ummm...CRAP---Piston Eyebrows / Bigger Valves - 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 06-08-2004, 05:34 PM
unstable's Avatar
Murderator
 

Last journal entry: Brackets, Stories and the future
Last photo:
Join Date: Feb 2003
Age: 35
Posts: 743
Wiki Edits: 0

Thanks: 2
Thanked 4 Times in 4 Posts
ummm...CRAP---Piston Eyebrows / Bigger Valves

I've got my heads in the shop now, getting bigger valves 2.19/1.88 from 2.06/1.72

My plan was to leave the shortblock together...but I was reading I may have a problem with the pistons now...man wtf?!

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-08-2004, 05:48 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
clay 'em.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 06-08-2004, 06:20 PM
unstable's Avatar
Murderator
 

Last journal entry: Brackets, Stories and the future
Last photo:
Join Date: Feb 2003
Age: 35
Posts: 743
Wiki Edits: 0

Thanks: 2
Thanked 4 Times in 4 Posts
that's the only thing TO do. Just not something I had thought about because I'm a *******.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 06-08-2004, 07:53 PM
Member
 
Join Date: Apr 2004
Location: Cassville,MO
Posts: 821
Wiki Edits: 0

Thanks: 21
Thanked 44 Times in 40 Posts
Not as much of a ******* as you're making yourself out to be. You figured it out before you bolted it together and turned the key.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 06-08-2004, 08:19 PM
ratlover's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: canada
Posts: 363
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
here's a pic of how much clearance I have with .525" lift and 2.06" valves. It amounted to .160" valve face to piston an about
1/3 of that to the side. (.053) you may just squeek by, but don't take my word for it. Check it with clay as well to be sure. Someone else will have to give you the tightest rec. clearance as I do not know what that would be. I also decked the block .020" before taking that measurement.
Attached Thumbnails
Click image for larger version

Name:	test vid&pics 001a.jpg
Views:	87
Size:	11.8 KB
ID:	1850  
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 06-09-2004, 07:30 AM
unstable's Avatar
Murderator
 

Last journal entry: Brackets, Stories and the future
Last photo:
Join Date: Feb 2003
Age: 35
Posts: 743
Wiki Edits: 0

Thanks: 2
Thanked 4 Times in 4 Posts
I've read about the procedure for checking...just not exactly sure what I'm doing. This will be a first for me.

I know you take the clay, about 1/4" thick, and put it into the eyebrows. Then you bolt the head on, and rotate the motor over to make the valves open.

This should leave an impression on the clay. But after this, I'm not quite sure on how to measure it, or what is acceptable...etc. etc.

Oh also, why I'm nagging about stupid stuff. Does anyone have a recommendation on a hot street cam for this thing? I'm goign to be running a standard tranny, headers...not sure of my rear gears ATM. I will run a dual plane intake. I'd like something pretty lopey, that has plenty of strength in the low RPMS so I can goose it up a bit. I like that mean sound with a rough idle.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 06-09-2004, 07:46 AM
killerformula's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Carburetor
Last journal entry: Clean up
Last photo:
Join Date: Oct 2003
Location: Northeast
Age: 34
Posts: 3,485
Wiki Edits: 3

Thanks: 13
Thanked 27 Times in 18 Posts
Suggested from a good source (30 machine shop guy) what do u guys think?

When i was bolting together my mopar the machine shop guy (who just got done doing my machine work and selling me slugs, pump, rings, pins, you name it) said to bolt the head on with about 20 ft lbs of torque in the normal, uniform pattern WITHOUT using the head gasket, then measure the piston to valve clearance. This because apparently (and maybe also because I was using a roller cam) at higher RPM the lifters have a significantly increase kinetic energy (make sense) and it causes the valve to lift some times .030 thousandths beyond normal spec lift! Also, your exhaust valve can expand (think he said something about that). Anybody heard this advice?

K
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 06-09-2004, 08:17 AM
unstable's Avatar
Murderator
 

Last journal entry: Brackets, Stories and the future
Last photo:
Join Date: Feb 2003
Age: 35
Posts: 743
Wiki Edits: 0

Thanks: 2
Thanked 4 Times in 4 Posts
I was reading the procedure on IskyCams.com:

http://www.iskycams.com/camshaft.html

It walks through the entire process...there's another way where you use a weak spring to check. I've just never done this and I don't want to screw it up. lol

I wouldn't imagine that I should have a problem. I have flat top pistons. I'm just thinking about the reliefs that are cut into the pistons...if they are too small or whatever...apparently they are there for a reason right? lol. argghghghg, I'm going to blow something up I'm sure of it.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 06-09-2004, 08:41 AM
ratlover's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: canada
Posts: 363
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
As you can see in the photo, you cut a section of the clay away, and I used the but end of a vernier caliper to take depth measurements at various points. You can also use a depth mic if you have one. With the flattop pistons, you have to watch how much cam you select as you will need more compression to run a long duration cam. The motor would have a great sound at idle, but in reality be a real dog. I chose a 268h comp cam and was pretty happy with the idle characteristics and power with the flatops.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 06-09-2004, 11:52 AM
E.T. divided by $ spent= Speed
 
Last photo:
Join Date: May 2002
Location: NYS america's unwiped butt
Age: 35
Posts: 1,858
Wiki Edits: 0

Thanks: 0
Thanked 5 Times in 5 Posts
I squirt WD-40 on the top of the clay(after its stuck to the piston)so that the valve doesn't stick to it and pull it off the piton and into the vlave seat.
Use a regular machinest's ruler to measure the impression in the clay.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 06-09-2004, 12:07 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
Quote:
Originally posted by unstable
I'm going to blow something up I'm sure of it.
i had that feeling too.

take your time, do it right, and it will not blow up.

if i can do it, ANYONE can.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 06-09-2004, 06:17 PM
ratlover's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: canada
Posts: 363
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
think of it this way. you currently have 2.06" valves, you switched to 2.19". That's a difference of .013" divide that by two and you have the amount of .0065" difference relative to the valve reliefs.(not a huge amount) assuming that your block has not been decked, I think you might have enough room if you base your camshaft selection relative to the amount of clearance that exists with your present cam. You could also try a thicker head gasket in the worst case scenario. (or lower lift cam.)
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 06-09-2004, 07:37 PM
unstable's Avatar
Murderator
 

Last journal entry: Brackets, Stories and the future
Last photo:
Join Date: Feb 2003
Age: 35
Posts: 743
Wiki Edits: 0

Thanks: 2
Thanked 4 Times in 4 Posts
Mr. Ratlover...oh great master of understanding these things...lol.

I have no idea what cam is in that thing now. I was planning on replacing it though.

Now, here's where it gets tricky. Help me here..

If I measure the clearance with the cam I have in now...is there a way of determing how much lift the current cam is? to where I can say "hey I still have room to move up...or hey I need to move down to something smaller"?

I'm perplexed. I tore these heads off and I feel like a *******. I had no idea there was this much involved. I'll get through it though...with everyone's help. No better way to learn than to actually do something...right?
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 06-09-2004, 10:08 PM
ratlover's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: canada
Posts: 363
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I appreciate your flattery, but I am just trying to help. I make no claim to be the all knowing chevy guru type. The easiest way is with a magnetic base dial indicator. They are great for measuring all kinds of things so it's not just a one use dust magnet. If you put the plunger on the lifter or cam lobe it will read the amount of travel in .001" of an inch increments. you would have to multiply that by your rocker arm ratio in order to get net lift.(1.7 on a big block usually-stock ratio) you can cheat if all you require is an approximation. take a vernier caliper or machinists rule and measure the shiny part of the pushrod where the pushrod guide rubs, and that will give you an idea or get you in the ball park. This is where degreeing a cam is very useful if the duration is also unknown. there's a thread recently started, but not many people there saw the use of this procedure. They were speaking of verifying known cam timing however. The dial indicator can also be used for measuring crank shaft endplay, true tdc, backlash .. the list goes on. I would also look on the cam for identifying marks which may save you all this measuring also. look on the back of the cam on the distributor end.
Attached Thumbnails
Click image for larger version

Name:	cam degreed 0040.jpg
Views:	36
Size:	29.7 KB
ID:	1855  
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 06-10-2004, 07:19 AM
unstable's Avatar
Murderator
 

Last journal entry: Brackets, Stories and the future
Last photo:
Join Date: Feb 2003
Age: 35
Posts: 743
Wiki Edits: 0

Thanks: 2
Thanked 4 Times in 4 Posts


I've been reading up on cam degreeing but much of it sounds pretty confusing...only because I've never done it before. I come from the school where, I can handle the procedure, but it's nice to have someone around or available to tell me if I messed up.

know what I Mean? I could get all the numbers and think I'm Kosher--when I'm actually not.

I'll post back when I'm further along. Heads are in another state right now getting worked over.
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 12:51 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.