Page 1 of 2 12 LastLast
Results 1 to 15 of 24

Thread: Which to modify - 18R or 21RC

  1. #1
    Forum Member Grease Monkey
    Join Date
    Oct 2009
    Location
    nsw
    Posts
    79

    Default Which to modify - 18R or 21RC

    Hey all, finally sourced a descent burnout car. My RT104 had way too much rust to save, so i picked up a 5 spd manual 81' RA60. The 21RC on board the RA60 does have a slight miss but nothing much to get worried about as i'm only using it for burnouts. But i also have the healthy 18R from my RT104, which also has an original 172,000km on it compared to the 244,000km on the 21RC. My question being, which motor should i focus my attention on? Was thinking of doing cam ,weber and extractors to one of them but can't pick which one i should do it too.
    Please do not suggest 18RG as i don't have one laying around lol.

  2. #2
    Junior Member Domestic Engineer
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    524

    Default Re: Which to modify - 18R or 21RC

    Aren't 21RC's crossflow? If so then there should be no question which one to work with O___o
    My Daily: NooB's Delivery Vehicle
    My wife's Daily: Series B RA40 Liftback 22RE, power steering, AC. Cushy as.
    Current Project: NooB 3TGTE swap
    Back Burner: 1964 Toyopet ToyoAce, and a Series B TA45 GT coupe
    Too many cars

  3. #3
    Toymods Net Nazi Too Much Toyota river's Avatar
    Join Date
    Sep 2005
    Location
    NSW
    Posts
    7,061

    Default Re: Which to modify - 18R or 21RC

    Hi,

    Both are boat anchors, but seems to be more wook on the 21 engine in the US of A 'cos they never got the twin cam 18R-G. So maybe go and check some US sites out and see what they've done. Not much modding in Oz on either engine 'cos we could get the twin cams easily.

    seeyuzz
    river
    The thinking man's clown and the drinking woman's sex symbol
    RA25GT - There is no substitute | 18R-G - Toyota's Dependable Masterpiece
    Toymods Car Club Treasurer, assistant Historic Plate Registrar & Forums Admin

  4. #4
    Junior Member Domestic Engineer
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    524

    Default Re: Which to modify - 18R or 21RC

    ^ Speaking of, RA40's over in the US only came out with 20R's and 21R's and I know a lot of people on Classic-Celica.com do a lot of work to them... I never understood why until they explained the 18RG practically doesn't exist over there =P
    My Daily: NooB's Delivery Vehicle
    My wife's Daily: Series B RA40 Liftback 22RE, power steering, AC. Cushy as.
    Current Project: NooB 3TGTE swap
    Back Burner: 1964 Toyopet ToyoAce, and a Series B TA45 GT coupe
    Too many cars

  5. #5
    Junior Member Grease Monkey
    Join Date
    Jan 2012
    Location
    Finland
    Posts
    154

    Default Re: Which to modify - 18R or 21RC

    18R is one stout engine and there is some cams available for it.46mm M-B valves with porting and it beats 18R-G.. In fact I have one for sale:40 mm sidedrafts with ported big valve head make 132 hp/214 Nm.Bottom end needs reconditioning due the coolant loss (must to drive home due -22ºC night).Run well but uses oil.Will sell the head only..
    21R have about same ports as 3T-GTE;as stock they are not anything to write home;properly ported they are great! Do 20R cams fit to 21R? I don't know.In here there is no either of the engines to make any knowledge base.

  6. #6
    Junior Member Domestic Engineer
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    524

    Default Re: Which to modify - 18R or 21RC

    Yes but doesn't a stock 18RG make 140? and if you spent the same money you did on an 18RG you'd have a killer engine.

    Anyways the 21R has aftermarket support in the US.
    My Daily: NooB's Delivery Vehicle
    My wife's Daily: Series B RA40 Liftback 22RE, power steering, AC. Cushy as.
    Current Project: NooB 3TGTE swap
    Back Burner: 1964 Toyopet ToyoAce, and a Series B TA45 GT coupe
    Too many cars

  7. #7
    Toymods Net Nazi Too Much Toyota river's Avatar
    Join Date
    Sep 2005
    Location
    NSW
    Posts
    7,061

    Default Re: Which to modify - 18R or 21RC

    Hi,

    Quote Originally Posted by MarcusEstevez View Post
    Yes but doesn't a stock 18RG make 140? and if you spent the same money you did on an 18RG you'd have a killer engine.
    Stock 18R-GR (230 head) makes 140. Stock 18R-G (210 head) makes 145. The later 18R-GU and 18R-GEU versions made less.

    And correct, if you did similar mods to an 18R-G that you'd do on an 18R-C, the 18R-G would be cream the 18R-C.

    seeyuzz
    river
    The thinking man's clown and the drinking woman's sex symbol
    RA25GT - There is no substitute | 18R-G - Toyota's Dependable Masterpiece
    Toymods Car Club Treasurer, assistant Historic Plate Registrar & Forums Admin

  8. #8
    Junior Member Grease Monkey
    Join Date
    Jan 2012
    Location
    Finland
    Posts
    154

    Default Re: Which to modify - 18R or 21RC

    Those 140 hp were JIS (much the same as SAE Gross)and in Europe the DIN (as it will be in the car) hp was only 124 hp.All the later engines made less.The 124 hp was for early 9,7:1 compression one;later have a 9,2:1 and then in EFI/smog engines only 8,4:1.18R-G/2T-G really need boost to wake them up!

  9. #9
    Junior Member Domestic Engineer
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    524

    Default Re: Which to modify - 18R or 21RC

    I'm an owner of an 18RG and 18R. There is a very noticeable difference! I had an 18RC without all the emission crap, 32/36 Weber and extractors. Had some power down low but that was it, Was slow as. My 18RG runs HKS cams, Lightened flywheel, Extractors but has a very restricting stock exhaust (Will fix later), It lacks that down low power the 18R had but fucking wakes up at about 4000RPM. There is no comparison, And again, If I were to spend the money you did on your 18R my 18RG would be a lot more impressive. The 18R isn't crossflow, It was designed as an economical engine with the exhaust on the same side to heat up the fuel.
    My Daily: NooB's Delivery Vehicle
    My wife's Daily: Series B RA40 Liftback 22RE, power steering, AC. Cushy as.
    Current Project: NooB 3TGTE swap
    Back Burner: 1964 Toyopet ToyoAce, and a Series B TA45 GT coupe
    Too many cars

  10. #10
    Junior Member Grease Monkey
    Join Date
    Jan 2012
    Location
    Finland
    Posts
    154

    Default Re: Which to modify - 18R or 21RC

    Of course you can't compare 18R-G with sidedrafts to 18R with two barrel carb.I have made the intake for 18R for sidedrafts and ported it make more power than 18R-G.All with the stock 8R cam and cast exhaust manifold.What it would make somethin like this? I'm such a poor guy that I cant afford one.. http://schneidercams.com/292-98f_18r.aspx
    G-engines just don't make power without boost (and there they exel!)

  11. #11
    Junior Member Domestic Engineer
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    524

    Default Re: Which to modify - 18R or 21RC

    Have you ever driven an 18RG? They make power without boost! And they rev so easily too, 18R's are slugs. There is no way a none crossflow, single cam engine would out do a similar engine with twin cam, Twin carbs and crossflow head. If you add a turbo to an 18R it pretty much eliminates the poor performance of the none crossflow design, but the 18RG would still own if it too was turbocharged.

    All I'm getting at is if you did the same work to both engines, The 18RG would always win.
    FYI, The 18RG isn't a G engine, It's an R engine. G just means it's twin cam.
    My Daily: NooB's Delivery Vehicle
    My wife's Daily: Series B RA40 Liftback 22RE, power steering, AC. Cushy as.
    Current Project: NooB 3TGTE swap
    Back Burner: 1964 Toyopet ToyoAce, and a Series B TA45 GT coupe
    Too many cars

  12. #12
    Junior Member Grease Monkey
    Join Date
    Jan 2012
    Location
    Finland
    Posts
    154

    Default Re: Which to modify - 18R or 21RC

    Ehh..I build my first 18R-G in 1988.When you did one?
    And I use the "G" separating them (18R-G/2T-G/3T-GTE) from other engines of same family.The "G" is for twin-cam head.
    But what the hell I know;I just port heads for living and never seen a twin-cam head!

    Dyno just tells that the 18R (the single cam non crossflow) made 132 hp/219Nm (hell,it's something like 10 year ago;may be slightly different!)
    What your 18R-G made?

    To be honest the first 8R-G/10R (even Toyota didn't know how to mark them!) I don't know what power they make.And I doubt that anyone else knows it either!Maybe you are the person to know it?

  13. #13
    Junior Member Domestic Engineer
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    524

    Default Re: Which to modify - 18R or 21RC

    I wasn't saying you didn't no anything about heads, And if you port them for a living then you must know the 18RG has a better head all round. What was done to that 18R to produce the 132hp?
    My Daily: NooB's Delivery Vehicle
    My wife's Daily: Series B RA40 Liftback 22RE, power steering, AC. Cushy as.
    Current Project: NooB 3TGTE swap
    Back Burner: 1964 Toyopet ToyoAce, and a Series B TA45 GT coupe
    Too many cars

  14. #14
    Junior Member Grease Monkey
    Join Date
    Jan 2012
    Location
    Finland
    Posts
    154

    Default Re: Which to modify - 18R or 21RC

    Well,it was done some 10 year ago..46 mm Mercedes intake valves,porting and the sidedrafts40 mm with 32 mm throats (just as in 18R-G).Stock cam,stock exhaust manifold,2" exhaust.Ehh..what else? nothing!

    Why some people think that Ford OHC or Volvo is something great!? The 18R head is in my opinion way better! But then again;it's just a 18R.. who gives a damn for it
    All it lacks is the text "FORD" in the casting and then it would be the most tuned engine in the world!
    The OHC have a nice chamber;that's about the only good thing I can say.
    But these thing are more of mark than engineering exellence..

    Yes,the 18R-G IS an exellent desing (at least for the time it was done) but the huge piston dome needed for compression is not.Flat tops and boost,yess!

    I'm sorry if I tend to sound sarcastic/rude but been in busines this long the treshold for BS goes high.
    I really don't know everything (and if someone comes with such a claim shoot him/she in situ!)
    Every time on flowbench teach me something and reading someone like David Vizard or Darin Morgan gives more insight!
    Last edited by MorGo; 08-11-2012 at 11:15 PM.

  15. #15
    Junior Member Domestic Engineer
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    524

    Default Re: Which to modify - 18R or 21RC

    To lower the compression on an 18RG just put 18RC pistons in it or put the head on an 18RC block. Done =P

    I am a Ford fan by default because of my family, But I love old Toyota's. My whole family is Ford, I own Celica's, Hehe.
    Sorry if I come off as rude also, I just thought my 18R was crap compared to my 18RG >____>

    We hijacked this thread something fierce!
    My Daily: NooB's Delivery Vehicle
    My wife's Daily: Series B RA40 Liftback 22RE, power steering, AC. Cushy as.
    Current Project: NooB 3TGTE swap
    Back Burner: 1964 Toyopet ToyoAce, and a Series B TA45 GT coupe
    Too many cars

Similar Threads

  1. Approval to Modify
    By gmonkey in forum Tech and Conversions
    Replies: 8
    Last Post: 09-02-2011, 08:07 AM
  2. How do you modify the dizzy to clear ARP head bolts:4AGZE?
    By benjamin in forum Tech and Conversions
    Replies: 28
    Last Post: 12-05-2008, 12:24 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •