This will take you to the main site where there is history, technical information and other information on these cars.
This takes you back to the main page of the forums.
This is the control panel to change your password, information and preferences on this message board.
Click here if your lost your password or need to register on this message board. You must be a registered user to post. Registration is free.
Search this board for information you need.
Click here to buy cool Squarebirds mechandise.
Click here to support Squarebirds.org. For $20 annually receive 20mBytes webspace, a Squarebirds e-mail address and member's icon on the message board.
  #21  
Old 02-06-2015, 04:20 PM
simplyconnected's Avatar
simplyconnected simplyconnected is offline
Slow Typist
 
Join Date: May 26 2009
Posts: 7,124
simplyconnected is on a distinguished road
Default

Something is missing between the machine shop and the owner. Steve is right, I have never heard of an engine machine shop that let the block go without proper honing. "Proper" is the operative. They usually under-bore, then 'finish hone', then 'brush' the cylinders to match the pistons. Also, I've never seen newly bored cylinders that are shiny-smooth. Cast iron requires honing after boring so how did they get so smooth?

Honing is done at 45-degrees both ways and it leaves deep grooves. This is important. It's all important. They measure the pistons and brush the tops off the cylinder walls to meet each piston size.

Ring gaps come two ways, 'File-to-Fit' or 'Pre-Gapped'. Isn't that wonderful? The problem is, you have not compensated for the type of alloy you are using. Find out what brand of pistons you are using.

Hypereutectic Alloy pistons are great. I use them, all the auto manufacturers use them and they are much better than your original pistons. Hypereutectic alloy also transfers MUCH less heat, so they run hot. You need to consult your piston manufacturer regarding the correct gap for your bore and rings. There is a big difference between piston alloys. If a ring sees too much heat, it expands, the gap closes and if you get lucky the ring breaks because it has nowhere to go. Otherwise it scuffs the cylinder walls. You need adequate gap; too much is always better than not enough.

How do you measure? Pull the rings off the piston, then put each ring in the bore it will live in (one by one) using the piston to shove it down at least two inches. The bare piston will make sure the ring is square and the end gap will be exposed for measurement with a feeler gauge. File or lightly touch a grinding wheel to the end gap until it is correct. Keep the top and second rings in order and pay attention to which way faces up.

Blocks are normally decked before they leave the machine shop, just to make sure they are square and not warped. A normal block needs very little shaved off, sometimes just enough to remove coolant pitting. I am bothered by the fact that one bank's pushrods bent but the other bank didn't. Right or wrong, both banks should be identical. - Dave
__________________
My latest project:
CLICK HERE to see my custom hydraulic roller 390 FE build.

"We've got to pause and ask ourselves: How much clean air do we need?"
--Lee Iacocca
Reply With Quote
  #22  
Old 02-13-2015, 04:51 PM
HighwayThunder's Avatar
HighwayThunder HighwayThunder is offline
Apprentice
 
Join Date: Nov 19 2013
Posts: 90
HighwayThunder is on a distinguished road
Default Valve varnish

Here's a pic that conveys what old bad gas can do to your valves. This valve is for the #2 intake port. Once the springs are compressed and removed the valve should just slide out. This one had to be tapped free with a rubber hammer. The gummy residue on the stem caused the valve to be stuck.

This valve's pushrod is one of those that bent.

Cheers,
Attached Images
File Type: jpg FouledValve.jpg (74.9 KB, 76 views)
__________________
Richard
1966 Thunderbird Hardtop,
390 with Edelbrock heads. Visit my restoration blog at hwythunder.com .
Reply With Quote
  #23  
Old 02-19-2015, 11:23 AM
HighwayThunder's Avatar
HighwayThunder HighwayThunder is offline
Apprentice
 
Join Date: Nov 19 2013
Posts: 90
HighwayThunder is on a distinguished road
Default Hydraulic roller lifters and cam conversion

I'm planning to covert to a roller camshaft and hydraulic roller lifters. Summit has COMP Cams Xtreme Energy Retrofit Cam and Lifter Kit (CCA-CL33-432-9) that has the cam and lifters. My engine is a '66 Ford 390-FE with Edelbrock Performer RPM Heads. I plan to re-use the stock rocker arm assembly.

What size Pushrod Length Checker tool should I get to measure for the pushrods?

Cheers,
__________________
Richard
1966 Thunderbird Hardtop,
390 with Edelbrock heads. Visit my restoration blog at hwythunder.com .
Reply With Quote
  #24  
Old 02-19-2015, 06:21 PM
simplyconnected's Avatar
simplyconnected simplyconnected is offline
Slow Typist
 
Join Date: May 26 2009
Posts: 7,124
simplyconnected is on a distinguished road
Default

Did you roll this valve to check for straightness?
I'm looking at the carbon witness mark where it seals to the mating valve seat. It appears to be low on one side and high on the other.

I have also seen valves much dirtier than this from the days when gasoline contained lead. Sometimes a bad running engine only needed a high speed run on the expressway for an hour or two so the valves would clean themselves.

The procedure for determining pushrod length was already given in Post #18. Whether you use a roller or flat, hydraulic or solid, the setup is the same. You must measure your 'stack'. Everyone will have a different height depending on the head gasket and splash pan (used or not). - Dave
__________________
My latest project:
CLICK HERE to see my custom hydraulic roller 390 FE build.

"We've got to pause and ask ourselves: How much clean air do we need?"
--Lee Iacocca
Reply With Quote
  #25  
Old 02-23-2015, 11:57 AM
HighwayThunder's Avatar
HighwayThunder HighwayThunder is offline
Apprentice
 
Join Date: Nov 19 2013
Posts: 90
HighwayThunder is on a distinguished road
Default Cylinder crosshatch

Quote:
Originally Posted by simplyconnected View Post
Something is missing between the machine shop and the owner. Steve is right, I have never heard of an engine machine shop that let the block go without proper honing. "Proper" is the operative. They usually under-bore, then 'finish hone', then 'brush' the cylinders to match the pistons. Also, I've never seen newly bored cylinders that are shiny-smooth. Cast iron requires honing after boring so how did they get so smooth?

- Dave
I got in touch with the machine shop. They did hone the cylinders. The cylinders looked smooth because the photo I posted didn't have sufficient resolution for the crosshatch to be visible. Upon closer inspection the crosshatch is visible.

Cheers,
__________________
Richard
1966 Thunderbird Hardtop,
390 with Edelbrock heads. Visit my restoration blog at hwythunder.com .
Reply With Quote
  #26  
Old 03-09-2015, 10:24 AM
HighwayThunder's Avatar
HighwayThunder HighwayThunder is offline
Apprentice
 
Join Date: Nov 19 2013
Posts: 90
HighwayThunder is on a distinguished road
Default

I ordered an adjustable pushrod. I was expecting it to be marked with a graduated measurement scale, but it's not.

My digital caliper is only 6". Do I need to get a bigger caliper, or is there another method for determining pushrod length?

Do you have any tips on how to take accurate measurements?
__________________
Richard
1966 Thunderbird Hardtop,
390 with Edelbrock heads. Visit my restoration blog at hwythunder.com .
Reply With Quote
  #27  
Old 03-09-2015, 01:25 PM
simplyconnected's Avatar
simplyconnected simplyconnected is offline
Slow Typist
 
Join Date: May 26 2009
Posts: 7,124
simplyconnected is on a distinguished road
Default

Set the adjustable pushrod to the correct length.
Unscrew the rocker shaft and gently lift the pushrod out.
Take the pushrod to a local machine shop and ask them to measure it.
Order 16 of them.

When a machine shop decks a block, it is sitting on the main journals so all cylinders are the same exact height and it is square with relationship to the crankshaft.

You have CNC-machined aluminum Edelbrock heads, so they are geometrically correct. When a rebuild is machined correctly, all cylinders are the exact same size and length. Measuring ONE pushrod should be the same length for ALL pushrods. If there is a slight variation, after all, these are hydraulic lifters that do compensate for one or two thousandths here or there. Just make sure your pre-load is correct and you'll be good.

Those of us with solid lifters (like all Y-Blocks) MUST have individual means of adjustment. Sometimes the rocker arm has a jack screw and sometimes adjustment is done on the pushrod. Either way, when you add up the 'stack' of tolerances, none of the valve trains are exactly equal after running for some time. Oiling and other factors play a huge role in how metal wears or how metal parts wear-in to mate with each other.

Valve seats wear just from running unleaded fuel. When that happens, the preload becomes deeper because the spring pulls the valve stem up higher. Cam, lifter and pushrod wear does the opposite, relaxing the rocker arm which makes preload more shallow.

You can see that preload becomes more important later than sooner. What happened to your initial preload? You said your new build ran well at first, then it started bending pushrods. Your preload had to be WAY down there on the lifters. So much so that they bottomed out then kept going.

I know you said, 'bad gas'. Each valve is in a bronze (oilite) guide with two hundred pounds pulling up from the spring. I have seen engines go through a whole tank full of bad gas without damaging valves. If this were my engine, I would pull each valve and spin them to make sure none are bent.

Before you start the engine, check your piston-to-valve clearance. Think about this... even if a valve sticks part way down, the rocker arm relaxes on the pushrod. Then the piston pushes the valve up. The problem with that is, pistons are at an angle from the valve. They touch on one edge of the tulip and the guide is not straight up. So, valves tend to bend and guides tend to chip off inside the runner.

Carefully inspect the tops of your pistons for collision witness marks. It will explain your bent pushrods. - Dave
__________________
My latest project:
CLICK HERE to see my custom hydraulic roller 390 FE build.

"We've got to pause and ask ourselves: How much clean air do we need?"
--Lee Iacocca
Reply With Quote
  #28  
Old 04-02-2015, 08:35 AM
HighwayThunder's Avatar
HighwayThunder HighwayThunder is offline
Apprentice
 
Join Date: Nov 19 2013
Posts: 90
HighwayThunder is on a distinguished road
Default A bit of good news

I finally got around to pulling the engine to install the new roller cam/lifters and to fix the oil leak at the back of the engine.

The good news is that the leak is not from the rear crank seal. The leak is from two of the oil passage plugs -- the crankshaft will not have to be removed.
__________________
Richard
1966 Thunderbird Hardtop,
390 with Edelbrock heads. Visit my restoration blog at hwythunder.com .
Reply With Quote
  #29  
Old 04-02-2015, 09:45 AM
Yadkin Yadkin is offline
Banned
 
Join Date: Aug 11 2012
Posts: 1,910
Yadkin is on a distinguished road
Default

Quote:
Originally Posted by HighwayThunder View Post
I ordered an adjustable pushrod. I was expecting it to be marked with a graduated measurement scale, but it's not.

My digital caliper is only 6". Do I need to get a bigger caliper, or is there another method for determining pushrod length?

Do you have any tips on how to take accurate measurements?
As Dave said, or I just measured several with a good tape measurer, ordered all the same length, and have adjustable rocker arms to fine tune.
Reply With Quote
Reply


Thread Tools
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 12:22 PM.

Driving, racing or working on cars can be hazardous. The procedures and advice on this website including the message board are opinion only. Squarebirds.org and its webmasters and contributors do not guarantee the correctness of the advice and procedures. The Squarebirds.org and its webmasters assume no liability for any damage, fines, punishment, injury or death resulting from following these procedures or advice. If you do not have the skills or tools to repair your car, please consult a professional. By using this site you agree to hold harmless the Squarebirds.org, its authors and its webmasters from any resulting claim and costs that may occur from using the information found on this site.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Any submissions to this site and any post on this site becomes property of Squarebirds.org . The webmasters reserve the right to edit and modify any submissions to this site. All material on this is site is copyrighted by the Squarebirds.org. Reproduction by any means other than for personal use is strictly prohibited. Permission to use material on this site can be obtained by contacting the webmasters. Copyright 2002-2016 by Squarebirds.org.