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Discussion Starter #1
Recently rebuilt the 302 in my 68 FB. Can't get a good smooth idle even after a trip to a carb specialists who set it up better than I had it. Are my expectations unrealist considering it's got a new Edlebrock Performer intake with their 600 electric choke carb (factory rebuilt) and a warmer than stock Crane cam? Don't know how to describe the cam properly (it was recommended by engine builder). The spec sheet on the cam lists it as part # 13004, (Hydraulic Energizer) LIFT: INTAKE @ CAM 2934, @ VALVE 469; EXHAUST @ CAM 2934, @ VALVE 469. There are two references to Cam timing: CAM TIMING @ .004 INTAKE, OPENS 24 DEGREES BTDC, CLOSES 62 DEGREES ABDC, DURATION 266; TAPPET LIFT EXHAUST OPENS 64 DEGREES BBDC, CLOSES 22 DEGREES ATDC, DURATION 266. Below on the sheet is: CAM TIMING @ .050 INTAKE, OPENS 0 DEGREES BTDC, CLOSES 30 DEGREES ABDC, MAX LIFT 105 DEGREES ARDC, DURATION 210 DEGREES. TAPPET LIFT EXHAUST 40 DEGREES BBDC, (10) DEGREES BTDC, MAX LIFT 115 DEGREES BTDC, DURATION 210 DEGREES. Sorry for all the detail but am not sure what is relevent. One final bit of information, went to a chrome HIPO air cleaner and didn't close off the hole in my stock exhaust manifold for the heat pipe. Am constantly shifting my C4 into neutral at lights because it's pulling the car. Would appreciate any help you guys can give me. Mark
 

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I didnt calculate the overlap....but if Im reading right, thats not a very big cam.

What kind of ignition are you using and is it in good shape?
 

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Discussion Starter #4
Timing set at 6 degrees BTDC but yes, turned idle screw up to smooth out idle to some extent. Mark
 

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IIWY I'd try to advance my initial timing slightly and see if that makes it idle better. If that doesn't help, you can set your idle up a bit higher to keep it from dying.

Phil
 

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What idle RPM are you running? 210 degree duration with 469 lift is not a huge cam but a lot larger than stock. You should be able to hear the cam. To compare, the stock 5.0 cam is 204 degree duration with 444 lift. You did not build a Lexus and its a good thing also :) But if the car is really rough below 1000 rpm and your vacumme drops below 12 inches or so then you might have a problem. I would recomend making sure the firing order is correct and check all spark plugs for black carben build-up. You might have a dead cylinder. Good luck and hope this helps :)
 

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BTW - since i am still very green about setting timing....did you set it with the vacuum line off and plugged up? If not, it would read wrong and when you set it 6 BTDC the car would run terrible, require alot of idle screw to stay running and would be hard to restart.
 

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Discussion Starter #11
Will check plugs tomorrow, doubt a dead cylinder with 300 miles on professional rebuild. Now if I had done it, that would be a different story! Mark
 

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Discussion Starter #12
I didn't have vacuum line off but had it retimed by carb specialist, he did. One other thing, my "dash pot" or whatever the correct name for the rig attached to the front of my distributor is, is loose. I snapped off one of the two screws. Could this have an affect on idle? Mark
 

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If the vacuum advance can is able to move under vibration, the initial timing can move around.


I have a slightly bigger cam in my "non-squish" 351.....my initial timing is at 18BTDC.
 
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