Re: stroke mathematics

[David Costello]

I'm currently using a Z18 head but I was thinking of using a Z20 head instead because of the bigger valves the chambers are apparently the same size on all Z series motors.   Compression isn't really that much of an issue as I'm getting the pistons custom made anyways, so I can just get a deeper dish made.   the reason for all the calculations is I'm trying to work out the longest rods I can use to keep some kind of revability, then just get the pistons made to suit that rod   Dave  ----- Original Message ----- From: Cleary Signs To: [EMAIL PROTECTED] Sent: Tuesday, January 15, 2002 9:33 PM Subject: Re: stroke mathematics Z22 would work to use zero deck height with that combo, compression is going to be your biggest problem.   the L i was going to build before the CA with the Z22 crank 37cc head, 35mm pin height (mahle VW 88mm forgies) with zero deck height my compression worked out to be close to 14:1 a bit to high, but your running more stroke and a turbo, what cc are your chambers?   Heath ----- Original Message ----- From: David Costello To: [EMAIL PROTECTED] Sent: Tuesday, January 15, 2002 9:16 PM Subject: Re: stroke mathematics that being the case I'm confused again   Z20 block = 227.45mm L20b Rod = 145.9mm Z20 piston= 35.56mm Z24 crank = 96mm   48+145.9+35.56 = 229.46   that's above deck height straight away, but that's the combo of parts people have been telling me to use   Dave ----- Original Message ----- From: andrew smith To: [EMAIL PROTECTED] Sent: Tuesday, January 15, 2002 8:42 PM Subject: Re: stroke mathematics David, Half the stroke is 48mm plus the rod 145.9mm is 193.9mm and if you take this away from the block height 227.45mm it leaves you with 33.55 piston pin height required to put the piston level with the block assuming factory tolerances and an unmachined block.But before you order pistons you need to measure the cc's of combustion chamber,head gasket cc's depends on bore size and thickness,a theoretical piston dish size(eg 15cc) and work out your compression ratio according to piston bore you intend using.You may not be able to get the comp low enough with a zero deck height and large dish pistons so thats where the piston pin height can come into play.Remember the old saying,measure twice cut once.Ive done many stroker bikes and cars over the years. Andrew Smith David Costello wrote: guys I'm trying to teach myself how to do all the mathematics involved in deciding what internal parts to useand I seem to be stuck Z24 crank is 96mm strokeZ20 block is 227.45mm heightand most people use the L20 rods for this combo, they're 145.9mm when I wanna work out what height pistons I need is it rod mm plus piston mm should equal block height, or does the stroke of the crank come into it some where I was doing 96mm + 145.9mm and coming up with 241.9mm which was way above deck height even without adding pistons on top of that, then I realised the 96mm stroke of the crank is from the centreline of the crank to the centre of the part where the con rod bolts onto the crank (HAHAHA forget the name) so if I add that in I'd have to subtract 96mm from the deck height anyways, hmmmm I really should have thought about this some more before writing this email hahahaha it's all sorta coming clear as I'm typing it. I'm assuming therefore block height is measued from centreline of the crank to the deck height, so when working out what combo of parts I need I just add rod + pistons and try to get a combo that is equal to the block height? Dave --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/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --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/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --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/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --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/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --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/membersozdat@datascribe.com.au/ ---------------------------------------------------------------------