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

[crowncustom]

okay guys, was speaking to Leso yesterday, checking a few things between engines and we noticed that my block is different to either of the 2 18RG blocks he had, OR the 18RC block he had there... my dizzy mounts differently (though in the same spot), i have a stud in the block on the lower rear side of the dizzy, where as the others had a tapped hole on the top forward side of the dizzy, also the crank case breather on mine has a large weird thing on the extractor side next to a small blanked off hole (has bolt in most cases) but in my case, the mount for this weird thing is cast into the block, whereas the other block we had were void of any such mount. they did their breathing through a plate just under number 1-2 runners on the manifold which i'm sure your all familiar with.

what is my block from? can i ditch this weird breather thing? can anyone suggest why i'm flat spotting above idle? how do flys land up side down on the roof?

It sounds like it could have been built from a 18R.To make sure check to see if the engine number is written upside down,if it is then its a RG block.Thats usually an easy way to detect an RG block.
Cheers Brett.

[leso]

thanks brett...but we checked that, definatley a rg block. This thing that the breather pipe comes out of looks like a cast in dizzy mount..???

[river]

Hi,

It might be an 18R-GU block.

Check the fuel pump. Refer to the "Mammoth 18R diagram thread" and look at diagram 81 and 104. The 18R-GU has an extra pipe coming out of the fuel pump, as compared to the 18R-G. I am assuming the fuel pump is still original, or not replaced with a mechanical pump.

Also, check the dizzy vacuum advance and compare it to the diagrams in the Mammoth thread. I think the outlet pipe is in a different place for the 18R-GU and it's also has a deeper body than the 18R-G dizzy vaccum advance.

seeyuzz
river

[leso]

ok found what we were seeing, like ra28 said niether of my rg blocks had it nor did either of my r blocks,,?????

[RAd28]

Hi,

It might be an 18R-GU block.

Check the fuel pump. Refer to the "Mammoth 18R diagram thread" and look at diagram 81 and 104. The 18R-GU has an extra pipe coming out of the fuel pump, as compared to the 18R-G. I am assuming the fuel pump is still original, or not replaced with a mechanical pump.

Also, check the dizzy vacuum advance and compare it to the diagrams in the Mammoth thread. I think the outlet pipe is in a different place for the 18R-GU and it's also has a deeper body than the 18R-G dizzy vaccum advance.

seeyuzz
river

definatly an 18R-GU head, i would have assumed the block is the same, think from memory the head is 88253.

had a good look on that mammoth 18RG thread, and posted a responce, but noone seems to check it anymore. and i don't have the bandwidth to load all the pics on it.

dizzy WAS a bosch unit, though has since been replaced with a Nippon unit gratefully supplied by Leso (big thanks)

next time i get a chance will have a look see if i can spot other differences, will try and get some pics up of the engine too..

cheers

[RT104GT]

Can someone confirm something for me? I cant remember who gave me the part number, but I have a part number for 18RG oil filter is 15601-33021. When I first did the oil change on RAd28's 18RG, toyota wasnt open on the weekend and needed an oil filter, Aussie Auto matched up the equivalent Ryco oil filter based on the toyota filter. It looked about the same height as the one on the left of the photo. If thats the 18RG filter, is that what River, Witzl etc all use on their cars and swear by? The filter on the right is also a 2TG filter. We all know both of these engines 2TG and 18RG have oil pressure problems on start up if the wrong oil filter is used, and you get bad chain rattles etc. Why then are they both different in size? I take it then based on Norbie's post that you can use the filter on the right on an 18RG?

FYI:

REPCO ROF-93 Z62 or Z68,

No chain rattles as the filter has anti=drain back valve.

My parts book 1979 also says 15601-33021 all series including carburetted 18RG I imagine number has long been superceded.

ROF 93 is ggod except you have to take input airbox off to fit in my GT whereas the smaller less efficient filter is fitted from below if you have a small hand.

Small filter less time on engine say 5000 km. Big filter 10,000 km??

Also I use the long life Gulf Oil ex SAFEWAY or Autpro at $14/4l and it is magic stuff.

2 cents.

Try the internet.

[Steve M]

ok found what we were seeing, like ra28 said niether of my rg blocks had it nor did either of my r blocks,,?????

Does that hole line up with a rotating part of the crank or one of the main bearings?

Just thinking of it as a possible point for a turbo oil drain.
Damn I wish I had one of those blocks if it is suitable.

[crowncustom]

I thought the same thing that it may be for a turbo drain but as far as I know that Toyota never made a factory R-RG turbo motor
I do recall a few years back I had a block with this provision but it never had anything bolted to it just a blank area.
I also checked the two motors I have but they dont have this either.
Cheers Brett.

[Steve M]

I know it's not meant to be an oil drain, I am yet to see one that's actually got a hole in it.
But it could be suitable if it lines up with a bearing.

[The Witzl]

Steve,

I've got a couple of these blocks in my garage, i'll have to have a look when i start moving them about. Norbie's block definitely has it....

[RAd28]

couldn't say fellas, but a definate possibility i'm sure...

guys, any suggestions as to what might be causing my flat spotting?

[crowncustom]

Can you elaborate on what it is actually doing?
Could be a number of things eg.wrong timing,heat range of plugs,point gap,not enuff fuel,carbies up the stuff.
Cheers Brett.

[RAd28]

spent ages playing with the timing and points gap last night, dwell was at 48deg, timing approx 20-22deg advance,
heat range i don't know about, does it hot or cold makes no difference,
not enough fuel? carbies are 45DCOE webbers, should be enough there.
carbies APPEAR to be working pretty well, progression ports are clean, no crap in them, and accel pump works fine.


another thing too, how does 150PSI compression pressure rate for these things? i'm trying to find out whats been done to my engine previously so i know where to go...

[crowncustom]

150psi sounds to be ok.Its kinda hard to work things out when you dont know whats been done to it(if anything has).
I'm almost finished my RG rebuild and I will check what the compression pressures are when the engine goes in.
The only difference I will be running is stock flat top 18R pistons and rods.
253 head,40mm solex's,electronic dizzy(21R internals into 18R dizzy).
Cheers Brett.

[o_man_ra23]

The fact you have adjustable cams makes the compression figure useless on its own. What you need is to find out the variance between the cylinders. If they are all close together, then your engine is healthy and should run smoothly. If they are all over the shop, you have a problem.

Cheers, Owen