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

[JustenGT8]

Hi,

keep in mind though most of the time 45mm webers are choked down to 38 or even 35........

bEn

Not 'choked' as such, more matching the venturis to the jetting/cam etc. True though that 40mm solxes are plenty big enough for most 18RGs.

My 200hp n/a 18RG ran 45mm Webers with 38mm venturis from memory (maybe 36's?)

[7t5-27]

The cars will run strongly on the top end with the 2ndary venturi's removed and the jets adjusted accordingly, I ran my tg with 288/304 cams with 44mm mikuni's with no secondary venturi's. Milage did suffer but it ran well enough around town and came alive when it came on cam at around 3000 or so RPM, and would pull to 8000 if I would let it. with cams exhaust and strong bottom end don't be afraid to open up the induction save the parts and change it back if you don't like it. Good Luck Be safe
Greg

[river]

Hi,

Be careful going over 5,000 rpm with an 18R-G, unless you have special permission by the the government and scientific institutions, due to the time-warp affect such brute power can create.

Remember, Toymods promotes not only safe driving, but also safe 18R-G revving to ensure the planetary systems are not affected.

seeyuzz
river

[o_man_ra23]

Willofan, that's a serious bumpstick!! Degreewheel and a dial indicator can tell you what lift and duration you have if you know how to use them.

River, did you notice the big glitch in the time/space continuum the other week when my 18R-GTE hit over 10PSI boost and 6500rpm?? The men in black broke into my shed that night and destroyed my rings in 2 and 3 as an attempt to save humanity.

[river]

Hi,

River, did you notice the big glitch in the time/space continuum the other week when my 18R-GTE hit over 10PSI boost and 6500rpm?? The men in black broke into my shed that night and destroyed my rings in 2 and 3 as an attempt to save humanity.

Yes I noticed - I think I was sent back to puberty!

MIB visits is the fear us 18R-G owners must endure, but a small price to pay to own the greatest IC engine of all time.

seeyuzz
river

PS: As an aside... I'm sure it's not the first time some man has tried to break your ring.

[o_man_ra23]

Well, I am just that attractive aren't I Rivvy

[Willofan]

Willofan,

Check where the timing sprocket secures onto the face of the camshaft.

Is there a number stamped into that face?
That's where Wade stamp their grind numbers.

We've identified a set of mystery camshafts that way.

Thanks Steve M, you were spot on. there is a number 132 stamped on the face and I have since found a matching camshaft in a box of goodies with a tag on it from WADE's also scribed Grind No. 132.

Its specs are;
EX Opens 80 Closes 50
IN Opens 50 Closes 80
Lift 0.379"

From my calcs this is a serious cam grind, I also notice the head has been ground around the valve buckets for the lobes to clear.

Now back to my question, what is the key to setting up the camshaft timing on monsters like these, surely they aren't aligned as per the book???

Any help would be appreciated.

Rgds, Willofan

[Steve M]

I think you'll need to be really careful when setting up those cams because they will have a very agressive lift action.

[Steve M]

Which pistons would you be using with these cams?

The 9.7:1 pistons might have deep enouch valve reliefs for these cams, but the later era pistons have shallower valve reliefs and so you would probably have insufficient clearance and root your valves.

custom pistons with extra deep releifs are the way to go for safety with anything this big.

[big_zop]

I have some questions on 18RG Camshaft selection and Timing settings

In my array of 18rg engines and race parts, I have uncovered some serious go fast bits including various profiles on camshafts. What I cannot find out is what the profile of the camshafts are.

Does anyone knopw who can I talk too to have the camshaft profiles and lifts measured?? so I can work out what camshaft timing should be used to set these up for future builds. Someone in local Sydney would be handy........

In all the threads, can anyone direct me to information on setting up Camshafts for performance & race set ups.

Thanks in advance.

Rgds, Willofan

I know its a bit delayed, but I dont look at this thread all that much.

This thread would give you a good starting point in regards to measuring the cam profile, I have done something similar at uni but on a mostly assembled engine so we had to setup the dial indicator to read from the top of the head and directly off the cam profile itself. Just make sure if you do it this way that whatever you use to guide off the cam that it does not make any damage - not a problem for us as these were only little 2 stroke mower engines.

[Willofan]

Which pistons would you be using with these cams?

The 9.7:1 pistons might have deep enouch valve reliefs for these cams, but the later era pistons have shallower valve reliefs and so you would probably have insufficient clearance and root your valves.

custom pistons with extra deep releifs are the way to go for safety with anything this big.

Hi Steve M and Big Zop,

These cams mounted in the head have already been used in this engine that was using a copper plate head gasket and the block is O'ringed, the pistons are fresh custom forged and the valve recesses are really deep. I have mounted the head again using a standard headgasket without torquing it down then wound the motor over and nothing appears to hit. Cant say the same won't happen at 8,000+rpm if the timing is not set up correctly.

The pistons look like they are very close to a set of 10.5:1's I have in another motor. So they could be as high as 11:1 by the size of the dome. see pics The head inlet ports are huge and measure 42mm, the same treatment on the exhaust.

I will take your advice on setting the head up with a dummy chain and then do a playdough check to measure valve depth in the pistons with the head sitting on the block again and be really careful with the cam settings.

The crank is a serious knife edge unit and the rods are serious with massive rod bolts. The flywheel face is 3 pinned and dowled for a special flywheel, wish I knew where that went too.

This thing must have been built for 200hp, but came to an end when the car had an off on its first run and took out the front end at a track in Victoria some time ago thus resulting in the engine damage only being crank pulley copping the hit and breaking in half.

Back to checking the Cam timing, I have found a Timing degree wheel and will pull out the old dial guage to set these up at 0.050". The lift on the tag is only 0.379" not as high as you have specd and the valve clearance is noted at 0.009" which might make a slight difference.

Anyway, I will find some time next week to play some more. Thanks to all for your info and appreciate any further comments.

Anyone that has a proven sump design they could share, it would be appreciated. I feel the need to go Accusump as insurance on this motor when loaded into my next car. Any thoughts??

Rgds, Willofan

[timbosaurus]

yes... yes, that is indeed a serious engine!!!

Willofan, Can I suggest you look into loading your pics into something like imageshack?

http://imageshack.us/

You can upload them at a higher resolution that the toymods storage allows.

Once uploaded, you can insert the link into your threads (which will show up as a picture instead of an attachment), to give you a picture in your post - like this:

[timbosaurus]

Anyone that has a proven sump design they could share, it would be appreciated. I feel the need to go Accusump as insurance on this motor when loaded into my next car. Any thoughts??

Rgds, Willofan

Interested to hear the responses.

The CCCVic club car may need a simple baffled sump soon, so we're all ears to solutions.

[big_zop]

Posted this in response to Willofans wanted thread, but may as well put it here.

You might want to start here as although it is no longer available, it has some detailed photos and JMR is also on the forum for you to ask questions (YelloRolla)

http://www.toymods.net/forums/showthread.php?t=49614

[Willofan]

Thanks for the image tip, I knew there was a way, I was just too lazy to figure it out. Now I will do this from now on.

Cheers, Willofan