Terry, Sorry I was vague on my previous post. The clearances I'm talking about is between the SC mounted where the AC pump used to be, and the passenger side chassis rail. The SC is wider than the AC pump was and there is about 8mm gap between the SC and the chassis rail (note: now 25mm and now the top of the SC hits my extractors.. grrrr.. going to slot the sc mounting bits so i can try to find a nice even spot). Anyway.. what I meant was in relation to how an engine will "twist" when its revved? How it moves sideways a bit? How much clearance do i need between SC and chassis rail so it won't bang when i plant it?
The L28 sits exactly (as near as I can tell) where the L24 did so the angles between gearbox etc should still be good. Thanks for the detailed response, appreciate your time/input as always. :) Dave >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<< On 8/18/02, 11:02:16 PM, "Terry Rudd" <[EMAIL PROTECTED]> wrote regarding RE: L28->240Z almost there! Questions.: > Dave, > You have been busy. > With regards to your question I don't fully understand what you are asking > about so I'll write in very general terms - usually clearances are seen to > be OK by engineers RTA types etc as long as there isn't any evidence of > solid component contact at anytime. They mainly look at exhausts, alternator > brackets, filters, air cleaner assemblies and the like. > What component(s) are you referring to that have only 8mm clearance eg sump > to xmember? > Does a 240Z have a split tailshaft? It's so long since I looked under one I > can't remember. If they have a split shaft then ignore what I'm about to > write as it only applies to single piece tailshafts. > One thing to watch when you modify the natural position of the engine > and/or gearbox is that you don't upset the plane between the gearbox output > uni the diff input uni. If the distance between plane is outside 5% from > parallel then this will put the unis out of harmony with each other and it > will cause all sorts of noises and/or vibrations at certain speeds on the > road, technically it's relative to tailshaft revolutions but much the same > thing. I've seen this problem with gearbox conversions in 1600's as it's > very often overlooked and it will also come into play if you modify engine > mount heights and not modify gearbox mounting heights. I'll try to draw a > simple picture as if you've never had someone explain this to you while > under a car, it's a bit difficult to get a handle on. > gbox uni ---------------- > ---------------- diff uni > A one piece tailshaft typically follows a straight line from the beginning > of the top broken line to the end of the bottom broken line and as the > gearbox and diff in the example are in a parallel plane the angles that both > of the unis spin in are the same and everything will be sweet. If you move > either of these components up or down so the angle on the unis is greater > than +-5% of each other then they'll rumble. How did manufactures get around > this problem in the family car or race car for that matter? Invent the split > tailshaft, and I wish our early Dattos had them, especially those with IRS > ala 1600. > Does this problem occur in IRS uni half shafts? Short answer is Yes, but as > a driveshaft is ~2' long, then 5% is a much greater distance to modify the > position of either the diff or the short axle. Interestingly, lowering a > 1600 has far less effect on this in the rear end as does fitting > wheels/tyres that are way oversize from stock. Anyone who's been in a 1600 > with 17's with the rear springs that have about 1/3 of them cut off and > stock uni half shafts fitted would have noticed the racquet that goes on in > the rearend. How did manufacturers fix that one? They invented the CV > shafted rear end. > I recall reading recently that someone is snapping half shafts or unis, I > would mind betting that there is a bit off, could even be something along > these lines in the rearend of that Datto as you have to really try hard to > snap a uni - side stepping the clutch at 6 grand with 300 hp on tap on > slicks can do it though. > regards > Terry > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of David Andrews > Sent: Saturday, 17 August 2002 8:24 PM > To: [EMAIL PROTECTED] > Subject: L28->240Z almost there! Questions. > G'day All, > Well I spent today plonking my L28 into my 240Z and am happy to report > that everything is going well so far. This is the supercharged (baby > SC12) engine I just purchased and my query is with regards to clearances > for the chassis. How much clearance between engine/chassis is required? > Currently there is bugger all (8mm) but I'm modifying the mounts tomorrow > which should take it up to around 25mm. Will this be enough? > Regards, > 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/[email protected]/ ---------------------------------------------------------------------
