I don't think that pinging is the major issue with lead free gas. The
newer methods
that are used to raise octane still produce ping resistance (octane rating).
What is missing from
the new fuels is the lubrication/heat properties that lead provided on the valve
seat areas. In an
engine that is constantly run hard disassembly will show that the valve seats
have become
recessed into the head; literalily pounded back. Engines with inserted and
hardened valve seats
do not suffer from this but the earlier iron heads had no inserts, the seats
were machined from the
head material and therefore unable to withstand the unlubricated conditions
present under heavy
load for extended periods of time.
Aftermarket heads and head rebuilds now include hardened inserts which are
simply installed in
place after spot milling a recessed area to press fit them into.
Jim
----------
From: INTERNET:LeBrun@hii.hitachi.com
Sent: Friday, May 31, 1996 11:07 AM
To: INTERNET:GARY_WINBLAD@CA.CREDENCE.COM; Roland Dudley
Cc: 102430,3640; INTERNET:TIGERS@AUTOX.TEAM.NET
Subject: Re[2]: "K" vs "HP"
Roland;
-Right after purchasing our TIGER, I went by my "local" 76
station & there were some, older faded bottles labeled
"lead substitute". Reading the fine print, they contained
MEL, so obviously pre-dated the phase out in CA. The bottles
were so faded, they'd been on the "rack" outside for quite
some time. The newer stuff of course, has dropped the MEL
from the ingredients list.
-I put in a bottle every 2-3 tanks of gas & I use 87 Octane
with no pinging. Even without the additive, I have no
pre-detonation on the 87. Since my engine is slightly
"pumped", I thought this would be a problem, (nothing a
2-3 degree retard in timing won't cure) but it hasn't been.
-I haven't experienced any "gumming" either and our car may
not get driven every week. I sprayed a couple cans of B-12
through & over my carb(also good for cleaning c. chambers of
all your carbon buildup) after getting the car home 6 months
ago. I haven't had any deposit problems since then either.
Phil
______________________________ Reply Separator _________________________________
Subject: Re: "K" vs "HP"
Author: Roland Dudley <cobra@cdc.hp.com> at ~INTERNET
Date: 5/31/96 10:33 AM
>
> >I have a 2V 289 in my snake at the moment (CR=9.3:1 + 31 years of
> >carbon build-up) and it runs just fine on el cheapo 87 octane.
>
>
> And that is the engine your Tiger has (only if its a Mark II, all others
> are 260 engines).
>
> Octane enhancer is not required but is lead substitute??
>
> Gary
And another question: do any of the lead substitutes really work?
I've head that none of them do anything except gum things up.
Note I said substitutes. Adding MEL doesn't count, since it's not
available for street use here in CA.
Roland
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