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

[Omegaman]

I happen to have some diagrams of vacuum lines for 18rg, see if these help.

Id love to stand at my engine bay and tell you where the hoses all go. But itsnot stored near by.

[Steve M]

# EDIT#

I measured the hole positions in an unreliable way,
*here are the latest, more reliable measurements*
I double checked, the hole spacing are not all the same, infact each cam gear is slightly different, BUGGER.
I checked four cogs this time.
The thickness of material between the holes varies This is what was measured this time.
The first two holes (clockwise from front) are 7.3 -7.35mm apart. (two of each)
The 2nd and 3rd holes are mostly 7.4mm apart. (one was 7.3mm)
The 3rd and 4th holes are 7.5-7.6mm apart. (two of each)

The second hole (clockwise from front) is displaced 4.12 degrees clockwise from the centre of the marked tooth.
Hole diameters are 6.15mm
Holes are 17.1mm from the centre of the cog.

Sorry about the mix up,

Witzl, are you able to get those cogs measured?
I'm not sure how the extra four holes would be spaced now.

[Steve M]

I just want to attempt attaching a picture.
Here's a dump from the CAD file.
The quality is a bit crap, I couldn't fit the .bmp or .png in the size restriction

[Steve M]

While I'm at it, here's an idea of the manifold I'm working on now.

[scootaphill]

steve i have a HKS adjustable cam gear... when i get back from the buggy trip (late july) remind me and i may be able to send it over for you to have a look at.... i may even attach a HKS intake cam

cheers

phill

ps i know someone who casts aluminum....

[The Witzl]

STeve - closer look at those gears says they are drilled aftermarket....

[Steve M]

Phil, have you got a photo? Does it look like either of these?


Witzl, that doesn't really surprise me.
Chances are that even to genuine TOSCO items look aftermarket. I imagine they would have taken 4-hole stock items and drilled them out after on a different machine when they needed them.

[Steve M]

Phil, I'm getting some machining done for the manifold bits, then I'll have it welded up.
After that I might think about making some sand molds and casting up a couple.

I know someone who used to work at an alloy casting place. We also have a manufacturer of thermostat housings here, I could get some hints from them.

[tricky]

Ooh! I wouldn't mind tracking down a couple of those vernier adjustable cam gears! Steve, do you know how they are fixed on the cam? What I mean is the original ones are bolted on, but are actually fixed in place with the pin. Do those funky ones have a notch or something? BTW, I had no idea you were planning a turbo RG until I checked out the RGT thread.. That manifold looks even better for forced induction, 'cos of the nice, short, straight runners. Good to hear it's coming along!

[Steve M]

Tricky,
I have no idea how they are fixed. It doesn't appear that they are.

They are 2TG gears, whic means they will fit 18RG cams.
vernier adjust ~ $200 + freight
13 hole adjust ~ $93.75 + freight (based on 80y:$1 exchange rate)

I reckon I'd be putting a hole in them to locate them if I got some.
Both gear types come from Japan, Kameari Engine works, but I can't find their site.

PitRoad Motorsport in Japan stock them.
Here are the 2TG catalogue pages:

http://www.pitroad-ts.com/kameari-2/kameari19.htm
http://www.pitroad-ts.com/kameari-2/kameari20.htm

They also sell 92mm and 92.5mm 18RG pistons
~ $812 + freight
http://www.pitroad-ts.com/kameari-2/kameari07.htm


I'd like to get some of those gears too and I like the look of those pistons, but the prices are a bit high.
My custom pistons are going to be AU$828.60 delivered (+ rings)

[Ren_RG28]

Hey guys.

I'm new to this forum. Actually, I'm new to Toyota as I've just bought an RA28 GT 2000 replica. It's my 2nd car (my 1st being a 1977 LX Torana hatch). Anyway I just want to thank everyone for this thread as it's been an integral part of my 18RG research.

My RA28's got an 18R-GEU retrofitted with twin Mikuni-Solex 44mm carbs. Obviously someone thought they'd be able to get more performance out of the engine through carburetion and ditched the factory EFI. Alas, they obviously did not do their research into how much fuel this engine really requires.

Being the last of the 18RG's with the lowest compression, I'm sure dual 38mm Solex's would have been ample fuel for this engine. The engine is completely stock too, and could do with a rebuild. So I thought I'd take it to my local mechanic to give it it's first tune & service. Having recently acquired their own in-house Dyno (Dyno-Dynamics), he thew it on for an initial diagnosis. Initially it came up with 54rwhp (drove like crap, coughing bad past 4 grand), but after a tune he managed to get 87.7rwhp. However the mechanic told me I have the larger 44mm Solex's (P5 design as per www.wolfcreekracing.com), which are WAY too big for the engine. Apparently he tried to lean-out the carbs as much as possible, and would like to go down one size in main jets (if he can find some).

It was going like the clappers for a week or two , but then got richer and richer over time with the odd miss/stumble here and there. I then decided to convert the single point dizzy to electronic (using 21-R internals), and threw an MSD 6A and Blaster coil on it to try to burn all that extra fuel from the big bastard 44's. It helped a little, eliminating the odd miss under power and gave it a much stronger and smoother idle. Also the colour of the exhaust was a nice light grey (instead of charcoal black), and the spark plugs were burning at a nice light colour too. After that mod, it came up with 92.7rwhp. Still, the air to fuel ratio was way too rich down low in the rev range, but it leaned out ok by the time it powered to redline. I'm now in the process of getting some Top Gun 8.8mm ignition leads as the current ones are mismatched and old.

Anyway, thought I'd give a bit of an insight to my little project. Hope it sheds some light on retrofitting 18-RGEU's with carbs...

Ren.

[Norbie]

A little update on my project:

I've been given the opportunity to purchase an SC12 supercharger for $50. It has a munted clutch pulley but is otherwise in good condition. I already have a fresh 18R-GEU with programmable engine management, I have an intercooler, I have a friend who will do any welding or fabrication for free - so basically all I need to do is buy some stainless pipe and bends and get a suitable crank pulley fabricated and I could have an 18R-GZEU!

Obviously I'll be limited to fairly low boost with the SC12, and I'll have to convert it to a solid pulley since the clutch is toast, but for $50 it's hard to say no. The only thing that worries me slightly is the ~10:1 compression ratio - but I'm hoping I might get away with 5psi or so with careful tuning. Thoughts?

[JustCallMeOrlando]

It's all in the tuning...

[bullitt]

Hi, all..

I like to know,what are fuel pump you're using for 18RG engine...i going to replace my old mech pump to electric pump..Any help would be appriciate.Thanks..

[Ren_RG28]

Bullitt,

I'm glad you brought that up, I just went through the whole process of researching electric pumps for my 18RG...

There seems to be a bit of confusion surrounding electric fuel pumps, and whether or not they require a regulator. When I bought the car it had a Holley Red electric fuel pump. This pump puts out 5-7psi of pressure, and around 100, maybe more gph of volume. (I had one of the older models, they re-released the Red and Blue pumps not long ago. They might have changed its pressure and volume properties, but just check).

Now, there is nothing wrong with this pump. Actually, if you talk to anyone in the V8 world (like my Dad), the first pump they will recommend will be the Holley Red or Blue. My Dad swears by them, and has always had one on his 355 stroker. Obviously, if something works well on a 6ltr V8, it doesn't necessarily mean it will work well on a 2ltr 4... But it gave me no grief, and did the job quite well.

Why did I want to change? Well I had a chat to a Weber expert about fuel pumps. He's spent his whole life working on old school MG's, BMW's and VW's with single, dual and triple carb setups. The first thing he told me when I raised the question was that an electric pump is a MUST for any performance engine. They deliver an even, constant flow 100% of the time. Mechanical pumps rarely do this at all. So if eclectic pumps are so consistent with their pressure, why even bother with a regulator?

According to this mechanic, DON'T. Whilst they are designed to ensure constant pressure to the intake, they inhibit flow. See, a Holley Red puts out 5-7psi of pressure, and over 100gph of volume or flow. Apparently any Weber/Solex carb only requires a maximum of 4psi of pressure. So instead of throwing a regulator on a Holley Red (5-7psi) to keep the pressure at a constant 4psi, buy an electric pump that delivers 4psi and run that without a regulator. This would be a much more efficient setup.

This is why I converted to a Carter. They make a pump which delivers 4psi pressure and 72gph volume, which is perfect for a dual side draft setup. No regulator required. That way your carbs are getting the correct pressure at the right flow, without be restricted by a regulator. And I couldn't be happier with my Carter pump. And it's very, very quiet. The Holley Red was louder than my exhaust note, so people were asking me what was wrong with my car...

Anyway, hope this helps. I'd like to hear other opinions on this...

Ren.