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You should be able to get #4 up to at least .037 I would think, unless #3 has the longest rod/piston...

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He's talking about juggling rods and pistons to get everything closer to being the same dimension.

Sheldon

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Aaah, thanks Sheldon, now I get it!

Well, I don't feel like juggling rods and pistons again...I did it weight matching all the parts...with extremely good results BTW.

Looks like I can get gaskets with correct thickness and bore from here:
http://www.4secondsflat.com/cometic.html

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I'm tempted to go with the .051 gasket, it gives me 12.5 static comp, while a .060 gasket would give a min quench of .044 and the comp drops to 12.2


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Head gasket thickness inch 0,051
Cyl # Max out mm Max out inch Cylinder quench settings
1 0,35 0,014 0,037
2 0,25 0,010 0,041
3 0,35 0,014 0,037
4 0,40 0,016 0,035
5 0,35 0,014 0,037
6 0,25 0,010 0,041
7 0,35 0,014 0,037
8 0,35 0,014 0,037

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If he does not want to move 2 pistons, it is unlikely he'll have the tops cut.

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By going with a .009 thicker gasket you move the shorter pistons out to .050. If you are concerned with quench you need to look at all the numbers not just the minimum. It appears that the rods and/or pistons are not all the same length ?
I would do as 440jim suggests and cut all the tall pistons and get them all at .041.

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I'm more concerned about the minimum quench than the maximum.
Was assuming the heaviest rod could be the tallest, compared rod weights to the quench, but couldn't find any correlation.
Probably the biggest problem is can I trust my measurements? I need to do a new fresh round tomorrow to see what results I get.
Thanks for all comments!

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By going with a .009 thicker gasket you move the shorter pistons out to .050. If you are concerned with quench you need to look at all the numbers not just the minimum. It appears that the rods and/or pistons are not all the same length ?
I would do as 440jim suggests and cut all the tall pistons and get them all at .041.

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I'm more concerned about the minimum quench than the maximum.
Was assuming the heaviest rod could be the tallest, compared rod weights to the quench, but couldn't find any correlation.
Probably the biggest problem is can I trust my measurements? I need to do a new fresh round tomorrow to see what results I get.
Thanks for all comments!

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What are you using to make your measurements ?

I'm not sure how detrimental quench is with your compression and fuel choice, but the max number is as important as the minimum because once you get past a certain number you lose the quench effect. I try to build to .045 max, the engine the board built for the Enginemasters contest was run at .035, That motor was spun to 6700 rpm with no ill effects. If it was my motor I wouldn't be concerned with the .035, the spread you have to me is more of a concern.

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What are you using to make your measurements ?

I'm not sure how detrimental quench is with your compression and fuel choice, but the max number is as important as the minimum because once you get past a certain number you lose the quench effect. I try to build to .045 max, the engine the board built for the Enginemasters contest was run at .035, That motor was spun to 6700 rpm with no ill effects. If it was my motor I wouldn't be concerned with the .035, the spread you have to me is more of a concern.

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I use a dial indicator to find TDC, feel with a finger which side of the piston is lower, press that edge down with "some" force and measure at the opposite side of the piston, to simulate worst case piston rocking. There I use a feeler gauge next to the piston and just feel the edge with my finger. I've also used a steel ruler across the piston and a feeler gauge. Both methods give about the same result...using my finger is faster and easier...

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You saying that when you rock the piston in the bore it protrudes to the dimensions listed. If so what's the average between High and low? My bet is between .005"-.010". You have .035" when rocked I would run it. Doug

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Yes, that's right, the numbers given are when one side of the piston is pressed down using some force with my thumbs, i.e. worst case (?).
Yeah, I have to spend some "quality time" doing more measurements tomorrow...

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What are you using to make your measurements ?

I'm not sure how detrimental quench is with your compression and fuel choice, but the max number is as important as the minimum because once you get past a certain number you lose the quench effect. I try to build to .045 max, the engine the board built for the Enginemasters contest was run at .035, That motor was spun to 6700 rpm with no ill effects. If it was my motor I wouldn't be concerned with the .035, the spread you have to me is more of a concern.

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I use a dial indicator to find TDC, feel with a finger which side of the piston is lower, press that edge down with "some" force and measure at the opposite side of the piston, to simulate worst case piston rocking. There I use a feeler gauge next to the piston and just feel the edge with my finger. I've also used a steel ruler across the piston and a feeler gauge. Both methods give about the same result...using my finger is faster and easier...

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Feeler gauge and your finger ???? You need a tool like this if you want any reading that are remotely accurate ...
http://www.summitracing.com/parts/pro-66797

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Yeah, regarding a tool I came to think of the TDC finding toool I have fabricated, this one can easily be used for measuring the pistons as well. Will try that, but in this case of course there will be no more piston rocking than "normal" rocking...normal? Normal? What is normal rocking?

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Other than a custom-made gasket I don't know where you would get a .060" gasket.
I have EXACTLY the same problem due to decking and line honing ... pistons .016 above the deck. I use the .051 Felpro gaskets and I'm not worried about it. HOWEVER, every one of my pistons is dead on .016 above the deck - no variances. Mine is a 528" stroker kit with very short piston skirts.

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You do not take the rocking in to account. Measure the height from the center of the piston directly above the pin.

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as one side move up the other is going down
so average is at the pin center line

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You do not take the rocking in to account. Measure the height from the center of the piston directly above the pin.

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as one side move up the other is going down
so average is at the pin center line

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Thanks Guys, that makes it a lot easier, and more reliable...I think. Perkele!

I'll be back!

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how du you measure the distance above the deck?

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With a deck height gauge that looks like this:

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Ok, thanks, looks like a tool similar to the Summit one with magnets.

I modified a home-made TDC-finder and I have new, better numbers to report. Will do it later tonight.

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With the above tool you don't need a TDC finder, you zero the gauge to the deck once then measure each piston as it comes up to and past TDC.

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Yes , a nice tool, no doubt.

I attach a pic of my home made stuff, not as nice as the professional tools, but it works.

Anyway, here are the new numbers:

Head gasket thickness inch 0,051
Cyl # $$ Max out inch $$$ Quench inches
1 0,006 0,045
2 0,006 0,045
3 0,008 0,043
4 0,007 0,044
5 0,008 0,043
6 0,006 0,045
7 0,008 0,043
8 0,009 0,042

I think that's as good as it gets, and personally I think it's good enough, and I will run it this way unless anybody has some compelling reason not to...

Oh well, the formatting looked good when I posted it...but it's not the best possible when displayed here...

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... I now use the highest measurement for my piston to cylinder head clearances, .035 averaged made the pistons hit the head lightly when running, .042 didn't hit

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Thanks, sounds like I will be on the safe side then!

I found heads gaskets in my collection of the correct 051 compressed thickness...of course with a hitch...they are supposed to be good to 12:1 only...but I guess I run them anyway...

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cam degreeing w/more homemade stuff.

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Hahaha, a direct copy of my setup...same degreeing wheel, and 2 lifters welded together!!

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cam degreeing w/more homemade stuff.

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Hahaha, a direct copy of my setup...same degreeing wheel, and 2 lifters welded together!!

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Ya, but is your pointer a coat hanger or welding rod? Actually, the degree wheel is modified. Got tired of screwing around with the crank snout mounting problem, so I cut the center out, made an adapter with 3 set screws so I can rotate the outer ring without having to loosen the crank mounting bolt. Works great.

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Hahaha, a direct copy of my setup...same degreeing wheel, and 2 lifters welded together!!

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Ya, but is your pointer a coat hanger or welding rod? Actually, the degree wheel is modified. Got tired of screwing around with the crank snout mounting problem, so I cut the center out, made an adapter with 3 set screws so I can rotate the outer ring without having to loosen the crank mounting bolt. Works great.

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Now that's an excellent design not to have to loosen the crank bolt, which is annoying and can easily change the position of the crank!!! I will remember that idea!
My pointer is, as you can see, a multipurpose piece of soft iron wire...
Here is what my engine looked like yesterday...

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Cometic made me some .098 thick gaskets for my turbo build. There not cheep but they can make you any size thickness up to that.

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cam degreeing w/more homemade stuff.

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I was expecting a hand made degree wheel using an old clock face... that's too fancy a tool for you .

Swede , those numbers look good .

That tool is as good as the fancy anodized one from summit .

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I just bought .120 thick gaskets from them.

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I just bought .120 thick gaskets from them.

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That's not a gasket, that's a torque plate !!!

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Yeah I know. It wasn't the ideal thing but to make everything work with my heads and cam that's what I had to do. It still has 12.1:1 compression.

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I just bought .120 thick gaskets from them.

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That's not a gasket, that's a torque plate !!!

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Good to know they can do thicker.