Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - sbc 350 cam timing off?
View Single Post
  #2 (permalink)  
Old 10-05-2012, 10:54 PM
DoubleVision's Avatar
DoubleVision DoubleVision is offline
Not Considered a Senior Member
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 43
Posts: 10,733
Wiki Edits: 0

Thanks: 19
Thanked 77 Times in 71 Posts
I think it can be done by getting the cam specs and checking it with a dial indicator while verifing the piston is at top dead center. However I suspect the issue is elsewhere. For your compression ratio figures to be varied like that you either didn't perform the test correctly, or it's got a bore or ring issue or it's got some partially burned valves. You said the engine has been overhauled. How many miles since the overhaul? What type of oil did you use in the break in process? Were the heads reworked? Is it using any oil?
When you performed the compression test it's supposed to be done with the power wire off the distributor, all spark plugs removed and the throttle set to it's wide open position.
Standing in front of the engine pop the right side valve cover, cycle the engine to Top dead center and see if both valves are closed. If they aren't or if one is partially open then I would say the timing is off on the chain.
In the past I've seen guys replace the timing chain and install it 2 teeth off and the car would still run good. If it's off too much then it won't run at all. Also I wouldn't go by the oem timing spec. SBC's like 12 degrees before top dead center with vacuum advance disconnected and plugged. Once it's set at 12 degrees, reconnect the vacuum advance to a manifold vacuum source, one that pulls vacuum full time including at idle. Then recheck timing, it should be 18 to 24 degrees before top dead center. Do this and it'll pick up considerable more power, use less fuel and will have far better low speed cruise manners. What size camshaft did you use?
Reply With Quote
The Following User Says Thank You to DoubleVision For This Useful Post:
gfackrell (10-05-2012)