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

[RAd28]

The fact you have adjustable cams makes the compression figure useless on its own. What you need is to find out the variance between the cylinders. If they are all close together, then your engine is healthy and should run smoothly. If they are all over the shop, you have a problem.

Cheers, Owen

adjustable cams? lol... i wish...

compression figures were:

1= 145ish
2= 145-170 (spiked )
3= 145-150
4= 145-150

to me seems pretty healthy, i figured that assuming that it hasn't been bored out, someone else might be able to quote their compression figures (on the same bore size) so i could get some idea as to what compression ratio i've got... i'm almost certain there is some internal work, the engine is tired, and buggered, but will still rev happily and chirp the tyres into 2nd in a straight line...

[o_man_ra23]

No. 2 is a bit of an oddity. If you are unsure that the readings are accurate, I suggest you redo them, you cant identify an issue from unsure readings.

So you dont have the 4 pinhole adjustable cams?? Bugger, sucks to be you.

Cheers, Owen

[RAd28]

No. 2 is a bit of an oddity. If you are unsure that the readings are accurate, I suggest you redo them, you cant identify an issue from unsure readings.

So you dont have the 4 pinhole adjustable cams?? Bugger, sucks to be you.

Cheers, Owen

wouldn't have a clue what cams i've got in the car, haven't pulled it apart at all, trying to get it running smoothly before i go playing with cams...

[The Witzl]

take off the cam cover and you will see what cam gears you have.

[RAd28]

i'm getting to it... she's still running like a dog atm, impressive up high, crap down low...

is there a guide as to how to identify cams of various heads? (230, 250 etc)

[YelloRolla]

i'm getting to it... she's still running like a dog atm, impressive up high, crap down low...

is there a guide as to how to identify cams of various heads? (230, 250 etc)

with the cams that I have seen the numbers are cast into the Hexagonal bit on one of the flats.

[sillycar chick]

No. 2 is a bit of an oddity. If you are unsure that the readings are accurate, I suggest you redo them, you cant identify an issue from unsure readings.

So you dont have the 4 pinhole adjustable cams?? Bugger, sucks to be you.

Cheers, Owen

im pretty sure they all have the 4pin hole cam gears like the 2TGs, but they arent really there for adjusting cam gears as such, more to set them up to factory specs. The 4 pin holes are too far apart to use them for fine tuning of the cams (learnded from experience)

[TA-022]

head numbers are stamped onto them ... cam numbers as yellowrolla said on the cam hexs

[timbosaurus]

In my experience the numbers on pistons and cams don't necessarily line up with those on the heads. For exapmle, the slugs I pulled from an RG i have in Brissie are stamped 88251, and that is an 88253 headed engine. They look like some pistons Witzl photographed previously saying 8.7:1, so i'm pretty sure they are original for the engine.

It would be handy to draft up a table of different piston numbers vs comp, cam numbers vs profiles, head numbers vs features etc... and maybe a list of which combinations were available together. It would help to understand how many different peices of hardware are aroud!

I'm pretty sure most of the info is in this thread, it would just take a bit of collating.

[o_man_ra23]

Not all 18RGs had the 4pin types... later ones had fixed cam sprockets (identical to 18RC ones).

The 4 pins are actually pretty good for fine tuning... as they use a vernier type system to get about a degree or 2 of movement per pin. Sounds like you could have the cams too far overlapped if its good up top and bad down low. I did a writeup somewhere on it (I think I did it for Dana )

Or go read a book called "21st century performance" it has a great section on setting up adjustable cams.

Cheers, Owen

[RAd28]

when i get a chance i'll do up a chart of the cam profiles i have with the head on my car now, and the new head i get next weekend...

owen - i was under the impression that EARLIER ones had fixed sprockets... later ones got the 4 pins trick. my old man has that book laying around somewhere, must dust it off and have a good ol' look at it...

[o_man_ra23]

Could be that way around, I do get mixed up occasionally. But, my 88230 cams were adjustables...

Cheers, Owen

[river]

Hi,

I checked the info I have....

18R-G Block Assembly
Year-Month ---- Toyota Part Number ---- Vehicle ------------------ Engine
7304-7501 ------- 11401-39147 ----------------- RA2X --------------------- 18R-G (A)
7304-7509 ------- 11401-39157 ----------------- RA2X --------------------- 18R-GR (B)
7510-7611 ------- 11401-39245 ----------------- RA2X --------------------- 18R-GU (C)
7611-7707 ------- 11401-39246 ----------------- RA2X, RA35 ----------- 18R-GU (D)

(A) => Started with RA25-000001
(B) => Started with RA25-030229
(C) => Started with TA23/RA23/TA28/RA28-000001
(D) => Started with TA35-039999/RA35-029999


18R-G Head Assembly
Year-Month ---- Toyota Part Number ---- Vehicle ------------------ Engine
7304-7509-------- 11100-88231 ----------------- RA2X ----------------------18R-G, 18R-GR (A)
7509-7510 ------- 11100-88233 ----------------- RA2X --------------------- 18R-GR (B)
7510-7701 ------- 11100-88250 ----------------- RA2X --------------------- 18R-GU (C)
7701-7707 ------- 11100-88251 ----------------- RA35 --------------------- 18R-GU (D)

(A) => Started with 18R-9531192
(B) => Started with 18R-9531193 and RA25-030229
(C) => Started with TA23/RA23/TA28/RA28-000001
(D) => Started with TA35-019128/RA35-006397


18R-G Inlet Camshaft
Year-Month ---- Toyota Part Number ---- Vehicle ------------------ Engine
7304-7509 ------- 13501-88231 ------------------ RA2X --------------------- 18R-G, 18R-GR
7510-7701 ------- 13501-88250 ------------------ RA2X --------------------- 18R-GU
7701-7707 ------- 13501-88251 ------------------ RA35 --------------------- 18R-GU


18R-G Exhaust Camshaft
Year-Month ---- Toyota Part Number ---- Vehicle ------------------ Engine
7304-7509 ------- 13502-88231 ------------------ RA2X --------------------- 18R-G, 18R-GR
7510-7701 ------- 13502-88250 ------------------ RA2X --------------------- 18R-GU
7701-7707 ------- 13502-88251 ------------------ RA35 --------------------- 18R-GU

I haven't got any info for the 18R-GUE engine - but then again that engine was never in the "classic" Celica.

Hope you find the above to be interesting.

seeyuzz
river

PS: Don't take the (A) to (D) notes too serisouly, as I'm trying to decipher the production tables and some things don't make sense.

[o_man_ra23]

Yeah, like how 18RGs got stuck in TA23s, TA28s and TA35s

Cheers, Owen

[river]

Hi,

Yes, but the notes in the EPC are more generic. The note, where I have the first build RA/TA 23/28 doesn't necessarily mean that all these cars had an 18R-GU.

You will see that same marker on items like (for example) the front bumper, where the bumpers will be highlighted with different part numbers and there will be a note beside one particular front bumper that means it started to be built in Oct 75 for the first build TA/RA 23/28 models.

In the case of the 18R-GU above, where I have the first build TA/RA 23/28 models, doesn't mean that all the above models (ie TA) got an 18R-GU, but the RA23GT/GTV and the RA28GT/GTV did get that engine, but are grouped together as it was the start (OCt 75) of the 2nd generation Celica.... which includes TAs and RAs.

It's hard to explain. I was going to put up a few sheets of the EPC to show how it looks and how to interpret the numbers etc. But I was too lazy and time was too short and I still not sure how to read everything in the EPC.

seeyuzz
river