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

[river]

Hi,

Or Jason (YellaRolla) as he's built a few 18R-G/18R-GT engines and knows the contacts and other information to get things done or items purchased.

seeyuzz
river

[o_man_ra23]

He says to mill down the head, not the stud i believe

Upon a re-read, you are most correct. Can anyone see a reason why milling the posts would be an issue?? I can get that done for either no cost or a carton of beer (which no doubt I will get a few brews back from). Will a shortened post become an issue, or will it be an improvement given there will be less stud length to stretch?? It would most likely come in at a considerably lower cost.

EDIT: Summit Racing has the head studs for US$100 plus freight, and a friend of mine puts a big order in with them every month. So long as there is no issue with milling the posts, then this would be the way to go. My re-re-build cost is starting to get a bit less worrying.

[JustenGT8]

Less meat obviously, but you generally use a lower torque for studs compared to head bolts anyways. I'm not seeing anything i would be worried about. In fact i'll have a set too

[o_man_ra23]

So you reckon mill the bosses?? If you want me to order you some Mitsu studs, then freight should just be what it costs from me to you, plus maybe $5.

[mark corona II]

Hello. I am gathering parts for the machine shop, and I have a question. in reference to the pulley below. if i am using only one groove, why have the extra weight? I have plans to lighten the flywheel, why not the crankshaft pulley? I realize the gains are minimal, but I don't want to leave anything out. I feel as though I should "blueprint" every last component, is this needed? is it just plain stupid? also, is there any last minute advice for me, in regards to machining the block/head etc? This question is broad, but any advice is appreciated. happy holidays.

[JustenGT8]

The pulley is also the harmonic balancer to help with crank harmonics. I have run a milled down one just as you plan to do on a 3SGE with no issues and pretty sure i did the same with my 18RGT as well...just be aware there is a risk of failure. A billet alloy one is a bit more cost but for more result, or of course go the ultimate and get Ross balancer made.

[Steve M]

Justen,

When you did the 22R crank conversion did you have to remove material from the crank to stop the counterweight hitting the piston just under the gudgeon pin?

I did a test fit a little while ago and found this problem. It can be fixed easily, I only remember a mention of removing material so that the crank didn't hit the bottom of the cylinder bore.

[Steve M]

I have almost worked out my throttle linkages for the silvertop quad throttle conversion. I just need a couple of extra bits.

Has anyone got the throttle connection that has the pull-rod ball on it for a 20v silvertop?
I want the joining rod and the pressed metal plate that goes onto the throttle shaft and clips onto the pull-rod.

[JustenGT8]

Nope i don't believe so Steve? the combo uses the 22R pistons as well, with side ground 18R rods so while the block was clearanced for the crank i don't think the cranks weights were touched and should clear the 22R pistons?

[Steve M]

Thanks, Justen. That's what I thought.
I've already had the rods ground and they fit a treat. I had to do a little cleaning up on the inside of the block skirt (88210 engine) to clear the rods/bolts though, as I had to do with the block I was originally intending to use (88270 engine).

I didn't have to remove any material from the bottom of the bores of the RG block, but I did with the GEU. I think I had a little removed from the crank before testing in the RG block.

I did the test fit with standard 18RG pistons (no rings so that they could poke out the top) and found that they hit the crank when very close to BDC.

I haven't yet had the block bored to suit my pistons.

I think I will have some material removed from the counterweight (~5mm) so that it will clear the piston without doubt.

Does anyone have any ideas on how much it should cost to have a crank knife-edged? Also, is there a real benefit in doing so?

[JustenGT8]

No real benefit to knife edging bar the reduced reciprocating mass. It's done on mega high revvers or dinosaur setups that don't run a windage tray. If you are taking weight off the crank anyways you may as well do it knife edge style and get any tiny gains that come with it

Yeah RG pistons will foul but 22R pistons won't....no idea with custom pistons so you'd have to check as piston specific.

[Willofan]

Hello. I am gathering parts for the machine shop, and I have a question. in reference to the pulley below. if i am using only one groove, why have the extra weight? I have plans to lighten the flywheel, why not the crankshaft pulley? I realize the gains are minimal, but I don't want to leave anything out. I feel as though I should "blueprint" every last component, is this needed? is it just plain stupid? also, is there any last minute advice for me, in regards to machining the block/head etc? This question is broad, but any advice is appreciated. happy holidays.

Hi Corona MkII,
The dual belt balancer you have pictured is very common and would be of no benefit to machine this one down to a single. There where many variations of balancers used from single belt with rubber harmonics fitted, solid steel single belt and other multi belt arrangements.

The harmonic rubber inserts are there to reduce any vibrations caused by the mish/mash of harshness caused by uneven combustion strokes, im-balance of reciprocating parts and the old poor quality fanbelt spinning other items.

See if you can find a single belt solid pulley and have it balanced with every other rotating part, these were common on early single cam 18R's and will fit your 18RG. Failing that, have an alloy one machined up and stainless sleeved on the seal face to reduce wear.

I will PM a few pics of different ones I have put aside for my projects so you can see the various types when i get a chance.

Cheers, Willofan

[MnToyGuy]

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

[mark corona II]

Hi Corona MkII,
The dual belt balancer you have pictured is very common and would be of no benefit to machine this one down to a single. There where many variations of balancers used from single belt with rubber harmonics fitted, solid steel single belt and other multi belt arrangements.

The harmonic rubber inserts are there to reduce any vibrations caused by the mish/mash of harshness caused by uneven combustion strokes, im-balance of reciprocating parts and the old poor quality fanbelt spinning other items.

See if you can find a single belt solid pulley and have it balanced with every other rotating part, these were common on early single cam 18R's and will fit your 18RG. Failing that, have an alloy one machined up and stainless sleeved on the seal face to reduce wear.

I will PM a few pics of different ones I have put aside for my projects so you can see the various types when i get a chance.

Cheers, Willofan

all of you are incredibly helpful. I have a question. I am building a 22re and a 18rg, side by side. I have read posts about both until exhaustion. I am concerned about the lack of torque with the 18rg. (i haven't any real world experience with said 18rg). this is obviously an 18rg thread, but how does the 18rg compare to 22re as far as pushing the car? lots of shifts?, no low rpm grunt?, etc? pro's and con's? budget is a concern, and I'm trying to use what's available from a 1992 toyota pickup/hilux. this brings me to my final question. should I stroke the 18rg? I have read briefly what's involved, I need some guidance. the car is a 1970 corona mark II, 8rc. rt72. pictured below.

[river]

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