how to prepare a block - 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
  #1 (permalink)  
Old 08-12-2003, 08:16 PM
blndweasel's Avatar
paints everything flat black
 

Last journal entry: September 2005 - Current
Last photo:
Join Date: Mar 2003
Location: San Diego, CA
Posts: 363
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
how to prepare a block

hey all,

i'm about to take my block in to be prepped for a new build. I was wondering if anyone could share with me the various things i should really have done to the block in preparation for assembly. So far from what i've read I need to have the following done:

-hot tank to remove all oils, grime, etc.
-magnaflux to check for cracks

then i was planning on having it bored out .040" and decked .020"

what other prep work is necessary?
i'm willing to install all the block hardware myself, i.e. dowels, freeze plugs, etc. i don't feel it's necessary to have the block blueprinted or the rotating assembly balanced.

any input?

thanks

the blonde weasel
san diego, ca

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-12-2003, 08:25 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,088
Wiki Edits: 0

Thanks: 24
Thanked 258 Times in 242 Posts
Have the main bearing bores checked for straightness (line bore), check the cam gear thrust surface for wear, lifter bores for wear, have the block parallel milled rather than the .020 mill. Use aftermkt pistons that aren't for rebuilders and you will have a good deck height.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-12-2003, 08:32 PM
crazy larry's Avatar
Member
 

Last journal entry: better comparison before and after shots
Last photo:
Join Date: Oct 2002
Location: East Texas
Age: 43
Posts: 2,298
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
the blue printing begins when you get the block back home......

if it doesn't need it, i wouldn't deck anything..... unless it needed it.......

remove any and all plugs in the oil passages, as the machine shop probably won't take the time to do it.....
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-13-2003, 08:25 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 37
Posts: 4,078
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
Grind the rear main cap oil pump boss to unrestrict the oil passages to the pump. Increase the size of the gallery that feeds the pump to 1/2. Polish the oil return galleries down the valley and massage oil returns near the front of the block so the oil will return through the timming chain set rather than down through the cam and crank.

I always do these things to any block as part of my rebuilding process. You only save a few percent in power by better controlling the oil flow. But it's free and doesn't take that much time or effort. It will also increase the life expectancy of the engine as well as more efficiency.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-13-2003, 08:53 AM
WV hillbilly
 

Last journal entry: PTL 220CC
Last photo:
Join Date: Jun 2003
Location: WV
Age: 39
Posts: 784
Wiki Edits: 0

Thanks: 1
Thanked 2 Times in 2 Posts
All engine blocks have the oil passages drilled and they connect at various angles. There are many areas that could use some clean up to limit flow restrictions. Anywhere the oil flows through two parts that bolt together should have the oil ports matched so no sharp edges restrict flow (the rear main bearing cap on a small-block Chevy is a good example. Also give the edges of any drill oil passage a radius to avoid turbulence, the oil filter area will almost always need this. Place the bearings in place and check how the oil holes matched the ones in the block. If there is any misalignment, grind the port in the block to match the bearings.

Deflashing & Oil Drainback

You will want to remove and casting flash inside the block. There is usually lots of casting flash around cast in oil drainback holes. Not only will this help get out any trapped casting sand, but it will also aid in helping the oil run back to the pan faster. I've seen people grind the entire lifter valley smooth, but this is a wasted effort. On most V-8 engines there is an oil return port at both ends of the heads, so concentrate on helping flow where the majority of the oil is. Another downfall of a totally smooth surface is that a smooth surface has less surface area than a rough one. Oil helps cool the engine and oil splash in the lifter valley takes heat off the cylinders, more surface area will transfer more heat. The same goes for painting, I have seen no gains from painting the inside of an engine. Paint on the inside of a block also has a chance to peel and clog the oil filter. I do not recommend painting the inside of engine blocks.

Threaded Bolt Holes

When Using a tap to clean threads, it is a good idea to use a tap that was made to clean threads, not cut threads. These taps are slightly undersize and will not remove additional metal. After tapping the threads, used a chamfering tool to take off the first thread of all the holes. If the block is going to be decked, chamfer the head bolt holes afterwards. This will prevent the first thread form pulling upwards when tightening and limiting clamping force. The is especially important on head bolt holes. If the block originally had press in plugs for oil galleys, it a good idea to replace them with screw in tapered pipe plugs, but be careful not to tap too deep. If the plug goes in too far it can block oil passages, so be sure to check. If you decide to use the press in style plugs, be sure to stake them in to prevent them from getting pushed out by oil pressure. If any threads are stripped or damaged to the point that you don't think they hold, a heli-coil insert is a perfectly acceptable repair.

Main Bearing Bores

The first thing that should be done is making sure that the crankshaft bore is straight in the block. All other measurements will be taken from the crankshaft centerline, so if it is out of alignment, all the other machining operations will be as well. If crankshaft centerline errors cannot be fixed, scrap the block, or save it for something other than a performance engine. If you need to hone the main's (if you're installing different caps or to fix small errors), you'll need to mill the bottoms of the main caps, then hone them to size . If you are installing aftermarket steel caps for strength, there will be too much material to hone, so you'll need to line bore the block. The trick here is to set up the boring bar to just barely touch the block and take the material off the caps. If much metal is taken off the block, a shorter timing chain will be needed, because the crank will then be closer to the camshaft. If you must take some off the block to correct alignment errors, Cloyes does offer special timing sets for most engines if you give them a crankshaft centerline to camshaft centerline measurement. When doing any boring or honing of the mains, always have the caps torqued to spec and anything else that bolts to the caps (like an oil pump) should be on and torqued to assure roundness of the bores when the engine is assembled.

Cylinder Boring

Any machining to the bores for any high performance engine should be done with a torque plate installed and torque to specs. This will simulate any distortion of the bores from the cylinder head being torqued. A block may seem like a rigid piece, but is actually quite flexible. If the shop that is machining your block does not have torque plates, find a new shop, they are obviously not a performance orientated shop. When boring, you want the least amount of oversize that will get the engine to clear, do not think that boring it to the maximum size to get the most cubic inches will make more power. Thin cylinder walls flex more, loose ring seal and loose power. Make sure that the bores are machined in relation to the crankshaft centerline, this is something that machine shops rarely do unless you specifically ask for it. What this does is make sure that all the bore are the same in relation to the crankshaft centerline. The bore alignment has a large effect on where the piston is at certain camshaft positions. It's not good for performance if every piston reaches peak velocity at different cam lifts and the opening and closing of the valves are not all at the same pistons positions. BHJ makes a special fixture called the Bore True fixture to locate the bores correctly. Once the boring bar is set up right, bore the engine 0.003" less than the desired bore size. The remaining metal will be removed in the honing process. Once you know for sure what the bore size will be, you can then get pistons of that size.

Bore Finish

Once you have the pistons, you must measure them and add the recommended clearance to know what the final bore size will actually be. Most pistons will be measured on the skirts level with and 90° of the wrist pins bores, but always check the manufactures recommendations. Always used a torque plate to assure roundness of the bores when the head is torqued in place. The final honing grit will depend on the type of rings used. A Chrome or Stainless-steel ring will require 280 grit stones and the more popular Molybdenum (moly) rings will need much finer 400 grit stones. As near the final bore size, make sure you use plenty of honing fluid and minimum cutting pressure. If you are having this operation done, you can check the machinists work using a shim feeler gauge of the desired piston-to-wall clearance. the piston should slide snugly by the feeler gauge (make sure you put the feeler gauge in the same area that the piston is measured. Now used a feeler gauge 0.001" thicker, the piston should not fit through the bore with the gauge in place. Be very carefull doing this check, it is very easy to damage the piston skirts.

Decking

To resist the chances of detonation, a close piston to head clearance is needed. Most engines will have the pistons below the deck at TDC. Decking will bring the piston closer to the heads and also straighten out any machining errors. You want to make sure that the decks are parallel to the crankshaft centerline and they are at the correct angle. A BHJ decking fixture is used to make sure the decks are in the correct position in relation to the crankshaft centerline. This is not common equipment for the average machine shop, so you must look for a performance orientated shop. When figuring piston to deck clearance, be sure to add the compressed thickness of the head gasket. Measure the piston deck height over the wrist pin, otherwise piston rock will change the measurement. Piston to head clearance is critical, the pistons must come as close to the heads as possible when running, but not hit them. You must take into account any piston rock, pin flexing and rod stretch. The average street motor with steel connecting rods can go as tight as 0.035" piston to head clearance, but 0.040" is the norm to allow a little room for error. Aluminum rod or high revving motors will need more clearance to allow room for more stretch. The idea here is to get as close to zero clearance as possible when the engine is revving at its peak rpm.

Camshaft & Lifter Bore Alignment

This is something that is almost never checked, but can be, and usually is, as big power robber. The camshaft bores are commonly out of alignment. When the cam is moved left or right in a V-8, one bank will be more advanced and the other will be retarded. To find such errors it is always recommended to degree the cam on cylinder 1, then check it against cylinder on the opposite bank. When degreeing the cam, you can split the difference of minor errors with little effects, but large errors need attention. I have seen over size cam bearings to repair such errors between the left and right banks, but be careful, boring the cam bearing bores will reduce the size of the oil grove around them and restrict flow. So if this is done, make sure that the oil grooves are opened up a like amount to compensate. A better solution is to relocate the lifter bores to cam bore centerline (if the errors are minor). Lifter bore errors can be as much as 0.020" and this can change the cam timing events 5-7° from cylinder to cylinder. This will compound any cam bore errors. It may be an expensive operation to straighten them out, but it is well worth the money. The BHJ Lifter True fixture is used to bore the lifter bores accurately. When fixing lifter bore alignment, they must be bored oversized, unless rules require stock lifter diameter it is a good idea to leave them oversized, as this allows peak lifter velocity to be higher. A Chevy lifter for instance is 0.842" which can be bored to 0.875" (a Ford size). If the rules require a stock diameter lifter, you must bush the new correctly aligned bores back down to 0.842". BHJ also makes the bushings you'll need. There is a lot of time and effort in this process, but it gives very good returns for the time involved. Most people know about the advantages of camshaft degreeing, but few people seem to get past cylinder number 1. There's little sense is degreeing the cam to the last degree, if the all the cylinders vary as much as 5°of each other.

www.grapeaperacing.com

Last edited by 2wld4u; 08-16-2003 at 08:04 AM.
Reply With Quote Quick reply to this message
The Following User Says Thank You to 2wld4u For This Useful Post:
bfreeasme2 (07-07-2014)
  #6 (permalink)  
Old 08-14-2003, 12:53 PM
Hollywooding's Avatar
Canknuckle Head
 
Join Date: Jun 2003
Location: Edmonton, Alberta
Posts: 165
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
whoa,...... deep

wanna do my block, wow!

Hollywooding
__________________
Hollywooding :cool:
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-14-2003, 01:42 PM
Jon's Avatar
Jon Jon is offline
Hotrodders.com Administrator
 
Last wiki edit: Removing stuck fasteners Last photo:
Join Date: May 2001
Location: Colorado
Age: 37
Posts: 3,206
Wiki Edits: 7314

Thanks: 0
Thanked 12 Times in 9 Posts
2wld4u -- I understand you went out of your way to provide a top-notch answer, but, unfortunately, reproducing other authors' articles without giving proper credit to the original author places us in a legal grey zone. I know a lot of people aren't aware of this, as the legislation (the Digital Millennium Copyright Act) is fairly new.

Quoting a sentence from an article is OK. If we're going to quote a paragraph, we'll need to properly credit the original author. If we're going to quote an entire article, it's best to just post a link, or to refer someone to the Knowledge Base, which (ahem) should have been consulted before posting this question on the board in the first place.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-14-2003, 07:17 PM
New Member
 
Join Date: Aug 2003
Location: Sheffield Lake, Ohio
Age: 53
Posts: 24
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I guess we are getting a free copy of "step by step guide to engine blueprinting".


Fill
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-15-2003, 10:24 AM
WV hillbilly
 

Last journal entry: PTL 220CC
Last photo:
Join Date: Jun 2003
Location: WV
Age: 39
Posts: 784
Wiki Edits: 0

Thanks: 1
Thanked 2 Times in 2 Posts
oh, sorry, the article is from www.grapeaperacing.com I wanted the whole article on there, It shoould have had the credits with it, anyways, its from GRAPE APE...great article...

Last edited by 2wld4u; 08-16-2003 at 08:02 AM.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-15-2003, 10:34 AM
woodz428's Avatar
Troll Hunter
 
Last photo:
Join Date: Sep 2002
Location: Philo,Il
Posts: 2,702
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Arrow

Also a lot of that is unnecessary to the average builder. If you can't trust your machinist to mike the pistons and give the right clearances then you need a new machinist. Most people don't need or would benefit from "blueprinting" an engine, that's why it cost so much more than a good quality rebuild.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-15-2003, 10:58 AM
WV hillbilly
 

Last journal entry: PTL 220CC
Last photo:
Join Date: Jun 2003
Location: WV
Age: 39
Posts: 784
Wiki Edits: 0

Thanks: 1
Thanked 2 Times in 2 Posts
I wouldnt be so sure, the reason I went to this site is to get some idea on the cam problems I was having with a 402 bbc, and this article does touch on blue printing but is not a blue printing article...these are some aspects of engine building that is overlooked and needs to be addressed, this is why most performance builds only last maybe 50,000 miles if your lucky, horsepower is easy to make, throw this with that and you have a performance engine, making it last and reliable is another story...cheap is as cheap does...dont forget that.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-15-2003, 11:45 AM
gt2betubbed's Avatar
Kid With A Wrench...
 

Last journal entry: The Blower and test fit.
Last photo:
Join Date: May 2003
Location: Cali Baby!
Age: 35
Posts: 1,106
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally posted by woodz428
If you can't trust your machinist to mike the pistons and give the right clearances then you need a new machinist.
I don't know about that one, because no matter how good my machinist is, I still double check his work. I don't like to take people's word for it when I didn't see it myself, especially with clearances.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 08-15-2003, 11:52 AM
BstMech's Avatar
NYOFP4RJ3CHRIS
 
Join Date: Sep 2002
Location: TN. In the corporate states of America
Age: 41
Posts: 1,552
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
I can remember a few times that I caught a mistake from the machinist. Particularly with placement of the cam bearings and the oil holes.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 08-15-2003, 12:26 PM
woodz428's Avatar
Troll Hunter
 
Last photo:
Join Date: Sep 2002
Location: Philo,Il
Posts: 2,702
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Arrow

As a longtime machinist, I know the local guys pretty well, and I too have had problems with some things (usually on motorcycle engines), but when you deal with machinists over the years you know what their abilities and shortcomings are. Maybe working as a machinist they make sure mine gets done right, because they know that I will make it right, and they may be required to pay for it. But overall boring a cylinder is really one of the simplest jobs,especially with modern equipment, crank grinding is one thing I always do a double check on.

Last edited by woodz428; 08-15-2003 at 05:24 PM.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 08-15-2003, 12:28 PM
BstMech's Avatar
NYOFP4RJ3CHRIS
 
Join Date: Sep 2002
Location: TN. In the corporate states of America
Age: 41
Posts: 1,552
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
AMEN.
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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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



All times are GMT -6. The time now is 01:03 PM.


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.