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

[demios]

Heya!

I recently got my 18R-G out of storage and finally got around to finding out why all the valves bent. When I pulled the timing cover off, the timing gear on the crankshaft was in two pieces, which would explain why turning the crank didn't turn the chains! Anyway, I've got a replacement head which I'll be using, and a brand new lower tensioner + guide. I haven't had a decent chance to inspect the chains yet, but at first glance they looked ok.

Pics and a write-up can be found here.

Anyway, I was wondering whether I'd be able to use the timing gear and keyway from an 18R-C, since I have a spare sitting here. I'm also keen to hear where I could potentially source a new one, too, or even a decent second hand one that's already removed.

The other question, how much damage to the crankshaft is too much? I wouldn't want to slap it all back together only to have another failure a few months down the track.

And lastly, anyone have any suggestions on what I should do while the engine is on a stand? I'd rather not take out the pistons and crank, as they look pretty good as is.

Thanks!

[roadkill]

Hi,

completely rebuild that engine. You'll be very disappointed if you don't. Remember what hit the valves to bend them? Yep - the pistons. So quite possibly they are shagged/cracked/dinged etc. You may find there is a good chance that there is very little that is still usable in that engine. Unless you strip it down and measure it you'll never know.

bEn

[demios]

Hi,

completely rebuild that engine. You'll be very disappointed if you don't. Remember what hit the valves to bend them? Yep - the pistons. So quite possibly they are shagged/cracked/dinged etc. You may find there is a good chance that there is very little that is still usable in that engine. Unless you strip it down and measure it you'll never know.

bEn

I put up a post over a year ago asking for suggestions on the pistions and I'm still rather financially limited, to be honest. The upshot is that I've got a lot of spare time, so I might pop the pistons out and see what I can do. I'm just looking at making a reliable engine that'll last me a few years before I can drop something bigger and better supported than the 'ol 18R-G in.

[o_man_ra23]

Ben is on the money with regard to doing a proper inspection. As for the timing gear, the cogs found on the crank and aux shaft are common between the RC and RGs, as is the lower chain, guide and tensioner. The upper chain can be purchased new for about $40, and the upper cogs are one of two types, either the pin adjustable ones, or the non-adjustable which are the same as 18RC units (assuming they aren't aftermarket). The upper chain tensioner and guides are different to the RC units and only the top flat one between the cams is available new.

I am trying to get a local mob to refurb them with a highly durable polyurethane. Apparently they are currently designing the moulds for it. Once they have done mine, I will send the spare I gave them to the board for approval on a group-buy type arrangement to get everyone else's done as this is becoming the hardest to get part for these engines. Details will be given on how to get yours done once board approval is gained.

[2004lowlux]

hehe!

very good this

ive since took the efi manifold off but once i get the carbies ill be able to get it booked in for a new exhaust

[ra_28]

^^^An 18rg always looks good in an RT104 engine bay. One day i'll put up some pics of an 18rgte in an RT104 even more sexy. ;-)

[Suavemechanic]

I would....replace the core/ welsch plugs , all the oil seals , sump gasket etc clean everything and pop a couple of bearing shells out for a look , they are common to the 18 rc and quite cheap
for the money you save i wouldnt recycle any timing chains . if you have really a lot of time and no money run a tap through every threaded hole ,clean everything again and paint it
good luck

[egamirrorim]

Hi guys, am chasing a pair of either 18R or 18RG connecting rods for my rebuild. 2 rods were no good when the engine was dismantled and RG items were bought as replacements but it turns out that the motor had 18R rods so I need a another 2 of either to have a matching set.
Can anyone help?

[2004lowlux]

lol! thats gotta piss you right off you know if you can use 22r rods? i havent had time to pull my old 18rc apart yet but i spose i might be able to get the rods out of that

[o_man_ra23]

22R rods are different.

Send me a PM, I'll pick out the best 2 rods from my old engine (probably 1 and 4 as 2 and 3 had the cracked pistons). Feck it, I'll give you all 4 and you can pick what you want. I'll send them COD so you only have to cover the postage.

[egamirrorim]

PM sent!!!

[timbosaurus]

guys, anyone know what the size of the original 18RG injectors were?

Have a bunch of 320cc 1G injectors, and they're in much better nick than the RG ones. injector calculator says 4 x 320cc injectors at 80% should easily be good enough for a 200hp engine.

[o_man_ra23]

240cc was the information I dug up for the OEM injectors. I used 450cc Mitsubishi Talon injectors for my turbo engine.

[Dans_RA28]

hey guys, i have an 18r-g in my ra28. i wanted 2 put a electronic dizzy in it. i heard u can put a 22r or 21r internals from a hilux motor in it. i jut wanted 2 know how u can do it?
cheers, Dan

[timbosaurus]

thanks Owen. This is a simple NA motor, so 320's sounds about right then.

Not sure how the 1g spray pattern will suit the RG, but cant hurt too bad.