Rebuild 18R cylinder head *with pics*

[Screamn_Sleeka]

Cool, thanks for that, feels so much better to know whats doinging what now.
But what does the fast idle breaker do? mine revs to 2g when cold until the temp guage begins reading. (probably 50-80 degree water) and then it drops to my idle setting.

[mike1980ra40]

tosco

Fast Idle Cam Breaker (FICB)

once engine has warmed up to normal temp, vacuum forces fast idle breaker to move up to
its third step which drops the engine speed down to normal idle

Ive also started another thread which may be of interest and by the time I have finished it
will probably turn out to be a lot to chew on for a while. it also explains what that little
knob does on the side of the dizzy like mine (16R)

http://www.toymods.net/forums/showthread.php?t=9464

[mike1980ra40]

Just to confuse the issue slightly...

I have 2 18RC's, one has a nippondenso .......

heres another one, this one i've seen on other 18r's and is a bit more uncommon i think
its a dual diaphragm dizzy, previous owner disconnected the retard hose???

[Screamn_Sleeka]

^ thats the one ive got.

Is there still any advantage of a 16R dizzy over an 18R dizzy with the vac advance adjustment?

[mike1980ra40]

The advantage I have found in the past is when i've taken a drive out to country somewhere
where there might not be any premium ULP (98RON), just ordinary regular (89-91 RON).
with that little knob, the timing can be advanced with out any tools (excepte a long screw
driver) to compenstate for the lower RON. If your really familiar with the way your engine
behaves, you wont need a timing light. as the timing is advanced I turn down the idle speed.

[Screamn_Sleeka]

yea, i am going to get one of the knob dizzy's, i mean is there an advantage for the 16R ones to the 18R ones, as in both have the vac adjustment, but is either better for another reason?

[mike1980ra40]

in my own personal experience, i found the 16R better just for pure simplicity, for minor tune
ups and adjustments.

[mike1980ra40]

Both my dizzy's have the adjustable knob as below.

These are standard 18R distributors. Are these the same as the 16R dizzy's mentioned above? Or am i missing something?

it appears they are both identical, if yours is original with the engine then it is the first time I
have come across that. because all the 18Rs I've ever looked at have all had bosch dizzys that don't have the knob. even when I looked at both US and UK haynes manuals there is
no mention of this 16R dizzy.

[mike1980ra40]

These are the diagrams of the air injection system. Brain is too fried to deconstruct what each hose does, and post my pics of what it looks like on an actual engine, but i might get there eventually

thanks for posting those, I have just realised my choker breaker and charcoal canister
hoses are the wrong way round and I have a manual right in front of me
+rep for that one

[Screamn_Sleeka]

I have just realised my choker breaker and charcoal canister
hoses are the wrong way round and I have a manual right in front of me

ouch!

Where do u have 18R-C air injection diagrams? its not in the ra40 haynes is it?
how much is the same as 18R-U?

[mike1980ra40]

ouch!

Where do u have 18R-C air injection diagrams? its not in the ra40 haynes is it?
how much is the same as 18R-U?

I have been turning the shed upside down for a week looking for theses diagrams finally
found them these are not in any haynes manual, these are from toyota workshop manual
so I dont need a trip to the city now (yay).
I havent seen anything for an 18R-U, U I think means Japanese pollution control (unleaded
petrol)

these should hopefully help some

[Screamn_Sleeka]

thats awesome mike,
yea i had searched through the haynes manual for somthing like that, i actually was supposed to write "its not in the ra40 GREGORY'S is it?" - as i dont have the gregorys.
18R-U is what timbosaurus posted on page 2 (and yea it is the japanese emmisions, not sure if it means Unleaded though, dont know if any 18R's have vavle seals hardened for unleaded except the 18R-G).

[mike1980ra40]

Ive never see a gregorys manual for the ra40

found this website again http://ourworld.compuserve.com/homepages/stepho/
everything you need for engine codes body codes etc, you might have come across it before.

[river]

Hi,

The "U" generally means Jap emission controls and a part of that is a lower compression ratio. It doesn't specifically stand for Unleaded, as the Japs began to have unleaded petrol in the very early 70s. The 18R-G, which came out in 73 had hardened seat valves and the 18R-GU came later and so did the 18R-U - well after unleaded petrol was introduced in Japan.

In regards to the 18R, I cannot say unequivocally that the entire production run had hardened seat valves. However, the 18R was in production during 73-74 and at this time the 18R-G and the 2T-G and the 2T all had hardened valve seats, so I would assume the 18R also had them.

Wasn't the 8R the predecessor (ie engine that was modded slightly to become the 18R) of the 18R. This engine "may" not of had hardened valve seats, but I'm pretty sure the 18R would of.

seeyuzz
river

[mike1980ra40]

found some more diagrams for ya
i put them on my photobucket
http://s61.photobucket.com/albums/h5...ics-Technical/