got pinging

[Nacho-RT74]

yeah what you heard after try to get quench to save that, by machinist incompetence it wasn't posible to get the perfect quench so, now I'm into the pinging world.

what to do about that ?

timing its at around 15º iddling at around 850-900 RPMs ( needs to be revised because was jumping and I forgot to unplug the vacuum advance when put the lamp ), and MP dist adjusted to 20º degrees mechanical.

[maxwellwedge]

Try adjusting the vacuum can.

[Chryco Psycho]

Where is ti pinging [rpm range] ?  If it si down low you need a longer timing curve with idle closer to 12* & total around 36*
if it is around 200 don't change the curve just back the timing back 2*

[BSB67]

What heads, and what spark plugs?

[Nacho-RT74]

NGX V power plugs X5, 452 heads. 95 octanes gas ( if is true what is being sold here is 95 octanes ). The "quench" must be around 50-60 maybe some more in some pistons ( decking was not made flat, more with a slope )

I haven't certainly verified the RPMs when it happens because when I heard it I'm over 80-90 MPH cruising and I have the tach below the dash frame, on that moment I keep my eyes watching the road, but sure it's over 3000-3500 &/or giving full throttle

[BSB67]

NGX V power plugs X5, 452 heads. 95 octanes gas ( if is true what is being sold here is 95 octanes ). The "quench" must be around 50-60 maybe some more in some pistons ( decking was not made flat, more with a slope )

I haven't certainly verified the RPMs when it happens because when I heard it I'm over 80-90 MPH cruising and I have the tach below the dash frame, on that moment I keep my eyes watching the road, but sure it's over 3000-3500 &/or giving full throttle

If it only pings under WOT conditions, it could be fuel delivery, or lean carb.

Put a 160 T-stat in it.

Put NGK R5670-7 in it.  They might be a bit too cold.  If so, back down to -6s

Disconnect the vacuum advanced to see if that helps.  If yes, Do the timing stuff already mentioned

[flyinlow]

NGX V power plugs X5, 452 heads. 95 octanes gas ( if is true what is being sold here is 95 octanes ). The "quench" must be around 50-60 maybe some more in some pistons ( decking was not made flat, more with a slope )

I haven't certainly verified the RPMs when it happens because when I heard it I'm over 80-90 MPH cruising and I have the tach below the dash frame, on that moment I keep my eyes watching the road, but sure it's over 3000-3500 &/or giving full throttle

I thought they where using high octane fuel from switchgrass alcohol in Venezuela? If so even though the octane is high .with a a high percentage if alcohol it might be leaning out?


I am glad you are keeping your eyes on the road at 80 mph. I wish more of the drivers around here would do that.

[Nacho-RT74]

we don't have bio fuel down here... yet, pure OIL Gas only, unleaded

[firefighter3931]

It sounds like a potential tuning issue ; too much total advance. 

I'd verify the total advance and see what rpm it's coming in at. Shoot for 36* total @ 3000 rpm and see how it responds. The 282HDP cam will like 16* at idle.

I'd be interested to see what the cranking compression #'s look like....do you have a compression tester available ? 


Ron

[Nacho-RT74]

matematically goy AVERAGE 10.25 CR... and I say average because the bad decking job I got, with an around 13-15 cents of heigh diff between rear and front of both decks, being the center pistons just right at 0 deck. ( planing to fix that maybe in 2 months )

Now, a PSI test on cilinders, not yet but planned

What surprised me is how easy the starter motor cranks and turns the engine. I though it was to be harder with this CR... true my starter motor is a late 70s starter, with a gear reductor at armature, and matched parts of course for the gear reductor. Big fields too.

As Chryco suggested same as you I went more les with what you said. 14-16º initial, plus 20º mechanical on the MP dist with purple and orange springs ( look at PDF ) as first experiment... which does look not to be the correct spring set to get 36º at 3000 RPMs ?

http://www.jegs.com/InstallationInstructions/600/650/650-29014.pdf

which one would suggest ?

if what I got is too much totall advance able to cause the pinging, then the 36º at 3K sounds even worse than what I have, not?, unless the deal is at the inital timming being badly set

[firefighter3931]

Natcho, you need to figure out how much mechanical advance is built into your distributor and tune from there. For example ; if your distributor has 24* mechanical advance...that will leave you with 12* of initial timing at idle. You can rev the engine up to 3500 and set the timing at 36* then let it return to idle and check the timing. The newer MP distributors have adjustable slots which limit mechanical advance which allows you to run more initial timing if your engine combo wants it.

Some engine combinations like lots of initial timing to clean up the idle and improve throttle response.

Based on the chart you linked to i'd try the spring combo that yields a 3000 rpm total advance and if that doesn't stop the ping then go with the orange/purple springs and try again.

I mentioned the cranking compression test because if the engine is making 165psi or less cylinder pressure then it should run fine on high octane pump gas 


Ron

[Nacho-RT74]

will work on the Compression test.

my MP dist is already set at 20º degrees. I made the slot work with the MP curve advance adjuster kit setting it at 20º based on 16º initial I was to set ( and did ) by CP suggestion ( same suggestion you did ), to get 36º... true that the springs setup I set shows 36º is reached noticeably higher than 3K RPMs, what it looks will have to reset it.

What still dunno is if using double stage or single stage setup diagrams.

notes: Without a lamp, since I don't have access easily to one ( yet, since TODAY decided to get one... equus 3568, but will arrive in a month and a half maybe ), I got back the dist a few grades, and now cruised my car again. I could not reach more than 3700-800 RPMs due the traffic at local highway, but got not pinging on this test. Did get pinging still at WOT, around 3K RPMs

[firefighter3931]

Did get pinging still at WOT, around 3K RPMs

That sounds like a lean condition....it probably needs more fuel at WOT  

The timing at 16 initial with 20 mechanical for a 36* total should be fine assuming you're not making too much cylinder pressure.

A chassis dyno with a wideband o2 sensor would tell the whole story    Ideally you want to be in the high 12's - low 13's A/F ratio  

Have you made any jetting changes from the old 400 to the new stroker ? The bigger motor with more cam is going to want more fuel/air 


Ron

[Nacho-RT74]

my carb is suposselly originally for 440 ( TQ 6322 ) with its original jets. Considering what I have now is not more than a 440 overbored, Do you think is necesary ? I have some metering rods around to suit if needed.

Will grab rods PNs.

Just bought a compression tester locally, cheap but being I won't be using it constantly I think is enough... lets see when I can make the test

[MSRacing89]

IMHO, if it is a true 10.25:1 motor, the XR5's you are running would be a bit on the hot side.  I have a 10.9:1 aluminum headed motor with NGK 7's in it.

I would think you should be looking at NGK 6's or even 7's if you can get away with it.  I would say XR5 would top out at the 9.8:1 to 10:1 range.

[67Charger440]

Don't be afraid of less timing...  My 496 stroker picked up nearly 14HP by backing down from 35° to 30° total.  I run 10.44:1 with Eddie RPM heads on 91 octane pump and put out a shade over 640HP.

[Nacho-RT74]

ok, I got a new one. Today went to a close city, 60 miles from home, its a beach city, so of course, sea level. I live at 1000 meters above the sea ( thats around 3K feet I think )

well... the pinging threshold went down to around 2200 RPMs just cruising... no need to WOT to get pinging.

then returning to my city got pinging all the way up... of course I stopped to give gas as soon I heard the pinging. MAGICALLY arrived to my city and the pinging went out!

needless to say that going down to the sea level never needed to give gas due the slope is pretty much enough to simply let the car running down by itself, so I noticed the pinging when went flat on the road again at sea level.

I haven't modified anything on my car yet beside just step back a little bit the initial timing I set as mentioned earlier. I'm right now maybe around 12º. I don't have lamp, but pretty sure I'm around that.

[mhinders]

To me it sounds like you may have a lean condition...higher air pressure at sea level forces more air into the engine, leaning out the mixture.

[Nacho-RT74]

getting closer to the problem then HUH ?

[firefighter3931]

To me it sounds like you may have a lean condition...higher air pressure at sea level forces more air into the engine, leaning out the mixture.

It sounds like the motor wants more fuel based on the driving observations. 

How do the sparkplugs look ? 


Ron

[Nacho-RT74]

haven't removed yet.

rods change should work, right? maybe some float adjustemt too ?

[flyinlow]

Rod changes will make modest changes in the primary bores mixture. You can adjust the rod step up screw to make small adjustments to the part throttle mixture.

No rods in the secondaries. You can make some changes by bending the secondary air valve stop. Adjusting the valve slightly more towards closed will increase the vacuum signal to the fuel tubes and richen the mixture. Make sure you are correctly adjusted now for a base line.

Jet changes would be next. Of course check the float level first.

I have a wide range Air/fuel ratio gauge on my 440. With my Thermoquad it runs about12:5 A/F ratio at wide open throttle. I live 300 meters above sea level.

I did find that after about 10 seconds of WOT the mixture would suddenly go lean. I put larger needle and seats in, fixing that problem.

[FLG]

Nacho...curious, but why not run a nice holley or proform dp'er it will outperform the TQ easily.

[Nacho-RT74]

flyinlow I'm not sure what are we calling jet, seats and needles... pics of those parts please.

secondary air valve is definitelly something to check however that should be just when WOT. Maybe also tighten up a little bit the spring ?

Frank, I wan to keep my TQ as far is posible

[flyinlow]

Not good pictures . Secondary jets.