cam timing

Old 07-18-2011, 03:14 PM
  #1  
john910
Member
CRAFTSMAN
Thread Starter
 
Join Date: Mar 2005
Posts: 59
Default cam timing

over the winter i replaced my cam.. the car is i900lbs . power glide w/brake. 350 sbc 30 over . last year the cam was comp cams 292 , 501 lift hyd. cam 202 valves, vortec heads. 750 holley. car ran 6.50 -60s 1/8 mile. with 60-fts at 1.44. then i had a cower cam #00357 587 lift mech. installed with a adjustable cam gear, and have it set @ 0. with 35 degees timing. car runs the same as last year. my question is what wound help in timing advancing the gear 2 or 4 or more degees
john910 is offline  
Old 07-18-2011, 08:26 PM
  #2  
zipper06
Senior Member
RACING JUNKIE
 
Join Date: Jan 2006
Location: La.
Posts: 2,890
Default

I would suggest advancing the cam 4* and timing 40* BUT i think the cam is still too small for that weight car, it would run better with a 6.30/6.40 lift cam.

JMO

Zip.
zipper06 is offline  
Old 07-22-2011, 03:54 PM
  #3  
john910
Member
CRAFTSMAN
Thread Starter
 
Join Date: Mar 2005
Posts: 59
Default cam timing

now if i advance it, will i have any issues with valve to piston clearance. or will that stay the same. thanks for your help.
john910 is offline  
Old 07-22-2011, 06:43 PM
  #4  
wazup
Senior Member
EXPERT BUILDER
 
Join Date: Dec 2010
Posts: 345
Default

I agree with Zip on the bigger cam, something in the low six hunderds or advance the cam in the engine. This will give a little more bottom end power and when you advance it you will bring the intake valve closer to the piston. Would really need to know what size pistons and where the valves open and close. I would advance the cam and check the PVC this should help.
wazup is offline  
Old 07-23-2011, 06:08 AM
  #5  
oldandtired
Senior Member
RACING JUNKIE
 
oldandtired's Avatar
 
Join Date: Dec 2008
Location: Sugar Hill, GA
Posts: 1,365
Default Re: cam timing

Originally Posted by john910
now if i advance it, will i have any issues with valve to piston clearance. or will that stay the same. thanks for your help.
For stock motors, .045 is the minimum valve to piston clearance
On High RPM motors, use .080 on the intake and .100 in the exhaust.

1. Write down the lash you will use (example Int = .028, Exh = .030.
2. With the cam on the heel, adjust the lash to zero, do not lock the polynut.
3. Put a dial indicator on the rocker, just above the spring retainer.
4. Intake number = .080 minus lash (example .080-.028 = .052).
5. Tighten the poly nut .052.
6. By hand, rotate the crankshaft while watching the rocker go up and over the nose of the lobe "feeling" for interference.
7. If none, tighten another .020 and rotate again. Repeat and you will eventually find your clearance.
8. Repeat for the exhause (example .100 - .030 = .070).

If you change the advance on the cam, you must start over.
JMP but works from me.
oldandtired is offline  
Posting Rules
You may not post new threads
You may not 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


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -