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

[Steve M]

They can be redrilled quite easily, and it does make it easier to time in aftermarket cams. We got my brother cam's spot on by drilling two extra holes to the left and two extra holes to the right using the same spacing as the other holes (roughly). Tosco used this set up and it worked for them.

(We were setting up 13 hole HKS cams, which made it a little easier too).

[o_man_ra23]

Paying somebody to properly measure and drill a hole for you would likely be dearer than the aftermarket adjustables.

At some point I'll look at getting a set of the vernier adjustables, but that's going to be a little ways down the track, I'll see how the CT26 lasts first.

[Steve M]

It wasn't expensive when I got it done. I reckon it's a very easy job if you've got a drill press and a clue.

I set to work using the CNC mill during my last teaching placement.
All I have left to do on my prototype vernier cam gears is to grind off the excess stock from the back of the ring gear. So far it has all worked out very well.

They've cost me a grand total of about $20 in materials and only hours in labour.
I think I'd like to get some better quality sprocket blanks as the ones I bought were a bit shit ($5 each for a brand new through bored blank).

[TRD184]

never mind

[Rodger]

TRD184.

Never mind, but PHH44 Mikunis have been delivered on JDM Datsun Roadsters and some Datsun 510s.

The Roadster also came with the PHH44-2 (Type Q).

Mikuni make no more Sidedraught PHH styles since mid 90's but they can be found in all sorts of condition around the world.

Regards
Rodger

[egamirrorim]

Are the 18RC thermostats the same as the 18RG ones? Having trouble finding an RG one brand new...

[o_man_ra23]

egamirrorim,

The thermostat itself is interchangeable between the 18R-C and 18R-G. If you look properly, you will find a range of different temperature operations at your disposal, depending on how hot it gets where you live, and what temperatures your engine likes to run at will determine what thermostat you should get. The standard 18R-C item seemed to work fine for me in standard 18R-G's in Townsville's heat though.

[TRD184]

thanks, sorted

[o_man_ra23]

Clutch and gearbox input shaft spring to mind as possibilities.

[TRD184]

hmmm, sounds higher up then that. is there a known way i can confirm that if it was that?
got me thinking about thrust bearings now, or would that do it in neutral aswell? unless the pressure from the clutch moves the crank forward that little bit?

[TRD184]

hey guys
did a compression test on my 18R-GU today, ended up with 120 psi across all four of them, its great thats theyre all even but is that kind of figure normal for the emission controlled engine?

[o_man_ra23]

The figure can be greatly influenced by cam timing and valve clearance. I have seen 120 across all 4 on a healthy engine before. The aggressive cams of the 18R-G family of engines tend to give them low compression readings even though the static compression ratios are relatively high.

[TRD184]

aaah ok, i did a search and found some people mentioning figures as high as 175, and others as low as 110, so was worrying a bit. thank you

You must spread some Reputation around before giving it to o_man_ra23 again.

[egamirrorim]

egamirrorim,

The thermostat itself is interchangeable between the 18R-C and 18R-G. If you look properly, you will find a range of different temperature operations at your disposal, depending on how hot it gets where you live, and what temperatures your engine likes to run at will determine what thermostat you should get. The standard 18R-C item seemed to work fine for me in standard 18R-G's in Townsville's heat though.

I live in Sydney so I dont think extreme heat will be a factor...
Thanks heaps for the info! + rep

[o_man_ra23]

Flywheel question. Last piece to the Oman's 18R-GTE revision 2 puzzle is the flywheel. Stock item is not suited to that much power, and an aftermarket item is proving hard to find. Both Kameari and Jun Chromoly items are on 3 to 4 month back order, so the delay is pretty well unacceptable. The only other option I have come across is the Fidanza aluminium item (approx the same weight as the Kameari CrMo).

Are there any other light weight high strength flywheels suited to either 18R or 22R which anyone knows of that aren't exhorbitantly expensive?? I say 22R also because they run the 11 x 1.25 pitch thread that I have reamed my crank out to, as opposed to the 18R 10 x 1.25.