7747-7427 Swap

[Scooterwrench]

Maybe I'll try this VE table,

You must be registered for see images attach

Then again maybe not. This is for a 454. Thought a BBC VE may be a good starting point for my 355. This is the strangest VE table I've seen yet.

 

[Scooterwrench]

The rest of the story,

You must be registered for see images attach

 

[Scooterwrench]

I've got a piece of rubber inner tube that I cut a round wafer out of to put under the cap valve. No air in, no liquid out. The theory is sound, I'll have to see how it works. Once I get it broke loose I'll take the old one out with one hand and have the other one in the other hand ready to plug the hole. Usually I like to clean the threads in plug holes with a plumbers fitting brush. Not going to get to do that this time.

Oh yeah, by the way, the inner tube seal worked good. I lost maybe two tablespoons of coolant.

 

[L31MaxExpress]

Maybe I'll try this VE table,

You must be registered for see images attach

Then again maybe not. This is for a 454. Thought a BBC VE may be a good starting point for my 355. This is the strangest VE table I've seen yet.

Wrong OS. The 93-99 TBI PCMs have 6 different masks. $E6, $0E, $OD, $31, $63 (96+) and a 94-95 S10 2.2L/4.3 CPI specific one I am forgeting.

 

[Scooterwrench]

Wrong OS. The 93-99 TBI PCMs have 6 different masks. $E6, $0E, $OD, $31, $63 (96+) and a 94-95 S10 2.2L/4.3 CPI specific one I am forgeting.

It was on gearhedefi in the 7427 thread. That was a good teaching moment. Thanks Max!

 

[Road Trip]

I hate a working KS! Been chasing knock at 1000-1600 in the 60-80 MAP range. Pulled timing out three times and still the same affect with no reduction in knock. I'm beginning to think it's picking up the rod knock in that old boat anchor. Think I'm just going to turn it back off for now and go back to the ear sensor.
This can't be so much timing as to cause knock,

I'm assuming that you are tuning for 87 octane? I've found myself in a similar situation,
where I was having trouble figuring out if the knock was due to my tuning being too aggressive,
or if it was an underlying mechanical issue?

I've found that running the tank close to empty, adding 2-3 gallons of 93 octane, and retrying
my test was informative. If my timing curves were just a little too much of a good thing, then
the higher octane gas would clear up the pinging/knocking.

On the other hand, if the high test didn't make a difference, then I knew the root cause was
due to a mechanical issue. More octane won't fix excessive clearances. :0)

And before I knew enough to pay close attention to deck height & target a tight quench it
seemed that a sharp tune was kinda squishy. I didn't know if it was fuel distribution, or
a geographical heat distribution issue, but it always seemed like 1 cylinder start audibly complaining
first, so the most 'knock-sensitive' cylinder would set how much of a tune all 8 would get?

I remember when I had my first engine zero-decked, and set everything up for a tight quench.
When I went to tune this engine, it was so much easier. Instead of just 1 cylinder getting noisy
first, all 8 would be protesting in unison -- or all 8 would be quiet & pulling hard. (It's like the
valvetrain - an engine with 1 loose rocker arm & 15 correct sounds completely different than
the same engine with all 16 rocker arms loose. The former is an individual clonk clonk clonk
that stands out from the crowd, while the latter is a more uniform, 16x faster clatter.)

Same thing with 1 cylinder knocking vs all cylinders knocking in unison.

Of all the theoretical engine stuff I've chased and got minimal returns on the time &
money invested, the whole squish/quench thing was one area that really delivered a
difference in the real world.

That and oil control -- once I read that air/fuel/oil has a lower octane rating than the
same air/fuel charge that's oil free, this explained a lot of weird tuning issues I had worked
on in the past with no clue as to why this older, oil consuming engine wasn't happy with my
tuning recipe? :0)

****

Apologies for the length, but your comments about the working KS vs suspected rod
knock triggered some memories. A lot of the mystery issues that we used to cover up
by running Ethyl or Avgas is now much better understood thanks to the desire by all
involved to make big, reliable power on today's lower octane fuels.

Your writing on this tuning effort is really interesting. I'm looking forward to seeing
where you eventually end up with all this. Good stuff.

 

[Scooterwrench]

I'm assuming that you are tuning for 87 octane?

Yeah, I'm sure it would be less knock prone running better fuel but the idea was to tune for the fuel I was intending to run. I seriously doubt this old engine is making much more the 8.5:1.

I've found myself in a similar situation,
where I was having trouble figuring out if the knock was due to my tuning being too aggressive,
or if it was an underlying mechanical issue?

I've found that running the tank close to empty, adding 2-3 gallons of 93 octane, and retrying
my test was informative. If my timing curves were just a little too much of a good thing, then
the higher octane gas would clear up the pinging/knocking.

On the other hand, if the high test didn't make a difference, then I knew the root cause was
due to a mechanical issue. More octane won't fix excessive clearances. :0)

And before I knew enough to pay close attention to deck height & target a tight quench it
seemed that a sharp tune was kinda squishy. I didn't know if it was fuel distribution, or
a geographical heat distribution issue, but it always seemed like 1 cylinder start audibly complaining
first, so the most 'knock-sensitive' cylinder would set how much of a tune all 8 would get?

I remember when I had my first engine zero-decked, and set everything up for a tight quench.
When I went to tune this engine, it was so much easier. Instead of just 1 cylinder getting noisy
first, all 8 would be protesting in unison -- or all 8 would be quiet & pulling hard. (It's like the
valvetrain - an engine with 1 loose rocker arm & 15 correct sounds completely different than
the same engine with all 16 rocker arms loose. The former is an individual clonk clonk clonk
that stands out from the crowd, while the latter is a more uniform, 16x faster clatter.)

Same thing with 1 cylinder knocking vs all cylinders knocking in unison.

Of all the theoretical engine stuff I've chased and got minimal returns on the time &
money invested, the whole squish/quench thing was one area that really delivered a
difference in the real world.

That and oil control -- once I read that air/fuel/oil has a lower octane rating than the
same air/fuel charge that's oil free, this explained a lot of weird tuning issues I had worked
on in the past with no clue as to why this older, oil consuming engine wasn't happy with my
tuning recipe? :0)

I definately got some of that going on although I have noticed that after a few 5500 RPM pulls there is less smoke out the tail pipe first crank in the morning. Maybe it slung more of the antisieze up on the piston skirts and worked its way up around the oil rings. My oil pressure has gone up a little too. I've got 40psi when it's cold now,it was down to 20. Still bumping the 0 stop at hot idle.

****

Apologies for the length, but your comments about the working KS vs suspected rod
knock triggered some memories. A lot of the mystery issues that we used to cover up
by running Ethyl or Avgas is now much better understood thanks to the desire by all
involved to make big, reliable power on today's lower octane fuels.

Your writing on this tuning effort is really interesting. I'm looking forward to seeing
where you eventually end up with all this. Good stuff.

I kinda started from scratch this morning by pasting in a 305 VE table. I'm still running the same spark table and it seems to be liking it. I did turn the KS off and keeping an ear out for ping. I didn't datalog,just SOTP feel. I p#ssed my back off yesterday helping my brother with his well and mashing the go pedal was a little uncomfortable. I have to keep ol Smoky in operable condition,it's my DD.

 

[Road Trip]

Yeah, I'm sure it would be less knock prone running better fuel but the idea was to tune for the fuel I was intending to run. I seriously doubt this old engine is making much more the 8.5:1.

Understood. I was only advocating for the temporary use of 93 octane for diagnostic purposes,
and then reverting to the 87 once your tuning recipe is 100% good to go. (As opposed to only
running 87 and diagnosing using purely table changes.)

I'm a big fan of pulling all the troubleshooting levers possible. Sometimes you learn the most by
pulling a particular lever and having the opposite of what you predict occur. BTW, I might have
missed it -- are you planning on replacing this motor eventually, and this tuning exercise is just
to get familiar with the process in preparation for the swap?

 

[Scooterwrench]

You must be registered for see images attach

Isn't this a little drastic?

 

[PlayingWithTBI]

The way I see that is, these tables won't come into effect until you get to the "Maximum Knock Retard" so, IMO you shouldn't ever get to that point.