unleaded fuel in a 1970 vette?
05-25-2007, 02:40 PM
#21
im going to dump a can of seafoam down the carb and see if it helps at all.
if i still cant get it to stop pinging, im going to start mixing in 5 gallons 105+ octane and the rest 94.
05-25-2007, 03:33 PM
#22
Been putting 91 octane in my L46 for 20 years. No problems w/pinging.
I remember when 93 octane was available in CA. I really loath our state politicians. All HACKS IMO!
I remember when 93 octane was available in CA. I really loath our state politicians. All HACKS IMO!
08-26-2007, 10:55 PM
#24
Safety Car
I dont remember exactly which year hardened valve seats began appearing, and its entirely possible, likely even, that a recent rebuild may have added them to your heads (presuming original heads).
So its kinda hard to say...if you dont have hardened seats you would certainly want to add some, if you do have hardened seats then it really isnt doing you much good.
I guess if it were me, I would add it.
So its kinda hard to say...if you dont have hardened seats you would certainly want to add some, if you do have hardened seats then it really isnt doing you much good.
I guess if it were me, I would add it.
1975 started hardened Valve seats
08-27-2007, 07:00 AM
#25
Actually, 1971 was. That's when the hp ratings dropped, as well as how they measure hp.
I have the L46 11:1 optioned motor and I am having trouble getting it not to ping. I am getting ready to try mixing racing fuel w/ premium to see if it helps.
I've had my carb and dist gone over by Lars and I've tried setting the timing using Lars' paper on it, (36deg total timing).
There's a TON of power at 36 degrees, but also a lot of pinging. I have it set at 28 degrees now, and still get some pinging, especially under load, below 2500 rpm
If your motor runs fine with what you're using, I woudn't worry about adding lead or anything else to it.
I have the L46 11:1 optioned motor and I am having trouble getting it not to ping. I am getting ready to try mixing racing fuel w/ premium to see if it helps.
I've had my carb and dist gone over by Lars and I've tried setting the timing using Lars' paper on it, (36deg total timing).
There's a TON of power at 36 degrees, but also a lot of pinging. I have it set at 28 degrees now, and still get some pinging, especially under load, below 2500 rpm
If your motor runs fine with what you're using, I woudn't worry about adding lead or anything else to it.
Had the same trouble a few years ago as you are having now. Nothing worked other than AV fuel or lead additives.
I finally tried eliminating heat by blocking the heat crossover under the carb by installing intake gasets without cutouts for the crossover. I also eliminated the heat riser and put a spacer there instead. Disconnected the TCS and was able to bump the timing to 10 or it may even be 12 degrees. No pinging on 93 ultra.
Down side is it taked awhile to heat the choke coil. A trade off I can live with.
08-28-2007, 12:41 AM
#26
Burning Brakes
Member Since: Feb 2007
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I have a 69 vert with the L-46 350/350hp 11 to 1 ,4sp with 3.90 gears. While driving it for the short time I've had the car. I 've had no problem with running the 92 octane gas. I'm in the process of rebuilding the motor and wanted to know what the members with the 11 to 1 compression would do in my position. Stay with what came stock in my vette or drop down the comp? Some members say that the hight compression cause some pinging and some say not. The 350/300hp had the 10.25 comp. and the optional 350/350hp had the 11 to 1 comp. If I had no problem in the pass with the gas and pinging, should I go and put back the 11 to 1 or drop down to 10.50 or 10.75, if that's still availible. The problem I'm having it that the vette came with the 11 to 1 and if I drop it down it won't be the same car. It might as well be the 350/300hp. How do you sell a vette that's not what the spec states on the consul plate? Need your help to decide. Shop is going to tear down the motor and will I need to tell them what I decided.
I REALLY need your help in making the right decisision. Thanks
Tony
I REALLY need your help in making the right decisision. Thanks
Tony
08-28-2007, 01:08 AM
#27
Burning Brakes
Member Since: Sep 2004
Location: San Jose CA
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I have a 69 vert with the L-46 350/350hp 11 to 1 ,4sp with 3.90 gears. While driving it for the short time I've had the car. I 've had no problem with running the 92 octane gas. I'm in the process of rebuilding the motor and wanted to know what the members with the 11 to 1 compression would do in my position. Stay with what came stock in my vette or drop down the comp? Some members say that the hight compression cause some pinging and some say not. The 350/300hp had the 10.25 comp. and the optional 350/350hp had the 11 to 1 comp. If I had no problem in the pass with the gas and pinging, should I go and put back the 11 to 1 or drop down to 10.50 or 10.75, if that's still availible. The problem I'm having it that the vette came with the 11 to 1 and if I drop it down it won't be the same car. It might as well be the 350/300hp. How do you sell a vette that's not what the spec states on the consul plate? Need your help to decide. Shop is going to tear down the motor and will I need to tell them what I decided.
I REALLY need your help in making the right decisision. Thanks
Tony
I REALLY need your help in making the right decisision. Thanks
Tony
There is a gas station selling 100 octane(unleaded) race fuel in Redwood city.
If it pings, go mix up the pump fuel with a little bit of race fuel.
Last edited by GroundPounder; 08-28-2007 at 01:13 AM.
08-28-2007, 01:46 AM
#29
Burning Brakes
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I don't know the dynamic comp ratio of L46 and can not tell. Hope someone else will chime in.
The gas station is union 76 on Woodside Rd. This is the good backup just in case, so relax.
http://www.kings76.com
There are some more gas stations selling high octane fuel in bay area, but this one is the nearest to you.
Last edited by GroundPounder; 08-28-2007 at 01:55 AM.
09-18-2007, 07:50 PM
#31
Instructor
Member Since: Apr 2007
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09-18-2007, 08:25 PM
#32
Ok, I have to chime in. I had a 70 V8 Nova that I drove to work on the highway 100 miles a day after the phase out of leaded gas. Eventually I had to change the heads due to a burnt valve skip. When I broke down the heads, there was evidence of vavle recession. I alway attributed this to the lack of lead lubrication of the exhaust valves.
09-18-2007, 10:21 PM
#33
Hardened valve seats started in 1973. Even though compression dropped in 1971, GM figured there would still be enough lead around and did nothing with the seats til 1973. Some truck engines used exhaust valve rotators beginning in 1971 but passenger engines I believe did not.
