1969 L46 Spark Plugs
Thread Starter
Racer
Joined: Jan 2010
Posts: 348
Likes: 2
From: Lowell MA
1969 L46 Spark Plugs
What would be the best plugs to use?. 1969 L46 350 stock.
At the beginning of the Summer I installed AC44S plugs. For the first 100 miles or so, the car would climb to 6000 rpm with no misfire then after that it progressively got worse.
Replaced them with NKG V Power R5670-5 (Stk# 2298) and again the car ran fine and pulled strong up to 6000 rpm. After 150 miles or so, she started to misfire under load. Its a hassle to remove the shielding and replace the plugs so what are you using on your 1969 stock L46.
The temp runs about 180 and I use 93 octane mixed with Cam 2 racing fuel. Dwell at 31 and all in 36* at about 3000 rpm. Point gap set at about 34.
Lemans Blue 69
At the beginning of the Summer I installed AC44S plugs. For the first 100 miles or so, the car would climb to 6000 rpm with no misfire then after that it progressively got worse.
Replaced them with NKG V Power R5670-5 (Stk# 2298) and again the car ran fine and pulled strong up to 6000 rpm. After 150 miles or so, she started to misfire under load. Its a hassle to remove the shielding and replace the plugs so what are you using on your 1969 stock L46.
The temp runs about 180 and I use 93 octane mixed with Cam 2 racing fuel. Dwell at 31 and all in 36* at about 3000 rpm. Point gap set at about 34.
Lemans Blue 69
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Off the top of my head that point gap of 34 is not right. All my cars with points are 19
Race Director
Joined: Jul 2001
Posts: 15,892
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I think he meant plug gap.
If your car is not running cleanly on AC44s, there's something else going on, possibly overly rich mixture, weak coil etc. Try a set of AC45s.
BTW- there's probably no need to add 'racing fuel' to the tank. Your car should run perfectly well on pump 93.
If your car is not running cleanly on AC44s, there's something else going on, possibly overly rich mixture, weak coil etc. Try a set of AC45s.
BTW- there's probably no need to add 'racing fuel' to the tank. Your car should run perfectly well on pump 93.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
I think he meant plug gap.
If your car is not running cleanly on AC44s, there's something else going on, possibly overly rich mixture, weak coil etc. Try a set of AC45s.
BTW- there's probably no need to add 'racing fuel' to the tank. Your car should run perfectly well on pump 93.
If your car is not running cleanly on AC44s, there's something else going on, possibly overly rich mixture, weak coil etc. Try a set of AC45s.
BTW- there's probably no need to add 'racing fuel' to the tank. Your car should run perfectly well on pump 93.
Drifting
Joined: Sep 1999
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I went from 44's to 45's in my 70 L-46. (seem to burn better) Car likes them just fine. Can also run sunoco ultra with 12 degrees btdc and vacuum advance. bored .030 over 11-1 pistons.
The 44's used to foul up on me, but I think I created that monster. I blocked the heat crossover,(stopped the pinging), and took out the heat rise.(got tired of replacing the right side muffler). The gains were at the expense of a looooong fast idle which seemed to foul out the R-44's because the 45's are fine
The 44's used to foul up on me, but I think I created that monster. I blocked the heat crossover,(stopped the pinging), and took out the heat rise.(got tired of replacing the right side muffler). The gains were at the expense of a looooong fast idle which seemed to foul out the R-44's because the 45's are fine
Instructor
Joined: May 2010
Posts: 172
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From: Hesperia California
69 spark plugs
You have a carb, vacuum or timing issue, I run the ac 44s in my 69 350/350 at 8 btdc and it pulls excellet from a roll to 5500. Its all original bone stock with 68014 miles. Im afrade to really jump on it from a stop, oh but i would really like to, just to see how it comes off the line. Im older now and a chicken, afrade i might brake something. Oh its a 350/350 electronic ignition 4 speed wide ratio m-20 355s with 225/r60/15s.
Thread Starter
Racer
Joined: Jan 2010
Posts: 348
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From: Lowell MA
Need to put all perspectives in order.
Weinh suggested Autolite AP85. Will research those plugs.
Capevettes caught me on a typo. I meant to say point gap is set to .034.
Mike Ward suggested trying AC45S plugs and said something else could be going wrong. Pulled plugs tonight and 2 were slightly moist with what appears water. I have a problem.
Need to stop here and resolve the problem. By the way Firstvette69, no idea what old is when you are driving a Vette. I don't take mine out often but when I do, I have the biggest smile on my face. I do push it. 65 here.
Lemans Blue 69
Weinh suggested Autolite AP85. Will research those plugs.
Capevettes caught me on a typo. I meant to say point gap is set to .034.
Mike Ward suggested trying AC45S plugs and said something else could be going wrong. Pulled plugs tonight and 2 were slightly moist with what appears water. I have a problem.
Need to stop here and resolve the problem. By the way Firstvette69, no idea what old is when you are driving a Vette. I don't take mine out often but when I do, I have the biggest smile on my face. I do push it. 65 here.
Lemans Blue 69
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From: Cape Cod, Mass.
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Need to put all perspectives in order.
Weinh suggested Autolite AP85. Will research those plugs.
Capevettes caught me on a typo. I meant to say point gap is set to .034.
Mike Ward suggested trying AC45S plugs and said something else could be going wrong. Pulled plugs tonight and 2 were slightly moist with what appears water. I have a problem.
Need to stop here and resolve the problem. By the way Firstvette69, no idea what old is when you are driving a Vette. I don't take mine out often but when I do, I have the biggest smile on my face. I do push it. 65 here.
Lemans Blue 69
Weinh suggested Autolite AP85. Will research those plugs.
Capevettes caught me on a typo. I meant to say point gap is set to .034.
Mike Ward suggested trying AC45S plugs and said something else could be going wrong. Pulled plugs tonight and 2 were slightly moist with what appears water. I have a problem.
Need to stop here and resolve the problem. By the way Firstvette69, no idea what old is when you are driving a Vette. I don't take mine out often but when I do, I have the biggest smile on my face. I do push it. 65 here.
Lemans Blue 69
Sounds like you may have a head gasket problem. Good luck
