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

[7t5-27]

Mark, you can machine down the pulley to save weight and space. I did on mine and it saves close to 3 lbs:



Steve, I'm doing a similar thing with the TB on my RGTE. Using a Supra TB that swings forward, with a pivot arm mounted to the plenum so the thrttle cable can pull backwards. I'll post pics once it's done (hopefully this weekend). Here's a source for the linkage rod: http://www.webcon.co.uk/Downloads/20...age%20Rods.pdf

Pierce Manifolds also has them. Not sure about a AU source

I made my linkage rod from the metal rod I found in an old filing cabinet I hooked it up to the supra TB and it works like a champ without changing the linkage at all, might be easier to do on a RHD than LHD as my car is RHD. Be safe
Greg

[mark corona II]

Hi,

In the USA there is a lot of modified 22RE engines - more so than in Australia because you got a lot more of those engines over there than we did. I think if you look about locally you will find more 22RE performance parts and info than we have in Australia.

We did not officially get the 18R-G in any cars, but we imported the engines by the boat load, and that is why we have a lot of 18R-G information, including performance modifications.

The 22RE does have more torque than the 18RG, but then again the 22RE is more "agricultural" than the 18RG, and the 18RG is more powerful.

In a vehicle as light as your RT72 you will find the 18RG will have no trouble pushing the car quickly along the highways, and it will accelerate fast enough to keep you pinned in the seat. The stock 18RG engines have a street-friendly cam profile, as they came out of the factory in cars that were to be driven by the masses for street use.

It's when you start to modify the cam profiles to get more top end power that you will find it more sluggish at lower revs. So, it may be best, if you are worried about low end torque, to keep the stock cams in the 18RG.

Yes you can bore and stroke the 18RG out to 2.4litres, but this is not a cheap exercise, however it will offer you more torque. Boring it to 2.2litres is a cheaper option. To get it then to 2.4litres (ie the extra 200cc) will require stroking, and this means a 22R crankshaft and 16R rods are required. If I remember correctly, you may have to remove some metal internal to the block to stop the 22R crank from hitting it... but those that have done this mod and are reading the thread can provide more information.

It is your car and your canvas, so do what makes you feel happiest. For me, however, I'd use the 18RG. They are a great engine, sound wonderful with the induction noise from those side-draughts. Coupled with a nice exhaust they do sound horn. A rebuilt stock 18RG will be plenty powerful and torquey enough to bring a non-stop smile to your dial in a light car like the RT72.

I'd save the 22RE for my John Deere tractor.

seeyuzz
river

well put. there's a good 8r in it already. so I can afford to take my time finding parts for the 18rg. I need a proper oil pump, a dizzy, intake and exhaust manifolds etc etc. labor of love for sure. thanks for the help.

[o_man_ra23]

For the oil pump, check the 18R-GTE thread, as MnToyGuy is getting some uber pumps made for 18R-G.

If you are doing an 18R-G, definitely use the 9.7:1 compression pistons, as these will provide greater torque, and from experience, they certainly make a light car take off nicely, so no, you won't have torque issues. You only tend to get torque issues when putting a 4A-G into a car weighing more than 800kgs.

[mark corona II]

I have a 18rgeu. here is a couple pics for reference. the pistons, are decidedly not geu items. what engine configuration would use high compression pistons, and 270 series head and cam? It came with a super deep. milodin oil pan, that seems massive to me. should I consider the depth of oil pan vs. stock oil pump? head looks to be ported. I'm gonna carb it, and keep it simple. can any of you i.d this piston? the reason I ask, I have concerns about u.s. fuel and detonation. a local here is busting my balls about reusing these pistons. I've posted about this before. could I build the motor, and deal with static comp. via the head gasket sizes? in other words, if it detonates, pull the head and try a thicker gasket. is this half assed.? my priority is reliability.

[Steve M]

Could you please edit your post and press "enter" between the photos? It would make it easier for me to fit on my screen.

Can you show us some different angles of the pistons and also the underside (inside).
We might be able to give you an indication of what your compression ratio would be with those pistons.

Have you measured them for bore size? Measuring the block might be better.
(that will kame a difference to our compression estimations.

Can you put up any pictures of the cam lobes?
They may have been reground to suit the pistons but retain the original casting numbers.

Have you got pictures of the oil pick up? Does it reach the bottom of that sump?

It looks like you've got a good set of pistons there, I think it would be good to reuse them if they are not damaged. Engines can be set up to suit high compression pistons.

My brother's RG is running 11:1 compression on 98RON fuel (upper-premuim pump fuel) and is doing well. Still haven't finished running it in yet or had it properly tuned, but it look sto be fine.

[river]

Hi,

Could you please edit your post and press "enter" between the photos? It would make it easier for me to fit on my screen.

Agreed. I edited the post to make it more viewable friendly.

seeyuzz
river

[o_man_ra23]

Looking at the casting, those pistons are aftermarket, and way more than 9.7:1 compression. I would say the engine was originally an 18R-GUE, but has been uber worked. Agreed also that the cams would have been re-ground. That isn't a normal set of pistons, and if they aren't fooked, they should be re-used. If the bores are worn, an those pistons are bigger than standard, then get an 18R-C block (they should be common as dogs balls for you too) and get it built to suit. The actual block castings are the same between 18R-C and the -G series.

[Omegaman]

It would be interesting to see a pic of the oil pump used in this motor.
With the depth of the oil pan, some mods must have been done in that area.
If so, what mods were done?

[mark corona II]

here are the requested pics. no oil pump came with the motor. I think this will be the hardest to find/get right. are the pics better?

[river]

Hi,

The actual block castings are the same between 18R-C and the -G series.

Are you sure of that? I thought the oil dipstick was on the opposite side between the G and C blocks, along with a couple of other things. Nothing major, but something to be aware of, nevertheless.

seeyuzz
river

[JustenGT8]

Hi,



Are you sure of that? I thought the oil dipstick was on the opposite side between the G and C blocks, along with a couple of other things. Nothing major, but something to be aware of, nevertheless.

seeyuzz
river

castings are the same but the machining is different

[roadkill]

hI,

Not hard to swap the dipstick to the other side anyway. I think it is on the passengers side on the rg because the carbies make it difficult to get at. From memory though everything else is the same.

Keep in mind too though on the 88270 engine the pump drive shaft doesn't have the lobe needed for the fuel pump so you have to go for an electric one ;-)

bEn

[Willofan]

That is one serious hump in the sump and would have been one long pump to reach the bottom of the sump hump. It could have only been used in a 4x4 truck with that depth.

May I recommend you acquire a another sump and RG pump that better suits your crossmember/steering in the old RT MKII.

I am sure someone here in OZ can help you out if you need these bitz.

Rgds, Willofan

[Steve M]

Those cams have definitely been reground to something much more agressive than the standard 18RGEU cam.

For this reason, I think you will be ok with your big pistons as long as you have the ignition timing tuned properly and run it on high grade pump fuel. (I don't know anything about US pump fuels).

You should have the camshaft profile measured in relation to the standard timing mark so that you'll be able to set them up properly after the rebuild. If you have the specifications for them, then this will not be required.

[o_man_ra23]

Note the HKS cast into the underside of the pistons. These are definitely aftermarket. The cams are a regrind and look like a low lift, high duration item. Do they have any grindings in the front face of them (a number put there later??) This could give an indication of spec.

River, to move the oil dipstick, you remove the blanking plug from the non-dipstick side to reveal the already cast and machined hole ready to put your dipstick tube. That blanking plug then replaces the dipstick tube on the other side. Casting is therefore the same. There was also the stamping of the engine number which is upside down on -G blocks, but this is not a casting. I am yet to see a difference in casting between the blocks, even the oil and water galleries are in the same spots, and seemingly the same size.