[fordean]

These are dome.
Keith Black.
Claimer. Looks to me viewing dome. One side may be larger. I want to see documentation if its factual. Im curious.

9904HC-030 -4cc

Copied from a past post on here. Regarding domed pistons. This says. That some have (valve notch) to be specfic. Meaning I believe one piston has intake on left aond exhaust on right. And another exhaust on left and intake on right, You must match. up to head. I view the pistons this looks possible cause they look like one notch bigger then other and they are in wrong cylinders. In my motor.

Here is paste from post.

Re: Question on piston install
Quote:
Originally Posted by jodysss396
Thank you Jim! I'll get them in tomorrow night.
Jody

=
Jody,
There are not four right side & left side in a Rat or any engine with a dome piston
The dome goes to the outside, the flat (quench) to the valley & all the piston & rod assemblies will be the same with any dome piston for a BB
The bearing tang should face the dome (outside or pan rail) too

Just for info there are some small block dome pistons that are left & right but it refers to the valve notch location when the notches are valve specific.
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He mentions notch. I need to clean off piston to view this. This looks possible. And would answer many of my questions.
Can anyone verify this?

I just took the carbon off the Tops of pistons. I see no difference on my Valve notches. Just didnt realize that does exist. Maybe a small difference. But not much. I was wundering why their is no arrows on pistons.>

 

[fordean]

Usually the only time you run into right and left pistons on a smallblock is with a dome.

These are dome.
Keith Black.
Claimer. Looks to me viewing dome. One side may be larger. I want to see documentation if its factual. Im curious.

9904HC-030 -4cc

 

[fordean]

http://www.kb-silvolite.com/assets/claimer_installation.pdf

According to the KB Claimer instruction sheet, you've got piston-to-wall clearance that is...generous. Shouldn't be "excessive", but it's more than what the manufacturer calls for.

Your ring gaps are enormous.

Thanks for That link. I just noticed the # 3 piston I removed that was installed. Very hard to notice but. The Intake and exhaust indent in piston Dome. Are not lined up with the Cylinder head. ON piston 3 as I am viewing. Smaller cavity is on LEFT, LARGER ON RIGHT.
I looked at Head second cylinder 3. Left is Intake, Right is Exhaust.
Can PISTON be WRONG IN CYLINDER. Is this possible. Looks like that what is happening.
ARE THE PISTON DOMES SPECIFIC. right intake left exhaust. or it dont matter.

 

[fordean]

http://www.kb-silvolite.com/assets/claimer_installation.pdf

According to the KB Claimer instruction sheet, you've got piston-to-wall clearance that is...generous. Shouldn't be "excessive", but it's more than what the manufacturer calls for.

Your ring gaps are enormous.

This is where Im confused. Says. .0065 x 4.030 (bore) = gap.
This is .0026 for normally aspirated. Top ring.

I see they show clearance next to the ring gap. A little confusing if you dont look close. Generous on the Clearance for piston to wall. and gap.
Would this cause excessive leakdown ( 45% loss) and 200 psi compression. I dont want to put back together til I feel I figured this out.
I probably should have retorqued head and checked. Just as precaution.

Also. will these measurements. Change when head is bolted on. ( like a torque plate.)>?

 

[fordean]

I bet Carl Hinkson (CNC Blocks N/E) does more of this in a day than I do in three months...so if he replies, take HIS word.

I would set up a calibrated/verified outside micrometer at exactly 4.000 inches, and lock the spindle. LIGHTLY clamp it in a vice using a piece of cardboard to protect the mic from the metal vice jaws. Select your bore gauge rods accordingly. Install the bore gauge in the micrometer, wiggle it back and forth so that the big needle goes as far COUNTER CLOCKWISE as possible. This will take some finesse and patience. Truthfully, it's a royal pain in the ass, which is why pros have perfect-sized cylindrical standards to use instead of the tiny pads of the micrometer. I don't have those fixtures, and I'm guessing you don't either. Adjust the dial on the bore gauge so that "0" lines up with where ever the big needle goes to that most-counterclockwise position, and then lock the dial with the screw. The small needle will--most likely--be near it's "0" point too.

Pre-sizing the bore gauge like this is ABSOLUTELY CRITICAL and needs to be done with precision. It is NO FUN because the bore gauge wants to pop out of the micrometer and you lose the reading.

Then install the bore gauge into the cylinder you want to measure. You said in the first post that the cylinders are 4.030; so as you wiggle the bore gauge in the cylinder to get the most-counterclockwise movement of the big needle, the larger bore gauge needle should swing clockwise to the black "30" on the dial (Not the red 30).

If that's the case, your cylinders truly are at 4.030--the four inches of the bore gauge plus extensions, where you zeroed the gauge using the micrometer, plus the thirty thou indicated by the needle on the gauge.

If you would be ONE LINE short of the 30, the bore is 4.0295.
Two lines short of .030 would be 4.0290
Three lines short of .030 is 4.0285, etc.

The inherent accuracy of your gauge is four decimal places, but the fourth is either 0 or 5. If the needle doesn't exactly line up with a printed line on the gauge, you'll have to "interpret"; and that can get messy without some experience.

Just Completed All measurements. Look over tell me what I may need to do further. Fun but alot of work.
Thanks again. Comments welcome. This is a motor just rebuilt with 5oo miles.
1st oil change due to major flooding had a quart of fuel in oil. Holley float stuck and pressure was high on fuel pass regulator.

2 was dirty oil, fuel or Blow by contamiation. First start up had bad fuel
flooding.

Compression was 200 all cylinders, Leak down failed 45%.

 

[fordean]

I bet Carl Hinkson (CNC Blocks N/E) does more of this in a day than I do in three months...so if he replies, take HIS word.

I would set up a calibrated/verified outside micrometer at exactly 4.000 inches, and lock the spindle. LIGHTLY clamp it in a vice using a piece of cardboard to protect the mic from the metal vice jaws. Select your bore gauge rods accordingly. Install the bore gauge in the micrometer, wiggle it back and forth so that the big needle goes as far COUNTER CLOCKWISE as possible. This will take some finesse and patience. Truthfully, it's a royal pain in the ass, which is why pros have perfect-sized cylindrical standards to use instead of the tiny pads of the micrometer. I don't have those fixtures, and I'm guessing you don't either. Adjust the dial on the bore gauge so that "0" lines up with where ever the big needle goes to that most-counterclockwise position, and then lock the dial with the screw. The small needle will--most likely--be near it's "0" point too.

Pre-sizing the bore gauge like this is ABSOLUTELY CRITICAL and needs to be done with precision. It is NO FUN because the bore gauge wants to pop out of the micrometer and you lose the reading.

Then install the bore gauge into the cylinder you want to measure. You said in the first post that the cylinders are 4.030; so as you wiggle the bore gauge in the cylinder to get the most-counterclockwise movement of the big needle, the larger bore gauge needle should swing clockwise to the black "30" on the dial (Not the red 30).

If that's the case, your cylinders truly are at 4.030--the four inches of the bore gauge plus extensions, where you zeroed the gauge using the micrometer, plus the thirty thou indicated by the needle on the gauge.

If you would be ONE LINE short of the 30, the bore is 4.0295.
Two lines short of .030 would be 4.0290
Three lines short of .030 is 4.0285, etc.

The inherent accuracy of your gauge is four decimal places, but the fourth is either 0 or 5. If the needle doesn't exactly line up with a printed line on the gauge, you'll have to "interpret"; and that can get messy without some experience.

Thanks for patience and reply. very much appreciated. Very informative. Am in midst of measureing.
Big question is can I get viable measurement with no torque plate installed. ?

 

[fordean]

I have ABSOLUTELY no idea how you go from five decimal places to one. I have no idea how you're taking your measurements.

Can you give me how you would do. Without me explaining. I will listen.

 

[fordean]

What does the Bolts do without a Torque plate on boring. Curious.

I have to ask machinist this question. But he may lie anyway.
Can I remeasure with a bolts installed. And measurement will change?

 

[fordean]

Do you see that there are TWO needles on that gauge? The big one measures .050 per revolution.

The tiny one indicates the number of revolutions--.050, .100, .150, .200, .250. Sort of like a minute hand in comparison to the second hand of a clock.

So the gauge range is .250 in that the large and small needles together can show a quarter-inch of travel--but the large needle will make 5 revolutions in the process.


Good catch. Went right past me.

Ok I think I understand.

Piston is 23.6 on dial measurement transfered from Micrometer measured at Skirt.

Bore measure at 1/2 inch is

21.9 (12 oclk), 20.7 ( 2 oclk), 21 (3 oclk) 21.9 (5 oclk)

2.5 down bore is
22.1 (12 oclk), 21.5 ( 2 oclk), 22.2 (3 oclk) 22.6 (5 oclk)

So if piston is 23.6 - 21.9 = 1.7 (full slash .001) then
.001 x 1.7 = .0017 piston to bore clearance.

Am I correct ?

 

[fordean]

Means nothing, depending on leakdown tester used.


How do you reliably measure to five decimal places when using a gauge that only goes to half-a-thou?

I see 100 slashes. Shortest ones are half-a-thou, medium ones are one thou, longest ones count thousandths by five--five, ten, fifteen, etc.

One revolution of the big needle is .050, by half-thousandths.


Are you using the gap specs for KB hypereutectic pistons on a non-hyper piston???

.0005
You Say one circum is .050? why does it say on gauge. 0 - 0.25
I thought enscription is wrong on gauge. should be 0 - .025 Is gauge writing incorrect?
And yes using .o65 x 4.030 bore per KB top ring specs. But Machineist made a little larger. I gave measurements above.

 

[fordean]

I would think at 50% you would have major issues. I would have tried a different leakdown tester before I tore it apart. Only thing I see, using the supplied formula, is the top ring gap is wider than they recommend. I know the KB's require a pretty loose top ring, but the 2nd ring is pretty good. Ring gaps are not very consistent either. What do the cylinders look like? can you see the finish hone marks?

Looking for questions to answer. Tear down was couple hours not to bad. I figure to take a peak. I see honing marks. Minor scouring which I cant feel with a nail. Looks like wear ring gaps were riding. You see pics of hot exhaust valves. And burnt looking pistons sides. I had a major fuel problem at start up. Holley card was not floated good plus Pressure was a little high. Did flood bad for intial start up.

View intake valves on one pics. You can see pretty burnt looking.