I have an 8ba Flathead and I a trying to find top dead center with out taking the head off. Help please I'm having trouble sleeping
I don't know shit about flatheads but if the spark plug's above the path of the piston, you can screw something in the spark plug hole that's a little longer than the plug. Turn the motor by hand til the piston hits the whatever, and mark the harmonic balancer. Go back the other direction til the piston hits again. Mark the balancer again, and i think TDC is exactly BETWEEN the 2 marks. Now, for the tool, you can bust out all the porcelain from a spark plug and thread the hole for a bolt to screw down the middle. This can be an adjustable stop.
Aw run it the way it is. Haven't you heard all the old stories about how they drove the flathead from Missouri to California using their belt as a main bearing? Oh and how the went 150 mph in 1949 with 2-2's. Good Luck. If you want to get it right pull a head.
actually, hackerbill's link has a great idea, but i would use light oil though. read that article everyone!
Cooter, heres a method that should get you within 4 degrees. Remove the plugs so the engine turns easily and observe the valves through the plug hole.Find the place where both valves are open the same amount(overlap position) by rocking the engine back and forth and you will be at TDC provided the cam drive has not slipped.1 rev from this is TDC on power stroke. This method will also work for you when cam timing is questioned after cam drive work or suspect timing chain has slipped.Good luck.
I may be a Pole lock but I don't understand this idea??? WTF I just pulled my cam card and you are right TDC is right in the center of the over lap period.Learn something everyday .Thanks .
Where the valves both open is the exhaust stroke - 360 deg off. As enginenut said turn one more complete revolution for TDC. OR Plug the #1 hole with your finger, turn the crank till you feel compression. Align the pointer with the bump on the crank pulley and you're at the starting point. That bump is approx 4 deg btdc. 8BA/8RT's are easy. And it's not likely the cam can slip out of synch unless it breaks a gear tooth - in which case it will not fire.
Figuring yer running the dizzy and not a crab. Remove the dizzy cap, roll it over to the rotor faces number one. Remove number one plug. use long screwdriver, or light if you can see in the hole. If screwdrive hits piston top, you are TDC, if not you are 180 off. Rotate engine until rotor face number one agian.
Visual methods, including eyeball on piston, dial indicator on piston, or liquid in tube won't give you a truly accurate TDC--this is because of the engine's off set and because of the effect of the long connecting rod. This is true to varying degrees on all or most engines. If you put an indicator on a flathead (or SBC...) piston and a good big degree wheel on the crank and watch both closely, you will discover there's a space of about 2 1/2 to 3 degrees in which vertical motion cannot be clearly distinguished! This is what Yunick described as "Dwell" at TDC in his power book. I discovered this on my own when I bought my first precision tool (an ex-Wehrmacht dial indicator) about a hundred years ago. I saw it clearly and had a great deal of trouble believing what I saw--I only began to understand what I saw many years later when Yunick discussed this in relation to his theories on connecting rod length. Here's how to do the job: Flathead with head on--slide in a long large tie-wrap through plug hole so the buckle part goes all the way over to far cylinder wall. Overhead with head on--piston obstruction tool based on a sparkplug shell and bolt. Any engine with head off--strap across cylinder with bolt head as stop. Turn engine by hand until rising piston hits obstruction. Mark degree wheel or pulley. Turn engine backwards until it hits thataway. Mark again. TDC is 1/2 way between your marks. If using a rigid obstruction, you are done. If using the tie wrap through plug hole, repeat a couple times to make sure your helper really kept it in the same place throughout the operation. This is no harder or slower than any Mickey Mouse way.
Thats so frickin' simple! A positive stop on a flexible shaft! Very cool Mr Lancaster... BTTT for Cooter.
Thanks guys for all your help. That old flathead fired up for the first time in 2 1/2 years last night. Once I found TDC on #1 she fired right up. Thanks again Later
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