Had the engine rebuilt to try to get rid of the pinging but it’s still pinging so I change the camshaft and it still pinging do anyone have any answers to what I need to do to get rid of the ping

 

Do you use 93 or better octane gasoline ?

 

Welcome. I'm afraid we'll need a lot more info than that to provide a useful answer. What were the rebuild specs? What pistons? What heads? Were they milled? What head gasket? What cam? What distributor? What is the initial timing? What is the advance curve? When does it ping - under heavy throttle, part throttle, light loads? What carb? Do the plugs look lean?

 

He is right! Can't help tell we know what's been done.

 

There are a lot more learned guys here than me and they're spot on with their questions, but I'd start by getting some octane booster and dump a bottle or two in the tank just to see if that helped.

If octane booster helps, at least you know the engine can run without pinging, but that stuff adds up fast at $10/bottle or so.

Next try turning the timing back on the distributor. Looking at it from the top, turn it counter-clockwise. Just go incrementally one degree or 2, then drive it. Be aware that this may cause the engine to run a bit warmer.

 

I'm guessing you are either 10.25 :1 or 10.50:1 compression ratio which requires high octane gas. In my experience even 9.00:1 doesn't like regular gas from this era.

This is key, and as has also been posted octane boosters are a must. Assuming you want to get pinging reduced without going into engine again. With that said Lucas 3X booster works well for me ! I've also been told Royal Purple Max Boost is phenomenal but i have never tried. Keep in mind the booster will need to be added every tank full if you are high compression and stock timing for best results.

 

I can’t tell you what they put in there they gave me a piece of paperwork 40 pistons 10 rods10 Main Engine master kit number GK 424 Still was pinging talk to Montebello twister they told me to get a 45° cam which I put in still has the ping also what is the temperature should the engine run at i’ll try the octane booster to see if that helps it just doesn’t seem like I can get it on the correct time I have a 600 holly carburetor in it

 

Sorry, but you need to provide more info to get useful answers. Otherwise everyone is just guessing. 0.040 over pistons are not uncommon, but what matters is the specific part number and size of the dish. Ultimately we need to know the exact compression ratio, which means the size of the piston dish, the thickness of the head gasket, and the volume of the combustion chamber. As for the 39 deg vs. 45 deg cam, a 425 block could have come either way. Swapping the cam without knowing EXACTLY which block you have is a waste of time and money, and has as much chance of making things worse as it does of making them better. What distributor? What timing? What advance curve? Ported or manifold vacuum? And sorry, but a 600 cfm carb is too small for a 425. If the carb is running lean, that can cause pinging also. Who suggested using a carb that small? It sounds like you potentially have a bunch of mismatched parts.

 

[QUOTE=Gary Ward;1199284]talk to Montebello twister they told me to get a 45° cam which I put in still has the ping [QUOTE]
Mondello Twister ? That may explain a lot .

 

[QUOTE=Charlie Jones;1199321][QUOTE=Gary Ward;1199284]talk to Montebello twister they told me to get a 45° cam which I put in still has the ping Mondello Twister........UGH !!!!!!!!!!
I have a 1966 Toronado with a 425 and I don't have any problems and I run it on 93 octane pump gas. It has the original Quadrajet and the engine has never been apart.
The car painter loves driving my "Toro". He wants to finish so we can take it out on the street and SMOKE the tires (tire).

 

Thanks a lot Joe I appreciate all the information I restored a 1955 Chevy truck that was my dad and he had put the 425 engine in it and I was just trying to keep it the same way had the engine rebuilt and put it back together and now trying to dial it in and can’t get it to.

 

Joe Quick question what size carburetor do you think I should put on here

 

750 CFM would be a better choice.

 

Hey Joe I Disconnected the vacuum advance on my distributor and a truck ran great had plenty of power but when I try to step on it it started to ping then once I got off the gas pedal it stopped could it be that I have the wrong distributor in here

 

You need to bump your distributor back a couple degrees (retard the timing) to see if that helps.

 

Very doubtful; an Olds distributor is an Olds distributor. You just need to tune it appropriately as mentioned above.

 

Answer what you can. Without answers to these questions no one can answer yours correctly.

 

What temperature should the 425 Oldsmobile engine run at

 

180-200ish

 

Mines will go as high as 225 is that normal or too much I did have it rebuilt

 

Is that driving at speed or extended idling. With or without a/c? Either way that's a bit high. Did you get your pinging under control, and how did you do it? If you retarded the timing too much that could cause an engine to run hotter.

 

Do not have ac/ I kept messing with the timing and I also put octane booster in it but what I did that I think helped it was unhook the vacuum advance Went to the car show the other night on my way back coming up the hill I could hear a little bit of ping but not as much is it was

 

So where is your timing set now? Disconnecting the vac adv is a good idea until you get the mechanical timing in order.

 

7 1/2

 

7 1/2

 

Your still running points? Is your dwell at 30*? I know you added octane booster, but what octane fuel are you running?

 

Using a HEI distributor and 91 octane gas that’s all you can get in California

 

The engine is going to run like cahcah and it will run hot with an hei @ 7 1/2 BTDC.

 

Give me some feedback on what you think should be done

 

What brand and model HEI?

 

It’s a top street performance HEI JM6503BL

 

You need to see how much mechanical advance is built into the unit. You'll need a dial back timing light and a tach. Basically set the initial timing to 16*, run the rpms up and watch the timing light for when the timing stops advancing, note how much advance is showing when the timing stops and at what rpm it stops. Subtract 16 from the number you get from the amount of advance you got in the previous step.

If you can accomplish this, please post the results.
I read the instructions and they do not tell how much advance you get.
https://www.topstreetperformance.com...stributor.html

 

What I’m going to do is take it over to the shop and have them put it on the Dino and see if they can dial it in for me

 

Ok... let us know how it turns out.