Steve
Excuse my ignorance, are we referring to Eastern Creek or another location
which in WA changed weekly.
Jim
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]] On Behalf Of Steve Taylor
Sent: Wednesday, 8 November 2000 12:06
To: [EMAIL PROTECTED]
Subject: Re: Z18et Cam Timing/Power
Jim,
Good to hear, maybe the power losses can be attributed to de-compression
thru
the chamber work on the new head, as it was fairly extensive!!It wasnt
pinging
on 20 degrees advance and around 15psi, but wasnt makin anymore power so i
thought id drop the timing back to about 18ish. Umm i run nothing but
optimax
thru it - was never aware that super was runable?!?!
The bottom end on the engine is as it was when i got it, arghh slightly
oversize
normal pistons, standard turbo, standard throttle body. As for pressure
testing
the intercooler - no i havent done this, should i??
O-ringing the block and forged pistons, bigger turbo etc are planned for the
Z20
block that i have on an engine stand in the garage waiting for the funds
become
available!!!
Im am in Sydney but ive got heaps of shit on for uni over the next couple of
weeks. Will be going out to the drags with the car for a couple of runs
tomorrow
night though if you can make it, if not would be good to catch up at some
other
time - let us know!!
Cheers
Steve.
Jim Jones wrote:
> Steve
>
> The output matches the modifications. Happened to speak to Brett this
> afternoon and as he dynoed a z18T in late September with similar
> modifications with 165rwhp your figures sound about right.
>
> If it is pinging at 20 degrees your compression still sounds like 7.5:1 or
> above. We axed the in chambers in my old motor and reduced it down to
6:1,
> sat the pistons down the bore, hence the love for boost and ignition
> advance. From memory on 25PSI we were still running 25 degrees advance
and
> still no detonation/pinging on pump super, however we did learn from the
US
> that 'high speed detonation' on turbo motors running large boost is
> practically undetectable, so who knows. I don't know if we were lucky but
> both my motor and Bretts FJ ran on pump super. I see a lot of guys on the
> list running premium/optimax etc for street driving and have often asked
> myself the question why, again maybe just the characteristics of the
motors.
>
> A couple of things that I am unaware of with your motor
>
> Is the block o-ringed, if not it would be a wise investment next time you
> need to rebuild?
> What throttle body do you have?
> Have you ran a pressure test across the intercooler to note any drop, ie.
> inlet side 15psi outlet side 12psi?
> What size turbo?
> Forged Pistons?
>
> If you are in Sydney we could arrange to meet as it has been a while since
I
> sat my arse in a 1600.
>
> Jim
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]] On Behalf Of Steve Taylor
> Sent: Tuesday, 7 November 2000 9:26
> To: [EMAIL PROTECTED]
> Subject: Re: Z18et Cam Timing/Power
>
> Jim,
> Im not too sure on this one, should of cc'd the head while i had it off i
> know,
> but b4 it was a totally standard head and the only decompressing ive done
is
> in
> the chambers of the new head, still just a standard head gasket, can this
> sortof drop in compression be achieved thru extensive chamber opening??
> If so well that may be the problem im not sure. Tryed up to 20 degrees
> advance
> on the dyno with no increases so ive dropped it back to around 17-18 to
ward
> off pinging. As for the cam yeah like u and a few others have said the
> standard
> cam had a much better overall curve than the modified one but still made
> exactly the same overall power - so it cant be blamed for the loss of
power!
> Umm apart from that im not too sure what to do next? Im thinking of
getting
> a
> vernier cam gear and trying to get some horsies out of the cam timing??
Dont
> know how successful this will be.
> Does that sortof power seem about right for my setup?? Or is something
> defintely amiss??
> Cheers
> Steve.
> (p.s. she still hoots along anyway!:)
>
> Jim Jones wrote:
>
> > Steve
> >
> > Steve how far did you go down in compression ie. before and after. We
> have
> > seen many cars on the dyno lose anywhere between 20 - 50hp after they
have
> > decompressed the motor. As an example if you went say from 8:1 to 7.5:1
> > with the same ignition settings then a loss of 20hp is possible. Did
you
> > screw any more advance into it after you decompressed the head, try 5
> > degrees and see what the difference is.
> >
> > Decompressing will change the characteristics of the motor.
> >
> > As far as the cam, as I suggested the 'standard' cam was better overall
(
> > curve) than the special grinds so a portion of the loss may be
> attributable
> > to a change in cam?.
> >
> > Let me know how you go.
> >
> > Jim
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]] On Behalf Of Steve Taylor
> > Sent: Monday, 6 November 2000 6:23
> > To: ozdat
> > Subject: Z18et Cam Timing/Power
> >
> > Jim Jones might be able to throw some light on this one?? Anyway i
> > recently blew the head gasket on my Z18. Its running a digi 1,
> > intercooler etc and on 15psi was makin 180hp@wheels just b4 it blew....
> > I rebuilt the motor with a polished, decompressed head, with heaps
> > bigger ports and port matched manifolds and a new cam. Got it all up and
> > running and it is now only makin around 160hp@wheels!!!! I tryed the
> > standard cam and it makes the same power just with a bit better curve.
> > Does anyone have any idea where all my power has gone or is hiding -
> > cause id love to know!!! Can there be that much power in cam timing?
> > Cause i set it to factory specs and maybe it was advanced b4 i took it
> > apart?
> > Sorry bout the length but im screwed if i know whats going on
> > Steve.
> >
>
--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]/
---------------------------------------------------------------------
