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

[jeffro ra28]

leroy, good luck finding some 18rg pistons aswell.

[RA23]

Strictly speaking, that part is not really needed. As long as you've got the tappet cover breather flowing well, you shouldn't have any troubles with the engine.

I removed one before so that it would look like all the emmossion points were still linked up and active for registration purposes.
One thing I would suggest for all 18RG owners is a catch can, especially when using ramflo filters with the tappet cover breather plumbed into the back of the filters.
We had a few issues with oil vapour soaking the air filters.
With a catch can with a great deal of stainless steel scourer in there to catch the vapour, we haven't had half the problem we had before.

I will add this though, make sure that the PCV system does vent correctly because if it doesn't, you lose your dipstick as it flies out of its hole and sprays oil all over your engine bay.

What do you use as a catch can? and what happens when it is full? Could you perhaps use the block breather to run the oil back into the block? Can you post a pic of your PCV systen?

[Mr DOHC]

Do you wanna PM me with a price?

if i send it COD, and u pay the postage, u can HAVE it

[Steve M]

What do you use as a catch can? and what happens when it is full? Could you perhaps use the block breather to run the oil back into the block? Can you post a pic of your PCV systen?

1. Catch can is made from an International Roast coffee tin (small one) that has two 90degree copper plumbing elbows soldered into the lid. One for in, one for out.
The one that carries the gas intot the can extends further into the tin so that the drips don't get blown straight through into the out pipe, which can happen.
Tube goes from tappet cover to the can. Second tube goes from the can to air filter.
As stated in previous post, we stuffed a whole lot of stainless steel scourer (curly stuff, not steel wool) into the can to act as condensation nuclei.

2.Easy, that's why we used a coffee tin, you just take the lid off and empty it.
It also has a nice little flange that supports the can on the 0.8mm steel tape bracket.

3. I suppose so, but that would mean that the air coming from the block breather would blow up from the bottom of the catch can and put all the oil straight up into the out hole, thus defeating the purpose of the catch can.
It also means that we would have soldered another outlet onto the tin, which just would have been a pain in my arse.

4. Not really, no digicam and I still haven't figured out the whole hosting pistures thing, I'm sure it isn't that hard but I have a car to finish before I take on any more heavy study.

Here's a concept map of how the gas flows through our PCV system:

Tappet cover -> tube -> can inlet pipe -> st. steel scourer -> can outlet pipe -> tube -> engine intake.

I hope that explains it, if not, just ask more questions or PM me.

[crowncustom]

Also 18R-C pistons fit in the 18R-G with no problems at all plus 18R-C conrods work as well plus they are lighter than RG ones but make sure u use the 4 18R-C ones,not like I did and busted a piston and bent a rod plus from my own experiences with RG'S I reckon with using flat top 18R-C pistons the engine revs alot smoother than RG pistons,and it also revs harder and not as harsh as RG pistons.
Cheers Brett.

[Steve M]

Also 18R-C pistons fit in the 18R-G with no problems at all plus 18R-C conrods work as well plus they are lighter than RG ones but make sure u use the 4 18R-C ones,not like I did and busted a piston and bent a rod plus from my own experiences with RG'S I reckon with using flat top 18R-C pistons the engine revs alot smoother than RG pistons,and it also revs harder and not as harsh as RG pistons.
Cheers Brett.

Hmm, I don't really like that idea.
point 1: major compression ratio drop from upto 9.7:1 down to about 7:1. (turbo?)
point 2: the valve reliefs in 18RG(E)(U) pistons are actually taken below the level of the block's deck. 18RC flat tops do not have this relief. If someone used a head that had been surfaced, those hard to find valves would be getting very close to the pistons.

I don't see how using mixing and matching 18RG and 18RC pistons would result in a busted piston and a bent rod. A serious imbalance I would expect, but those results I would not.
I know 18RC pistons have been used with 18RG heads, most times I've heard of this it has been to drop compression for forced induction, but most times I have heard of this the pistons have been modifies to suit the different valve positions.

Thiat post surprised me and now my brain is spinning, it goes against all of my thoughts and expectations but hey, each to their own. I for one will never be using 18RC pistons in any of my 18RG engines.

[tricky]

I'm with steve on this one. The cause of the busted piston could well be independent of the parts mismatch unless the incident occured at stratospheric RPM, but that seems unlikely considering that the engine was smooth. Also, the compression would be less than desirable for NA applications. The piston is not only lower, the 18RG combustion chambers differ from the RC ones, so there is a significantly greater combustion volume. This leads to lower efficiency, less economy and poorer response.

leroy, FWIW, I have a funny feeling that my engine started life as an 18R-C. I say this because it is a diverse mish-mash of mis-matched parts (lol). My block has the dipstick on the correct side and the oil filter mounting block is correct, but other than that, almost every part of the engine is from a different model... 18RC dizzy (now 88270), 18RC/88270 rods, 88210 head, 88270 cams, 88270 aux shaft, 9.7 pistons, 88251 timing cover, no block breather... Ya get my drift. Basically, I'd only convert an 18RC to RG spec using 18RC parts if I needed one in a hurry and I was short a few parts. Otherwise, I'd spend the time to source proper bits.

[Mr DOHC]

also, the rods may be lighter {not sure} but they are weaker

[RA23]

Thanks for that Steve.

3. I suppose so, but that would mean that the air coming from the block breather would blow up from the bottom of the catch can and put all the oil straight up into the out hole, thus defeating the purpose of the catch can.

Yeah, of course. didn't think of that. I was just wondering where that breather is originally linked to. I'll look that one up in the manual.

[scootaphill]

an 18RC Block has the numbers stamped "normally"
an 18RG Block has the numbers stamped "UPSIDE DOWN"

just a quick way to pick the difference in blocks

cheers

[ra_28]

Hmm, I don't really like that idea.
point 1: major compression ratio drop from upto 9.7:1 down to about 7:1. (turbo?)
point 2: the valve reliefs in 18RG(E)(U) pistons are actually taken below the level of the block's deck. 18RC flat tops do not have this relief. If someone used a head that had been surfaced, those hard to find valves would be getting very close to the pistons.

I don't see how using mixing and matching 18RG and 18RC pistons would result in a busted piston and a bent rod. A serious imbalance I would expect, but those results I would not.
I know 18RC pistons have been used with 18RG heads, most times I've heard of this it has been to drop compression for forced induction, but most times I have heard of this the pistons have been modifies to suit the different valve positions.

Thiat post surprised me and now my brain is spinning, it goes against all of my thoughts and expectations but hey, each to their own. I for one will never be using 18RC pistons in any of my 18RG engines.

The 18rc pistons do not have to be modified for the 18rg valve tust me i used a set hypoid 18rc pistons in my first turbo 18rg motor and they have no clearance problems only when i broke a timing chain the valves hit the pistons.

[jeffro ra28]

after a head and block surface grind you may loose .040". Will they still clear?

[scootaphill]

Does anyone know the
a: M.O.P (Maximum opening point) b: "Lobe centres" or c: "Phase" All the same thing

OF

1. STD 18RG
2. STD 18RGR
3. STD 18RGEU

any ideas on what lobe centres you would run on 272/288 or even 304 cams?

food for thought

[The Witzl]

Phill,

I dont have any tools to measure this, but i certainly do have a spare set or two of 18RG cams - 88250 set and 88251 set.
I'll be fudged if i know what the differences are, but i'll certainly try to borrow a cam dial or something to measure them.


Comparing the 18RC and 18RG rods - i would certainly not be using 18rc rods myself. They just look so pissy and weak compared to the 18RG ones. I'll get some side on comparisons to go with the comparison pics earlier in this thread.
I'm with Steve on the 18RC piston usage too...




Now here are some more reference pics

Here is a direct comparison of the EFI thermostat housing and the carby one. The EFI one is on the right....




This is my engine at the moment, part the way through putting on the EFI manifold....

[scootaphill]

looking good Karl...are you going to use the original fuel pump as a lift pump to a swirl pot then high pressure from there to rail?
if you dont already have the fuel line that screws into the rail, i would be looking for it now... its a pain in the ass to get to with the plenum and throttle body in place...
as for the MOP, Phase ect im just trying to get more out of her b4 i sell her back to simon so i can put the price up "evil laughing is over coming me"
cheers