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

[SilverRA23]

ah feck knows... 10.5:1 rings a bell but I can't find my paperwork to confirm that.. I am sure that is what my engine builder said would be fine on 98ron

I bought my head gasket through CV products in the USA. CV - Everything Racing

The part number for the head gasket was COM-C4172-059

[TRD184]

thanks mate infinitely helpful my car thanks you

[SilverRA23]

No problems at all.. this thread was a massive help to me when I was doing my build, so its good karma to help back!

Now my own question.. can I pull the cam cover off my 18RG to paint it, and bolt it on again with out having to buy new gaskets/seals or what ever it has holding the oil in?

Needs some crinkle paint finish for Toyotafest and I figured since its two weeks away I better get on it

[timbosaurus]

nah, there is nothing special about the rocker fitment (unlike trying to remove the timing chain cover on it's own!)... just one gasket around the perimeter, and two figure 8 gaskets around the spark plug holes.

just see what type of gasket he used... if it's the genuine toyota rubber gasket, then you'll have no problem. If it's an aftermarket cork one, whether it seals again well usually depends on how long it's been used for.

[jabbatron]

..........

[egamirrorim]

Does anyone have an 18RG oil pressure sender they are willing to part with?
My engine just got rebuilt and I'd like to monitor oil pressure during the run in...

[Steve M]

Unless you've got after market camshafts or re-grinds, there is very little point in changing your cam timing.
The original holes allow crude adjustments. The original camshafts will not give you much more benefit in any position other than their original position.

I don't tink it's worth playing with your cam timing on standard cams if you're not adding a turbo / supercharger. I'm not saying that you'd benefit from timing changes if you had a turbo, I just don't have experience with Forced Induction yet and am allowing someone else to give input in that area.

I've ordered two sets of pistons through Atomic Speedware (Nick Arias III) and was very impressed by the service I received from Nick. Only one set have been installed (11.5:1) and they appear to be doing well. My stroker pistons (10.5:1) have not been installed yet as I've still not finished the work on the 22R crank.

[Omegaman]

I remember i changed the exhaust i think, 1 hole advanced and it gave me better acceleration. A more responsive bottom end.
It's one of the 2 cams.
Something to do a search on, is the tensioner in the AFM. you can adjust the tensioner to get a better airflow. Again better responce down low.
This i have got info on, if you need more. (this is on STD 18rgeu motor, std ECU)

[o_man_ra23]

Back to timing chain guides. It would seem the only option available to have them re-coated is with ebonite, a really hard rubber which won't grooves like the originals (and all new replacement parts). I have been thinking about this recently though. Why do they all have grooves, and why are new ones susceptible to grooving? Surely over the years manufacturers would have replaced the material with a harder one?

Then it dawned on me, perhaps the grooves are deliberate. If we think about the anatomy of a timing chain, it is made up of a series of hard links which pivot against each other every second roller. Then there are the rollers. These are designed to rotate around the pins on the hard links to prevent excessive wear. To stop them wearing against the pins, there is an oil layer, hence the oil squirters.

So, by having grooves in the guides, the chain will slide on the rollers, much like a bearing on a race, reducing friction. If the guide material is hard without grooves, then the links are rubbing against it, causing wear on the links, and increased friction, which will increase wear on other timing components, such as the sprockets, and will accelerate chain stretch.

Can anyone find a flaw in my logic? Any further information I have missed? I am interested to know as everyone seems to want to eliminate the grooves as they look like wear (yeah, technically they are wear, but possibly they are similar to the wear on rings you put on during the bedding in process), when it seems to me as if they are actually a very deliberate design feature.

[The Witzl]

brand new factory Toyota guides dont have the grooves.

[o_man_ra23]

No, but they are soft, and wear the grooves in within a short period. According to Sillicar chick that is...

[Rens]

One flaw in your logic could be, with the grooves more of the chain comes into contact with the guide causing more friction. ( if only very minor). I'm pretty sure the guides are smooth when made ie no grooves

[o_man_ra23]

Yes, as mentioned earlier, eluded to, and otherwise described, it is commonly understood that the guides are smooth when new. They are however, also soft (unlike re-coated items), and wear grooves early on in their life before hardening due to the heat cycling and oil immersion. Rings are made with rough outer surfaces, however once they are run for a few hundred k's, the outer surface becomes relatively smooth - so part of my logic is based on the grooves being meant to be worn in in accordance with the installed conditions, thus removing issues associated with manufacturing tolerances, rather than having grooves from factory.

As for the increased contact area from the side contact between the chain and guide, that's a valid point, and I might line up one of my chains along a grooved guide and see what kind of clearance there is. It is possible that there will be increased loading from this.

[2004lowlux]

ive got mine running finally and just had the exhaust done but the clutch slave popped out on me so its stuck in castle hill till i can get a new one (the rear seal got munched)
does anyone know any places in sydney i can get a accelerator pump diaphram and seal mines leaking fuel pretty badly and the only place ive found that has one is in burwood and ive got no time to get there

[Suavemechanic]

just get them to post it to you, the guys in burwood are very good .

oman im not sure toyota designed our little motors to last this long ,
and the downside of the grooves is noise ,not loosing the race .
the engineer would have been thinking " 40 000 ks and its on a boat !"