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]/
---------------------------------------------------------------------
