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Hey guys, finally got the car put back. Engine compartment painted, Steel braided hose are put on, engine is all dressed up. Now for the timing, I think it suppose to be set at 6 degrees BTDC, but someone told me I should advance it to 9 or 10 because I have the RV Cam, headers, edelbrock intake/Carb 4bbl, and an HEI Mallory (GM style,one wire) Distributor. I already brought up the #1 cylinder up and checked the Rotor for #1 wire. The sparkplug wires are put in the order 1-3-7-2-6-5-4-8. I've never really done timing before, so should I remove the vaccum advance hose before setting the timing? Once timing is set, Do I need to shift in to Drive and check the timing again? Is before top dead center mark onto the left side of the Harmonic balance? As always, any tips, ideas, or process would be greatly appreciated. Pics will be posted soon.


Thanks, SharpStang72

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Since you swapped cams and other goodies the 'factory' initial timing won't help you a lot.


Hook a vacuum guage up to manifold vacuum (high when idle). With the car in park set the idle speed close to where it should be. Increase the initial timing until you get 'highest' vacuum. You can check it with a timing light and it will be farther ahead of BTDC than 6 degrees. Probably in the 12 to 15 range. Take it for a drive. If it pings under load or is hard to start you will want to back it off a few.


You will also want to check 'total' advance, on a Cleveland you don't want to go more than about 34 degrees. You can do this with timing tape or use a timing light that allows you to adjust when it fires. (You set it for 34 and if you are really at 34 then it will fire the light when your HB is at TDC). You want to rev the engine to about 3000 RPM and check. If you go much above 34 you will either want to reduce your initial timing or recurve the distributor.


(Thought here guys, couldn't you hook the light up to a different spark plug wire when trying to determine total advance? If you picked the right one and checked at 3000 RPM... hmm have to think this over)


You will need to then set idle speed and adjust idle mixture. i don't know sqwat about edelbrocks carbs.


There is a really good write up on the process posted. Let me see if I can find the thread.

Found it:




Really good info on what I see as page 3 on initial setup and then adjusting and readjusting timing/idle/etc.


Also, is this a brand new motor?



73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)


Pics of modifications included in: [button=http://www.7173mustangs.com/thread-1973-convertible--3335]My Garage[/button]


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Your going to want to do your cam break in/ring seat first. Adjust the timing enough to run smooth during break in according to your cam specs. Typically 2000 rpm half hour upping to 2500-3000 every five minutes or so for 30-45 sec. Then do your carb and timing fine tuning.



Just cruising along minding our own business when BAM!!! The LAWS show up.

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  • 2 months later...

We just made final adjustments on the Cleveland.

Started with 6 BTDC and a 950 RPM idle for break in.

This is a newly rebuilt D1ZE quench head with a cam.

We took the RPM down to 350 and adjusted the carb to

obtain a smooth idle. Then set the timimg to 12 BTDC

and brought the idle up to 750. The manifold vacuum

reads 16.5





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Initial timing is set with the vacuum hose disconnected and plugged. As others have already stated you will need more than 6 degrees, probably 12-14. The idle speed must be low enough so that no mechanical advance has started. Total mechanical advance should be 34-36 and fully advanced by 2600-2800. If you have vacuum advance the rate, not amount, of advance may be adjustable using a small allen wrench inserted into the vacuum port. This can be useful if trying to eliminate "pinging" under part throttle acceleration. The timing pointer is on the passenger side. Make sure #1 is up on the compression stroke and not exhaust stroke. Your biggest concern with a new flat tappet cam is getting the engine to start quickly and get engine speed to 2000 RPM and keep it there for 15-20 minute while varying speed upward occasionally. I strongly suggest you use an appropriate break-in oil with high levels of ZDDP. It is cheap insurance. Prime the oiling system with a large reversible drill. Pre-filling the carb will help quick start until the fuel pump can fill the lines (and don't run out of fuel). You need to monitor the coolant temperature during break-in to make sure it doesn't over heat. Towards that end, make sure the block still has the thermostat seat/flow director in place and a Cleveland specific thermostat is used. A fan in front of the radiator will help keep the temperature down. A second person to help with the process is a good idea. I hope everything goes well. The first start of a new engine is always exciting. Chuck

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