Stroker pistons protrude more than expected...quench...

Stroker pistons protrude more than expected...quench... - 04/28/13 11:33 AM

Building a 512 based on the 400-block, using the 12.5 comp strokerkit, Stealth heads, steel billet main caps etc. from 440Source.

Probably due to the block decking and the line boring of the main caps the pistons now protrude up to .016 inch above deck (including piston rocking).
If I choose the .051 thick head gasket my min quench will be .035 inches.

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

It's an E85 engine and it likes compression. See measurements below.

What do you guys think about the worst case .035 quench on cylinder #4?
------------------------------
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

Posted By: BSB67

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 11:57 AM

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

I don't know if yours will hit as the skirts are short. But if I wanted the compression, I would probably try it....JMO.

Posted By: 440Jim

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 12:39 PM

That sounds like a flat top piston.
You could just have a little taken off the top (milling or lathe). I would do the entire set for the desired piston to deck measurement. But you could just do piston #4 about 0.003"

Posted By: gregsdart

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 02:48 PM

avoid any gasket with too big of a bore if you can. Too much crevice volume (far edge of the bores) can cost enough hp to make getting it to fit the bore worth while.

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 04:21 PM

Quote:

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

Thanks for your comment but I don't follow you here, can you explain please?

Posted By: RUNCHARGER

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 04:48 PM

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

Sheldon

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 05:07 PM

Quote:

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

Sheldon

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

Posted By: JohnRR

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 06:32 PM

Quote:

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

------------------------------
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

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.

Posted By: BSB67

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 07:17 PM

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

Posted By: Crizila

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 07:34 PM

Quote:

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

True, but it's still the best option IMO.

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 09:09 PM

Quote:

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.

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!

Posted By: JohnRR

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 09:54 PM

Quote:

Quote:

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.

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!

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.

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 10:03 PM

Quote:

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.

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...

Posted By: dvw

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 10:04 PM

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

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 10:10 PM

Quote:

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

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...

Posted By: DJVCuda

Re: Stroker pistons protrude more than expected...quench... - 04/28/13 10:53 PM

From a blueprint standpoint I'd like to know where the deck is. Is it flat and square?

Posted By: JohnRR

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 12:05 AM

Quote:

Quote:

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.

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...

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

Posted By: Stanton

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 01:02 AM

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.

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 06:34 AM

Quote:

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

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?

Quote:

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.

You are right, the 060 would most likely be a custom gasket.
- Interesting, how du you measure the distance above the deck?

Posted By: jyrki

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 07:02 AM

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

Posted By: MR_P_BODY

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 07:19 AM

Quote:

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

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

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 08:02 AM

Quote:

Quote:

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

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

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

I'll be back!

Posted By: Stanton

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 01:00 PM

Quote:

how du you measure the distance above the deck?

With a deck height gauge that looks like this:

Attached picture 7686583-2319580157_2b22268631.jpg

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 02:18 PM

Quote:

With a deck height gauge that looks like this:

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.

Posted By: Stanton

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 04:04 PM

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.

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 04:42 PM

Quote:

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.

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...

Attached picture 7686803-P4292323.JPG

Posted By: Cab_Burge

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 05:22 PM

I use a depth mike, you can use your tool with the dial indicator, some people use a dial caliper, some use feeler gauges like you did. Lots of ways to get results, I like to use a very thin flat screw driver blade to wedge between the piston top and the cylinder bore to rock it and hold it while measuring it

I do measure them all at the front and back of the bores above the pins at the edge of the piston and the cam and then the outside of the block side also. 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

Posted By: Crizila

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 05:57 PM

I have always used the positive stop method. Most accurate IMO. BTW, you don't need fancy color anodized tools to get accurate readings. Much of my stuff is home brew.

Attached picture 7686931-positivestop.jpg

Attached picture 7686931-positivestop.jpg

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 06:02 PM

Quote:

... 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

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...

Posted By: Crizila

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 06:02 PM

cam degreeing w/more homemade stuff.

Attached picture 7686939-camdegreeing.jpg

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 06:06 PM

Quote:

cam degreeing w/more homemade stuff.

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

Posted By: FastmOp

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 06:17 PM

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.

Posted By: Crizila

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 06:23 PM

Quote:

Quote:

cam degreeing w/more homemade stuff.

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

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.

Attached picture 7686965-camdegreeing2.jpg

Attached picture 7686965-camdegreeing2.jpg

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 07:43 PM

Quote:

Quote:

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

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.

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...

Posted By: Guitar Jones

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 08:24 PM

Quote:

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.

I just bought .120 thick gaskets from them.

Posted By: JohnRR

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 10:02 PM

Quote:

cam degreeing w/more homemade stuff.

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 .

Posted By: Stanton

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 10:32 PM

Quote:

I just bought .120 thick gaskets from them.

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

Posted By: Guitar Jones

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 10:38 PM

Quote:

Quote:

I just bought .120 thick gaskets from them.

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

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.

Posted By: FastmOp

Re: Stroker pistons protrude more than expected...quench... - 04/29/13 10:51 PM

Quote:

Quote:

I just bought .120 thick gaskets from them.

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

Good to know they can do thicker.

Posted By: Swedcharger67

Re: Stroker pistons protrude more than expected...quench... - 04/30/13 06:23 PM

I've started working on the valve train, and checked the clearance between valves/pistons/heads...
Using modelling clay, the quench was as calculated. What was a slight surprise though was the huge clearance between valves and piston.
I don't have the exact numbers here right now, but you can see the thick layer of modelling clay in between.
The cam is a Lunati 10230703 hydraulic installed straight up. Seems I have a lot of room for future maneuvering with cams...

Forgot to say that the roller rockers are 1.6 ...

Attached picture 7688578-P4302333.JPG

Posted By: gregsdart

Re: Stroker pistons protrude more than expected...quench... - 04/30/13 07:11 PM

avoid any gasket with too big of a bore if you can. Too much crevice column (far edge of the bores) can cost enough hp to make getting it to fit the bore worth while.