18R/RG performance

[dale30]

Been racing an 18R on speedway.
Its has lightened and ballanced crank/rods/flywheel etc: and has been bullett proof in its stock trim,running 6500 all night long.

Time has come for some more power.
Going to do cam,carby,head work to get about 140hp and i need it to run to 7500.

Question is will it keep staying together .????? Are they as tough as i think they are.

[kingmick]

there tough and they can hadle 140hp no problem.

[Screamn_Sleeka]

Mate, the originals came out 140hp from the factory, she'll be cruzn.
There are a few different heads, get the latest one, #...~270~, ther is a LOT of info on cam profiles and figure, ask one of the 18RG nuts on eher and they will email it over, make sure ur using the 9.7:1 compression pistions, use webers not the solexes, blast past the 140 mark.

Additonal: Yea mate they are tough, i can vouch for the block anyway, smoky old 18RC is still a beut when stripped down.

[dale30]

Thanks guys.
Its only an 18R at the moment,Not RG but im led to believe thay are the same bottom end.
will consider going rg later in the season.
Car keeps running 2nd and 3rd to honda crx and 4AGE corolla so im chasing about 40 more horses for now to try beat them,more when budget allows.
any clues on how is best to achieve this would be great.

[kingmick]

car setup will have a lot to do with it. is it cambered neg,neg,pos,pos?
have you goyt the weight that can be moved on the outer side of the car?
are you using the tires the others are using and are you playing with pressures?

if everything has been done to the engine like you say it should be over 140hp anyway. it might be tired and have plenty of blowby. do a compression test and see how your pots are before you start doing anything.

[Screamn_Sleeka]

O, fuck!
Ur racing an 18RC? ur a hero. -although possibly mental.
U can get it to 6500rpm? i couldnt get mine past 4000

In that case, nah i cant see 7500 happening, its a non crossflow head.
If u really want to work the RC, shave the head, and get a weber blah blach, the bottom end is the same, although RG rods are much thicker, but ill be fine.

What car is this is btw?

[dale30]

car setup will have a lot to do with it. is it cambered neg,neg,pos,pos?
have you goyt the weight that can be moved on the outer side of the car?
are you using the tires the others are using and are you playing with pressures?

if everything has been done to the engine like you say it should be over 140hp anyway. it might be tired and have plenty of blowby. do a compression test and see how your pots are before you start doing anything.

This thing is a speedway car and setup is spoton for the driver,
Under last seasons rules it must be stock except extractors and cardy jets,balancing..
60overbore,10of block, 30 of head.so i have taken it to the limit.( crank was badly out of balance so had to take lots of...lol..)and rhree angle valve job.stock points dissy

Bear in mind its only an 18R so i doubt its 140 more like 105..!!

BTW engine is fresh, no blowby...

[dale30]

O, fuck!
Ur racing an 18RC? ur a hero. -although possibly mental.
U can get it to 6500rpm? i couldnt get mine past 4000

In that case, nah i cant see 7500 happening, its a non crossflow head.
If u really want to work the RC, shave the head, and get a weber blah blach, the bottom end is the same, although RG rods are much thicker, but ill be fine.

What car is this is btw?

I thought the same when i bought this car but its been bullett proof.

Its number 3 in NSW behind the two pocket rockets so cant be all bad.
It will free rev to about 7500 but wont pull past 6600, Cam should fix that.
I need some cheap horepower to chase these two cars.

[river]

Hi,

You'll have to do a hell of a lot of work to get your old 18R to 140hp - and such changes would negate the rules you're running under. You'll need an 18R-G if you want to get 140hp.

Don't bother about using the 18R block and trying to put on an 18R-G head. The amount of work, time and money stuffing around isn't worth it. The best option is to buy a compete 18R-G and put it into your car.

You can build quite a good 18R-G engine by swapping around heads and cams from the different versions of the engine, but I'm not sure if your rules allow that. The most powerful stock 18R-G that came out of the Toyota factory was the first one - the 18R-G, with the 210 head. In descending hp order of stock 18R-G engines (after the 18R-G) is the 18R-GR (approx 135hp), 18R-GUE(approx 125hp), 18R-GU(approx 120hp). These are approximations 'cos I haven't got the info readily handy, but if you scan the net I'm sure you'll find the powers.

The 18R-G had the highest compression but the smallest valve diameter and used Solex carbs. The 18RG-UE had a lower compression, bigger valves, better designed head and EFI. I've been told the early 210-head 18R-G had the most aggressive cams, but I'm hoping someone here can tell us if that is indeed correct.

seeyuzz
river

[kingmick]

well all this would have made it a little easyer from the start!
what fuel you running?what cams? you running an alternator? whats the exhaust like?
what comp you running?were do you want the power in your setup?
etc. need to know were everything is to know what you can gain cheap.

[dale30]

well all this would have made it a little easyer from the start!
what fuel you running?what cams? you running an alternator? whats the exhaust like?
what comp you running?were do you want the power in your setup?
etc. need to know were everything is to know what you can gain cheap.

New rules this year,Anything goes.

BP 100 may go to methanol if its worth the hassle
will be getting new cam ground by Sure cams in Brissy to pull from about 4500-7500.
Dual custom made mufflers by performance exhaust co.
yes it runs an alt driving a VS commodore fan.

Comp.? stock flattop 60 up pistons with 30 off head.Will be shaving more off soon.

Is 140 realistic.????

[dale30]

Hi,

You'll have to do a hell of a lot of work to get your old 18R to 140hp - and such changes would negate the rules you're running under. You'll need an 18R-G if you want to get 140hp.

Don't bother about using the 18R block and trying to put on an 18R-G head. The amount of work, time and money stuffing around isn't worth it. The best option is to buy a compete 18R-G and put it into your car.

You can build quite a good 18R-G engine by swapping around heads and cams from the different versions of the engine, but I'm not sure if your rules allow that. The most powerful stock 18R-G that came out of the Toyota factory was the first one - the 18R-G, with the 210 head. In descending hp order of stock 18R-G engines (after the 18R-G) is the 18R-GR (approx 135hp), 18R-GUE(approx 125hp), 18R-GU(approx 120hp). These are approximations 'cos I haven't got the info readily handy, but if you scan the net I'm sure you'll find the powers.

The 18R-G had the highest compression but the smallest valve diameter and used Solex carbs. The 18RG-UE had a lower compression, bigger valves, better designed head and EFI. I've been told the early 210-head 18R-G had the most aggressive cams, but I'm hoping someone here can tell us if that is indeed correct.

seeyuzz
river

I agree but cant afford one at the moment..

If i cant do it cheaply i have a V6 commodore setup here which will drop in real easy.Not my preferred option but im running two cars and budgrt is tight..

[kingmick]

New rules this year,Anything goes.

BP 100 may go to methanol if its worth the hassle
will be getting new cam ground by Sure cams in Brissy to pull from about 4500-7500.
Dual custom made mufflers by performance exhaust co.
yes it runs an alt driving a VS commodore fan.

Comp.? stock flattop 60 up pistons with 30 off head.Will be shaving more off soon.

Is 140 realistic.????

Yes methanol is worth it for sprint racing.
Get the cams done to suit methanol.
Dont need duel mufflers, you need a good race setup.
Ditch the alternator and use just the battery{ carbies}. plenty of power in the battery to get you threw a race. 10 laps races? even double that the battery will be fine.If you go efi run the alternator of the diff hub.
Raise comp to 13.5-1 if you run methanol or 11.5-1 on pull buy using good dome piston.
Yes 140hp easy on methanol and the above..

[o_man_ra23]

I believe Mr DOHC has a very good 18RG setup and ready to go for sale. May be sold by now, but its better than spending big on the 18R then ditching it all for the 18RG anyways. 18RG should be able to easily run 8500rpm with appropriate cams and good valve springs. A balanced bottom end will ensure things stay together. Best of all they are easy to lift the compression on... just get the 12.5:1 pistons... again see Mr DOHC about these.

There was a race version of the 18RG bored out 100thou (made it 2.2L) back in the early 80s which was making around 300hp on race fuel. So, figures over 250hp should be quite acheivable with high compression, high rpm and high octane.

The 18R is just too restrictive a head to be able to make that sort of power.

Cheers, Owen

[jonra23]

To run 7500 rpm will be beyond points dizzy reliably, have you cleaned up ports etc?