Author
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Topic: How to find TDC
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bluestreek Gearhead Posts: 1289 From: Athens,GA Registered: Jul 2001
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posted 11-06-2002 11:30 PM
I'm trying to see if my pointer is correct for the markings on the balancer. What is a accurate way of finding TDC with the engine in the car? I thoughtabout sticking a small screwdriver in #1 hole to find it, but not sure if that would be true TDC.The reason I'm not sure of the markings is because I'm using a 351W cam with an aftermarket crank and fluidamper on a 289. Today I set the timing by ear and took it for a roadtest. It cranked a little tight but ran very strong under hard acceleration. (the drag radials were no match until 3rd gear). I brought it back and checked the timing with a light and it was set on 26 deg. @ idle, and went up to around 48 deg. @ 3000 rpms. ------------------ 1966 Mustang Coupe: Custom glass hood and BIG scoop sits atop a 289 stroked to 331 c.i., Steel crank and girdle, 5.4 H-beams, Forged slugs, ported TFS alum. heads, ported Stealth 8020 intake, CompCams Xtreme Solid Roller, Holley 750 HP, long tubes, 4speed, 9" 3.50 posi, BFG Drag radials..
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jsracingbbf Gearhead Posts: 1677 From: Batesville,MS. , U.S.A. Registered: Mar 2002
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posted 11-07-2002 12:35 AM
You can pull the number one plug and put your finger over the hole (not in it) and have someone bump the engine over until you start to feel pressure, then you can look at the dampner, if it is coming up on "zero" that is the compression stroke. At the top of this stoke just before the piston starts bakc down, is TDC. Or you can pull a valve cover and look at the intake and exhaust valves. Just after the intake opens but before the exhaust valve opens you will have pressure on your finger. If you wait until the exhaust valve opens you will be on the exhaust stroke, you can tell this by looking at the dampner, it will be 180 away from zero. yet another method would be to pull the cap on the distributor. TDC is when you feel pressure on your finger AND the rotor points to where the number one plug wire came out of the cap. Hope this helps Jerry
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Just Strokin Gearhead Posts: 754 From: Tuscaloosa, Alabama Registered: Dec 2001
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posted 11-07-2002 07:44 AM
Take an old spark plug and break the internals out of it until all you have left is the outer shell. Have someone weld a rod of sufficient size inside the shell and extends out the threaded end by an inch to inch and a half.DISCONNECT THE BATTERY!!!! Screw this into number one cylinder after removing all the spark plugs. WITH A RATCHET and 15/16" SOCKET slowly rotate the engine in either direction until it stops. Make a mark with chalk or soap stone on the damper where the timing point is above the it. Rotate the engine in the other direction WITH THE RATCHET AND SOCKET. Again, when it stops make a mark on the damper where the timing point is above the it. If the marks are too far apart to see both at the same time, shorten the length of the rod that you welded into the spark plug shell and repeat above. Once you have two marks that are reasonably close together you and then get an idea if the outer ring has slipped since TDC should be an equal distance between those two marks. REMOVE THE TOOL YOU MADE BEFORE RE-CONNECTING THE BATTERY!!!! Hope this helps. Also, the tool is available from places like Summit or Jegs or maybe your local speed shop. ------------------ Larry No fast Fords at this time but one fine cruising 96 F350 CC DRW Power Strokin diesel. And one rusty 64 Fairlane nick-named the Rust Bucket....And sometimes called the Money Pit... [This message has been edited by Just Strokin (edited 11-07-2002).]
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bluestreek Gearhead Posts: 1289 From: Athens,GA Registered: Jul 2001
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posted 11-07-2002 12:17 PM
That's the method I was looking for. Thanks, Dan
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jsracingbbf Gearhead Posts: 1677 From: Batesville,MS. , U.S.A. Registered: Mar 2002
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posted 11-08-2002 12:14 AM
Heck, I thought you just wanted to time your motor...... did not realize you had a suspect dampner. My mistake. I think TAVIA makes the tool Larry mentioned. Jerry
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bluestreek Gearhead Posts: 1289 From: Athens,GA Registered: Jul 2001
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posted 11-08-2002 09:07 AM
The damper is not the suspect, it's my pointer. Thanks------------------ 1966 Mustang Coupe: Custom glass hood and BIG scoop sits atop a 289 stroked to 331 c.i., Steel crank and girdle, 5.4 H-beams, Forged slugs, ported TFS alum. heads, ported Stealth 8020 intake, CompCams Xtreme Solid Roller, Holley 750 HP, long tubes, 4speed, 9" 3.50 posi, BFG Drag radials.. [This message has been edited by bluestreek (edited 11-08-2002).]
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