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

[floppy]

Hey guys,

Well been a bit busy and have finally got the 18rg rebuilt and in the car.

Was checking the valve clearances tonight and they are what we think are too low.

Had the head reco'd by a shop so not sure why they are shimmed so tight. Will call them on monday to see what the go is.

Anyway here are the clearances.

Intake
1 - 0.20mm
2 - 0.19mm
3 - 0.20mm
4 - 0.23mm

Exhaust
1 - 0.25mm
2 - 0.25mm
3 - 0.23mm
4 - 0.23mm

The green book states:
Intake: 0.26-0.32mm (0.010 - 0.013 in)
Exhaust: 0.31-0.37mm (0.012 - 0.015 in)

What say you guys on the clearances that have been set for mine?

Thanks
Dave

PS Will get some photos up over the weekend. All painted pretty yellow and black

[leso]

IMHO i think there is nothing wrong with your clearances as they are, wouldnt be good if they were much smaller ie 0.10mm ......... If you have lumpy cams i might suggest some more clearance.
some good info here http://www.motorcycleproject.com/mot...ows-clear.html

cheers leso

ps we'll share that six pack soon dave ???

[RAd28]

Hey guys,

Well been a bit busy and have finally got the 18rg rebuilt and in the car.

ps we'll share that six pack soon dave ???

hahaha... dave, i'm expecting a visit some time soon.

leso, i'm expecting to come visit some time soon.


me thinks someone needs to organise a BBQ...


P.S. dave, those clearances are probably fine for a new head, once it's run in it may very well 'loosen' up a whisker.

[o_man_ra23]

Yeah, let it seat for a few hundred k's. People often tighten up clearances to to get more lift and duration out of the same cam (can make quite a difference), so long as the valves shut properly and stay shut while the lobe is off, they will be fine. Those clearances sound like plenty to stop anything untoward.

On the subject of people visiting, I am trying to get a meet n greet going while I am down there, so Dave, the Sunday of the Aus day weekend you should come round to Leso's (or another designated meeting spot if so required)

[Sagluren]

come to sa come to sa. i have to virgin rg's to play with

[JustenGT8]

Hey guys,

Well been a bit busy and have finally got the 18rg rebuilt and in the car.

Was checking the valve clearances tonight and they are what we think are too low.

Had the head reco'd by a shop so not sure why they are shimmed so tight. Will call them on monday to see what the go is.

Anyway here are the clearances.

Intake
1 - 0.20mm
2 - 0.19mm
3 - 0.20mm
4 - 0.23mm

Exhaust
1 - 0.25mm
2 - 0.25mm
3 - 0.23mm
4 - 0.23mm

The green book states:
Intake: 0.26-0.32mm (0.010 - 0.013 in)
Exhaust: 0.31-0.37mm (0.012 - 0.015 in)

What say you guys on the clearances that have been set for mine?

Thanks
Dave

PS Will get some photos up over the weekend. All painted pretty yellow and black

A little tight on the exhaust but they will open up a bit so just take it easy on the break in and see where they end up after 500km.

[o_man_ra23]

Worst comes to, put the shims on a magnet, and rub them along some 1000 grit sandpaper... that should wear a couple of thou off them.

[RAd28]

Need some suggestions to gently pry my manifold off the side of the head... i've removed the carbies, and all the mounting hardware (8 nuts on studs) but the bloody thing is still firmly secured, i've tried belting it with a rubber mallet, and gently levering it off... but nothing is working... there isn't another nut or two i've missed is there?

any suggestions?

[Steve M]

RAd28, There are only 8 studs and nuts.
Have you drained the coolant from the head yet? Make sure that has been done or it will all get messy.

Sometimes if the correct washers aren't used, the nuts squish metal from the manifold into the stud holes and the manifold effectively becomes threaded on. I had that issue with a set of carbies.

I think is basically comes down to belting it some more or removing the studs while it's still on the head, but it'll still be stuck then too.

[floppy]

Hey Rad,

I had this problem as well. I wanted to use the manifold from the other head and it wouldnt budge.. The metal of the manifold had been "squished" onto the studs.

It took my mate a bit of effort but he got it off.

He sprayed and soaked each of the studs with penetrating oil...

waited....

Then using a rubber mallet and a small block of wood started hitting around each thread that could be gotten to.

At the same time levering as best possible without putting too much pressure on the thin parts of the head.

I reckon it too him a good 20minutes.. (prior to my efforts of about 30 minutes using only a rubber mallet and swearing heaps!!!!

He suggested once you get it off to use a drill of the correct stud diameter to just "clean" the holes and make them slightly larger, but only marginally.

Of course I didnt do this in my rush to get the engine running and will probably pay for it down the track....

Dave

[floppy]

Hey again,

Continuing from my last post....

The 18RG is in the yellow beasty.

Few teething problems relating to gaskets, fuel pump gasket at the block I used one that wasn't quite right (bottom part didnt fit the spacer block properly).

Forgot a bolt in the timing cover, the one that the green book suggest putting thread sealer on. so after the test drive noticing oil smeared down the block and dripping didnt make me happy.

BTW that bolt is a bitch to put in once the head and manifold are on (lesson learnt)

We went on a family day trip to maroon and moogerah dams today and I took the celica.

The engine went pretty well. I've only done 200k's so far and its feeling pretty good. I'm getting a fair bit of backfiring out the exhaust and only a few out of the carbies.

Been adjusting the timing to find the best spot.

I'm wondering if some of this is due to the tighter valve clearances.

it doesnt happen when the revs are down low that much, around 3000-4000 any time I was backing off the accelerator there was pops galore. At the first rest stop I adjusted the timing some more and got rid of most of it.

So more tuning to go and searching for a minor oil leak and it will be even better.
I have to say it was frustrating not being able to get some gaskets that I thought would be available. Oil filter asembly gasket, front timing plate gasket (rear) (*toyota had none and the local parts places could only get me the front acl on. )

Making gaskets was a fun and all, but I think I may have made some out of too thin a gasket paper (all was the oil safe stuff)......

Anyway I'm tired and not sure if this post all makes that much sense!!!

Dave

[floppy]

Oh one last one,

o_man_ra23, on the last RG, thats pretty much what I did to get the clearances to what we wanted.

I didnt use a magnet though, just my stupid little fingers and boy did I get some blisters.

And i used a lot rougher paper to get even anything coming off them....

If I am going to chance the values, I'll just measure and order the ones I need this time !!

Dave

[o_man_ra23]

Or you can take them to a machine shop that has a magnetic thicknesser... cost me $20 to get 4 shims done, but was a lot cheaper than ordering new shims, and the thicknesses were exact after that. Magnet is to stop the blisters

As for your leaky gasket woes... did you put Permatex No. 1 on there (the brown aviation stuff that never goes hard)?? That stuff is the bomb when it comes to paper gaskets, never had one leak after using that stuff, unless there was a problem with the mating surface.

[RAd28]

Hey Rad,

......Then using a rubber mallet and a small block of wood started hitting ....

Dave

went and attacked it with some fresh swear words, a block of wood and the rubber mallet and wadda ya know... first hit it budged, 2nd hit and it was loose...

was looking at the manifold and it got me thinking, it's tapered from 45ID to approx 35ID and it's a long manifold (85ish mm). is there any perfect way to taper the inlet runners? would it be better to make it 45 all through the manifold, then taper the head ports from 45 down to what ever valve size? or is it better to get the taper out of the way early? i can only conclude in my thinking that like most things it's a balance, early taper = (somewhat) better responce, late taper = (somewhat) better top end... maybe. then also there's the length of the taper...

anyone done research on this aspect of induction at all???

[o_man_ra23]

Not sure, but that kind of tapering is used often in V8 supercharged drag cars to create a vortex effect, the runners taper before the head.