Spark Plug Gap
- Thread starter robert b. mccarthy
- Start date
FWIW:
I've used the .80 since day 1 some 200+k ago. Though I have changed cap 2 or
3 times and am probably on 3 set of wires, the changes were always as PM,
not breakdown. Last wire and cap change was in conjunction with change to
ported EFI.
Anyone else running other than .80? Comments? Observations pre/post change
from .80?
TIA - Heinz
'76 Transmode
- -----Original Message-----
From: RickStapls
To: gmcmotorhome
Date: Sunday, December 13, 1998 8:27 PM
Subject: Re: GMC: Spark Plug Gap
>
>> What is the correct spark plug gag for a 455 HEI engine?
>
>.060", NOT the .080 listed in the original manuals. This is one case where
>RTFM will get you in trouble, as the .080 gap raises voltage so high it
burns
>holes in the distributor rotor, arcs down the cap on a damp day, and eats
plug
>wires, even the $100 ones.
>That's what I've heard.
>
>Rick Staples
>'75 Eleganza
>Louisville, CO
>
I've used the .80 since day 1 some 200+k ago. Though I have changed cap 2 or
3 times and am probably on 3 set of wires, the changes were always as PM,
not breakdown. Last wire and cap change was in conjunction with change to
ported EFI.
Anyone else running other than .80? Comments? Observations pre/post change
from .80?
TIA - Heinz
'76 Transmode
- -----Original Message-----
From: RickStapls
To: gmcmotorhome
Date: Sunday, December 13, 1998 8:27 PM
Subject: Re: GMC: Spark Plug Gap
>
>> What is the correct spark plug gag for a 455 HEI engine?
>
>.060", NOT the .080 listed in the original manuals. This is one case where
>RTFM will get you in trouble, as the .080 gap raises voltage so high it
burns
>holes in the distributor rotor, arcs down the cap on a damp day, and eats
plug
>wires, even the $100 ones.
>That's what I've heard.
>
>Rick Staples
>'75 Eleganza
>Louisville, CO
>
Interesting indeed.
Now I really don't know what to do...
make the change next time around or stick with what's worked sofar
Heinz
>-- [ From: Eugene Fisher * EMC.Ver #2.5.3 ] --
>
>Yep, there is something to be learned here.
>
>Read about this on my web jpage, There seems to be a lot of history on
>this from the ranks of the past.
>
>http://www.california.com/~eagle/
>
>gene
>
Now I really don't know what to do...
make the change next time around or stick with what's worked sofar
Heinz
>-- [ From: Eugene Fisher * EMC.Ver #2.5.3 ] --
>
>Yep, there is something to be learned here.
>
>Read about this on my web jpage, There seems to be a lot of history on
>this from the ranks of the past.
>
>http://www.california.com/~eagle/
>
>gene
>
I have used .060" gap from the beginning.We already have impossible heating
conditions under the hood and the higher voltage in the wores caused by the
.080 gap makes things even worse for the ignition circuits.
>FWIW:
>I've used the .80 since day 1 some 200+k ago. Though I have changed cap 2 or
>3 times and am probably on 3 set of wires, the changes were always as PM,
>not breakdown. Last wire and cap change was in conjunction with change to
>ported EFI.
>
>Anyone else running other than .80? Comments? Observations pre/post change
>from .80?
>
>TIA - Heinz
>'76 Transmode
>
>
>-----Original Message-----
>From: RickStapls
>To: gmcmotorhome
>Date: Sunday, December 13, 1998 8:27 PM
>Subject: Re: GMC: Spark Plug Gap
>
>
>>
>>> What is the correct spark plug gag for a 455 HEI engine?
>>
>>.060", NOT the .080 listed in the original manuals. This is one case where
>>RTFM will get you in trouble, as the .080 gap raises voltage so high it
>burns
>>holes in the distributor rotor, arcs down the cap on a damp day, and eats
>plug
>>wires, even the $100 ones.
>>That's what I've heard.
>>
>>Rick Staples
>>'75 Eleganza
>>Louisville, CO
>>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
conditions under the hood and the higher voltage in the wores caused by the
.080 gap makes things even worse for the ignition circuits.
>FWIW:
>I've used the .80 since day 1 some 200+k ago. Though I have changed cap 2 or
>3 times and am probably on 3 set of wires, the changes were always as PM,
>not breakdown. Last wire and cap change was in conjunction with change to
>ported EFI.
>
>Anyone else running other than .80? Comments? Observations pre/post change
>from .80?
>
>TIA - Heinz
>'76 Transmode
>
>
>-----Original Message-----
>From: RickStapls
>To: gmcmotorhome
>Date: Sunday, December 13, 1998 8:27 PM
>Subject: Re: GMC: Spark Plug Gap
>
>
>>
>>> What is the correct spark plug gag for a 455 HEI engine?
>>
>>.060", NOT the .080 listed in the original manuals. This is one case where
>>RTFM will get you in trouble, as the .080 gap raises voltage so high it
>burns
>>holes in the distributor rotor, arcs down the cap on a damp day, and eats
>plug
>>wires, even the $100 ones.
>>That's what I've heard.
>>
>>Rick Staples
>>'75 Eleganza
>>Louisville, CO
>>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
Heinz,
I, too, am using the 0.80 gap (I didn't know any better.)
Can't report on long-term, as I only have put about 1000 miles on, but
starts well, passes emissions and pulls strongly without detonation. That's
with the MSD multi-spark Ignition with its variable timing control set at 4
degrees more advance than spec due to our altitude in the Denver area.
Richard Guthart
'77 Birchaven with 455
>FWIW:
>I've used the .80 since day 1 some 200+k ago. Though I have changed cap 2
or
>3 times and am probably on 3 set of wires, the changes were always as PM,
>not breakdown. Last wire and cap change was in conjunction with change to
>ported EFI.
>
>Anyone else running other than .80? Comments? Observations pre/post change
>from .80?
>
>TIA - Heinz
>'76 Transmode
I, too, am using the 0.80 gap (I didn't know any better.)
Can't report on long-term, as I only have put about 1000 miles on, but
starts well, passes emissions and pulls strongly without detonation. That's
with the MSD multi-spark Ignition with its variable timing control set at 4
degrees more advance than spec due to our altitude in the Denver area.
Richard Guthart
'77 Birchaven with 455
>FWIW:
>I've used the .80 since day 1 some 200+k ago. Though I have changed cap 2
or
>3 times and am probably on 3 set of wires, the changes were always as PM,
>not breakdown. Last wire and cap change was in conjunction with change to
>ported EFI.
>
>Anyone else running other than .80? Comments? Observations pre/post change
>from .80?
>
>TIA - Heinz
>'76 Transmode
