lexussc94

iTrader: (2)

I'm ready to degree my cam, but I need the tool that finds TDC with the heads off. Everyone tells me to make one.How long should the bolt in the middle be,(The bolt that actually hits the piston), or it doesn't really matter?Would It be at different lenghts if people are making their own? Also the piston is really not all the way to the top, right? Someone explain this to me please Thanks

jcb999

Best thing to do is get a solid piece of aluminum or steel stock.

Drill 2 holes (cylinder head bolt diameter) in it. One on each end.
On one end put a bolt and nut. Now bolt it to the deck using the other bolt hole.

Put the degree wheel on and rotate the motor until it touched the nut. Note the degree wheel position.

Rotate the motor the other direction until it touches the nut again. Note degree wheel now.

Add both numbers together and divide by 2. Remove the stop and rotate the motor to the number you just got. Zero the degree wheel. Bingo.. TDC..

PS: I have a lex GS400 as my daily driver.



[This message has been edited by jcb999 (edited November 01, 2001).]

JoelOl75

The bolt length isn't important. You have to turn the crank till it hits the stop. Then write down the # on the wheel. Then turn it back until it hits the stop, then take the 2 numbers and compare them to make sure they are the same (adjust the wheel to get the same number)

It's kinda hard to explain, but if turning the motor forward hits the stop at 10 BTDC and turning it back hits at 20 ATDC then your wheel is skewed 5 degrees off.

A fresh timing chain makes a big difference in this reading.

E-Z Rollin

You can make a great piston stop by using one of your old spark plugs.Knock out the center and insert metal rod of the right diameter,braze it in place and lightly file off the sharp edge at the piston end of the rod,doesn't need to be a specific length as long as it will touch the piston.