Rebuild 18R cylinder head *with pics*

[mike1980ra40]

Hi,

The "U" generally means Jap emission controls and .............

seeyuzz
river

that all makes perfect sense.

everything I've read says 8R was the predessosor to the 18R.
Also I have read and heard of of people putting 8R heads on 18R blocks to increasr CR.

cheers.

[Screamn_Sleeka]

nice uploading there mike, downloaded them all.
Are they from the Green 18R book? I am yet to get one of those.

Is the dual diaphram dizzy to any advantage over the single one?
Is the dual diaphram dizzy avalible with the adjsutment (that might answer the 1st q's)

I have also heard that the 8R head will increase compression ratio, but i dont see how its worth it as u will get smaller valves and ports, may as well jsut shave the 18R head, but i havent looked into it, so maybe you have valve/piston distance problems.

Ur ra40 looks good in ur pic, are they ma61 rims? wat size tyres? it must be lowered, if they are bought springs tell us the part number. Is ur rear side windows tinted? If u personally took of the rubber strips off, can u tell me how u did that, lol that sounds pethectic but i jsut cant get them off, and to much force will rip the paint of...
should this be in our ra40 dedicated thread

[mike1980ra40]

some of the technical pics are from the green haynes (US), others from the blue (UK)
and emmisions from wookshop books.
with the 8R/18R i wouldn't bother myself either.
DD dizzy cant see much advantage to it, with a single diaphram theres one less hose, one
less diaphram to eventually split etc and iff you go for the dizzy i got and put in optical setup
you can immobilise it.

about my car will reply to that in RA40 dedicated thread

cheers

[mike1980ra40]

if you haven't seen this
http://www.toymods.net/forums/showthread.php?t=9588
check it out!!! its got the diags your looking for

[Ben Wilson]

FWIW, I've just converted my emissionised Navara ute to a weber (off an Escort), the difference is like chalk and cheese. It is so much more responsive with the weber, idles smoother and sounds better.

The fact that all the other emmissions control somehow got 'lost' while I had it apart might have had something to do with it

[timbosaurus]

Quick update on my engine too. Sorry i haven't been responding to this thread much... lots of interesting info from you guys that i would love to respond and add to, but time doesn't allow at the moment. I'll explain in a sec.

I got a second hand head, lapped the valves and put it the engine back together with a new VRS kit. Apart from a **minor** mishap of a bolt getting caught in the timing chain, snapping it, crunching the chain gear, smashing the timing chain cover and requiring a complete build again, it all went smoothly.

After swearing a lot I replaced all the timing gear and the cover with the stuff of the spare engine and tried to put it all back together without taking the head or sump off just to make sure it still ran. I damaged the sump gasket in the process and didn't have a new timing chain cover gasket so it now leaks oil like a sieve! BUT, it runs just beautifully! I might be wrong, but it feels much more like a stock, fresh 18RG to drive now! So responsive, revvy (for an 18R) and sounds fantastic!

I've just ordered a carby kit for the 32/26 ($40) and a full rebuild gasket kit (~$100) so it's now time to replace all the gaskets that i damaged trying to get the timing chain cover on.


then once that is done i have the second '28 and another 18RC that i have to combine and sell before i move to melboune! I hate stress!!!

Needless to say, a new reliable car is looking much more enticing by the day

[mike1980ra40]

hi peoples, some where in this thread i think, someone mentioned davis craig EWP.
I had a look at the specs for it and all looked good except for the rating on its life,
only 2000 hours. doesnt seem like much. is that a maximum life span or just a general
guess? driving for 3 hours a day 7 days a week then you'd expect pump to fail after 1 year
9 months.

[Screamn_Sleeka]

Hey mike, i think you are referring to my "18RC donate to science" thread, and yea it was the davies, craig ewp. From memory 2000hrs was what the old model guarantee lasted for, where as the new model (8005, and the other one 800?), has a 2year warrantee.
That still isnt anywhere near the reliability of a mechanical pump which last for decades.
Im going to do some more research, see how long people are getting out of them, although that will be for the old model as the new model is, well, new.
If i find the EWP worthy ill make a thread in the 'tech and conversions' area.

[Screamn_Sleeka]

My 18R-C has jsut developed a 'noise'.
Sounds similar to timing chain slapping that ive experienced with other cars, but difference, maybe because there are two timing chains (well actually 4).

I have the ra40/ra42 haynes manual but find it very hard to find anything about adjusting the timing chain tensioners. I think there is 2, one for the bottom and one for the top row of chains? Any idea's on how to adjust them with out taking off the timing chain case?

[18rc turbo]

My 18R-C has jsut developed a 'noise'.
Sounds similar to timing chain slapping that ive experienced with other cars, but difference, maybe because there are two timing chains (well actually 4).

I have the ra40/ra42 haynes manual but find it very hard to find anything about adjusting the timing chain tensioners. I think there is 2, one for the bottom and one for the top row of chains? Any idea's on how to adjust them with out taking off the timing chain case?

I'm pretty sure the timing chain tensioners are self adjusting on an 18r-c. If your timing chain is noisy it is probably coz its worn out, your tensioner will have big grooves in it and wont be tensioning the chain properly. You might be able to take the spring out of your top tensioner and stretch it a bit to buy you a few weeks, but the timing cover has to come off to get to the bottom tensioner.

[Screamn_Sleeka]

I'm pretty sure the timing chain tensioners are self adjusting on an 18r-c. If your timing chain is noisy it is probably coz its worn out, your tensioner will have big grooves in it and wont be tensioning the chain properly. You might be able to take the spring out of your top tensioner and stretch it a bit to buy you a few weeks, but the timing cover has to come off to get to the bottom tensioner.

Hey, thanks.
So really, i need new timing chains and tensioners.
I know where to get the chains from, do you (anyone) know where to get the tensioner pads? (or new tensioners) or if M or T engine ones fit and are cheaper?

[mike1980ra40]

well well well,.......
after yesterday, looks like I'm up for a rebuild now, looks like it's going to have to be the whole
donk this time, not happy jan, I wanted to go to jamestown in october.

[Screamn_Sleeka]

well well well,.......
after yesterday, looks like I'm up for a rebuild now, looks like it's going to have to be the whole
donk this time, not happy jan, I wanted to go to jamestown in october.

Really? what happened? i didnt know you were having any problems with urs.

Is a compete reuild/new engine worth it?
I cant even decide if a new timing chain and tensioners are worth it, might jsut get my act together and get the RG in.

refering to my previous post, u get tensioners with chain kits, and even sprokets for complete kits, unless u buy individual part no.'s

[mike1980ra40]

Really? what happened? i didnt know you were having any problems with urs.

Is a compete reuild/new engine worth it?
I cant even decide if a new timing chain and tensioners are worth it, might jsut get my act together and get the RG in.

refering to my previous post, u get tensioners with chain kits, and even sprokets for complete kits, unless u buy individual part no.'s

18R's are a throw away engine, i'm convinced they were designed that way so when the
timing gear goes, the whole engine has to go.

last lot of parts i bought for a job like that (5 years back) were all seperate, oil chain, timing
chain, gaskets, etc the only thing I couldn't get was a new tensioner and spring. I dont think there is any complete kit to do just the timing gear. If the timing chains have to be
changed you might as well rebuild the whole motor because the head and sump have to
come off and your half way there anyway.

has been mentioned somewhere here before, 18R's arn't worth the money people are
asking for a new rebuild motor, best quote I have got so far for a long motor was 1500,
the worst quote 2500.

my 18r well, its done 189,000 k's and 200,000 is usually end of life, (other 18R done
206000) also my water pump started squeeling yesterday so that has to be changed, I did
check the belts even though they are only 3 weeks old, it squeeled when you take off in
first after that nothing, plus theres the small ratlle of worn pump bearings as well.

If you've got the RG definitly put it in, what ever could be spent on the RC you could spend
some of that on the RG and have 50% more power

I've been looking at doing an RC to RG rebuild either way its going to work out costing as
much.

[Screamn_Sleeka]

If u can get a cheap good condtion 18RC then for sure, a new timing kit isnt even worth it, and paying for it to be rebuilt is definatly not worth it. I would get the RG in now, but it will take atleast a week, and i jsut need my car on the road.
A 18RG jsut went on ebay for $250 NO BIDS, said it was excellent condtion etc, 88253 (best head, worst compression) in vic, probably melbourne, is that worth it to u? I figured it would cost me $100 to go and get it, either with a trailor or in the back of the ra40, and for 350 it isnt worth it to me as a 2nd one.