Does anyone know of a brand/company that makes a whistling tdc locator? I have heard them being talked about. Or does someone have an easier way? Usually I try to have a buddy hold a finger over the #1 plug hole while I turn the crank and he lets me know when he feels pressure. I have also tried using a TDC locator but its a guessing game if i am at tdc on the compression or exhaust stroke.

 

if you are just trying to find where to put a mark on the balancer it don't matter what stroke you are on. TDC is TDC. But if you are trying to install the distriutor then you have to be on the compression stroke.

 

Just pull the valve cover and watch your rockers to know if your on compression stroke. A whistling tdc locater? Somebody is always trying to make a quick buck.

 

Not sure what your trying to do, but comp cams make a TDC piston stop so you can degree your cam with the heads on

 

The thumb is heck of a lot faster and cheaper than wasting your time and a valve cover gasket. The whistler is a great tool establishing a motors displacement, used in stock car motor checking by tech inspections. Not just another money grabbing gimmick.

 

On my 390, a good flashlight, and just look in the spark plug hole. I can see the piston. #1, and #6 are at TDC at the same time. Use your thumb to check. Turning the motor over by hand, with your thumb on the plug hole, you will feel compression and exhaust stroke difference. If you use the starter, you will still feel the pressure on both strokes, but compression will be much stronger.

 

I thought it would be a good idea, because its usually just me when im working on the bronc. Its pretty hard to keep a finger over the plug hole and turn the motor over by hand at the same time

 

Remote starter switch, locate compression then bump until your close,turn the motor over by hand to TDC. This all fine and dandy for dropping in the dizzy or setting valves only. For a true TDC you should of indicated the motor during build up and noted the location on the damper, also a good idea to scribe a line across damper and hub in case the damper slips. Just a way of telling if it has slipped in the future.
Going for a piston stop install a 1 1/4" long piece of aluminum into a old spark plug body with the piston contact end rounded over, a degree wheel then pull the motor thru both directions by hand making a note of degrees you stopped at then split the difference.

 

Whistler, I thought of that after, but just left the post. took awhile for someone to call my bull**** though. Heard of it but Ive never seen one. Oh, the comp and crane TDC locaters probably whistle cause of the small hole in it but thats not really its purpose. Yes thumbs faster but he never said what he was trying to accomplish either. Hows that whistler work exactly? must measure cylinder volume?

 

It measures the difference of a sound frequency between the combustion space at TDC and the combustion space with the bucket at BDC, electronics take over and analyze the data for a instant reading. It will detect the difference between a cold or hot engine with different displacement readings.
I wasn't aware of a device that installs in the plug hole that will whistle when the bucket comes up on compression, maybe not a gimmick to someone if it works for them. I survived all these years without one.

 

Yes those whisles were supplied by Sun for one with their leak detectors. Sun of course is now Snap On and do they still make them, good question. All it was was a piece of aluminum tubing with a wedge cut out of it like we used to do when we were kids with wood to make the whistle. It was pushed into a piece of hose and that went to whatever size plug thread adapter was needed for the engine. Crank it over and you got a whistle with the piston coming up. We marked the balancer as needed for the crankpin interval from TDC mark so we could get all the cylinders at TDC because the compressed air would kick them off if not perfectly on. Leak test is a bit different than holding valves closed to change seals. kotzy