up the power on the 18r

[kylestyleup]

Alrighties... Yes, the mods listed will certainly add HP to the old 18R.

After all this, you will *possibly* have a 200hp motor. It will use a lot of fuel, need constant maintance, and possibly not last long. This is why we usually take a standard 250hp EFI, 2 litre, twin-cam turbo engine and bolt it into our celicas

Cheers,
Timbo

200hp is possible then... lol
I was just aiming for 150hp and a 7000rpm.

Machinist's labor here is very cheap so work is not a prob.
Tuning and dialing in will be the problem and details on the cam profiles and that forged piston.

I think I'll play around with with the stock till I come across with a hi-comp piston with the correct profile for the 18R.

- Port and Polish
- 48 or 44 dual Weber
- 1.75 or 2" primary and 2.5" pipes
- look for a good cam profile
- good oil pump..???
- engine balance
- hardened valve seats - Can I go big valves?

Will that do?

[kylestyleup]

Hello again...

I need your comment on this one.
I don't know anything yet about cam profiles but I am just looking at it logically.
Which do you thing will be better?



I am planing for a cam reground.
Option 1 - is to add lift
Option 2 - is to add lift also but I think is mild
Option 3 - is which I think is milder staying to the stock lift.

[Matt-AE86]

I would have thought the best way to get power out of an 18r would be to replace it ?

[kylestyleup]

I would have thought the best way to get power out of an 18r would be to replace it ?

Well. It is not only you who have said that. as you have read from here.

Thread is "Up the power on the 18R" not "What is better than 18R?"

[clubagreenie]

Running it on the starter would be an improvement

[Lambolica]

You'll have to check this for accuracy however I believe the 22R-E Pistons are domed slightly, From what I understand they are the piston of choice for the stroked 18R-G.

Cheers
Simon

[glytch]

Hey all this talking has spurred me to get a 44 Solex, manifold and cam. I'll let you know what the results are when I get them and find time to install.

[Lambolica]

you found 44s? where?

[glytch]

In storage It came off a Renault 12 about 25 years ago, and has been sitting in the old mans shed ever since. Hooray for cleanouts.

[Spanner]

its been a long time in the making and lotsa $$$ spent but im finaly happy with the result.
What ive had done
block bored
head plained
hardened valve seats fitted
mild cam fitted
4-2-1 extractors 2in pipe with hot dog and dampener (sounds realy tuff)
electric fuel pump
electric dizzy with advance
larger radiator
32/36 webber
Finaly the tonne of steel 4wd can move at a reasonable pace, its not no V8 powered monster but it still has some balls
it only cost 3g with a workshop doing all the work.

[glytch]

Cool. That sounds pretty much what I have (and am in the process of doing) had a chance to tune it on a dyno? any idea at what power it is putting out?

[hosking1991]

how much could you take of an 18r head? 20 thou be too much?

[o_man_ra23]

20 thou should be fine. Just remember though that your already noisy timing chain will get noisier, and you may need to play around with the spring in the top timing tensioner.

My experiences have been:
manualise secondary in stock carb - gave far better top end, no extra bottom end torque
Replace carb with 32/36 weber and add 2" free flowing exhaust - massive amounts of improvement across the entire rev range. No jet tuning was done, the carb was off a 2Ltr escort.
Replace motor with 18R-G variant - massive improvement in accelleration, space time continuum bending ability, sound, and size of balls.
Replace twin carbs with EFI - burnt out alternator and forever had problems until I realised what I did, even after going back to carbs.
Replace motor with 18R-GTE rebuilt with CT26, new ECU, Electronic ignition, etc, etc - will let you know how it goes.

What I would do if I were to try and get more out of an 18R-C again and wanted to keep it:
Cam - lumpiest I could go
O/S valves, and stronger springs
EA foulcan throttlebody EFI onto modified manifold with MegaSquirt 2 ECU
electronic ignition
ARP rod bolts and head studs
biggest overbore I could get flattop pistons for
oval shaped head
CT20 turbo on custom manifold
lightweight flywheel with heavy duty organic clutch
18R-G oil pump and winged sump

That's just what I would do, and it would cost a lot more than the motor is worth. If I were to do it, it would be to say "Cause I could", and not be to try and have a power monster.

I would say that there are only 2 reasons why you should try and get decent power from an 18R, first is that you just want to, and second is because you are not able to get anything else engineer approved/race homolgated. Doing it because you think it will be 'cheaper' is just stupid. Of course, if you want just a bit of get up and go so that mopeds stop overtaking you, then 32/36 weber, extractors with 2" exhaust, electronic ignition from a 21R, and a mild to moderate reground cam will be your best bang for buck, and shouldn't be too expensive (most of it can be done by a half confident backyarder with basic tools).

[hosking1991]

I've got no noisy timing chain the tensioners havnt even done 1000 kays

My problem with the 18r in the ra40 is the no 1 cylinder is 110 psi whereas the rest are 145
the problem is defanatly not in the bottem end as i rebuilt it but i didnt reco the head

I suspect a valve is damaged, but i'll be taking my other 18r head into work and i will strip it, acid bath it. surface grind it,face valves and one of the tradesmen will cut the seats for me

So i thought while it has to be surface ground i'll try to get some more comp out of it



Luke

[MitchE]

about the 22R pistons if they are used to stoke the 18R out obviusly they are not going to fit as the pin height will be shorter.
so aftermarket 18R pistons will be the only option.