Hey Gang, So, I am working to get educated on a major service. Understanding the proper method to find TDC is one key element. I've read the WSM and see a method using a dial indicator (which I have plenty of at my business). So, I gave a call to a 25 year friend today who is 65 and has built race motors as a hobby for most of his life. He is a machinist / tool maker and one of the most talented guys I know. He said - don't waste your time with an indicator for TDC - use a dead stop. He explained that he has made dead stops that match the spark plug thread. He screws them in the head, installs an angle wheel and pointer, then rotates CW until he hits the dead stop (records angle, let's call it "A"). Rotates CCW until hits the dead stop again (records angle, let's call is "B") Then, he states TDC is 1/2 way between A & B. Anyone else doing this?
I use the dial gauge through the spark plug hole my self mate. I have not used the method you have high lighted although I know of it. Hey I don't want to tell you how to suck eggs mate, because you may already know. But remember number 1 cylinder is on the front right bank. Hey some people may not know mate
Hey Buddy, Yes, I do know the cylinder numbers - just leaned a few months back Image Unavailable, Please Login
1. According to that picture, and how it appears on my screen, number 1 is actually top left. (Just kidding) 2. Dead stop method is just fine. Just another method.
Dave I think the piston stop spec should be M10 x 1.0 (extra fine thread) to match the spark plugs we use (more common on cycles than autos). Most piston stops seem to be the more standard 14mm variety or 10mm but 1.25 fine thread. Let me know if you find one to match 355 specs as I am in the market also. This one looks sexy but at what thread pitch? TDC TOOL, 10MM PISTON STOP
We have these, from Hill Engineering: Ferrari Parts : TDC-KIT-01 Top-Dead-Center Tool Kit : Ricambi America .
From the looks of it, that's not a dead stop - just a nice method to secure an indicator. If you are a pro, $400 is not bad, but no way am I spending that kind of money when I can make a dead stop for next to nothing
Use a dead stop. A little calculus will tell you using a dial gage is completely inadequate. Piston motion is X =cos(angle), TDC is at angle = 0. The change in X with varying angle at TDC, dx/dangle = -sin(angle) = 0 for angle = 0. That is, the piston motion is extremely insensitive to slight change sin angle at TDC. So the dial gage, which measures X, doesn't reflect small changes in angle around TDC. This is why you should have paid attention in math class. Don't you just hate hearing that.
That is the dead stop I used. May have had to machine some clearance, can't recall. I am a bit OCD. Verified with a dial indicator. Waste of time. Don't know about your shop but mine couldn't produce for $37!
What you do it make it out of an old sparkplug. you smash the insulator and weld a shaft. Takes 10 minutes. Either method dial gauge or piston stop are known accepted methods. While the math is 100% correct piston stop or dial gauge is a 9mm Vs. .45 argument.
So I just ordered one of these Dead Stop tools, I have the Hill Engineering TDC tool but I have to free that gauge up to degree the cams as my other gauge is SAE, not metric. It should fit the 360. I know Dave is no longer here...has anyone else used one of these TDC tools yet?
