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

[o_man_ra23]

The device you are looking for is called a "manometer". Yes the motorbike ones will work perfect. I built a dual econogauge when I was working for a holden wrecker back in the day, but the 2 gauges were of different calibration, so couldn't get a good reading.

[cheviotrola]

Ok thanks again, but onto other troubling issues, the engine runs like a dog, sounds like a wrx and I did a compression test, 75-80psi on all cylinders. I spoke to two friends who are mechanics, one said- rings arent bed in properly
The other said- valves arent closing properly, need to be adjusted.
I personally think, that one of the cams is off timing alloing the valves to overlap on opening and closing.
Any other clues or suggestions to what is causing this?

[masterofsinanju]

Any smoke?

I had what sounds like a similar problem (some time back in the mezozoic). Ran like a dog. Lumpy at idle. All sorts of advice from a number of mechanics, valves re-shimmed etc. Turned out a venturi had dropped out of place in one of the solex's. Only found it when I pulled them off to be replaced by webers. Venturi dropped out.

Given what you've said about the state of the carbies. That's where I'd look (not that I'd know anything else to look at).

[cheviotrola]

There is smoke, but the carby's are running rich as fuck at the moment. The carby's are freshly rebuilt also. The dropped venturi doesn't explain the compression being half of what it should be though

[Willofan]

Well, given what you have described with low comps and what you have done so far, I would start at the begining of the base tune settings.

1. Using a depth gauge in No1 spark plug, check the TDC mark on the crank pulley and remark it if you have to as crank pulley marks are not always accurate.
2. Once the true TDC is set, recheck your camshaft timings to be perfectly aligned at the top rotating the crankshaft in a clockwise direction to ensure you take up the slack in the chains back around to TDC again.
3. Recheck valve clearances to specs
4. recheck compression with throttles wide open and spark disconnected.

Then tell us what you have found during these steps and we (fellow toymodders) can offer any further advice from there.

On a fresh 18rg motor build you are looking for no less than 145 +/1 10 psi. My recent reco with std pistons and a hi comp head gave me 160psi.

Rgds, Chris

[cheviotrola]

Awesome, thanks, will give that a go and update tomorrow

[Rens]

When i advanced my inlet cam 1 tooth it made that WRX sound you are talking about but didn't affect power too much

[cheviotrola]

No 4 intake closing exhaust opening

No 1 TDC comp, intake about to open


Looking down the cams, intake cam is dead straight, exhaust is delayed, is this normal?

So, from what I can see with no 1 at TDC comp, no 4 is rocking between intake closure and exhaust opening, you can slightly see the lifters sitting lower in the pic of no 4 compared to no 1. And the pic of the exhaust cam being delayed compared to the intake cam being on the mark at TDC. Is this my problem?

[Steve M]

If your chain tensioner is adjusted correctly, then yes, your exhaust cam is retarded.

[cheviotrola]

The dick I bought it off welded the upper chain tensioner, I'm guessing due to breaking it, and replacements being scarce. Any other suggestions as what to do? Or can I only sit and wait for a new tensioner to pop up

[Zammo]

if you cant find one

Modify a 4ME upper timing chain tensioner

or try SW motorsports

[o_man_ra23]

Sw sell new tensioners. A retarded exhaust will make the intake go straight out and lower the compression reading. Rings not bedded won't help the compression either. Have you checked the valve clearances with a feeler gauge?

[cheviotrola]

Going to SW tomorrow for a tensioner, and the valves that the green manual specified (intake 1 & 2, exhaust 1 & 3) are spot on, checked torque setting on cam caps beforehand too, they were all good too. Looking at it, I think the exhaust cam might be out a tooth as well, coz the chain is pretty tight despite the faggot welds on the upper tensioner (I'm speechless that 'Andre' would resort to something so fuckiing stupid)

[Zammo]

hey its a tractor engine some of those inbred country folk treat em like that literally

[Zammo]

+1 tooth out