For the love of a tractor engine: The life and times of the 18R-G

[bmxer54]

My dizzy consists of an RN105 hilux's weights and rotor. The weights are super light almost half the thickness of the std rg ones and the rotor has 14 stamped on it.
The coil, igniter and pickups are from and rt132 electronic dissy setup and everything else is set up as per ga61xx's thread
Still yet to be run, so will see how it all goes.

Cheers,

Peter

[andrewzuku]

We've all got distributor-fever

Photos for comparison would be helpful. I'm going to pick up a spare 18R-C dizzy tonight with the vacuum advance still in place.

I'll take photos of both my current setup, and what I pick up.

[allencr]

My reading suggested the weights are what defines the advance, the less weight the less rotation needed to throw out the weight, therefore advancing sooner. vica versa, the heavy weights take more RPM to throw out and therefore advance.

You've got your centrifugal force backwards.
Forget changing springs and/or weights if its all in by 3000, they aren't far off from perfect for any engine.
10degrees initial advance, then 20-30 more with the mechanical.

[Omegaman]

You've got your centrifugal force backwards..

yeh probably, but sounds right when i re-read it..cheers.




due to an initial bent dizzy shaft, changes were made, but i dont feel that they were for the better.
Hence my playing with dizzy config's again. But weights must make a difference, why would 3 dizzies for the same engine type (geu, gu+other ) be different inside?

[jabbatron]

..........

[RA35GT]

Centripetal force = m * [v^2 / r ] (m is the dizzy advance mass, say the CoG of the weight is at the same location thus r is constant, v is proportional to engine rpm)

The dizzy mass has to move against the spring, assuming a linear spring the Force = k * x. Where k is the spring stiffness and x is the distance the spring extends. (Distance is proportional to advance)

we now have:

k * x = m * [v^2 / r ]

If we take out the constants (assume same spring stiffness, radius) and just look at proportions we have:

x is proportional to m * v^2

So at a constant advance (x) a heavier mass would mean it comes in at a lower rpm (v^2).

[timbosaurus]

I like dinosaurs...

[bmxer54]

I like dinosaurs...

Fuck yeah Dinosaurs are the Bomb!!!!

[timbosaurus]

Cheers timbo seems like a micro will be the go, have picked up a 22r dizzy etc already so Ill bung that all together with it

I think the Microsquirt is an under recognised little gem.

Just remember if you go down that path though, it needs an external map sensor. I kinda like that, because you only need one bundle of wires between the ECU and engine, instead of wires and a vacuum hose. It's a bit neater, but the way some people wire their cars, that's the last problem they should be worried about...

You also should make sure you're running high-Z injectors.

You need to run an external coil driver (or make one from a VB921 chip). This is a much better solution than running the 10A coil current through the DB37 connectors on MS2.

You cant easily use a stepper motor for idle control, but on an RG you'd usually use a PWM valve anyways.

Other than that, it's a walk in the park

[river]

Hi,

You mean a walk in the Jurassic Park, with our dinosaurs?

seeyuzz
river

[Omegaman]

Centripetal force = m * [v^2 / r ]

Ha ha, I get it. Even if it above my current pay grade..lol cheers.

[matchan420]

Hey there good info here, I have not read the entire thread and have a short topic. I will read the entire thread eventually, but I do have a job and a wife (for now).

I have an 18rgeu and am in the middle of planing the build. So far here is what Have planned.

18rgeu

stock efi intake/injectors

SDS management-EM-5 E/MSD

w50 trans

stock flywheel

Questions on some Ideas I have...

supra throttle body

t3/t4 turbo?

turbo manifold?

which toyota injectors?

Air to air front mount or air to water intercooler?

I am thinking that I will have a friend water jet the exhaust flange using a TRD header for measurements then buying one of the turbo manifold kits available off the shelf. Im also wondering which motor; 4ag, 3sge etc has the most similar distance between the exhaust ports so I can put the turbo manifold kit on the jetted flange for the 18rg.
Now, this is all going into a 69 RT52 Corona Coupe. I felt that you on this forum would have the best info and experience for this type of motor build.

So far I have a 86 Corolla GTS LSD rear end and front disc brakes, still looking to upgrade the brake master to include a booster. I have drilled/slotter rotors with factory calipers. Going through the suspension now and really looking at how to make the leaf springs in the rear work well. I have 15inch Riken rims that will get some sticky 195/50's.

Thanks for the help. Once I start Ill do a small build thread if you all are interested.

[river]

Hi,

Welcome to the wonderful world of dinosaur DNA manipulation, where we mod these old oil burners to power our old classics.

Can't remember what throttle body was used on my engine. Think it's MA61, and changed the throttle linkages to a cable, using a Starlet throttle cable.

Running GT25R turbo on mine. It's a little baby one, but I like it as it has zero lag and as the vehicle is mainly street driven it's nice to have a zippy well behaved engine in traffic. Engine built to take up to 23pound boost, and the manifold is built to take bigger turbos, and the fuel injectors are big also. So, if I want more power all I do is bolt on the next biggest turbo, do a slight re-tune and I'm done. However, I am currently happy with 12pound boost and 170rwkw is plenty powerful enough for me. It's fun. Too much rwkw is not fun - especially for pleasant street driving. Track of course is a different set up all together.

Turbo manifold is custom built as I run air con and needed a manifold that can take the turbo and clear the air con pump.

I use Sard 700cc injectors, and the ECU is an Autronics SM4. Also, as a lot of time and money have gone into my engine, I have idle control installed (which is giving me a bit of a hard time at the moment, but will get it sorted) and low oil pressure cut off (hate to ruin this beautiful engine due to lack of oil).

I run the stock 18R-G inlet manifold.

I run the stock 18R-G oil pump. Despite what you may read or hear, it's a fine pump and you won't need a new one (unless the one you have is worn or busted) or special high performance oil pump unless you are thinking of putting it on the track.

Yes, please put up a build thread. We all like to watch these things getting built and seeing them finally on the road where they terrorise women and children.

seeyuzz
river

[Omegaman]

Question.

Is it ok to, adjust the AFM wheel to decrease the amount of fuel an engine receives.?
when running std injectors, ECU. fuel pressure is at 38psi
ATM its running rich at 9-10.1 at idle.
or
could this better be done another way.?

i acknowledge in nice to run a bit rich, but 12-13 would be the norm.

i can't seem to change the fuel readings, since i took out the Emanage.
Could the ECu, though an analoge one, (std ecu) be tricked into still thinking it requires fuel? I doubt it.
yr thoughts!!!

[Omegaman]

Thanks for the info.

I'm actually already running electronic ignition (Crane Cams XR700) instead of points.

On your weights, what is the 7-8 to 13 a measurement of? If it's grams, then that makes sense.

The 15.5° and 17.5° positions (remembering that one revolution of the distributor is two on the crank. So those numbers are doubled!) on my 18R-C mechanical advance cam are slots that a pin sits in. You can select either side by taking the cam out and rotating it by 180°.



I don't think the weights in my (18R-C) dizzy are changed when adjusting what RPM total advance is acheived. Instead, you would play with different strength springs. As far as I can find from Googling, I should have total advance at between 2500 and 3000 RPM.

From diagrams, it looks like the mechanical advance mechanism is the same between 4Ms and 18R-Gs. Diagrams seem to show 18R-C and 20R mechanisms are the same.

If this all ends up looking too hard, I may end up taking the car to a local classic car / carburettor guru (Motacarb in Nerang).



Your high idle sounds to me like either a vacuum leak somewhere, or the carby not directly connected to the throttle link/cable could possibly be out of balance, and not fully closing?

fyi
on the above, I've taken apart 3 18geu dizzies.
2x have 11.5 and 13.5 inside and
1x has 8 and 10.
which of the weight would prove beneficial?
At this point I will stick to the 11.5 & 13.5. vac Adv & Ret, unless someone says otherwise.

http://img21.imageshack.us/slideshow...hp?id=80u7.jpg