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

[andrewzuku]

Nice find. I'm pretty sure those are genuine TRD 8-position cam-gears for the 2T-G.

On page 22 of the TRD 1990 Catalog: They're listed as 13523-TA001. The 8-position 18R-G ones are a different part number again: 13520-RA051.

[egamirrorim]

Hey egamirrorim,

I spent quite a bit of time looking into cams a few months back. Here's what I learned (mostly from members on this forum )...

The numbers on yours make them standard 18R-GU cams. The specs provided by your builder look right.

18R-GU (88251) and 18R-GEU (88270) cams are worth about $50 - $70. It doesn't seem to make a difference to the price if they have the gears with them.

The earlier 18R-G (88210) and 18R-GR (88231) cams seem to be the ones everyone wants (fixed, 3-bolt gears).

There's also 88250s out there, which have the more aggressive profile like the earlier engines, but the single-bolt gears like the newer ones. I'm not 100% sure if they come from an 18R-GR or 18R-GU (anyone who knows, please step in here).

If they were reground, there should be a number stamped/engraved into the face that the gears bolt to. You'll have to take them off to see. Depending on the specs of the regrind, this would increase their value a bit. Genuine TRD cams would be a lot more expensive, and those Kameari ones are just ridiculous.

See page 20 of the 1990 TRD Catalog for info on the TRD Cams.

I missed this, thanks for the help!
+ rep

[egamirrorim]

How often in months/years or KM should my twin solex carbs need tuning?
They were installed by a professional and tuned to match the engine not long ago but I'm not really clear on what sort of maintenance regime they require...

[73GTV]

How often in months/years or KM should my twin solex carbs need tuning?
They were installed by a professional and tuned to match the engine not long ago but I'm not really clear on what sort of maintenance regime they require...

Read this info from this site about servicing these carbs and a timeline may, I repeat may be within this manual.

http://www.mikunipower.com/PHH01.htm

[MorGo]

Well,as they are OEM equipment you just look the factory manual how often they should be checked..
If not hamfisted or otherwise tampered they work just like any other carb(s) there is.It's funny how people think that "I have sidedraft carbs;they must be a hell to keep in tune!"
Yeah.. Factory choose to install carbs that are "impossible to be in tune!"
Forget those backyard wizards and learn how those carbs (be they Webers/Solex/Dellortos) actually work.Sure,it's not easy to tune them to perfection but to make them to win championships..still today..

[egamirrorim]

Read this info from this site about servicing these carbs and a timeline may, I repeat may be within this manual.

http://www.mikunipower.com/PHH01.htm

Thanks, a cool link which I'll save and print!

Well,as they are OEM equipment you just look the factory manual how often they should be checked..
If not hamfisted or otherwise tampered they work just like any other carb(s) there is.It's funny how people think that "I have sidedraft carbs;they must be a hell to keep in tune!"
Yeah.. Factory choose to install carbs that are "impossible to be in tune!"
Forget those backyard wizards and learn how those carbs (be they Webers/Solex/Dellortos) actually work.Sure,it's not easy to tune them to perfection but to make them to win championships..still today..

The green bible does not have a service schedule for anything really, both of these are just "how-to" books. With the amount of money I've spent on the engine, and the carbs in particular, I wont be touching them unless I am stuck on the side of the road.

Mine were installed and tuned by a specialist 2 years ago but the car has barely driven 5000KM since then. I'm just interested in how often they should be tuned or do I only get this done when the car sounds/idles rough?

[MorGo]

Generally they don't get out of tune unless something else happens on the engine.Synchroscrew "may" turn by itself but then again it's so easy to check that I don't count it as a "problem"

David Vizard once mentioned carbs being "self compensating low pressure fuel injection"!

Wrongly sized carbs WILL be headache but properly sized and tuned by someone who understands how they work the result would equal or sometimes surpass a FI.
Well,be a aftermarket ECU how Hi-Tech but it all boils down how good the tuner is.Sama as with carbs.

[JustenGT8]

Generally they don't get out of tune unless something else happens on the engine.Synchroscrew "may" turn by itself but then again it's so easy to check that I don't count it as a "problem"

David Vizard once mentioned carbs being "self compensating low pressure fuel injection"!

Wrongly sized carbs WILL be headache but properly sized and tuned by someone who understands how they work the result would equal or sometimes surpass a FI.
Well,be a aftermarket ECU how Hi-Tech but it all boils down how good the tuner is.Sama as with carbs.

LOL bollocks!! Carbies are tuned for idle and WOT...the rest is essentially luck Carbies will NEVER surpass injection if the injection setup is even half decent.

Sidedrafts do make the most awesome induction noises though and totally have their place on the right engine for the right purpose

[bermy]

LOL bollocks!! Carbies are tuned for idle and WOT...the rest is essentially luck Carbies will NEVER surpass injection if the injection setup is even half decent.

Sidedrafts do make the most awesome induction noises though and totally have their place on the right engine for the right purpose

Whoa that's only true if all you know is how to turn the idle mixture screw and swap around main jets. Get to play with different emulsion tube, modding one if necessary to suit your engine, correcting the "lean" slope of the main jet with the right air corrector and mess around with the correct progression holes at low throttle position will get you way closer than you might think compared to F/I. Saying that it will surpass fuel injection is a pretty bold statement too, but carbs can be made to run as good as f/i if you know what you're doing... only downside is that once it's tuned you have no way of compensating on the fly for difference in air density so it's a lot less user friendly than a half decent fuel injection setup. But it's not only "good for Idle and WOT"

[JustenGT8]

I didn't say " only good for" I said the rest is luck....you can refine as much as possible but at the end of the day there is no input ....you essentially guess to compensate for atm pressure and air velocity....both are highly variable. No question at all you can get carbies to run well, that's not my point at all. But to try and stack them up against injection? Nup

[bermy]

I didn't say " only good for" I said the rest is luck....you can refine as much as possible but at the end of the day there is no input ....you essentially guess to compensate for atm pressure and air velocity....both are highly variable. No question at all you can get carbies to run well, that's not my point at all. But to try and stack them up against injection? Nup

Agreed then!

[MorGo]

The EFI is just as good as the tuner.. If the tuner don't know what he/she is doing applies as well to carbs.
Most of carb tuning was/is done without the wideband AFR meters so they were/are just mostly quessimates.
But oh yes,it's the carbs fault that the tuner don't know what he/she is doing.And the (mention any brand here) EFI is crap and don't run well because even the basic understanding of how the engine works is missing.

Off the rant..

[JustenGT8]

That's comparing tuners Not carbs versus EFI. Regarding tuners you are totally correct....comparing systems though, EFI>carbs

[73GTV]

I kind of want in on this one...! You guys make me laugh, computer controlled fuel regulated distribution (EFI) over metered flow via pump action metered by jets spray mist (Carburetor). It is all gonna get you from point A to Point B.

[JustenGT8]

I kind of want in on this one...! You guys make me laugh, computer controlled fuel regulated distribution (EFI) over metered flow via pump action metered by jets spray mist (Carburetor). It is all gonna get you from point A to Point B.

LOL so will a horse...eventually