still having spark knock issues.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Why are you using 43 plugs? Way to cold for street cars.....Try some racing fuel and see if your problem goes away......You cant really trust the gas stations as their out for a fast buck realizing that only a few cars really need higher octane gas as they laugh all the way to the bank....
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Melting Slicks
Joined: Jul 2004
Posts: 2,871
Likes: 196
From: Maryland
While you have the distributor out do you have access to a Sun Distributor machine? The distributor might as you say have too an aggressive ignition curve although you say it ran well before. I have a similar engine 300hp- 327 w. the following curve
Start @ 800 RPM
13* @ 1700 RPM
26* @ 3100 RPM
I use BWD 112 hp points and a non emissions cap & rotor. The VAC is a B22, spark plugs are 5 heat range and initial timing 10* at 600 RPM.
Start @ 800 RPM
13* @ 1700 RPM
26* @ 3100 RPM
I use BWD 112 hp points and a non emissions cap & rotor. The VAC is a B22, spark plugs are 5 heat range and initial timing 10* at 600 RPM.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
Carbon promotes pre-ignition. Remove carbon and you have a chance to solve pre-ignition issues.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
It is not normal for a healthy SBC to accumulate deposits of any kind in the combustion chambers in sufficient quantity to induce pre-ignition. If seafoam or any deposit remover is required on a recurring basis (and not just a feel good placebo basis) the engine needs some serious help.
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
It is not normal for a healthy SBC to accumulate deposits of any kind in the combustion chambers in sufficient quantity to induce pre-ignition. If seafoam or any deposit remover is required on a recurring basis (and not just a feel good placebo basis) the engine needs some serious help.
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Racer
Joined: Dec 2005
Posts: 368
Likes: 4
From: . New Zealand
I have had a customer with this problem, it turned out to be oil mist carry over from a poorly set up valve cover ventilation system. We replaced the PCV and the valve cover baffles and the air cleaner vent tube baffles, (basically stopped the ingress of oil mist into the intake tract) and the pinging stopped.
A good way to check, is to isolate the PCV ventilation lines from the intake tract temporarily to see if that stops the pinging.
Another theory, a bit out this time, is cam wear, if the exhaust lobe(s) gone, the dynamic compression ratio increases causing pinging.
A good way to check, is to isolate the PCV ventilation lines from the intake tract temporarily to see if that stops the pinging.
Another theory, a bit out this time, is cam wear, if the exhaust lobe(s) gone, the dynamic compression ratio increases causing pinging.
Last edited by Thmprr; Oct 6, 2009 at 04:30 PM.
Thread Starter
Safety Car
Joined: Jun 2005
Posts: 3,775
Likes: 4
wiped cam... i think those were the last 2 words i wanted to hear.
ill toy with the pcv system when the weather clears up later this week.
i dug out my dads old vac/compression gauges last night, so ill play around with the idle mixture too.
looks like ive got lots of things to try. ill go from the cheapest/easiest to the most expensive/hardest.
ill toy with the pcv system when the weather clears up later this week.
i dug out my dads old vac/compression gauges last night, so ill play around with the idle mixture too.
looks like ive got lots of things to try. ill go from the cheapest/easiest to the most expensive/hardest.
Thread Starter
Safety Car
Joined: Jun 2005
Posts: 3,775
Likes: 4
this is good.... i cant even get the car to start now.
i reinstalled the points, weights, springs, and whatnot this evening after regreasing them. now the car isnt even starting.
hopefully the weather will be decent tomorrow and i can work on it.
i reinstalled the points, weights, springs, and whatnot this evening after regreasing them. now the car isnt even starting.
hopefully the weather will be decent tomorrow and i can work on it.
Thread Starter
Safety Car
Joined: Jun 2005
Posts: 3,775
Likes: 4
just a little update, i got the spark knocking issue all cleared up. i solved 2 problems at once.
for what ever reason, the points/condenser went out. the car wouldnt start and i had no spark.
a new set of points/condenser got me a running car and cleared up all spark knock. except for a little knock at 35-40mph in 4th gear going up a hill. thats to be expected though.
for what ever reason, the points/condenser went out. the car wouldnt start and i had no spark.
a new set of points/condenser got me a running car and cleared up all spark knock. except for a little knock at 35-40mph in 4th gear going up a hill. thats to be expected though.
Race Director
Joined: Oct 2000
Posts: 15,183
Likes: 79
From: central FL, near the beach.
good
i used points in the 70's and they were always a great hobby. back then they had things called "tune ups" which was points and plugs. the lead in the gas would ruin plugs in 10k or so. u know about points, completely obsolete, but still popular with guys that want to experience the "good old days" when there was nothing to do but fiddle with points. let's see how long they last 
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
This is the first part I bought, only a few months after the car itself.
It was 18 years ago. I never touched it since this date.
http://www.summitracing.com/parts/MAA-501/?image=large
It was 18 years ago. I never touched it since this date.
http://www.summitracing.com/parts/MAA-501/?image=large
Thread Starter
Safety Car
Joined: Jun 2005
Posts: 3,775
Likes: 4
This is the first part I bought, only a few months after the car itself.
It was 18 years ago. I never touched it since this date.
http://www.summitracing.com/parts/MAA-501/?image=large
It was 18 years ago. I never touched it since this date.
http://www.summitracing.com/parts/MAA-501/?image=large