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

[river]

Hi,

Yep.

Or just tell them the engine is out of a 1977 RA28 Celica with the W50 manual gearbox.

seeyuzz
river

[o_man_ra23]

W50 identity 101. The clutch fork will be one of two types. The early model is a cast iron item, and the clutch slave push pin will protrude through a hole in it. It also has a small hole on the end for a tension spring back to the slave cylinder. The other type has a pressed steel throwout fork. If you have an early type, then 1976 RA23 will definitely get you the right clutch kit. If you have the later type, then 1981 RA40 will get the right clutch kit. The throwout bearing is the only difference in the kits. The later kit will also fit the W55, 57 and 58. As mentioned, the 18R-C kit is the same in every respect to the 18R-G kit, aside from the stupid looks you get from unseasoned parts interpreters.

As for the 'baffling' mentioned earlier, what you see is actually a windage tray to scrape the excess oil off the crank (doesn't touch). This is present on both the 18R-C and 18R-G variants, and everything in between. The sumps are all fundamentally the same, aside from any oil level sensor fittings etc on specific models. Adding extra baffling if you want anything to go on a race track with turns is a good idea, as long right handers tend to turn 18R's to scrap metal all too often.

[jabbatron]

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[jabbatron]

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[checksix]

Update on the search for how to plumb the vacuum lines to an 18RG dizzy. BACKGROUND: For years I ran disconnected, as the thermal sensor I thought I was supposed to use was inop. Today I made several street runs with the vac off the carb outlet, and a few off the manifold outlet. I could see very little difference, but preferred the manifold connection. Not a clue if this is right or not, (damn a dyno would be nice but to sort this out not a cost effective solution). So for now I'm running off the manifolds unless someone who knows better can provide info.

Next question: What car can I find that has the pointless ignition that will fit in my current distributor (19100-88210)? I've seen other distributors (as a whole unit) that will fit (such as a 72 Cressida with 8R-G 19100-34044), but I'm guessing the advance and vacuum curves will be different. So what's the fix? Get a whole new dizzy? Find components that will adapt to mine so I can keep the mechanical and vacuum curves? My vacuum adaptor at the connector to the dizzy base plate is worn. I'll be looking for a new adaptor part. Any suggestions on what car to look in at the yard?

Thanks all, this is a GREAT forum!

[ra_28]

The most common way of getting electronic ignition is finding a 22r dizzy and using the internals out of it they bolt straight in.

Read this it might help you.

http://www.toymods.org.au/forums/showthread.php?t=16951

Regards
Alex

[checksix]

I had found a full dizzy (72 Coronia if I'm remembering right). I figured I could pull the guts from it and use in the 18RG, but the base plate anchors differently in the housing so I just put the whole thing in. Runs decent, and when I ran the curve against the green book it was quite close except the advance went further than the specs on the 18RG (9 degree at 3000) while the electronic one went to about 18 degree fully advanced.

The green book says 10 degree at 1600 RPM and then backs off to 9 degree at higher RPM. Is this right or a mis-print (19 instead)? I can't see how a centrifical weight system can go back a degree at higher RPM.

[checksix]

Went to several Pick n Pulls today, and finally located a 22REC distributor. It would be a drop in but for one thing.....the tail shaft is round and my 18RG has a flattened one. I wish I would have looked closer into the hole in the engine, because I'm not sure if I need that flat to drive "something". Because of this I didn't purchase the electronic dizzy. Would I have been able to use the 22REC dizzy? The base plate was also too big of diameter to fit in the 18RG housing so I can't go that route. Can one swap the tail shaft?

[Omegaman]

[QUOTE=I can't see how a centrifical weight system can go back a degree at higher RPM.[/QUOTE]

I believe the 18rg dizzy centre weight are different to say a 18r dizzy.
you will finf that the rg weight have 2 numbers stamped on them (11 and 13) i think.
where as the 18r has lower numbers ie (8-10 or similar).
I know this weight difference played a part in my tuning.
just check it out.
As far as the shaft is concerned, there normally is a pin, that can be removed to remove the shaft.
sorry thats all i got...

[jabbatron]

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[checksix]

Omegaman, I disassemble the 18RG dizzy this morning and couldn't find any numbers on the weights, The center post (that has the points cam), has a 75 on it. Pretty easy dizzy to take apart!

[Omegaman]

Strange there's no markings, both my geu and rc dizzy had them.
i've attached a diagram of a 18rg dizzy for you.

[checksix]

Thanks Omegaman! Your attachment must be for a later model as it has the electronic pick-up and mine has points. I currently pulled my points distributor and am running a 70's Corona (I think, the distributor has 8R-G on it, but the label is really beat up. It almost looks like 18RG but I think that is wishful thinking. HOWEVER, when I last ran it, I did a quick check of the advance curve, and it came out almost exactly as the green book calls for except the total advance goes to 16 degrees. The green book specified 10 degrees max advance at 1600 RPM then 8.9 at 3000 RPM. I posted previously to ask if the 8.9 degree is correct at 3000 RPM as I've never seen a advance curve go back at higher RPM. With weight even more engaged I don't know that can be. UNFORTUNATLY it seems no one knows, or hasn't responded yet.

I just looked at the original distributor (with points) and it also says 8R-G and the numbers 19100-88210 (which is the head number I have). Unfortunatrly this number isn't in my green book for ANY model. There were also the numbers 29100-1610 which also made no sense to me.

While continuing to search prior to posting this message I found the following which seems to pretty much match my electronic curve, so perhaps I'm just fine! My version of the book is 1982

Below are the specs for the 9.7:1 18R-G engine with the old, small style dizzy (88230 and before)

Vacuum Advance Angle
mmhg / inhg - Dis. advance angle Degrees
45 / 1.77 - Advance begins
75 / 2.95 - 4.3^
105 / 4.13 - 7.5^

Governer Advance Angle
Distributor RPM - Dis. advance angle Degrees
600 - Advance begins
1400 - 14^
3000 - 13.5^

(^ signifies degrees)
Published 1977 version of "The Green Bible"

Below are the specs for the 18R-C distributor

Vacuum Advance Angle
mmHg / inHg - Dis. Advance angle Degrees
80 / 3.15 - Advance begins
120 / 4.72 - 2^
200 / 7.87 - 5^
300 / 11.81 - 8^

Governer Advance Angle
Distributor RPM - Dis. Advance angle Degrees
600 - Advance begins
1050 - 5.5^
1600 - 13^

(^ signifies degrees)
Published 1977 version of "The Green Bible"

[Omegaman]

18rg dizzy with points.

[ian]

hey checksix
could you put up a thread on your bugeye
ta
ian
former owner of at least eleventeen sprites