What is the best type of spark plug to help reduce pinging in Clevelands? I have 302 closed chamber heads (with the chambers relieved) on a 351. The plugs are not fouling but there may be some carbon build up in the chambers. I only run 98PULP (Ultimate) and my initial advance is set at 12degrees. I have tried everything but am reluctant to take off the vacuum advance. Any suggestions as to which plugs might help?
What is the best type of spark plug to help reduce pinging in Clevelands? I have 302 closed chamber heads (with the chambers relieved) on a 351. The plugs are not fouling but there may be some carbon build up in the chambers. I only run 98PULP (Ultimate) and my initial advance is set at 12degrees. I have tried everything but am reluctant to take off the vacuum advance. Any suggestions as to which plugs might help?
#1 does the engine run on when you turn it off..
#2 did you change the advance RATE when you put the cc heads on..
#3 where is the vacuum advance connected to (ported or manifold vacuum)..
#4 has the pinging problem been there ever since you changed the heads,or has it started to do that some time later..
#2 did you change the advance RATE when you put the cc heads on..
#3 where is the vacuum advance connected to (ported or manifold vacuum)..
#4 has the pinging problem been there ever since you changed the heads,or has it started to do that some time later..
1. No it doesnt run on.
2. MSD dissy is set to the slowest advance curve, two heavy silver springs
3. Connected to ported vacuum on RH side of (Holley) carb. Yes we plugged the advance when we checked the timing. Total timing is 20 degrees in the dissy as it came from the factory.
4. The motor was built replaced as a complete unit. It only used to ping when towing originally but is worse now. It dosent run very well with the ignition retarded below 12 degrees. I think it may have a build up of carbon. I was going to throw some new plugs in and take it for a long drive.
May pay to do a compression check as well. My first engine had a ping and got worse over time, ended up with a head gasket blown between 2,3,4, cylinders.
May pay to do a compression check as well. My first engine had a ping and got worse over time, ended up with a head gasket blown between 2,3,4, cylinders.
I've had that too. Actually, they were blown on both sides in the same spot.
if you don't mind,can you give us the basic spec's of the car and engine..
what holley is it and what condition is it in..how much of the transition slot is showing with the butterfly's closed..
how much manifold vacuum do you have at idle..and does the car surge when you are cruising along in top gear say,at 60-80 km/hr..
how far out are the idle mixture screws and are they responsive when you move them..
if you don't mind,can you give us the basic spec's of the car and engine..
what holley is it and what condition is it in..how much of the transition slot is showing with the butterfly's closed..
how much manifold vacuum do you have at idle..and does the car surge when you are cruising along in top gear say,at 60-80 km/hr..
how far out are the idle mixture screws and are they responsive when you move them..
Yes it surges a little
Im not sure how to check the transition slot.
I have a 750 Vac newer type 80....series, its a Holley factory reco. very little use.
Cam is Crow: 2113675
IN.33/73
EX.78/35 duration: 286-293 Duration at .050": 226-232 valve lift: 530"
.548"2700-5800rpm K21043 "Popular hot street cam which delivers strong strip performance"
Mixture screws are two turns out from seated. Don't know about responsive?? Convertor is 2300rpm by dominator. I suspect it is a tad small as the idle drops back a fair bit when put into drive and even more when the thermofans cut in and you can forget about the air con at idle unless I screw the idle right up. We managed to get it idling nicely in gear but its now pinging.
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