Sputter, sputter

[dwleo]

Hi again,
As I get ready for my inspection on Thursday, I have been driving it around the neighbourhood to get used to it and to see if there are any other problems.
When applying throttle from idle, in gear, it would sputter a bit so I would give it more fuel and away I go - a bit quicker than I would like.
I have not allowed it to die during the sputter but it seems like it would. There appears a starvation for fuel at idle. I still get popping from the pipes until it is warmed up and, once warm, no popping.
I adjusted my mixtures on the Quickslayer 650 to 1 + 1/4 turns and the plugs are staying clean. My vacuum is 12.
The idle, when warm, is about 700-800rpm. This is on a 350 sbc with a th350 tranny. The cam is a bit above mild but no where near crazy.

Any ideas?

- Daryl

[Indycars]

Start with the basics!
Have you check your timing? Initial and total? At what RPM do you reach total
advance? You might even need to verify TDC to make sure it’s correct on the
balancer. If it’s not right then none of your numbers are right.

Are the float levels are correct?

Is the transition slot adjusted correctly? If it’s not correct, then you will be
chasing the wrong problem. Many times with a more radical camshaft the idle
has to be set higher for the engine to idle without dying, but then the transition
slot is open too far. You will have to pull the carburetor off to check this
adjustment, since it’s viewed from the bottom side.

http://tmpcarbs.blogspot.com/p/blog-page.html

ExcessTransitionSlot.jpg (81.75 KiB) Viewed 557 times

CorrectTransitionSlot.jpg (81.02 KiB) Viewed 557 times

Buy a couple of books and do some reading.
https://www.amazon.com/Build-Power-Holl ... tor+tuning

https://www.amazon.com/Holly-Carburetor ... tor+tuning

https://www.amazon.com/Holley-Carbureto ... tor+tuning

[dwleo]

Interesting. I will definitely consider this.
But I took a step back on this project. I pulled the plugs all were looking good except a bit of darkness on #3 and #7. Because the damper and pointer were new, I reaffirmed TDC (I was out a little). Found a burnt plug wire as well.
Later today I will check the valve lash especially on 3 & 7. and reset the timing again.

[Indycars]

Let us know what you find out!

[dwleo]

I think this is where I start getting a problem.

I just adjusted the lash for all cylinders. TDC, tighten until no spin on pushrods, tighten 1/2 turn to preload and lock down. Move on to the next in firing order. After I finished all cylinders I went back to #1 on curiosity. TDC and I could spin the pushrod - not easily but still could. My normal inclination is to re-lash it again but I don't think so.

Am I wrong?

[Lee in KC]

Assuming you have hydraulic lifters they will bleed down to relieve the half-turn past zero lash spring pressure. This is normal.

[dwleo]

So I should just leave it?

[Lee in KC]

Yes

[dwleo]

Thanks.

[Indycars]

Many people like to twist the pushrod to determine valve train setup before starting
the engine the first time. Then a short time later after the engine is broke-in, they
come back and adjust the valves with the engine running and hot. It can be messy
when it throws oil on the headers. They do make a clip to go over the end of the
rocker arm to keep the oil from squirting out. Some cut-up an old valve cover to keep
the oil in.

https://www.summitracing.com/parts/mrg- ... oCVsvw_wcB

RockerArmClips.jpg (6.82 KiB) Viewed 516 times

.

ValveCoverModification.jpg (62.67 KiB) Viewed 516 times

.
Since I had a two piece valve cover I made a shield from flat bar aluminum that covered the
push rod end of the rocker arm.
.
https://www.youtube.com/watch?v=wDvDOtu ... tjhARxbd9Q
.

FP02_OilDeflector_5284.jpg (69.39 KiB) Viewed 516 times