Rebuilding a 350 into a 383 stroker. Need help on pistons and deck clearance. - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



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

Closed Thread
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-24-2016, 08:16 AM
Registered User
 
Join Date: Aug 2016
Posts: 23
Wiki Edits: 0

Thanks: 9
Thanked 0 Times in 0 Posts
Rebuilding a 350 into a 383 stroker. Need help on pistons and deck clearance.

I just tore down a Chevy 350 engine and I'm about to bring it to a machine shop to get cleaned up. I'm starting to make my 'wishlist' for the setup and configuration I want for the engine (pistons, heads, rods, intake, etc.). I am a little lost on what my starting point should be however. I know the piston and head choice depends on the compression ratio I am aiming. But I can't calculate my compression ratio without knowing my deck height, and how can I measure my deck height without having my pistons already, but I don't wanna buy any pistons yet until I know my deck height to calculate my compression ratio! I know that might sound a little confusing but I just don't know where my starting point should be. Should I buy a set of pistons. then measure deck height, and then buy matching heads to adjust the compression ratio later?


Thanks in advance,
Mario.

    Advertisement
Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-24-2016, 08:25 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Join Date: Jul 2002
Location: Columbia, Mo
Age: 42
Posts: 6,839
Wiki Edits: 0

Thanks: 99
Thanked 667 Times in 548 Posts
The best thing to do wait untill you get the block back from the machine shop.
If they want the pistons for the an over bore then that will be your first purchase and the ywill tell you what you need if you ask em.

The chances of the block needing decked is close to 100% so the shop will probably plan for a 9.005.
Quick reply to this message
  #3 (permalink)  
Old 08-24-2016, 08:27 AM
Registered User
 
Join Date: Aug 2016
Posts: 23
Wiki Edits: 0

Thanks: 9
Thanked 0 Times in 0 Posts
Thanks for the quick response, I'm going to bring it to the machine shop sometime this week. I'm getting a little anxious haha.
Quick reply to this message
 
  #4 (permalink)  
Old 08-24-2016, 08:28 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Join Date: Jul 2002
Location: Columbia, Mo
Age: 42
Posts: 6,839
Wiki Edits: 0

Thanks: 99
Thanked 667 Times in 548 Posts
You basic plan of attack will always be put your desired goals on paper.
Put together a list of parts to reach that goal
If you need to adjust for budgeting reasons now is the time for that.
Once you have the parts list and a plan of attack take yout parts to the shop and talk to them about your plan. Listen carefully to them but remember they are just another opinion and not the only way to do things.
Post here or make your final plans and decisions and move forward.
Quick reply to this message
The Following 3 Users Say Thank You to johnsongrass1 For This Useful Post:
64nailhead (08-24-2016), BROWN616 (08-27-2016), techinspector1 (08-24-2016)
  #5 (permalink)  
Old 08-24-2016, 08:32 AM
Registered User
 
Join Date: Aug 2016
Posts: 23
Wiki Edits: 0

Thanks: 9
Thanked 0 Times in 0 Posts
Is there a reliable way to calculate deck clearance without having the pistons on hand?
Quick reply to this message
  #6 (permalink)  
Old 08-24-2016, 08:33 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Join Date: Jul 2002
Location: Columbia, Mo
Age: 42
Posts: 6,839
Wiki Edits: 0

Thanks: 99
Thanked 667 Times in 548 Posts
These things are fun and exciting and the feeling of accomplishment will reward to greatly. These things take time and thought. That's why not everyone builds engines and why there's an art to it. However don't let your self cut corners and make assumptions. Doing so will surely never end up in your favor. Patientience no matter how hard to come by will be your best friend.
Quick reply to this message
The Following User Says Thank You to johnsongrass1 For This Useful Post:
Evilash1996 (08-24-2016)
  #7 (permalink)  
Old 08-24-2016, 08:37 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Join Date: Jul 2002
Location: Columbia, Mo
Age: 42
Posts: 6,839
Wiki Edits: 0

Thanks: 99
Thanked 667 Times in 548 Posts
Quote:
Originally Posted by Evilash1996 View Post
Is there a reliable way to calculate deck clearance without having the pistons on hand?

GM specs them at 9.000 on the blue prints so most calculations are based on that but that's assumed and not verified as an industry standard. Some shops like 9.005 to give room for a clean up when the engine needs overhauled again. You'll see that more in racing when engines are used up quickly and you wanna get several refreshes out of the block. It's still not a bad practice even for a street ride though.

There are so many pieces that go into this that tiny differences start to add up. That's why you cannot assume anything. When you buy the crank, rods, and pistons each will have it's own sizing tolerance. In reality the tolerance can be +/- .001 so now your DH can fall any where from 8.997 to 9.003 so you can't really know until parts are in hand and verified for sizing but the goal usually 9.000.

Last edited by johnsongrass1; 08-24-2016 at 08:46 AM.
Quick reply to this message
The Following User Says Thank You to johnsongrass1 For This Useful Post:
Evilash1996 (08-24-2016)
  #8 (permalink)  
Old 08-24-2016, 08:40 AM
Registered User
 
Join Date: Aug 2016
Posts: 23
Wiki Edits: 0

Thanks: 9
Thanked 0 Times in 0 Posts
I am a little confused when you say some shops like 9.005. I thought that if there were resurfacing a deck the deck height measurement would go down so its essentially getting shorter from being grinded down?
Quick reply to this message
  #9 (permalink)  
Old 08-24-2016, 08:55 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Join Date: Jul 2002
Location: Columbia, Mo
Age: 42
Posts: 6,839
Wiki Edits: 0

Thanks: 99
Thanked 667 Times in 548 Posts
GM block are production pieces where good enough to get out the door is all they reach for so GM blocks can range from 9.000 to 9.035 with 9.020-9.025 be more average. The deck is almost never square with the cam tunnel either.
Quick reply to this message
  #10 (permalink)  
Old 08-24-2016, 08:57 AM
Registered User
 
Join Date: Aug 2016
Posts: 23
Wiki Edits: 0

Thanks: 9
Thanked 0 Times in 0 Posts
Ahhh gotcha I understand now. Thanks for the help, once I bring the engine to the shop I'll post my ideal setup and see what you guys think of it.
Quick reply to this message
  #11 (permalink)  
Old 08-24-2016, 08:59 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Join Date: Jul 2002
Location: Columbia, Mo
Age: 42
Posts: 6,839
Wiki Edits: 0

Thanks: 99
Thanked 667 Times in 548 Posts
A popular term the shop might use is "squaring up". That basically means the decks, bores and mains are all machined square to the cam tunnel.
Quick reply to this message
  #12 (permalink)  
Old 08-24-2016, 09:01 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Join Date: Jul 2002
Location: Columbia, Mo
Age: 42
Posts: 6,839
Wiki Edits: 0

Thanks: 99
Thanked 667 Times in 548 Posts
Quote:
Originally Posted by Evilash1996 View Post
Ahhh gotcha I understand now. Thanks for the help, once I bring the engine to the shop I'll post my ideal setup and see what you guys think of it.
Keep in mind your going to get all kinds of differing opinions. They are worth about what you paid for them so I'd advise you not get to caught up in them.
If you can find someone you can communicate with and you trust that's worth more than a 1000 opinions.
Quick reply to this message
  #13 (permalink)  
Old 08-24-2016, 09:03 AM
Registered User
 
Join Date: Aug 2016
Posts: 23
Wiki Edits: 0

Thanks: 9
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by johnsongrass1 View Post
A popular term the shop might use is "squaring up". That basically means the decks, bores and mains are all machined square to the cam tunnel.
Is there an average price I can compare my machine shop's prices to for these services? When I called they told me for them to bore the cylinders, hone the block, deck the block, wash, put in freeze plugs etc. it would cost $500. And for balancing the rotating assembly they quoting me to around $250. Are these reasonable prices? I'm NJ if that matters at all.
Quick reply to this message
  #14 (permalink)  
Old 08-24-2016, 09:09 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Join Date: Jul 2002
Location: Columbia, Mo
Age: 42
Posts: 6,839
Wiki Edits: 0

Thanks: 99
Thanked 667 Times in 548 Posts
Quote:
Originally Posted by Evilash1996 View Post
Is there an average price I can compare my machine shop's prices to for these services? When I called they told me for them to bore the cylinders, hone the block, deck the block, wash, put in freeze plugs etc. it would cost $500. And for balancing the rotating assembly they quoting me to around $250. Are these reasonable prices? I'm NJ if that matters at all.
That's what my shop is getting too. Shop prices are kinda based on quality. Carl at CNC blocks in NE is likely wanting $1500 but the work he does is impeccable and likely within .00001 whicj is good when you make 800hp at 8000rpm for hours and hours at a time but for a street car I think you quoted price is pretty good.
My shop bases the balance job on the time it takes so it's usually around $175 for me because I do the static weights my self like matching pistons, pins, rings, rods big and small ends before it gets there so they only need to put it on the machine and measure, then drill the crank and remeasure.
Quick reply to this message
  #15 (permalink)  
Old 08-24-2016, 09:10 AM
OldTech's Avatar
Registered User
 
Join Date: Jun 2016
Location: S. E. Washington
Posts: 772
Wiki Edits: 0

Thanks: 36
Thanked 148 Times in 129 Posts
Machine work varies in price all over the country. what I pay here in farm country is a lot less than I would pay in the metropolitan Seattle area of WA. state. It is more important to find a shop and machinist you can trust than paying less for a mediocre job. Check around your area and look at comments from folks who use them. Ask your friends, look at BBB stats and talk to the machinist about your build. Make your machinist your best friend... people go out of their way to do things right for friends.
Quick reply to this message
The Following User Says Thank You to OldTech For This Useful Post:
Evilash1996 (08-24-2016)
Closed Thread

Tags
383, compression ratio, deck height, heads, pistons

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:
Insurance
Please select your insurance company (Optional)

Log-in



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
383 Stroker crank-rods-pistons questions darefugee Engine 17 05-11-2014 04:50 AM
Rebuilding my 383 stroker Spaghetti Engine 0 03-28-2009 07:31 AM
383 stroker clearance dirtracerx Engine 5 10-09-2006 10:46 AM
Deck Clearance-SBC 350 Mr. Goodwrench Motor? acr Engine 7 04-20-2005 04:11 PM
383 Stroker clearance question draven Engine 16 12-06-2004 06:59 PM


All times are GMT -6. The time now is 03:02 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.