craig,
thanks for the site tip.....had a look and it is very interesting
andrew
Date sent: Tue, 19 Sep 2000 07:23:02 +1000
From: Craig Overend <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Send reply to: [EMAIL PROTECTED]
Subject: Re: 2.4L
> Andrew,
> I used to be a Computer Network Administrator there before I got
> totally sick of students and lecturers, now i'm an email freeloader. :)
> I now only use computers for things I enjoy, like the Datsun list.
> If your interested in engine development theres a new course at RMIT
> Mech Eng. The lecturer is a visiting professor from the US. Pity it a
> final year elective.
> Check out http://web.mm.rmit.edu.au/Web_Page/ME478_Front_Page.htm
> The lecture notes are definatly worth downloading.
>
> Craig.
>
> Andrew Robert GREENBURY wrote:
> >
> > craig,
> > i note you are from rmit.....what do you do?? staff or student
> > andrew
> >
> > On Thu, 14 Sep 2000, Craig Overend wrote:
> >
> > > I think Cameron was talking about using the FIA head on a 2.3 or 2.4L.
> > > The additional 400cc would lower the powerband approximatly 1000rpm
> > > compared to a 2.0L engine according to my calculations.
> > >
> > > The only reasons a Z24 cranked L20B wouldn't rev out is because people
> > > use rods that are too short and valves that are too small.
> > > The way I see it you only have one option if you want to use all
> > > standard Nissan parts for a large capacity L20B.
> > > An L20B 2.3L 89mm bore x 92mm(Z22) 2289cc using 145.9mm L20B rods and
> > > KA24 34mm pin height engine with a rod/stroke ratio of 1.59 might be OK.
> > > Generally a rod to stroke ratio below 1.55 is considered to be bad for
> > > engine wear and reliability.
> > > If you wanted a 2.4L then 89mm x 96mm(Z24) 2389cc using 152.45mm
> > > rods(Z20) and ~27mm piston pin height would give rod/stroke of 1.59 you
> > > just need to find the pistons to suit.
> > > I put this info into my engine simulator and I got the following:
> > > Using 44mm valves, 41mm ID seat and 13.45mm(.530) lift both of these
> > > engine give a mach index (average airspeed) of 0.5. Meaning that the
> > > airspeed though the valve on average is at the valve/port maximum value,
> > > maximizing volumetric efficiency.
> > > The 2.3L would produce its max HP at ~6059RPM and max TORQUE at ~4767RPM
> > > if I did my maths right. If the cylinder head port was 74% efficient
> > > this would require ~43mm ports. This is why I think the FIA head could
> > > be a good choice. I'd love the FIA actual specs please anyone.
> > > On the same engine using 42mm valves, 38mm ID seat and 11mm(.434") lift
> > > results in max HP at ~4663RPM and max torque at ~3099RPM. No wonder it
> > > dont rev!
> > > Whack a cam in this head to increase lift to 12.2mm(.480") and you get
> > > max HP at 5171RPM and max torque at 3811RPM a little better. Any more
> > > lift than this needs bigger valves and/or seats without sacrificing
> > > volumetric efficiency.
> > >
> > > A nice L18W out to 2.0L 88mm bore x 82mm stroke (1995cc) using 133mm L16
> > > rods and 34mm piston pin height using 44mm valves, 41mm ID seat and
> > > 13.45mm(.530) lift.
> > > Results in 1.62 rod/stroke and a .504 mach index, max HP at 7009RPM max
> > > Torque at 5471RPM. I think this is what Brad was building but with the
> > > FIA head? The only downside I see with this engine is the rod to stroke
> > > ratio could be better with 135mm L20A rods? for 1.65 and the bore to
> > > stroke improved aswell for less friction. To improve the bore to stroke
> > > may then require the block be sleeved if possible.
> > >
> > > Craig.
> > >
> > > Brad HALLETT wrote:
> > > >
> > > > Hate to tell you this Cameron, but you will have trouble getting midrange
> > > > out of an FIA head. They are designed to have maximum volumetric flow
> > > > meaning a narrow high rev powerband. They really are for maximum rev
> > > > applications only.
> > > >
> > > > Regards
> > > > Brad HALLETT
> > > >
> > >
> > >
> > >
> >
>
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