still with pinging

[Nacho-RT74]

Ok here is the cranking PSI, with air purificator on it:

passenger side:
8-150
6-160
4-160
2-145

driver side:
7-155
5-150
3-150
1-140

the fronts being lower sounds pretty logic since remember my block is not squared, and pistons sits a bit lower from deck than the rest

what got me really concerned is I EXPECTED MORE compression, if engine is stroked... maybe closer to 170 ? tell me newbie if I'm wrong but I thought was to be higher because that. Shouldn't be that a true ? I remember my stock low compression engine and  cranking pressure when I measured was on 125-140 PSI rate

took pics of spark plugs, will post them later.

[BSB67]

The carb should be open when you do the test ( i.e. throttle plates open). You should do it again if you did not do it this way.

Being stroked has nothing to do with compression ratio, or cranking pressure.  Total volume at BDC divided by total volume TDC for the ratio.  Cranking pressure is a function of when the intake valve closes (primarily).

Here in the states, with those numbers, you would be able to run premium fuel and not have detonation.  What is your fuel octane and what rating method is used?

[Nacho-RT74]

Yes full throtle but still with air purificator. I wasn't alone, was with my mechanic and friend.

I requested to make it without plugs anywhere to make easier to the starter motor spin, then rechecked some of them with plugs and didn't got variation ( for example, number 6 with engine spining free and then with rest of plugs in place and both readings were 160 PSI )

I was wondering about why with 8 CR on my "old" stock engine with 3.38 stroke got up to 140 PSI ( true was the max reading ), and now with 10.2 CR on 3.75 stroke got also 140 PSI ( true on the lower reading )... shouldn't be more ?

I'm runing 95 octanes fuel... but now... ARE WE REALLY GETTING 95 OCTANES GAS ON OUR GAS STATIONS ? good question!!!

Stock 850 cfm TQ carb, Performer intake, iron 452 heads, ported and enlarged valves size

[Nacho-RT74]

here the plugs I'm running since thursday, NGKs 7

they are from left to right view, front to rear. The yellowish one is the number 6 ( so those 4 are passenger side )

all 8s looks really clean although maybe the pics doesn't show completelly clear, with just the number 6 exception getting that color shade

[BSB67]

I too would expect a little more from a 10.2 with the 282 cam.

The stroke has nothing to do with it.  It is the combination of the parts.

I see that the cam was not degreed, so you cannot determine where the intake valve closes.

How was the CR determined?

[Nacho-RT74]

maths...

[mhinders]

.....
I was wondering about why with 8 CR on my "old" stock engine with 3.38 stroke got up to 140 PSI ( true was the max reading ), and now with 10.2 CR on 3.75 stroke got also 140 PSI ( true on the lower reading )... shouldn't be more ?
.....

You cannot compare cylinder pressures in engines with different cams and settings. The cylinder starts building pressure when the intake valve closes.
The plugs look a bit too white for my taste, I would try with colder plugs. They can also indicate that the mixture is too lean.

[justcruisin]

I would expect your cranking compression to be higher. My stock stroke 440, 10.2:1 with a comp xe275hl which would have slightly earlier but comparable intake closing specs to your cam cranks at 180psi.

[BSB67]

maths...

Are you trying to be difficult???

What are the measurements/values?

Again, What is the octane rating method?

Anyways, it should run without ping unless the fuel quality is the problem.

If you presume that your octane rating is good enough to support 155 psi, then there is something else going on.  Someone mentioned the plugs look like its running lean.  This could be your problem.  Fuel delivery, or carb is too lean.  I would start with the carb.

[Nacho-RT74]

well, at iddle at least the exhaust fumes are really "spicy". It hurt my eyes and don't smell good. Exhaust tips are all black inside and around edges ( they were red ).... maybe could try the secondary air valve to get rich when cruising, and give a little bit to the accelerator pump.

octane method ? damn, I don't know.

CR was calculated with all the maths formulas link we have around... stroke (3.75 ), bore ( 400 +0.020 ), chamber CC ( 91.5 ), deck height ( think on zero deck, although deck is not squared really, but center pistons are zero deck ), gasket thicknes ( composite ), piston volume ( they are KB215, can't recall the quench step and valve notches specs ).

valves are 2.14 and 1.81

mhinder... the plugs are already COLDER than the stock engine should get... they are NGK 7, from NGK XR5 it had

yeap justcruising... I was expecting more like 170 PSI , so I could get something wrong there, right ?

[mhinders]

I'm confused, the plugs don't look anywhere near any rich condition.
Could it be that they get so hot, that all deposits collected at idle are burned off when you start driving?

[Nacho-RT74]

dunno really but you got a point. I don't understand a lean mixture and the spicy fumes... true that at iddle since I can't smell it driving LOL, but then the black exhaust tips gets me confused.

the "poor" PSI, could be because requires some extra adjustment/preload at rockers to get valves open propperly ?

[mhinders]

I don't know about the smell and black exhaust but to me the plugs indicate that the engine is running hot and lean...

[BSB67]

Exhaust tips are all black inside and around edges .... maybe could try the secondary air valve to get rich when cruising, and give a little bit to the accelerator pump.

Everything running on today's unleaded (here) leaves black residue on everything from the combustion chamber to the end of the tail pipe whether it is rich or not.

Adjustments to the secondary air valve will do nothing for cruise, and changing the pump won't help either.  The WOT position of the air valve will affect the WOT A/F ratio.  I would look first at float levels, jet size, rod size and proper step-up function of the rods.

TQ are a bit of an animal especially if you don't have a well documented starting point that you know works.

[Nacho-RT74]

I already installed the bigger metterings and jets availabe around. I have the numbers on another thread I posted about my TQ. will search for that. I have a little knowledgement about them, althought I'm not THE GUY who knows about how to get the best juice from them

I took a pic of my exhaust tip ( the only one left LOL ) to show the black look of . Will post later

[Nacho-RT74]

I have been playing with TQ links. Some were not right, the choke links related and secondary air valve. But I don't think these will make difference.

I remember I set the floats at 29/32" per demonsizzler recomendations

[Nacho-RT74]

( By now, got at least better choking LOL )

[BSB67]

I have been playing with TQ links. Some were not right, the choke links related and secondary air valve. But I don't think these will make difference.

I remember I set the floats at 29/32" per demonsizzler recomendations

But what did you set them at in the up position?

[Nacho-RT74]

you meant the floats ?

yes of course, with gasket on top plate and facing up, 29/32"

[BSB67]

you meant the floats ?

yes of course, with gasket on top plate and facing up, 29/32"

It does look like the 9000 series has a 29/32" recommendation to bottom of the float when inverted.

[Nacho-RT74]

mine is a 6322... although slightly modified on jets and rods...

I can't find where I posted the info about what I built with all the parts I found, but I built the bigger jets with what I had in hands from around 5 TQs I have laying around

[Nacho-RT74]

can bad adjustment metering rods cause pinging under described circunstances ?

I found my metering rod link was too low, and had to raise it up. On a rebuilding kit instruction sheet found the recomended distance from top of air valve must be 11/32" and mine was around 3 milimeters below that

[BSB67]

can bad adjustment metering rods cause pinging under described circunstances ?

I found my metering rod link was too low, and had to raise it up. On a rebuilding kit instruction sheet found the recomended distance from top of air valve must be 11/32" and mine was around 3 milimeters below that

If the rods were not stepping to the right height, and the thicker portion of the rod was staying in the jet, causing the primary to go lean, than yes.

[Nacho-RT74]

ok... dunno where I read ( I think an old instruction sheet ) I should get the rod link presssed up up to the max, then set the adjusting screw getting the link at the point don't move up down more, and get it 1/4 of turn back. Now I found this instruction sheet ( I have 3 diff instructions sheet from diff TQ rebuilt kits ) the rods links must be set at 11/32" from top of air horn, and from there adjust the rods for the mixture. That got me around 3 milimeters difference upper from the point I had the link set

[Nacho-RT74]

well after some more carb adjusting as you read previouslly, still with pinging. Diff conditions but still...

I can feel pinging going up hills. This time I was able to feel pinging at ONE SPECIFIC POINT of acelerator pedal. When I felt some harder the pedal, somekind of "step" I heard the pinging too.