full throttle pinging....., wondering...???? Options

[crash914]

Ok, When ever I go full throttle, I get a lot of pinging....

in first or second, I can full throttle, but have to shift fast to the quick revs.

under part throttle, I can spin up to 6500+ with no pinging or problems. I just can't floor it.

seems odd to me.

my afr is down around 11:1 at full throttle, so I am running plenty rich. I am running 93 octane, might have to add some xylene.

I am wondering if my throttle bodies are too large. I don't know if my air fuel meter can pick it up that quick.

I really notice it when I am in 5th gear and am pulling from around 2500 to 6500.

I do have a spare set of heads that I can get cut...

all right here is the specs...103 by 80. .125inch barrel shims gives me around .1" clearance and around 9.7 to 1.

megasquirted with twin weber throttle bodies and large injectors...

herb

[Jake Raby]

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This will give me something to do this winter.... I will have to pull the heads and get a good CC #.

What was the CC to begin with?

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It will be easy to reduce the deck height, I can just shave my spacers.

BUT doing so without dishing the ppistons OR adding ccs to the heads will BOOST CR even higher and will probably make the situation worse.

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I did not spend very much time on the heads...used, reworked big valve heads...

Big NO NO! Spend ALL the time and money on the heads!

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Jake, I think that we had a discussion on the valve size...you thought that they were too large. I was wondering if I needed more static cam advance...

The valves being too large can add to the problems you are experiencing

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Other than that, this thing kicks ass. revs and pulls fast. Just can't go full throttle.

BUT beware that ypu can still be damaging the engine EVEN IF AUDIBLE PING IS NOT HEARD! Pinging that can be heard is severe, inaudible ping is just as dangerous and is a silent killer.

I'd approach driving this one with extreme care, especially if its detonating @ 11:1 AFR.

Its all in the combo.