[Joshua Lee]

[Joshua Lee]

All the combustion chambers looked like this:




Plugs were the same color why this color??

The bottom of the carb, top of the spacer, inside of the nitrous plate and the intake runners were this color:






Ideas?

[Joshua Lee]

up

[BogiesAnnex1]

Originally Posted by Joshua Lee

All the combustion chambers looked like this:




Plugs were the same color why this color??

The bottom of the carb, top of the spacer, inside of the nitrous plate and the intake runners were this color:






Ideas?

Reversion! You're see back pumping of the intake charge and its lightly coking the exposed surfaces, or an intake is/was leaking a little and the combustion gases are blowing back up the intake.

Bent valves are almost always a problem of the springs loosing control (surging) which could also be part of the reversion problem seen with the intake. This problem can be very complicated involving push rod bending, rocker studs weaving around, rockers bending or not tracking straight, as well the the expected issue of the spring loosing control for a host of reasons.

Some solutions can be 3/8s push rods even composite designs if you can afford it. The use of 7/16 studs with a girdle. Stainless roller rockers for additional stiffness and better tracking. Raised end guide plates to control the push rod higher up to the rocker so there are less angularity problems between the rocker and push rod. Additional spring pressure, though make sure you have adequate damping of the spring first before adding stffness, reduced weight of the retainer and lock assembly. Proper alignment of the push rod thru the rocker to the valve stem; the pushrod working at the slightest of angles is a reason for it to bend; in bending it acts like a spring becoming longer or shorter at a frequency that probably has nothing to do with the timing of the opening and closing cycle of the cam. Bronze guides or an alloy thereof are very helpful to insure that the stem and guide run tight without binding, cast iron against the stem often results in a loose clearance that lets the valve "orbit" and encourages grabbing the stem in the guide; always use a good hard chrome stem valve.

Anyway this can go on for a long time.

Bogie

[Joshua Lee]

damn.... lol so basically im screwed? lol... What would be your 1st step?

[RexRat]

Less cam. Hell, I run similar numbers in a 454 with 10-1 comp and a 800cfm Q- Bog duel plain manifold with 124cc chambers. And it's a monster 500ftlbs tq
Yes it pissed me off, but while scoring some quality time in a dino cell a guy (smart) was running impressive numbers (mouse 700 hp naturaly aspirated). He took the carb off for a swap and wouldn’t you know it he had filled half of his plenum with epoxy!!! He broke it down for me with one word VELOICTY!!!
Lift and lose

[Rick WI]

If it's reversion why do the intake runners look clean, at least in the picture they do apprea quite clean?

That whole head surface and all the combustion chambers basically look kind of like a mess. With nitrous being way too rich can be as bad, or worse as being too lean.

I would most certainly inspect all the pistons looking for crushed skirts and ring lands. I'd also measure the bores. I'd suspect your rings are shot as well. Just a guess.

When you have the heads rebuilt you really need to clay the tops of the pistons to check PV clearance.

[Joshua Lee]

It's all motor.... No nitrous being used at all yet.. Pistons are fine and rings all are within 10psi

Would driving down the track after that valve bent cause the black in the carb & spacer?? Since it was the intake valve the exhaust would be going up inside the intake correct?

The P-V clearance is great... With the bent valve it still didnt hit, lol..

Ok ANYBODY have a guess at why the combustion chambers and plugs are light tan/yellow??? It's 104 unleaded fuel if that helps!

I APPRECIATE THE HELP GUYS!

[nitro_baller4692]

Pistons are fine and rings all are within 10psi

is this before the bent valve?
can you post a pic of the piston?

[BogiesAnnex1]

Originally Posted by Joshua Lee

It's all motor.... No nitrous being used at all yet.. Pistons are fine and rings all are within 10psi

Would driving down the track after that valve bent cause the black in the carb & spacer?? Since it was the intake valve the exhaust would be going up inside the intake correct?

The P-V clearance is great... With the bent valve it still didnt hit, lol..

Ok ANYBODY have a guess at why the combustion chambers and plugs are light tan/yellow??? It's 104 unleaded fuel if that helps!

I APPRECIATE THE HELP GUYS!

Yes

Bogie

[Joshua Lee]

Yes, before I bent the valve and there is no way to tell now unless I pull the short block and that isnt happening...

The piston had a VERY small scuff and after I cleaned the carbon I could BARELY see where it hit...
I know what a broken piston looks like... Mine are ok unless your going somewhere with this and then I will post up a pic to satisfy you..

[Joshua Lee]

Originally Posted by oldbogie

Yes

Bogie

then Im not worried about the black... I drove (idle) all the way down the 1/8th without the valve hitting the piston, lol.. I have a lot of room w/ 9:1 pistons and 68cc heads... trust me

What about the color of the plugs bogie? any idea? looks to ME like burnt water?

[tdkkart]

What were you running for fuel?? That color in the chamber is not all that unusual for some race gases, especially if it's leaded fuel. Might be a bit rich but that's all.

Reversion is not at all uncommon, and will happen in a perfectly functioning motor. It's a combination of things, intake and exhaust timing, pulse waves bouncing back through the cylinder from the exhaust, which will end up in the intake if the pulse arrives in the cylinder during overlap.

You definitely have a valvetrain issue to solve(weak springs), but the reversion probably has little to do with it.

[nitro_baller4692]

i thought the same about the water but if you had alot of carbon on the piston i would rule that out,also it would have to of been burning in all cylinders from the way it looks to me.

[Joshua Lee]

I run 104 unleaded Sunoco fuel

So the yellowish color is from the race gas? If so then Im not worried but the plugs are usually brown/black and now they are white/yellow?