Pinging on Acceleration.

[az_rat210]

Ok, been meaning to ask this and never got around to it.

 

Year and half ago, I developed a head gasket leak and had to pull the head and fix it.  A15 with H89 A14 Head, Weber 32/36 DGEV.

 

I had no pinging issues prior to  the head gasket replacement.  After the head gasket replacement the car pings on acceleration but ONLY when it has reached full operating temperature.

 

The distributor is properly aligned, timing is good, vacuum advance works fine.  I replace gaskets for the carb to intake twice a year (the adapter screws like to loosen up).  Plugs are good, gap is at .035 per manual.

 

The car runs fine, the pinging is not major, and only happens for a second or 2.

 

Ideas, Thoughts?

[banzai510(hainz)]

try retimming it to less of BTDC

[G-Duax]

Buy better fuel.

[noramost]

Might have milled too much off the head, limit was .005 and raised compression ratio, switch to premium.Remember when the A14 was created they recommended regular 98 octain or higher, now things have changed. I wonder if you can still buy a thick copper head gasket  too lower compression. Set your total timing to 32 if it pings at 32 your compression is probably over 150lbs. You might be able to still get dished pistons. Retarding timing adds engine heat and lowers HP which you have none to spare with the A. Water injection also works but crude and ugly.

[skyblue]

yes, retard timing, or bump up fuel to premium.

[Doctor510]

Check that your total timing isn't reached too soon, 2,800 RPM is a good sweet spot

[wayno]

Try a degree or 2 less advanced, if you cannot get it to stop then you will need to either buy better gas or re-curve the distributor.

[az_rat210]

Thanks all, I don't remember if I retarded the timing or not as a test.  Will give it  shot and then try higher octane.  It is possible I shaved the head too far.  Makes sense.  I actually thought of that after I had done this post.  Funny how asking for advice helps get the brain juices flowing.

 

Will see how it goes and let you know.

[G-Duax]

"helps get the brain juices flowing."

 

Funny how that works.

Also funny, that some people get pissed off when you suggest something to them.

[datzenmike]

A12 head gasket by mistake. Fire ring is exposed and gets hot enough to become an ignition source.

 

Head/block dowel is missing and gasket is skewed doing the same thing.

 

If compression did go up try a heat range cooler on the plugs.

[distributorguy]

Pinging or detonation is caused by extreme hot spots or by incorrect timing (too advanced).  Sharp edges from the recent head shave could be a problem, higher compression ratio by changing heads, thinner head gasket, or if you really screwed up and the gasket is skewed, you likely would have other problems.  

 

When does it ping? 

1.  Only from 2500-3000 rpms under hard acceleration?   Then backing off the timing a couple degrees will help, but getting the advance mechanism inside the distributor fixed will solve the issue.  

 

2.  Any time you lightly accelerate?   Try running with the vacuum line pulled off the distributor and plugged.  The diaphragm may be leaking, which leans out the mixture and creates hot spots (detonation).  

 

3.  All the time?  Then maybe something went wrong on the reassembly.  It'd be time to go over every step beginning to end.  

[racerx]

What's ur timing?

[noramost]

A12 head gasket by mistake. Fire ring is exposed and gets hot enough to become an ignition source.

 

Head/block dowel is missing and gasket is skewed doing the same thing.

 

If compression did go up try a heat range cooler on the plugs.

Good advice BP6ES if you are running electronic distributor -II wider gap plugs 

[noramost]

Check that your total timing isn't reached too soon, 2,800 RPM is a good sweet spot

Doc has a point, he also has a friend with an old Sun Distributor Machine that might be able to re-curve you dist around the ping. Barrow a portable tack-dwell  machine, record the ping RPM and talk to Doc. If I remember rite the A-14 head runs the vacuum advance through wax filled switch that only allows the vacuum advance to work when warmed up which would enplane the only when hot thing. It's possible even though you probably have 10:1 compression now with a milled head, switching to high-test, running a cooler plug and re-curving your distributor you can tune around this issue. And dont run an A-12 head gasket, that is a noise you will never forget.

[noramost]

How I sopped my ping – In 1977 I was working for ABC Datsun in Phoenix when the King-Cab came out, my legs no longer touched the steering column so I bought one, canary yellow with a hounstooth  butterscotch and yellow seat inserts. I installed AC, radio and a step bumper and they made Steel-Stream campers down on Grand Ave so I got one and put in a carpet kit we could get at the time. I realized 5th gear was a down hill only gear so I installed a turbo. In those days I had to make my own manifolds. The stock carb wasn’t big enough so I ended up using the biggest SU  I could find off a Jag XKE, it did everything I wanted  and I could use 5th gear. I had a friend with 3 beach houses in San Carlos Mexico near Guaymas so I drove down a lot to help him remodel but my pickup would ping on the Mexican fuel, I found out adding a ½ pint of Bacardi 151 Rum to my tank stopped the ping.

[G-Duax]

The bull-shit meter just pegged.....

[skyblue]

hahaha wtf?

[wayno]

The tank he is talking about is his stomach............

[datzenmike]

I just turn the volume up.....

[racerx]

Sounds like that MSA exhaust popping

[noramost]

You Kids….. Don’t know your auto history! Old guys like Doc and I should call you the Over-Head-Cam-Generation. In the old days, back when they first came out with Flat-Head-V8’s, before NASCAR, before oversize exhaust, before cardboard, the vary first performance part was Shine. The best was called White-Lightning; the Moon-Shine Runners would pull a qt Bell-Jar of White-Lightning out of a wooden box, pour some in their tank and drink the rest. Those days, mostly dirt roads, the cops drove cars with long stroke in-line engines to torque through the mud and with the wash-board dry dirt conditions most people drove around 25-45 then the Shine Runners found out they could glide over the bumps and drifting through the curves doing 45-65 with their V8’s and outrun the law. Henry Ford even offered a still as an accessory for the Model-A if you lived in the Corn Belt. Alcohol has always been used now they call it ethanol. In the 60’s we used to take a date to the drags, the cars all used alcohol and as a teenager we would get a buzz just walking around breathing the air, we thought the buzz might turn a No into a Maybe. At the circle tracks they always had Shine around for medicinal and mechanical purposes, we even cleaned our carbs with it, the Shine has now evolved into barrels of racing-fuel.

 

You might do a Google Search on things like

1. Flathead V8’s
2. Henry Ford
3. When girls said no

[racerx]

Who u calling kids? I'm 57

[distributorguy]

And I drive an old Willy's pickup with a Flathead Ford motor in it.  Did you know that the Ford engine bolts directly to the early Willys transmission???

 

I also know that if you dump pure alcohol into modern fuel, your mixture will go lean, you'll burn valves, and it may not ping but it will likely detonate - whether your old ears can hear it or not...  Its not a viable option unless you plan to specifically jet for that blend.  Alcohol jets are roughly 40% larger than gasoline jets.  

[noramost]

Who u calling kids? I'm 57

If you ware your baseball cap backwards - you are a kid

[datzenmike]

Pure alcohol also needs extreme compression to extract the most energy from it. It also is extremely high octane rating.