Engine Pings Under Load?
Thread Starter
Instructor
Joined: Jun 2002
Posts: 176
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From: New Albany IN
Engine Pings Under Load?
Just rebuilt my '70 350. 11:1 compression pistons. 93 octane gives me the ping. What is the best way to boost the octane? Do the octane boosters work? If so what is the best brand? I have been mixing 109 octane with 93 but I only know one station that sells it which doesn't allow traveling very far from home. Sugestions?
Melting Slicks
Joined: Jan 2003
Posts: 2,804
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From: OKC Oklahoma
Team Owner
Joined: Feb 1999
Posts: 34,455
Likes: 665
From: Republic of Texas
Re: Engine Pings Under Load? (Raydon 3000)
I'd re-check the timing while you're at it. I had the same problem w/ a 327 I had, azaming what a few degrees can do. I think 104+ has two versions. One boosts the octane rating 2-4pts while the other is like 5-7pts.
:cheers:
:cheers:
Drifting
Joined: Dec 1999
Posts: 1,462
Likes: 1
From: Reno nevada
Re: Engine Pings Under Load? (Corey 68)
I have 10.7 and 91 octane. Your rebuild need a quench space of near .040 if it's .055 or larger your going to have detonation problems sooner.
For your timing you might have to do what I did. Recourve the distributer for max mech advance of 22 degrees and all it at 3000 rpm. Then you can set your initial at 14-16 degrees to get a really smooth idle and still only have 36-38 total.
Your pother problem might be your cam choice what is it?
For your timing you might have to do what I did. Recourve the distributer for max mech advance of 22 degrees and all it at 3000 rpm. Then you can set your initial at 14-16 degrees to get a really smooth idle and still only have 36-38 total.
Your pother problem might be your cam choice what is it?
Le Mans Master
Joined: Oct 2001
Posts: 6,925
Likes: 0
From: Paradise City
Re: Engine Pings Under Load? (Lt1er)
Do you have aluminum heads (i hope)? You can try mixing your own gasoline with products like toulene and xylene-it really boosts your octane, and therefore resistance to detonation. Its not like that stuff in a can that supposedly boosts octane, toulene and xylene are chemical compounds used for paint removal, etc...A few of our forum members do this, its (fairly) cheap (compared to buying 103 octane), easy to do (go to paint supply store). There is a great write up one of the members did, try searching for it, it'd be under "Toulene/xylene" or "boosting octane" :cheers:
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: Engine Pings Under Load? (Raydon 3000)
I have been extremely disapointed with every fuel additive except one, Lead Supreme 130. It works for my 12:1 L88 on the street. Check the web site below.
http://www.kemcooil.com/product_info.php?pId=61
Chuck
http://www.kemcooil.com/product_info.php?pId=61
Chuck
Burning Brakes
Joined: Apr 2003
Posts: 844
Likes: 0
From: Central KY
Re: Engine Pings Under Load? (Raydon 3000)
I didn't get your cam info - but if it is high-lift, short duration (like most of our street cars really need for 90% of our daily driving) then your problems are worse than if you put in a loping long duration cam - in general... 11:1 is a bit high with modern gas. I still believe that 9:1 will give plenty of power if all the components are matched. Do check your timing. No more than 52 degrees total (vacuum + centrifugal + initial) or ping will be there....
Good luck!
Good luck!
Thread Starter
Instructor
Joined: Jun 2002
Posts: 176
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From: New Albany IN
Re: Engine Pings Under Load? (djcwardog)
To answer your questions. I do not have aluminum heads, I have the original double hump heads. The cam is a Lunati P/N 00010, advertised duration intake 292 exhaust 292, valve lift intake .480 exhaust .480, cam lift intake .320 exhaust .320. Timing 12 degrees BTDC @ 800 rpm. It runs good at these settings and dose not ping when I mix the 93 and 109 octane fuels. I just need a way to boost octane when on the road.
[Modified by Raydon 3000, 9:25 AM 10/22/2003]
[Modified by Raydon 3000, 9:25 AM 10/22/2003]
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Michael S. Palmer
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Engine Pings Under Load? (Raydon 3000)
.320 X 1.5 = .480 Your rockers are standard 1.5 ratio. For years I ran double hump iron heads with high 10/1 compression. For years I ran octane booster and found Moroso 104+ or methanol to be the best.
That was until I learned a few things.:) Lt1er is right - It's allot cheaper to recourve the ignition advance. Run an adjustable vacuum advance canister right off the full vacuum so you timing drops out at the hit of the throttle. Go to higher overlap cams to bleed off pressure.
I never use octane booster and I'm now running a true 11.2/1 with aluminum heads and thermal coated pistons.
That was until I learned a few things.:) Lt1er is right - It's allot cheaper to recourve the ignition advance. Run an adjustable vacuum advance canister right off the full vacuum so you timing drops out at the hit of the throttle. Go to higher overlap cams to bleed off pressure.
I never use octane booster and I'm now running a true 11.2/1 with aluminum heads and thermal coated pistons.
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
Re: Engine Pings Under Load? (Chuck Harmon)
I have been extremely disapointed with every fuel additive except one, Lead Supreme 130. It works for my 12:1 L88 on the street. Check the web site below.
http://www.kemcooil.com/product_info.php?pId=61
Chuck
http://www.kemcooil.com/product_info.php?pId=61
Chuck
[Modified by pws69, 11:31 AM 10/22/2003]
