Help with another 355 build! - Page 4 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #46 (permalink)  
Old 09-27-2013, 06:18 PM
Registered User
 
Last photo:
Join Date: Sep 2013
Location: Eastern Shore Maryland
Age: 59
Posts: 23
Wiki Edits: 0

Thanks: 6
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by techinspector1 View Post
I think you need to re-examine what you said here. If you cut the block decks to zero, it doesn't matter what the compression height of the piston is, the piston deck height is still zero and you'd need a ~0.039"/0.040" gasket to set the squish. Now, if you wanted to cut the block decks to 0.010" or 0.020" piston deck height and use the 0.028" gasket, ok.
Quote:
Originally Posted by jokerZ71 View Post
I was thinking all wrong.When I hear 0 deck,I just assume cutting approx .025 for a 9" deck hgt which in his case would still leave him .020 in the hole.I don't have a lot of experience with decking.So,you are saying for him to cut .045 from,or,there about?How much can you safely remove?
OK>>now I'm totally lost Should I have them cut the deck AND install different pistons? Or, can I just have them clean up the block deck and go with the pistons that are in there now.

Joker; you are correct. My pistons are .045 down the hole at TDC. I borrowed a depth gauge and checked it today.

Thanks for the help fellas.
Attached Thumbnails
Click image for larger version

Name:	1-1.jpg
Views:	25
Size:	286.5 KB
ID:	84362   Click image for larger version

Name:	1-3.jpg
Views:	33
Size:	479.0 KB
ID:	84370   Click image for larger version

Name:	1-2.jpg
Views:	30
Size:	361.0 KB
ID:	84378  

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #47 (permalink)  
Old 09-27-2013, 06:40 PM
jokerZ71's Avatar
Wrench Turner
 
Last photo:
Join Date: Jun 2013
Location: Stanton,Tn.
Age: 52
Posts: 2,250
Wiki Edits: 0

Thanks: 163
Thanked 375 Times in 334 Posts
You can go either way.As I said,I wrongly assumed when Tech said 0 deck,that meant cutting .025,which'in your case,would not be 0 deck.You would need to cut .045 for a true 0 deck.Judging from the pics,I doubt,.010,or,.020 would clean those decks.You want a piston to head clearance(quench) of .040 to .045,so,I would cut enuff to get a smooth level deck.Then measure the depth of the 4 corner pistons plus the correct gasket thickness to give you a .040 to .045 quench.You can remove the .045 for a 0 deck & the .039/.040 gasket.I can't believe the shop didn't @ least call to give you the option to clean those up.
Reply With Quote Quick reply to this message
The Following User Says Thank You to jokerZ71 For This Useful Post:
BaySox1 (09-28-2013)
  #48 (permalink)  
Old 09-27-2013, 06:51 PM
jokerZ71's Avatar
Wrench Turner
 
Last photo:
Join Date: Jun 2013
Location: Stanton,Tn.
Age: 52
Posts: 2,250
Wiki Edits: 0

Thanks: 163
Thanked 375 Times in 334 Posts
If you deck the block,your current pistons will be fine.Just use the correct gasket thickness for the proper quench.I've never decked a block anymore than to get a clean level surface,but,ppl 0 deck all the time.I have heard that when using the shorter piston combined with 0 decking,will keep the ring Pak cooler by placing it closer to the water jacket @ TDC.
Reply With Quote Quick reply to this message
The Following User Says Thank You to jokerZ71 For This Useful Post:
BaySox1 (09-28-2013)
  #49 (permalink)  
Old 09-27-2013, 07:54 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,310
Wiki Edits: 326

Thanks: 838
Thanked 1,151 Times in 950 Posts
I'm a fan of using the tallest piston I can find, resulting in the least material off the decks to engineer a good, tight squish, 0.035" to 0.045" with the piston at top dead center and the head gasket in place. I have a fear of cutting too much off the decks, because you begin getting into fitment problems with the intake manifold. The more you take off the decks, the narrower it is between the heads when they are bolted on. One of the most critical things in a build, to my mind, is the sealing up of the ports between the heads and intake manifold. That's why I suggest bolting the motor together, torquing everything down just like you're finished with it, waiting until the next day and removing the intake manifold to inspect the intake gaskets for sealing up all the way around each and every port. If the port is gapped open on the top side, you will probably be able to find a vacuum leak with a combustible spray. If the port is gapped open on the bottom side, you will never find it with a combustible spray and the motor will be pulling in oily vapors every time the intake valve is opened. That's where oily plugs come from many times. If the gasket is pinched all the way around each and every port and you can witness that there is a seal, use another set of the same part number gaskets, bolt it back together, torque and you're done, knowing that the motor is sealed up.
Reply With Quote Quick reply to this message
The Following User Says Thank You to techinspector1 For This Useful Post:
BaySox1 (09-28-2013)
  #50 (permalink)  
Old 09-27-2013, 08:40 PM
GMC boogie's Avatar
Member
 
Last photo:
Join Date: Nov 2004
Location: Louisiana
Age: 49
Posts: 637
Wiki Edits: 0

Thanks: 1
Thanked 22 Times in 22 Posts
Have the decks cut to a 9.00 deck height. This will leave you around .020 in the hole. Use a .028 gasket.
Reply With Quote Quick reply to this message
The Following User Says Thank You to GMC boogie For This Useful Post:
techinspector1 (09-27-2013)
  #51 (permalink)  
Old 09-27-2013, 08:57 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,310
Wiki Edits: 326

Thanks: 838
Thanked 1,151 Times in 950 Posts
Quote:
Originally Posted by GMC boogie View Post
Have the decks cut to a 9.00 deck height. This will leave you around .020 in the hole. Use a .028 gasket.
That would work fine in my opinion.
Reply With Quote Quick reply to this message
  #52 (permalink)  
Old 09-28-2013, 08:17 AM
Registered User
 
Last photo:
Join Date: Sep 2013
Location: Eastern Shore Maryland
Age: 59
Posts: 23
Wiki Edits: 0

Thanks: 6
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by GMC boogie View Post
Have the decks cut to a 9.00 deck height. This will leave you around .020 in the hole. Use a .028 gasket.
Quote:
Originally Posted by techinspector1 View Post
That would work fine in my opinion.
OK>>pardon my ignorance, but a 9.00 deck is measured from what point to what point? So .020 and using a .028 gasket, wouldn't that give me a quench of .048? Or is that .028 the gasket thickness prior to torquing the heads therefore giving making my quench much lower?

So I can better understand, and gain some perspective, can you explain what the effects of for a larger quench, ie. I'm currently .045 down and I go ahead and use an .028 gasket and result in an .073 quench?

Thanks All
Reply With Quote Quick reply to this message
  #53 (permalink)  
Old 09-28-2013, 08:34 AM
jokerZ71's Avatar
Wrench Turner
 
Last photo:
Join Date: Jun 2013
Location: Stanton,Tn.
Age: 52
Posts: 2,250
Wiki Edits: 0

Thanks: 163
Thanked 375 Times in 334 Posts
After .050 or so,you lose the benefits of quench.Your engine will be down on power & more prone to detonation.You also won't have an efficient & complete burn of your fuel.The advertised gasket thickness is the actual thickness after torquing head down.That is the actual compressed thickness.Your engine will run as is,but,the effects of a proper quench are well worth the effort.My main concern in your case is gettin a good seal with the condition of your deck.So if your gonna have the deck cleaned up,it won't be any harder to go ahead & set the proper quench distance.You know your .045 deep now,so,have the shop remove .025 from the deck.
Reply With Quote Quick reply to this message
The Following User Says Thank You to jokerZ71 For This Useful Post:
techinspector1 (09-28-2013)
  #54 (permalink)  
Old 09-28-2013, 08:40 AM
jokerZ71's Avatar
Wrench Turner
 
Last photo:
Join Date: Jun 2013
Location: Stanton,Tn.
Age: 52
Posts: 2,250
Wiki Edits: 0

Thanks: 163
Thanked 375 Times in 334 Posts
Standard deck hgt on an SBC is 9.025.This is the measurement from the center of the crankline @ BDC to the top of the deck.Removing more than .025 from the deck could start causing fitment/alignment issues with the heads & intake.It can also cause valvetrain geometry issues requiring different pushrods etc.
Reply With Quote Quick reply to this message
The Following User Says Thank You to jokerZ71 For This Useful Post:
techinspector1 (09-28-2013)
  #55 (permalink)  
Old 09-28-2013, 11:38 AM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,310
Wiki Edits: 326

Thanks: 838
Thanked 1,151 Times in 950 Posts
Most everyone, including David Vizard, agrees that the tighter the squish, the more power the motor will make. Mr. Vizard tested a tighter and tighter squish on a small block Chevy and didn't encounter a piston to head collision until......I believe 0.027". That's why you will see a range of 0.035" to 0.045". That range allows for the piston growing taller from the heat of combustion, the connecting rod stretching a little and the crankshaft bowing a little at speed. I agree with Jay that over 0.050", you begin to lose the squish effect. Your example of 0.073" squish might better be termed a "lack of squish".

Tighter than 0.035" could get you into a piston/head collision situation and looser than 0.045" will not be as effective as a tighter squish. The idea is to blow the mixture across the chamber by squeezing it out from between the crown of the piston and the flat area of the cylinder head opposite the chamber, homogenizing the mixture and eliminating any rich or lean pockets of mixture so that they will burn completely. I generally try to spec a piston that has a generous amount of flat area on the crown to accomplish this squishing. If you get the squish right, you can generally use a lesser grade of fuel without suffering detonation.

Here is an example of a flat-top piston that would work well.....
http://www.summitracing.com/parts/su...0-30/overview/
Here's a D-Cup piston with a generous flat area on the crown to mate up with the underside of the head....
http://www.summitracing.com/parts/ue...make/chevrolet
I don't use pistons that have a thin ring of crown material all the way around the perimeter and a shallow dish. Not enough flat area to effect a good squish. I couldn't find a photo of that type of piston right away.

I have little experience with blower motors, but I'm told that they will not benefit so much from a tighter squish as a naturally-aspirated motor will. The mixture is homogenized by the blower on the way in.

Last edited by techinspector1; 09-28-2013 at 11:52 AM.
Reply With Quote Quick reply to this message
The Following User Says Thank You to techinspector1 For This Useful Post:
BaySox1 (09-30-2013)
  #56 (permalink)  
Old 09-30-2013, 01:21 PM
Registered User
 
Last photo:
Join Date: Sep 2013
Location: Eastern Shore Maryland
Age: 59
Posts: 23
Wiki Edits: 0

Thanks: 6
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by techinspector1 View Post
Most everyone, including David Vizard, agrees that the tighter the squish, the more power the motor will make. Mr. Vizard tested a tighter and tighter squish on a small block Chevy and didn't encounter a piston to head collision until......I believe 0.027". That's why you will see a range of 0.035" to 0.045". That range allows for the piston growing taller from the heat of combustion, the connecting rod stretching a little and the crankshaft bowing a little at speed. I agree with Jay that over 0.050", you begin to lose the squish effect. Your example of 0.073" squish might better be termed a "lack of squish".

Tighter than 0.035" could get you into a piston/head collision situation and looser than 0.045" will not be as effective as a tighter squish. The idea is to blow the mixture across the chamber by squeezing it out from between the crown of the piston and the flat area of the cylinder head opposite the chamber, homogenizing the mixture and eliminating any rich or lean pockets of mixture so that they will burn completely. I generally try to spec a piston that has a generous amount of flat area on the crown to accomplish this squishing. If you get the squish right, you can generally use a lesser grade of fuel without suffering detonation.

Here is an example of a flat-top piston that would work well.....
http://www.summitracing.com/parts/su...0-30/overview/
Here's a D-Cup piston with a generous flat area on the crown to mate up with the underside of the head....
http://www.summitracing.com/parts/ue...make/chevrolet
I don't use pistons that have a thin ring of crown material all the way around the perimeter and a shallow dish. Not enough flat area to effect a good squish. I couldn't find a photo of that type of piston right away.

I have little experience with blower motors, but I'm told that they will not benefit so much from a tighter squish as a naturally-aspirated motor will. The mixture is homogenized by the blower on the way in.
Tech, thanks so much for the education. It would have been EXTREMELY useful today when I took the engine back to the machine shop. I was, however, armed with the squish, quench rate, knowledge which was a great help in my argument.

They, Bob at the machine shop, really didn't want to take the block back apart and deck it because I had not specifically asked that it be done. My first argument was, "well at the very least, I should have received a phone call" Bob just shrugged his shoulders and stuck with "the gasket will seal that".

So I posed the quench rate argument for about 2 minutes. I got a blank stare and he said, "bring it back in and I'll disassemble and deck the block for $100. I felt, particularly with my dearth of knowledge, further argument would only hurt me so I agreed. I don't think I'll be dealing with them anymore.
Reply With Quote Quick reply to this message
  #57 (permalink)  
Old 09-30-2013, 01:34 PM
jokerZ71's Avatar
Wrench Turner
 
Last photo:
Join Date: Jun 2013
Location: Stanton,Tn.
Age: 52
Posts: 2,250
Wiki Edits: 0

Thanks: 163
Thanked 375 Times in 334 Posts
Quote:
Originally Posted by BaySox1 View Post
Tech, thanks so much for the education. It would have been EXTREMELY useful today when I took the engine back to the machine shop. I was, however, armed with the squish, quench rate, knowledge which was a great help in my argument.

They, Bob at the machine shop, really didn't want to take the block back apart and deck it because I had not specifically asked that it be done. My first argument was, "well at the very least, I should have received a phone call" Bob just shrugged his shoulders and stuck with "the gasket will seal that".

So I posed the quench rate argument for about 2 minutes. I got a blank stare and he said, "bring it back in and I'll disassemble and deck the block for $100. I felt, particularly with my dearth of knowledge, further argument would only hurt me so I agreed. I don't think I'll be dealing with them anymore.
Which is when you should have replied<"I didn't request it becuz I didn't know you were gonna use El Cheapo Pistons ". Good deal tho>Glad you are getting it took care of.
Reply With Quote Quick reply to this message
  #58 (permalink)  
Old 09-30-2013, 01:39 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,643
Wiki Edits: 0

Thanks: 364
Thanked 858 Times in 820 Posts
when the engine performs well,go back and praise him for a good engine.He will be happy for good news.He might learn something for future customers???Not every machine shop does high performance engines,and stock engines will run fine as long as the fitment is all "close enough".
Your next engine you will be better equipped to do a better more powerful engine. Next time you will take the same care custom fitting piston to wall clearances and ring gaps for even more power
Reply With Quote Quick reply to this message
  #59 (permalink)  
Old 09-30-2013, 02:11 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,643
Wiki Edits: 0

Thanks: 364
Thanked 858 Times in 820 Posts
$100. to deck the block is very fair.Make sure you bring a bottle of whiskey/bourbon or w/e to smooth things over.well worth the few extra bucks
Reply With Quote Quick reply to this message
  #60 (permalink)  
Old 09-30-2013, 02:15 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,310
Wiki Edits: 326

Thanks: 838
Thanked 1,151 Times in 950 Posts
Quote:
Originally Posted by vinniekq2 View Post
$100. to deck the block is very fair.Make sure you bring a bottle of whiskey/bourbon or w/e to smooth things over.well worth the few extra bucks
I agree. Make sure he checked the mains for being round and parallel.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
355 build??'s about compression and build impalaman355 Engine 5 06-06-2011 11:20 AM
355 build corkym Engine 16 10-19-2010 07:11 PM
355 build help old76c10 Engine 10 08-25-2009 08:07 PM
355 build jgh64pkup Hotrodding Basics 19 03-20-2009 11:53 AM
355 build Titanium Engine 3 08-28-2007 03:01 PM


All times are GMT -6. The time now is 02:14 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.