347 surging and pinging
09-19-2007, 09:31 AM
#1
2nd Gear Member
Thread Starter
Join Date: Oct 2006
Location:
Posts: 215
347 surging and pinging
At idle my 347 likes to surge kinda sounds like i have a 800 lift cam in it or something and when the engine temp gets about half way up and i give it a lot of throttle it pings a lot (makes the sound of a piece of foil bouncing around in the motor.) any suggestions on how to fix either of these. thanks
09-19-2007, 09:38 AM
#2
6th Gear Member
Join Date: Feb 2006
Location:
Posts: 5,263
RE: 347 surging and pinging
The surging comes from the computer having a hard time
with the cam and stroker swap. A good custom dyno tune should smooth it
out to some extent.
The pinging when hot is detonation. DO NOT drive it till you figure this out.
Not sure why you're getting detonation.
What gas are you running? what's your timing set to? Whats compression ratio of the motor?
with the cam and stroker swap. A good custom dyno tune should smooth it
out to some extent.
The pinging when hot is detonation. DO NOT drive it till you figure this out.
Not sure why you're getting detonation.
What gas are you running? what's your timing set to? Whats compression ratio of the motor?
09-19-2007, 11:35 AM
#5
6th Gear Member
Join Date: Feb 2006
Location:
Posts: 5,263
RE: 347 surging and pinging
ORIGINAL: buget94gt
just retard your timing and start using higher octane fuel. hes runnin a good fuel set up but 91 octane. it started all this after a head swap.
just retard your timing and start using higher octane fuel. hes runnin a good fuel set up but 91 octane. it started all this after a head swap.
09-19-2007, 12:44 PM
#7
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
RE: 347 surging and pinging
Are you using a head gasket with the same bore size and compressed thickness? And have you checked for a vacuum leak? Sounds like it may be a vacuum leak, spray some Brakleen along the lower intake gasket with the engine running at idle, if the idle quality changes then you have a vacuum leak
09-19-2007, 02:24 PM
#9
6th Gear Member
Join Date: Feb 2006
Location:
Posts: 5,263
RE: 347 surging and pinging
If you went from stock E7 head to a TFS head I would bet $100
you went to a smaller conbustion chamber and significantly raised your compression ratio.
You need to back the timing off and the ping-ing will go away.
Surging idle can be any number of things. Like they said, start with vac leaks
Might need a better tune too though.
you went to a smaller conbustion chamber and significantly raised your compression ratio.
You need to back the timing off and the ping-ing will go away.
Surging idle can be any number of things. Like they said, start with vac leaks
Might need a better tune too though.
09-19-2007, 02:34 PM
#10
5th Gear Member
Join Date: Sep 2004
Location:
Posts: 3,145
RE: 347 surging and pinging
ORIGINAL: Bwebb Stang
yeah when i had the stock heads on the stroker it would never ping the pinging just started when the heads got swapped into the mix. they are tfs highport heads.
yeah when i had the stock heads on the stroker it would never ping the pinging just started when the heads got swapped into the mix. they are tfs highport heads.