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

[floppy]

Hey Owen,

When I purchased the car, the intake manifold I have (not the carbs), there is 2 pipes that connect to the back of it, one was blocked off and the other went down to the block pipe with a PCV valve in between.

The one from the valve cover has a pipe with a PCV going into the front carbs pipe behind the air filter.

I have some photos i will upload tonight when I get home.

It is a weird setup

Dave

[o_man_ra23]

The 2 pipes are probably your balance pipe... they should be joined together

[Rodger]

The Pipe from the block is the one that needs the PCV Valve. It should connect to the balance tube in between the two manifold halves.

The OEM spacer has a groove or grooves arranged so the two barrels of each carb are connected and with help of engine vacuum it draws fumes evenly into each port from the block.

The second big pipe in the balance tube is for the Air Valve system and was plumbed to an electric solanoid valve and then to the air filter housing. This allowed a big gulp of fresh air to enter into the manifold at shut down to stop 18R-Gs from running on. The valve was mounted on top of the cam cover using those two M6 thread holes every cover has.

The pipe fitting on the Cam Cover is the fresh air inlet for the PCV system. Fresh air is drawn into the engine, combines with any oil and fuel vapours and gets drawn back out the PCV pipe to be burnt in the engine. It should be connected without a PCV valve to a filtered air source, such as the filter backing plate. Or it could simply have a small filter directly attached to the fitting. However a lot of Road User Authorities do not like to see that small filter and like the pipe to go somewhere.

If a PCV pipe is not connected or is blocked this Cam cover port is where all the blow by gases and excess oil ends up coming from. Hence a lot of engines have very oily filters or the engine is a mess.

If it is blocked or has another PCV in it and the block's PCV pipe is connected correctly then you create a vacuum inside the motor, which if good enough sucks more fuel past the rings and raw oil out of the sump which can really muck up fuel mixtures and foul plugs.

If you have Softmounts then there is nowhere for the fumes to be drawn into and any PCV system will not work as intended. So you would need to drop the PCV system. In this case make sure you run the Cam breather to a filtered catch tank.

Regards

Rodger

[The Witzl]

translation for EFI:

- Cam cover vent: Connect with pipe directly to intake, after airfilter but before throttle
- Block Vent: connect with in-line PCV to plenum (allowing gas to flow from block to intake), between throttle and intake valves.


Roger - is there anything wrong with T-ing both lines together, then through a catch can, then into the intake between air filter and throttles?

[Rodger]

Karl,

As long as that point in the intake before the throttle plate has a higher pressure (less vacuum) more than on the other side of the throttle plate/s.

But if you mean "T" the pipe from the cam cover and the one from the block. Then yes that would be wrong.
If the two pipes go into a catch can and then to the to anywhere there is a vacuum then it will create a vacuum in the block. If the catch can has an opening to atmosphere then the manifold will draw extra air from there into the engine, perhaps changing the mixtures. So it needs to be before any air flow sensing device also.

To make the PCV system work as designed, fresh clean air needs to be drawn into the engine and drawn out and burnt in the cumbustion chamber.

It gets even more interesting if a force feed motor needs a PCV system. Where is the Vacuum to suck and where is the fresh air to draw in? That I do not know.

[o_man_ra23]

Well, I don't have the block PCV port, so I will just send my cam port through an oil catch can into the intake between the filter and turbo methinks.

EDIT: unless somebody has a block PCV port they don't need?? And an external PCV (or a good source for getting one)??

BTW... my engine machining, apart from rings is done... they said they can ream the pistons out to suit 18R-C rings, except they reckon the oil control ring groove in the 18R-GUE pistons are 4.5mm where 18R-C are 4.0mm... anyone got any thoughts on that?? Or know where I can get a set of .5mm over 18R-GUE rings from??

[floppy]

Hey guys,

Sorry got home late and cant find the pics I took.

Will take some tomorrow morning.

The one from the valve cover never used to have a PCV it went straight to the connector on the front carby behind the filter.
(Mate of mine told me it was supposed to be a PCV!!!!!) I'll rectify that tomorrow too.

The manifold pics will explain the connections I have better.

Thanks for the good info guys.

Dave

[floppy]

Pics time.

Hopefully these can help explain my previous post.

(Soz couldnt figure out how to get the picassa links embedded)

Image of the way the PCV is connected to the manifold
http://picasaweb.google.com/floppydj...56241625123026

Original shot engine as I bought it with the balance tube with the blocked off connection.
http://picasaweb.google.com/floppydj...56321585881890

Orignal shot of the engine with the valve cover connected to the front carb
http://picasaweb.google.com/floppydj...56382004451698

Shot of the front of the balance tube when I had it off
http://picasaweb.google.com/floppydj...56099792495106

Shot of the back of the balance tube when I had it off
http://picasaweb.google.com/floppydj...56176313308770

[Rodger]

Floppy

Pictures worth a thousand words.

The Air solinoid thing I was on about actually went into the front top port, the one with the orange 90 degree bend bit of pipe.

So now I forget what the other downward port was for.

Regards

Rodger

[floppy]

Floppy

Pictures worth a thousand words.

The Air solinoid thing I was on about actually went into the front top port, the one with the orange 90 degree bend bit of pipe.

So now I forget what the other downward port was for.

Regards

Rodger

Ok cool.

So the 2 on the back are the ones that I am unsure of.

With one being blocked off I am unsure if its all hooked up right.

On the front (where the orange 90 degree one is) there is also that small one which is blocked of on my engine as well.

So hard to find a diagram of the vacuum hoses for the RG and this manifold.

I have bought another manifold from a fellow toymods member but havent hooked it up yet because it didnt have the same inputs.

Dave

[Omegaman]

Quote' adjust your valve clearances...(existing shim size + valve clearance measured) minus the required valve clearance = the size shim u need to buy.' end quote'

regarding 18rgeu shims.
I've taken my shims out as the motor runs like a bag of s#*t.

My clearances and shims were.

exhaust
clearance+shim-gap req'd= new shim
1 - 0.25 + 2.3 - .34 = 2.21
2 - 1.03 + 2.1 - .34 = 2.79
3 - 0.25 + 2.2 - .34 = 2.11
4 - 3.00 + 2.1 - .34 = 4.76

intake
clearance+shim-gap req'd= new shim
1 - 0.35 + 2.1 - .29 = 2.16
2 - 1.13 + 2.2 - .29= 3.04
3 - 0.00 + 2.0 - .29 = 1.71
4 - 0.25 + 2.1 - .29 = 2.06

they seem way out of whack, i did get two valves peplaced on this head a while ago. but this is just way out.
This is just the job for a professional, me thinks

in the event that I want to recheck, now that the shims are out. How do I do that, please don't say to take the valves out and measure. Any thoughts?

[Omegaman]

On another cams issue.
What is the correct cam set up for the RG ***231 cams (three bolt type)



Should the intake cam be 1 tooth to advanced. like in pic.
1. Is the cam notch in advance & 2. is the marking at top dead centre on the cam gear.

Where the exhaust the cam notch and the gear notch are at top dead centre.
Or should both cams be at top dead and the intack gear marking sit one tooth retard?

what is the desired solution. I do believe the adjustable cams on the later heads will be set differently. Is this true?

[floppy]

On another cams issue.
What is the correct cam set up for the RG ***231 cams (three bolt type)

Hey,

Just a quick one after a long day.

Looking at the first pic the Notch on the intake cam and the Notch on the exhaust cam should BOTH line up with the arrows on the Cap.

I've gone through some fun setting up the engine I had and all the help from the guys on here brought me to that area (Along with the Green 18RG book.)

If they are out by that much it wont help too much with the running of the engine.
(again as far as I know)


So when the Engine is at TDC those two notches in the cams should be lined up with the arrows on the caps. Then you use the closest hole in the cam gear to keep it in that position.

Dave
(Who is knackered after driving to Hervey Bay from ipswich for another 18RG - only to forget to get the crankshaft from the seller - call tomorrow should sort that out)

[floppy]

On another cams issue.
What is the correct cam set up for the RG ***231 cams (three bolt type)

Hey,

Just a quick one after a long day.

Looking at the first pic the Notch on the intake cam and the Notch on the exhaust cam should BOTH line up with the arrows on the Cap.

I've gone through some fun setting up the engine I had and all the help from the guys on here brought me to that area (Along with the Green 18RG book.)

If they are out by that much it wont help too much with the running of the engine.
(again as far as I know)


So when the Engine is at TDC those two notches in the cams should be lined up with the arrows on the caps. Then you use the closest hole in the cam gear to keep it in that position. *My cam gears had a few more holes though*

Dave
(Who is knackered after driving to Hervey Bay from ipswich for another 18RG - only to forget to get the crankshaft from the seller - call tomorrow should sort that out)

[Steve M]

Omegaman,

double check your Inlet 3 shim clearance.

If there is no clearance, you won't be able to accurately calculate your required shim size.
There must be clearance for it all to be measured properly. Might have to try a thinner shim.( I have notice that that shim is the thinnest in your set, though)

Setting up 88231 cams should be a lot easier than setting up later cams unless your timing chains have stretched.
As Floppy wrote, both cam timing notches must be at 12:00, (lines up with arrows)
If you're one tooth out, it should be easy to fix, just shift it one tooth.
When you're check the timing, make sure that the engine is tensioned in it's usual rotation direction to take out chain slack.