Depends on how big you want to go I personally would avoid the L20B crank and do a combined bore/stroke increase so as to maintain reliability and minimise stroke:rod ratio and also cylinder flex.
I think you would gain a lot more in engine life, reliability and revs by stroking/boring the L18. Don't forget though that this can probably only take you to 2.0 litres. You can build a maximum Hp High torque L18 Frankenstein that lasts one event, or you can build a reliable smooth engine that produces a little less but is good useable grunt that oesn't need rebuilding every run -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of nat P. Sent: Tuesday, 18 March 2003 7:19 PM To: [EMAIL PROTECTED] Subject: RE: L20 crank into L18? Good, bad or ugly? Thanks Brad, I was hoping you were online!! Cheers NAT Do you think there is much of a Hp/Torque difference between a L18block/L20 crank and a simple L18 bored 30thou that can rev? Cheers NAT --- Brad Hallett <[EMAIL PROTECTED]> wrote: > There are a lot of considerations to be taken into > account Nat. Using > L18 rods will result in poor angulation causing > scuff. Eliminate this > problem by using long rods and short pin heights. > L20 crank can be used > as mains can be ground down to fit. > > I personally think you are better off using an L18 > crank and sroking it > 4mm per throw, and boring the L18 block to get > 1999cc. Need an L18W > block though to handle the 89mm bore or use sleeves. > Remember that > stroke is 4mm on throw meaning 8mm stroke increase. > Combine all this > with long 240K rods and short pin height forgies and > you have a reliable > revver. 4mm can be welded on saving you money on > metal spraying. Make > sure you get it all balanced and nitrided though. > > Cheers > Brad > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of nat P. > Sent: Tuesday, 18 March 2003 12:19 PM > To: [EMAIL PROTECTED] > Subject: Re: L20 crank into L18? Good, bad or ugly? > > > But is that the only concern! What about revs? Crank > to piston angle? I dont know what are good figures > and > what are bad? Anyone? > > > > --- Kristian Walsham <[EMAIL PROTECTED]> wrote: > > > Nat, > > The L20B crank has a main bearing journal of > > 59.95mm compared to > > L16/L18 of 54.95mm. > > > > I think it`s possible to use a Z20 crank but not > > sure. > > > > Kris. > > ----- Original Message ----- > > From: "nat P." <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Tuesday, March 18, 2003 11:50 AM > > Subject: L20 crank into L18? Good, bad or ugly? > > > > > > > Mornin all!! > > > > > > Has anybody put a L20 crank into a L18? I'm > > thinking > > > about doing for my rally car! Which will give me > > the > > > most out of my 3 litre class! BUT I've heard > > different > > > things, Can someone tell me the pro and cons of > > such > > > an act! > > > Cheers NAT > > > > > > http://mobile.yahoo.com.au - Yahoo! Mobile > > > - Check & compose your email via SMS on your > > Telstra or Vodafone mobile. > > > > > > > > > > > > > --membersozdat------------------------------------------------------- > > OZDAT Mailing List Please Note:- > > Send (un)subscribe requests to > > [EMAIL PROTECTED] > > Send submissions to > [EMAIL PROTECTED] > > No unauthorised redistribution of this email > > http://www.ozdat.com/ozdatonline/index.htm > > http://www.ozdat.com/ozdatonline/listindex.html > > > http://www.mail-archive.com/[EMAIL PROTECTED]/ > > > --------------------------------------------------------------------- > > > http://mobile.yahoo.com.au - Yahoo! 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