around but what are the main differences in between the spec of Formula Atlantic and N2 4AGE engines?
And what advantage does carby setup have in comparison to EFI ? Is it just a cheaper setup that can achieve something similar to EFI setup ?
Thank you

[Rice86]

i came across a detailed write up of a FA 4age showing complete built specs and power/rev like 5years ago on google...will try to find it again.As for N2 4age specs, like said earlier, they are what i call "still basic engine builds with plenty of money gone into it"..just think high comp engine with everything balanced, port and polished to perfection and stage 3 cams, everything internally the best that a manufacture can produce or a privateer can buy, don't forget about drive train such as lighten flywheel, high finial diff ratio and upgraded gear ratio in gbox as well..

i think the best way to put it is, an average engine builder can build a N2 spec 4age with parts provided...Formula Atlantic are built by engineers
im not saying an engine builder cannot build a Formula Atlantic engine even with part provided but to you get the idea now? i mean 14k for an engine speaks for itself

the debate with carby vs EFI of pros and cons have been a long story, but still not resolved and wont be anytime soon
i think the BIGGEST advantage of being carby is weight saving as you will have LESS wires and cables in the car compared to a EFI setup..winning already in a race
and self tune, saving money and can self tune at anytime

Basically whatever works best for your money is what you want
Most N2 AE86 privateers run carby setup i have noticed, why? only thing i can think of is because of TUNING time, it cost money to dyno tune your car and after all the money spent on engine build+upgrade transmission and awesome looking N2 kits..carby setup for self tuning does not sound like a bad idea + in japan there are plenty of track days where self tuning is as easy as dyno tuning and being in japan, im pretty sure your best friend will have a best friend that knows how to tune a carby setup 4age

EFI will always be easier and more "direct" in tuning as someone that knows there shit can tune it for best performance, all you have to do is pay money right?

EDIT

Found it,

TRD Formula Atlantic Engine Specs

So, you have always wanted to build your 4A-GE to Formula Atlantic specs, you just couldn't find them.
Well, here they are, courtesy of TRD. I recieved these specs from TRD back in 1988. Thanks a lot, TRD.

General:

Cylinder Firing Order: 1-3-4-2
Engine Bore: 81mm (3.189")
Engine Stroke: 77mm (3.031")
Oil Viscosity: 40 or 50 weight, depending on air temperature
Fuel Octane Rating: 108 prefered
Operating Oil Temperature: 200º-230º F, above 230º there is power loss
Operating Water Temperaure: 180º-200º F
Oil Pump Operating Pressure: 80-90 lbs
Spark Plug: Champion C55C or C57C
Compression Ratio: 12.7:1 maximum
Intake Camshaft Timing: 102º Lobe Center
Exhaust Camshaft Timing: 102º Lobe Center
Intake Valve Lash (cold): .012"
Exhaust valve Lash (cold): .013"
Ignition Timing: 28º BTDC @ 2,000rpm

Clearances'

Valve Lifter to Bore: .0005" - .0028"
Camshaft Journal: .0014" - .0028"
Piston Ring Gap (#1): .016" - .018"
(#2): .015" - .017"
Piston to Cylinder Wall: .0045" - 0050"
Wrist Pin Diameter: 19mm (.7480")
Wrist Pin: .0006" - .0015"
Main Bearing: .0020" - .0028"
Thrust Bearing: .003: - .006"
Con Rod Large End Diameter: 1.7726" - 1.7716"
Con Rod Bearing: .0025" - .0030"
Con Rod Side: .008" - .012"
Crankshaft Nose Diameter: .9842" - .9834"
Crankshaft Main Journal Diameter: 1.8897" - 1.8892"
Crankshaft Con Rod Journal Diameter: 1.6525" - 1.6520"
Pilot Bushing ID: .678" - .676"
Input Shaft Diameter: .669" - .668"
Cylinder Head Flatness: Within .001"
Valve Spring Height (installed): 1.425" - 1.398"
Valve spring Pressure (installed): 50 psi @ installed height
Final Combustion Chamber Volume: 33.9 cc minimum per cylinder, including Cylinder Head Gasket.

Bolt Torque Specs

Crankshaft Front Pulley: 60ft/lbs
Camshaft Pulley: 35 ft/lbs
Idler Pulley: 27 ft/lbs
Crankshaft Main Bearing: 47 ft/lbs
Cylinder Head: 43 ft/lbs
Flywheel: 85 ft/lbs
Connecting Rod: 45 ft/lbs

[Kenex05]

^ thanks for your detailed explanations, somehow the link above remains 404 to me.
What about the reliability in between a carby and EFI ? It seems like with a proper tuning, a carby can also be as good as a EFI setup.

It is just so amazing how some of those N2 AE86s can brake 1-minute barrier on Tsukuba Circuit over the years.
Cheers

[johl]

i think i read some where they prefer carby just for cheap tuning on the road, rather than paying for dyno time

[xero]

the only one with a FA motor was tsuchiya's TRD machine, but that has since retired. but even then it wasnt called a formula atlantic motor it was just refered to a TRD engine.

but otherwise your spot on matty, all the engines are wildly different from each other. the only thing they share in common is that they are a 4a engine and 1600cc's

[pen15]

well im going to throw a spanner in the works a TRUE FA motor cant take a t50 or w series box because the mounting holes on the side of the block there the 2 long bolts on the side of the block witch a t50 or w series box are gone they have been machiened off because if they are intact the motor wont fit into the FA chassis with that the sump casting holds on the trans axle gearbox onto it dont get me wrong you can have a formula atlantic built motor but you wont be getting it to work with a t50 or w series you will need a custom job

i have a pic from hasselgren of their atlantic long motor in the build here you can see what i mean


compare this block to the one under i call them wings no wings mean its a true FA motor



how do i know this i helped build a true FA motor last year i worked on the block so it was my job to know every difference in the 4a blocks there is many more features like oil squirters and block bracing witch N2 cars dont get done but thats a bit over the top

cheers
mat

[stx-16]

im pretty sure he still has them