Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic
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> Cam Question
User Name
Password
lost password?   |   register now

Thread: Cam Question Reply to Thread
Title:
  
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :

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:

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.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
02-10-2013 12:42 AM
pilona42 Think I found the problem. Had the intake off and checked my lifters. Sure enough they were all stuck up. This motor sat in my shop for a couple years and that must have done them in. Gonna throw a new set on in the morning and see what happens.
02-09-2013 03:21 PM
F-BIRD'88 If the dots are not infact lined up the cam will move approx 20deg for each tooth it is out.

a non stock cam will need a non stock timing curve. usually a lot more initial idle timing.

if it was the 350-290HP GM crate motor it has a high perf cam and will like a moderate increase in idle timing
18 to 24deg at idle is typical.
measure the cam lobe lift. a wiped cam lobe is a possibility watch the rocker motion as the engine turns.
02-09-2013 01:48 PM
pilona42
Quote:
Originally Posted by Richiehd View Post
Sounds like maybe the cam is wpied a lobe or maybe you have a timing chain set withe the 3 different settings and you have the marks wrong.
Only 1 keyway in my crank gear! Its my understanding that with that setup it is impossible to be so far off that it wont run as long as the dots are lined up. Would you agree?
02-09-2013 01:45 PM
pilona42
Quote:
Originally Posted by F-BIRD'88 View Post
what crate motor? they do not all have the same cam in them?

what else did you change.. everything...
Just put a set of fresh 2.02's on and a Q-jet intake. New cap, rotor, wires and plugs. The lower end came from a buddy that had a problem with it so he just bought a new long block. I tore it down and found 3 burnt intake valves. He told me it only had 12,000 miles on it and compression was good. As for the cam specs. I dont know. Is it possible the lift/durration is incompatable with these 2.02 heads?
02-09-2013 01:43 PM
Richiehd Sounds like maybe the cam is wpied a lobe or maybe you have a timing chain set withe the 3 different settings and you have the marks wrong.
02-09-2013 01:34 PM
F-BIRD'88 There is NFW you could build your own race motor and not know that the intake valve closes after BDC.

the basics
http://www.iskycams.com/degreeing.php
02-09-2013 01:32 PM
F-BIRD'88 what crate motor? they do not all have the same cam in them?

what else did you change.. everything...
02-09-2013 01:30 PM
pilona42
Quote:
Originally Posted by F-BIRD'88 View Post
after installing the cam and timing gears dot to dot. You must rotate the crankshaft 1 revolution, before
installing the distributor. just like the cam install instructions (that you did not read) tell you. or the spark timing is 180deg out.
and it will not run.
it is fireing on the overlap . make it fire at TDC on the power stroke by installing the distributor correctly.

I never uninstalled the cam. Just replaced the chain and gears. Ive been keeping an eye on the oil and It is contaminated. Not my first time. Ive put a sbc together many times on my racecar but it has been about 5 years. Thats why this is so frustrating!
02-09-2013 01:21 PM
pilona42
Quote:
Originally Posted by F-BIRD'88 View Post
You are likely hearing it leak past the piston rings. If the cranking compression is 150 its good.

On a stock OEM cam the intake is not fully closed until 40deg ABDC +/- The piston is approx 1/3 past BDC

The bigger the cam the later the intake closes (generally)

Did you verify accurate timing tab TDC location, using a piston stop to find true TDC?
often a issue with non stock aftermarket parts. inaccurate timing setting is the result.

what cam?
It is a stock cam from the crate motor short block.
02-09-2013 01:19 PM
F-BIRD'88 large non stock duration cams need a lot of spark advance at idle.
stock timing and a stock timing curve will not work with big cams.
Post all the engine specs.
02-09-2013 01:18 PM
F-BIRD'88 If you filled the cylinder with gasoline remove all the spark plugs and disable the spark power.
Crank it over and all the fuel will come flying out.
reinstall the spark plugs and CHANGE THE OIL. the oil is gas deluted now.

get the spark set up on the TDC ont he fireing stroke not the overlap.
5psi fuel pressure. more is not better. it will flood with more than 7psi.
this must be your first time.
02-09-2013 01:18 PM
pilona42
Quote:
Originally Posted by F-BIRD'88 View Post
after installing the cam and timing gears dot to dot. You must rotate the crankshaft 1 revolution, before
installing the distributor. just like the cam install instructions (that you did not read) tell you. or the spark timing is 180deg out.
and it will not run.
it is fireing on the overlap . make it fire at TDC on the power stroke by installing the distributor correctly.
I understand that the dot to dot position is the compression stroke for #6 and I have verified that I am on the compression stroke for #1 when dropping in my dist.
02-09-2013 01:15 PM
F-BIRD'88 fuel pressure 5psi
02-09-2013 01:14 PM
F-BIRD'88 after installing the cam and timing gears dot to dot. You must rotate the crankshaft 1 revolution, before
installing the distributor. just like the cam install instructions (that you did not read) tell you. or the spark timing is 180deg out.
and it will not run.
it is fireing on the overlap . make it fire at TDC on the power stroke by installing the distributor correctly.
02-09-2013 01:11 PM
pilona42 Thanks, it must be somthing stupid. Ive tried a couple different carbs because I noticed excessive fuel in the intake when I removed it. Got a edelbrock off a running vehicle and installed it with no better result. When I took the heads off a few of the cylinders were flooded with fuel! I cant remember if I had the plugs out and turned the motor over after I pulled my bad holley so Im hoping it was just extremely flooded.
This thread has more than 15 replies. Click here to review the whole thread.

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


All times are GMT -6. The time now is 02:51 AM.


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.