engine gremlins. - Team Camaro Tech
Engine General Engine Discussion.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 23 (permalink) Old Apr 12th, 09, 12:53 PM Thread Starter
Senior Tech
Ashlee and Andy
 
Join Date: Dec 2008
Location: Indiana
Posts: 178
engine gremlins.

I decided to do a quick tear-down and regasket on the 350 in my 68 camaro, I had the valves in the heads freshened up last year, checked the cam (one low lobe, nothing to bad) and aligned the cam-crank.

I have tried to start the car for a few days now, I'm getting around 50lbs of compression on all cylinders, which is very low, and can't seem to get any extra compression out of it. I've adjusted valves several times, tighter, looser, zero lash and "clacky" and haven't had any improvement, also rechecked and re-aligned the cam and crank.

Any ideas or suggestions? I don't have a leak-down tester handy or a spark checker either.
ap68 is offline  
Sponsored Links
Advertisement
 
post #2 of 23 (permalink) Old Apr 12th, 09, 03:11 PM
Senior Tech
Steps
 
Join Date: Dec 2005
Location: New Zealand
Posts: 13,316
Re: engine gremlins.

Even at 50 lb the engine will fire if has spark, compression and fuel.

My Spelling is not incorrect...it is creative

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Steptoe is offline  
post #3 of 23 (permalink) Old Apr 12th, 09, 03:16 PM
Senior Tech
Brandon
 
Join Date: May 2004
Location: Monroe, NC
Posts: 2,049
Garage
Re: engine gremlins.

threre is that 180* out thing to consider.

Brandon J. licence 1NASTY67

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Nantooch is online now  
 
post #4 of 23 (permalink) Old Apr 12th, 09, 04:40 PM Thread Starter
Senior Tech
Ashlee and Andy
 
Join Date: Dec 2008
Location: Indiana
Posts: 178
Re: engine gremlins.

timing is set so the dot on the cam and crank are straight up, rotor pointing at number one.

50 psi, would be like runnign a 5:1 CR. is there an actual likely hood of the car getting a better compression or did I end up doing something wrong?
ap68 is offline  
post #5 of 23 (permalink) Old Apr 12th, 09, 07:01 PM
Gold Lifetime Member
jared
 
Join Date: Sep 2008
Location: Fairfax, Mo
Posts: 1,097
Re: engine gremlins.

Should'nt the two timming marks be pointing at each other<cam pointing down and crank shaft pointing up> and could have the crank gear on the wrong degree mark!
jcfcamaro is offline  
post #6 of 23 (permalink) Old Apr 12th, 09, 08:02 PM Thread Starter
Senior Tech
Ashlee and Andy
 
Join Date: Dec 2008
Location: Indiana
Posts: 178
Re: engine gremlins.

pointing at each other is to fire #6, both pointing up supposedly fires #1 TDC... I checked the cam 3 times today to no avail. still 50 lbs

Edit: motor is a 30 over 74 350, wiseco flat top pistons with valve reliefs, stock iron heads (1.90 intake) edelbrock performer RPM and holley 650 cfm, ran great last year, and I'm really thinking that 50 PSI is way to low for this motor.

Last edited by ap68; Apr 12th, 09 at 08:31 PM.
ap68 is offline  
post #7 of 23 (permalink) Old Apr 12th, 09, 09:31 PM
butch
 
Join Date: Mar 2009
Location: mississippi
Posts: 20
Re: engine gremlins.

you are 180 out you need the cam and crank dots pointing at each other cam down and crank up you were mis informed about your setting
ugot86d is offline  
post #8 of 23 (permalink) Old Apr 13th, 09, 07:57 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,593
Garage
Re: engine gremlins.

A couple things you can do as others have suggested.
With camshaft arrow/mark pointing down and directly over the imaginary centerline between the cam & crank, place the crank socket pointing directly in the middle of the chain slack. If they don't align/poin to each other, the cam or crank might be off a tooth or so. I have worked on a Buick 350 being three teeth off still collect 90 PSI of compression.

Advance/retard the camshaft a tooth at a time and take a compression reading for each tooth. The higher the compression, the right direction.

Fifty PSI in all cylinders? Correct head gaskets used? Torqued correctly?

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - maybe this year, 2019 ...
Everett#2390 is offline  
post #9 of 23 (permalink) Old Apr 13th, 09, 08:17 AM Thread Starter
Senior Tech
Ashlee and Andy
 
Join Date: Dec 2008
Location: Indiana
Posts: 178
Re: engine gremlins.

Yup... Thats why it was hard to understand what could be wrong for them all to have such low compression... it wouldn't be so odd if one or a couple had low compression, but all of them?
ap68 is offline  
post #10 of 23 (permalink) Old Apr 15th, 09, 12:56 PM
Tyler
 
Join Date: Apr 2009
Location: Council Bluffs Ia
Posts: 3
Re: engine gremlins.

I agre with ugot86d you were misinformed on you cam intall.. get #1 to top dead center and line up the dots.
wyant777 is offline  
post #11 of 23 (permalink) Old Apr 15th, 09, 01:25 PM
Senior Tech
Shawn
 
Join Date: May 2005
Location: PA
Posts: 1,339
Re: engine gremlins.

Quote:
Originally Posted by ugot86d View Post
you are 180 out you need the cam and crank dots pointing at each other cam down and crank up you were mis informed about your setting
#1 firing TDC on my engine was when both dots were pointing up
victimizati0n is offline  
post #12 of 23 (permalink) Old Apr 15th, 09, 04:39 PM
Senior Tech
Al
 
Join Date: Nov 2002
Location: Vancouver, USA
Posts: 10,511
Re: engine gremlins.

Assuming the cam was installed correctly - it sounds like it was. Cam dot down, crank dot up. (dot to dot) If you removed the crank gear during the freshen up, some of those buggers have 3 keyways on them and can be confusing. If you didn't remove the crank gear, disregard.

You are correct - when the cam is installed "dot to dot" it is ready to fire #6, not #1. Crank dot up and cam dot up is ready to fire #1 - so you got that right.

You are getting the lifters on the base circle as you adjust the valves, right? And you trust your compression gauge?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BPOS is offline  
post #13 of 23 (permalink) Old Apr 15th, 09, 06:16 PM
Senior Tech
Shawn
 
Join Date: May 2005
Location: PA
Posts: 1,339
Re: engine gremlins.

Quote:
Originally Posted by BPOS View Post
Assuming the cam was installed correctly - it sounds like it was. Cam dot down, crank dot up. (dot to dot) If you removed the crank gear during the freshen up, some of those buggers have 3 keyways on them and can be confusing. If you didn't remove the crank gear, disregard.

You are correct - when the cam is installed "dot to dot" it is ready to fire #6, not #1. Crank dot up and cam dot up is ready to fire #1 - so you got that right.

You are getting the lifters on the base circle as you adjust the valves, right? And you trust your compression gauge?
thanks for the info, when i tore my timing cover off, i was confused when i saw that, because i thought dot to dot should be firing on #1, until i did a bit of research, and this thread pretty much confused me
victimizati0n is offline  
post #14 of 23 (permalink) Old Apr 16th, 09, 05:40 AM
Senior Tech
 
Join Date: Jul 2003
Location: california
Posts: 662
Re: engine gremlins.

You can line it up either way. I always go dot to dot so that there is less chance for error. If it is 180o out, just drop the distributor 180o the other way. If the compression is low try backing the rocker arms off some and checking. It could be a valve tightened down a little too much.
lluciano77 is offline  
post #15 of 23 (permalink) Old Apr 16th, 09, 07:48 AM
Senior Tech
 
Join Date: Dec 2003
Location: Wyoming
Posts: 1,635
Re: engine gremlins.

There is some very confusing information here! When I install them, first verify that #1 piston is at top dead center. Then I line the dots so that the crank dot is straight up and the cam dot is straight down. Move nothing now until you install your timing cover and pointer. Verify that your pointer is actually pointing at 0* (some will point at 4* BTDC which is fine). You just might have the balancer that has the timing mark up near the 12 o'clock position at TDC. If so, mark your damper with a paint stripe at zero. Now, after marking 0, rotate your crank 180* and install your distributer to fire at #1 piston. You should now be good to go. From youir description, I suspect you have the 8" balancer with the timing mark at near 12 o'clock.
deerhunter is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user 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.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome