Initial timing for 1968 327 HEI
Thread Starter
Instructor
Joined: Mar 2008
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From: Farifax Station VA
Initial timing for 1968 327 HEI
Guys...I bought my car a few years ago, and believe it or not just figured out that it has a 327 vs a 350. anyway, it has been overheating and my next step is to check the timing. what should the initial timing be for this motor with HEI. thanks
Race Director
Joined: May 2006
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using a dial back timing light you should have about 36 degrees total at about 3000 rpm with the vacuum advance disconnected. Depending on what has been done to your distributor the intial timing will vary.
Former Vendor
Joined: Apr 2009
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From: Charlotte North Carolina 704-394-5150
ASSUMING that the outer ring on your harmonic balancer is IN THE CORRECT POSITION..and has not spun....so a timing light will give you a CORRECT reading...I would start at 10 degrees before top dead center. It could be 8 degrees. There is a variation that is in play here when it comes to timing adjustment that will allow you to adjust it at a different setting other than what the "book" says to set it at. Fuel quality, compression, and other factors can allow this setting to be altered. I use a vacuum gauge when I set timing and then use my advance timing light to check it, so I can make my notes for my records. Often times I have to check to make sure that the outer ring has not spun...becasue it will throw off your reading ...IF you ASSUME that it is correctly positioned for checking your timing for number one cylinder.....as many do.
READ the "sticky" post above that is about timing.
It is possible that your timing can cause overheating but I believe that IT has to be something else.
"DUB"
READ the "sticky" post above that is about timing.
It is possible that your timing can cause overheating but I believe that IT has to be something else.
"DUB"
Thread Starter
Instructor
Joined: Mar 2008
Posts: 221
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From: Farifax Station VA
I printed a "long" post on how to set timing. The first thing I did was use rubber bands to hold down the centrifical advance, I plugged the vaccum advance as well, and I adjusted the carb RPM to the slowest I could get it. Then I used a dial back light to see where the timing was set..I found it was set at 44 deg at idle with no advance!!!! I backed it down to 12 deg. I then took the rubber bands off and checked the timing again, everything is set at 12 deg still. I then set the dial to 36 deg and increased RPM until the line on the balancer hit zero deg...so far so good. Now the PROBLEM-I reconnected the vaccum adv, which did not change the RPM (I thought it was suppossed to increase, it did not). I test drove the car and it is a DOG, it totally bogs down. Any ideas? with all the lines connected, and initial advance set at 12 deg, the car idles great.
Race Director
Joined: May 2006
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The idle will increase with the vacuum line connected only if the hose is connected to manifold vacuum. If it's connected to the timed port on the carburetor it will only advance past a certain throttle position beyond idle. It's a little hard to believe that the car was starting with 44 degrees initial and didnt ping like crazy while driving it. Are you sure the outer ring on the harmonic balancer hasnt slipped?
Thread Starter
Instructor
Joined: Mar 2008
Posts: 221
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From: Farifax Station VA
I will go check the harmonic balancer right now. how can I tell if it has slipped, will it be loose? Should I connect the vac adv to the port that is constant vac or ported vac? as for the 44 deg. all I did was hook up the timing light and dial back the gun until i got it to read zero. The dial read 44 deg when I did this. I rotated that dist about 20 deg to the right (clockwise), and the timing came down to 12 deg. then I was able to get the timing all in at 36 deg at 2900 RPM. But I still have a prob with the BOGGING down trying to accel...something is still not right.
Thread Starter
Instructor
Joined: Mar 2008
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From: Farifax Station VA
Also, when I am running the rpms up to 2500-3000 to check all-in timing, the balancer mark starts below the deg indicator...and moves up to the zero mark. does this have any significance? to make sure I set the timing right, is it correct to set the dial on the light to 36 deg, and then increase the rpm until the balancer line hits zero. seems right to me, but not sure.
Thread Starter
Instructor
Joined: Mar 2008
Posts: 221
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From: Farifax Station VA
I finally did it. I used my remote start trigger, removed the #1 plug, and found TDC, made a mark on the balancer next to the zero deg mark...Perfectly dialed in at 12 deg...now I will check the all in timing of 36 deg and I should be good to go.
thanks lars and everyone who contributed.
thanks lars and everyone who contributed.
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