Author Topic: Checking squish clearance  (Read 2833 times)

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Offline thumper 823

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Re: Checking squish clearance
« Reply #25 on: June 04, 2019, 05:23:55 PM »
angle tops

The best pics I have as of right now-
In this pick I am fusing with the oil control spacer attempting to get less drag.
I made a special tool to get a nice slow push dwn through on an electric scale.
The tool is a snowmobile clutch tool, but seriously a couple of sticks of wood bolted to gather would do the same thing.
I got front piston dwn to 11 lbs and the rear to 10 lbs.!
She will either be an oi blower or a real goer.
The weird part after the cylinders was installed- pistons,  rings and all
it took less the 5lbs to spin the engine over .
I thought the drag would be cumulative  (times two)
That is a lot less than a stocker which can be as high as 30 and more!

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« Last Edit: June 04, 2019, 10:29:23 PM by thumper 823 »
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Amateur engineering with bad math.

Offline thumper 823

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Re: Checking squish clearance
« Reply #26 on: June 05, 2019, 02:07:08 AM »
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Offline thumper 823

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Re: Checking squish clearance
« Reply #27 on: June 05, 2019, 02:29:57 AM »
I use dental plastic as it will it mar the ceramic coatings on the pistons and the top of the combustion chamber



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Offline Hillside Motorcycle

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Re: Checking squish clearance
« Reply #28 on: June 05, 2019, 04:15:38 AM »
How is the helicopter coming along?
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Offline thumper 823

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Re: Checking squish clearance
« Reply #29 on: June 05, 2019, 05:22:34 AM »
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It is all almost.
need one more roof built here (wood blades)
And its dwn to the valve train on the other engine.
It was all cockeyed and imposable   to get centered
the enginamaneer went with 1/2 longer rods
a redo in the oiling system so oil to the top main bng.
line bore
and a bunch of other boring things..
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Amateur engineering with bad math.

Offline thumper 823

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Re: Checking squish clearance
« Reply #30 on: August 28, 2020, 04:57:05 PM »
Finaly did the dyno !
1994 EVO, std stroke, 80 inch (20 over)
Hill side gets the thank you for the final volly and tune    [ You are not allowed to view attachments ]  
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Amateur engineering with bad math.

Offline Adam76

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Re: Checking squish clearance
« Reply #31 on: September 07, 2020, 04:58:57 PM »
Finaly did the dyno !
1994 EVO, std stroke, 80 inch (20 over)
Hill side gets the thank you for the final volly and tune    [ You are not allowed to view attachments ]

Wow, nice result thumper.  👍
What was done with the voes?
« Last Edit: September 07, 2020, 05:56:03 PM by Adam76 »

Offline Adam76

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Re: Checking squish clearance
« Reply #32 on: September 07, 2020, 05:02:17 PM »
I'm currently aiming for .030" myself, with zero deck and .030 HG..... From everything everyone's told me so far, this is ideal for performance and burn efficiency as far as safe before running into possible detonation problems?? 
I've been aiming for .030 -  0.032 from the beginning.... Should have it all together soon -- but now I'm thinking I should be checking piston to valve clearance? I didn't think it would be a problem worth checking for with my build?
Thanks
« Last Edit: September 07, 2020, 05:55:34 PM by Adam76 »

Offline kd

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Re: Checking squish clearance
« Reply #33 on: September 07, 2020, 05:18:16 PM »
 :up:
KD

Offline RTMike

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Re: Checking squish clearance
« Reply #34 on: September 07, 2020, 05:19:24 PM »
.030 is a little tight..035-.040 is what I shoot for

Offline kd

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Re: Checking squish clearance
« Reply #35 on: September 07, 2020, 05:23:39 PM »
.040 is oem  :scratch:
KD

Offline turboprop

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Re: Checking squish clearance
« Reply #36 on: September 07, 2020, 06:52:52 PM »
I'm currently aiming for .030" myself, with zero deck and .030 HG..... From everything everyone's told me so far, this is ideal for performance and burn efficiency as far as safe before running into possible detonation problems?? 
I've been aiming for .030 -  0.032 from the beginning.... Should have it all together soon -- but now I'm thinking I should be checking piston to valve clearance? I didn't think it would be a problem worth checking for with my build?
Thanks


If there is any doubt then there is no doubt. Unless you just enjoy not sleeping and having endless  online discussions based on conjecture and what others are simply repeating as fact. Check that piston to valve clearance. The other person that sleeps in you bed will thank you.
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Offline kd

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Re: Checking squish clearance
« Reply #37 on: September 07, 2020, 08:19:04 PM »
 :agree:  You’ll find it interesting to do and it will be a huge stress relief knowing as turboprop has pointed out.
« Last Edit: September 07, 2020, 08:31:04 PM by kd »
KD

Offline Adam76

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Re: Checking squish clearance
« Reply #38 on: September 07, 2020, 11:09:41 PM »
I'm currently aiming for .030" myself, with zero deck and .030 HG..... From everything everyone's told me so far, this is ideal for performance and burn efficiency as far as safe before running into possible detonation problems?? 
I've been aiming for .030 -  0.032 from the beginning.... Should have it all together soon -- but now I'm thinking I should be checking piston to valve clearance? I didn't think it would be a problem worth checking for with my build?
Thanks


If there is any doubt then there is no doubt. Unless you just enjoy not sleeping and having endless  online discussions based on conjecture and what others are simply repeating as fact. Check that piston to valve clearance.The other person that sleeps in you bed will thank you.
Ok, thanks. I guess I just made an assumption and I was wrong..  Never done any of this before, so everything is a learning curve. Appreciate the advice.
I don't  sleep at night much, but that's another story.
« Last Edit: September 07, 2020, 11:17:55 PM by Adam76 »

Offline Adam76

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Re: Checking squish clearance
« Reply #39 on: September 07, 2020, 11:15:40 PM »
:agree:  You’ll find it interesting to do and it will be a huge stress relief knowing as turboprop has pointed out.
Yep,  will do. And it will be an interesting exercise to do and learn for this and future builds. 
Cheers

Offline Adam76

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Re: Checking squish clearance
« Reply #40 on: September 07, 2020, 11:25:40 PM »
Close, I use a known thickness flat bar across the cylinder bore. Mine happens to be 0.080" thick. I set the dial indicator to 0.080" while it rests on the bar stock. Then when the bar stock is removed, the virtual 0.000" depth is calculated from the actual piston height or depth. +/-
Ohio, is it still an ok method to set up the dial indicator and zero it out using the top of the barrel surface like D-1 mentioned?  I was going to use this method to check my deck height once my cylinders go back on. Kind of like the picture you posted.
Thanks.

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Re: Checking squish clearance
« Reply #41 on: September 08, 2020, 02:32:40 AM »
Close, I use a known thickness flat bar across the cylinder bore. Mine happens to be 0.080" thick. I set the dial indicator to 0.080" while it rests on the bar stock. Then when the bar stock is removed, the virtual 0.000" depth is calculated from the actual piston height or depth. +/-
Ohio, is it still an ok method to set up the dial indicator and zero it out using the top of the barrel surface like D-1 mentioned?  I was going to use this method to check my deck height once my cylinders go back on. Kind of like the picture you posted.
Thanks.

The reason I do it as I mentioned is I have a fixed indicator bracket for use on HD motors. Once bolted to the cylinder I don't want to move it. This is why I do it as I explained. Moving the indicator base once zeroed might be accurate, it might not be. It's just not good machining practices to move your point of reference. 

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Offline Adam76

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Re: Checking squish clearance
« Reply #42 on: September 08, 2020, 03:03:35 AM »
Close, I use a known thickness flat bar across the cylinder bore. Mine happens to be 0.080" thick. I set the dial indicator to 0.080" while it rests on the bar stock. Then when the bar stock is removed, the virtual 0.000" depth is calculated from the actual piston height or depth. +/-
Ohio, is it still an ok method to set up the dial indicator and zero it out using the top of the barrel surface like D-1 mentioned?  I was going to use this method to check my deck height once my cylinders go back on. Kind of like the picture you posted.
Thanks.

The reason I do it as I mentioned is I have a fixed indicator bracket for use on HD motors. Once bolted to the cylinder I don't want to move it. This is why I do it as I explained. Moving the indicator base once zeroed might be accurate, it might not be. It's just not good machining practices to move your point of reference.
Ok thanks, that makes sense.

I was going to use a traditional deck bridge like this one.

Offline thumper 823

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Re: Checking squish clearance
« Reply #43 on: September 08, 2020, 03:06:21 AM »
A tight Squish is part of what is needed to combat spark knock with High comp, and low octain gas .
I am at an honest .026 and have about a 1000 miles on it.
(Plus Scott @ Hillside said it would work.)
This is Dual plugged-  225  front and 235 rear CCP, @ 65F -OAT,    1700 feet above seal level.   W8 Cam
Keep in mind most pistons will not give a constant number through the outside radius (Uness they have been chucked up)
I have measured the leak dwn @TDC (minus a couple of deg)  and it is near zero.
 I am not exagerating.
Now keep in mind I have nodular cylinders and all the graphs I have read say Nodular does not have near the growth that AL jugs do.
You will have to do your own math to figure out what you get with al @ operating temps.
A std Evo head comes with a lot of area to be removed as a virgin head can have .050 to .070 to get it to pefomance area. AFAIK.

Yes STD  VOS hooked up.
« Last Edit: September 08, 2020, 03:11:10 AM by thumper 823 »
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Amateur engineering with bad math.

Online Ohio HD

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Re: Checking squish clearance
« Reply #44 on: September 08, 2020, 03:38:08 AM »
Close, I use a known thickness flat bar across the cylinder bore. Mine happens to be 0.080" thick. I set the dial indicator to 0.080" while it rests on the bar stock. Then when the bar stock is removed, the virtual 0.000" depth is calculated from the actual piston height or depth. +/-
Ohio, is it still an ok method to set up the dial indicator and zero it out using the top of the barrel surface like D-1 mentioned?  I was going to use this method to check my deck height once my cylinders go back on. Kind of like the picture you posted.
Thanks.

The reason I do it as I mentioned is I have a fixed indicator bracket for use on HD motors. Once bolted to the cylinder I don't want to move it. This is why I do it as I explained. Moving the indicator base once zeroed might be accurate, it might not be. It's just not good machining practices to move your point of reference.
Ok thanks, that makes sense.

I was going to use a traditional deck bridge like this one.

That's fine to use. Put it in place over the center of the piston, use a precision thickness flat stock, set the indicator to the flat stock thickness, not zero, Then when the flat stock is pulled out, you have a zeroed indicator for over the bore.

I prefer a bolted down or magnetic base indicator so I can slowly roll the motor back and forth to make sure I have a good reading as to what the piston measures at TDC.

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Offline kd

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Re: Checking squish clearance
« Reply #45 on: September 08, 2020, 05:19:34 AM »
Close, I use a known thickness flat bar across the cylinder bore. Mine happens to be 0.080" thick. I set the dial indicator to 0.080" while it rests on the bar stock. Then when the bar stock is removed, the virtual 0.000" depth is calculated from the actual piston height or depth. +/-
Ohio, is it still an ok method to set up the dial indicator and zero it out using the top of the barrel surface like D-1 mentioned?  I was going to use this method to check my deck height once my cylinders go back on. Kind of like the picture you posted.
Thanks.

The reason I do it as I mentioned is I have a fixed indicator bracket for use on HD motors. Once bolted to the cylinder I don't want to move it. This is why I do it as I explained. Moving the indicator base once zeroed might be accurate, it might not be. It's just not good machining practices to move your point of reference.
Ok thanks, that makes sense.

I was going to use a traditional deck bridge like this one.

That's fine to use. Put it in place over the center of the piston, use a precision thickness flat stock, set the indicator to the flat stock thickness, not zero, Then when the flat stock is pulled out, you have a zeroed indicator for over the bore.

I prefer a bolted down or magnetic base indicator so I can slowly roll the motor back and forth to make sure I have a good reading as to what the piston measures at TDC.

Very important.  Measurements at each side and above the pin can vary when the piston rocks in the bore.
KD

Offline Adam76

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Re: Checking squish clearance
« Reply #46 on: September 09, 2020, 01:39:41 AM »
Very important.  Measurements at each side and above the pin can vary when the piston rocks in the bore.

Thanks kd, my piston being a KB forged with a small dome (9.5 pistons) don't have many areas on the actual top surface of the piston to measure from? I'm only really able to use one section on the right hand side of the  piston top that isn't affected by the dome or the valve reliefs?
« Last Edit: September 09, 2020, 01:43:52 AM by Adam76 »

Offline thumper 823

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Re: Checking squish clearance
« Reply #47 on: September 09, 2020, 04:46:02 AM »
Your squish is the closest area to the head,   no matter where it is.
AFAIK you want it as tight as posable, and there is endless theory on it.
Even maching groves to the other side.
The importatnat part is close, but not so close they kiss each other.
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Amateur engineering with bad math.

Offline kd

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Re: Checking squish clearance
« Reply #48 on: September 09, 2020, 04:49:47 AM »
What year and type cylinder head are you using?
« Last Edit: September 09, 2020, 05:01:15 AM by kd »
KD

Offline Adam76

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Re: Checking squish clearance
« Reply #49 on: September 09, 2020, 05:17:49 AM »
What year and type cylinder head are you using?
If asking me?  I'm using 1996 softail motor with stock heads that now have 0.010" off them just back from the machine shop. Because it wasn't a high performance precision build, I didn't cc the heads, so I have no idea where they're at.... but they looked virgin to me when I pulled then off. Then again, how would I know?
Cheers