Pinging 505 help

[murfman]

Hi all,
I’ve been racking my brain and trying everything I can think of but my 505 build pings pretty good under load. The motor only has 1500 or so miles on it but the issue seems to be getting worse as it gets driven more. Here’s the list of things I’ve tried:

- I have a Wide Band O2 gauge that shows 10-11.5 under load and the plugs also show no lean conditions. Rejetted the carb every way to Sunday.
- Tried 110 VP race fuel. This did quiet it down a lot but it was still there under heavy load. Normally I run 93 with a mix of 100LL AvGas
- I backed the timing off considerably and limited the overall advance to 18 total (starts at 10 goes to 28) with the heaviest springs. It has an MSD ProBillet distributor and a 6AL box
- Took the PCV system off and replaced with a couple breathers on each valve cover
- Checked for vacuum leaks with a smoke machine. Capped off everything. No heater controls, not power brakes, no PCV.
- Pulled the heads and had them checked. No issues found
- Lowered the compression from 10.5:1 to 10:1 with thicker Cometic MLS head gaskets.
- Reset the cam timing to straight up.
- check and rechecked valve preload.
- tried colder spark plugs

Details of the engine build are as follows:

• 77 440 RV block bored, clearanced and checked by LRB performance in Franklin, NJ
• Edlebrock RPM heads (60185) w/ 88cc chambers
• Eagle Competition Rotating Assy (B21202030) stroker crank, rods and pistons
• Mahle BBM475350F08 pistons (part of the Eagle kit)
• Comp Cams 23-712-9 hyd roller cam and lifters (Duration 286/294, Lift .544/.541)
• Hughes 1.5 roller rockers
• Edlebrock RPM air gap intake manifold
• AED 950 carb
• TTI 1 ⅞ headers
• Edelbrock Performer RPM Street Fuel Pumps 1723
• All ARP hardware

Some other symptoms I’m seeing that may or may not be contributing factors

• Coolant keeps getting dirty/muddy. I flushed the block several times but it keeps coming back. Tested for combustion gasses in coolant but it showed none. No water/coolant in the oil.
• Blow-by over 3k rpm. This is tested under no load. I don’t have a dyno so it’s really hard to test this under load at any higher rpm
• Scoring on the lower cylinder walls at the 12 and 6 o'clock positions. It’s not very deep although I can feel them with my fingernails but not catch on them.

I have a complete handwritten list of all the assembly measurements I checked as I built it along with the cam card that I’ll try to attach here somehow.

Any advice would be appreciated.

Any updates?

 

[PeteyDaMan]

I sent it off to a dyno and them them tune and run it. They detected no pinging at all so it isn't the engine. I put it back in the car and while I still hear the noise I'm looking for other sources.
It could be the exhaust cutouts, throw-out bearing, random rattling or vibration, who knows.
All I care about is having fun with it now without worrying about damaging it.

 

[beanhead]

Agreed, which brings us back to the fact that it may not even be engine ping that the OP is hearing....

In other words, it's worthwhile IMO to take the necessary steps to be certain it really is a pinging problem before resorting to doing things like pulling the engine!

 

[PeteyDaMan]

I'm not sure why everyone thinks pulling the engine is a big deal? It's an hour, tops.
I like working on my car. It's fun to turn wrenches. I've done it for my entire life and plan on doing it for whatever time I have left.

Next step is to pull the trans so I can put on a scatter shield and replace the throw out bearing.
Once I get that done, a call to Dr Diff to get an S60

 

[padam]

I'm not sure why everyone thinks pulling the engine is a big deal? It's an hour, tops.
I like working on my car. It's fun to turn wrenches. I've done it for my entire life and plan on doing it for whatever time I have left.

Next step is to pull the trans so I can put on a scatter shield and replace the throw out bearing.
Once I get that done, a call to Dr Diff to get an S60

That S60 is the best bargain going.

 

[Bee1971]

Hats off to the individuals who said it wasn’t pinging early in this thread , and to look elsewhere
Great responses

Thanx for the follow up after the results

Now find the issue LOL Let us know if you do

Peace

 

[6PKRTSE]

I have the exact camshaft degreed in as the o.p. has in my 440 Sixpack engine with reconditioned iron 906 heads with 10.75 compression, and I run it on pump gas 93 with no issues. I have over 60,000 on it now.

Every once in awhile if I get fuel at a lower named station I might get some pinging under a slight load, say from like a 30 roll if I tip into it, but not hard enough to have it kick down. Get fuel from somewhere else next time and it goes away.

 

[PRHeads]

I sent it off to a dyno and them them tune and run it.

Let’s see the sheet!!

 

[66 Sat]

I'm not sure why everyone thinks pulling the engine is a big deal? It's an hour, tops.

Petey, if you're pulling the engine in 60 minutes  max then you are indeed the man.

If everything is already set up, engine crane, lifting chains & bolts, engine stand, every tool you're going to need, then maybe the physical job of pulling the engine takes an hour. But there's no way I could do it in that time, it's a half day operation easy, just in preparation time. If the transmission is staying in the car, then just jacking up the car and unbolting the starter can take me an hour, by the time I climb under, position myself to get access between the headers...and then realize I have the wrong socket.

The last time I reinstalled my engine I dropped it in in about 40 minutes, had lunch, and then spent 2 days connecting everything back up and putting all the tools away.

 

[68 Sport Satellite]

I sent it off to a dyno and them them tune and run it. They detected no pinging at all so it isn't the engine. I put it back in the car and while I still hear the noise I'm looking for other sources.
It could be the exhaust cutouts, throw-out bearing, random rattling or vibration, who knows.
All I care about is having fun with it now without worrying about damaging it.

when I had pinging with my motor before, I swear I could also feel it in my foot when I put the Go pedal down. Can you feel anything or just hear it?

On my car, I had pinging until I reduced overall timing to 32 total (low deck B motor that runs great). Once at the track on the 2nd run I had pinging at WOT. I had 5 gal of 110 mixed with 5 gal of 91. That's strange..I checked the timing and the hold down had come loose and instead of 32 total I was at 40-something total. Re-set timing and locked it down and all was good.

What about the blow-by comments? It still seems like something may not be right, but what do I know?

 

[68 Sport Satellite]

I only read post #1 because the clue was there: blowby.

Rings not seating, lets oil into chamber which reduces the octane rating of the fuel.

Was this engine run on a dyno to 'seat' the rings?
Wrong oil for break in can cause bore glazing...which causes the above. It is very hard to see with the naked eye.

Is there any evidence that this is NOT occurring?

 

[PeteyDaMan]

when I had pinging with my motor before, I swear I could also feel it in my foot when I put the Go pedal down. Can you feel anything or just hear it?

On my car, I had pinging until I reduced overall timing to 32 total (low deck B motor that runs great). Once at the track on the 2nd run I had pinging at WOT. I had 5 gal of 110 mixed with 5 gal of 91. That's strange..I checked the timing and the hold down had come loose and instead of 32 total I was at 40-something total. Re-set timing and locked it down and all was good.

What about the blow-by comments? It still seems like something may not be right, but what do I know?

It did need a re-ring as they never seated properly.
they also layed the cam back a few degrees among a few other things.