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

[Slidin23]

hey im currently building a 18rg for a grip set up ra23...

im using 20r pistons... couldnt find any new 18rg ones in my price range
fully ballenced bottom end 30% lightened flywheel

stock early 18rg cams with double valve springs and portmatched and flowed head
gonna run stock carbys still

my engine builder done a test and recones the compression should be around stock even maybe a slight gain because of the mass overbore....

what do you guys think of the set up? what sort of power should i make?

[JustenGT8]

hey im currently building a 18rg for a grip set up ra23...

Whoa a grip setup...never seen one of them before

Reckon you'll need to change your username

It'll make what it'll make if that's what you are stuck with...if you have a hp target in mind then use the parts to get that.

[Slidin23]

lol was gonna drift it but got a 180sx instead and now i just wanna fun hills car

was mainly just wondering if anyone has used the 20r pistons with carbys iv seen alot of turbo 18rs with 20r pistons..... and what sort of power figures they have reached because im intersted to see what kind of power i will be looking at

not aiming for anything special just something drivable...

[JustenGT8]

lol was gonna drift it but got a 180sx instead and now i just wanna fun hills car

was mainly just wondering if anyone has used the 20r pistons with carbys iv seen alot of turbo 18rs with 20r pistons..... and what sort of power figures they have reached because im intersted to see what kind of power i will be looking at

not aiming for anything special just something drivable...

Stock cams....150hp but nice and torquey with plenty of bottom end and midrange. Will suit street use perfectly.

[Slidin23]

ok awsome thanks

so you have used 20r pistons? in a carbed 18rg?

[o_man_ra23]

$750 delivered got me custom 92mm Arias forgies, so wasn't worth mucking around with the valve clearancing on 20R pistons.

[Slidin23]

if i had known that i would have gone with them....... i asked many times on this fourm and anot of other places and my engine builder sugested the 20r pistons he didnt charge much for the valve cut outs

[JustenGT8]

ok awsome thanks

so you have used 20r pistons? in a carbed 18rg?

Nope but stock cams will be the restriction regardless of capacity. You will see good torque gains though at lower revs from the extra cubes.

I am building (well rebuilding) a 2.4 litre using 22R pistons on carbs.

[Slidin23]

ok cheers.... is it easy to change out the stock cams later?

and how much would i be looking at for some good cams? and where do you get them from?

cheers for all the help should have asked questions in hear a long time ago lol

[JustenGT8]

Changing cams will usually dicking around resetting valve clearances but no hard, just time consuming. A few cam options, discussed a few pages back i think.

[Slidin23]

was looking more for new cams dont really want ground down cams as iv had bad expriances with them

e.g griding the hardened surface off and the cam wear quickly.....

[timbosaurus]

New cams will still require resetting valves.


RG cams are usually welded, reground, then hardened. Not perfect but if done properly they are fine, and much cheaper than billets.

edit: i meant adjusting valve clearance obviously, not restting valves, lol

[Slidin23]

yeah where are you getting these cams done? like the welded and hardened ones? and how much do they cost?

[o_man_ra23]

Off hand, look for Tighe cams, or Kelford cams. Both should be capable of hard surfacing and grinding stock cams into a more aggressive profile.

Do you know what static compression ratio you are getting with the fly cut 20R pistons, and whether the dome thickness has suffered getting the valve reliefs cut??

[Slidin23]

my builder said the 20r pistons took the cut outs fine with plenty of "meat" there and im unsure what the static compression ratio is but im sure i could get him to figure it out

he said it was somewhere around stock.. with maybe a slight increase becuse of the massive over bore.....