Windsor TDC

[Dave]

Ok here's my problem.

I have a 302 windsor that has no timing marks on the timing cover and incorrect marks on the crank pulley.

Now i know i can pull a plug and find tdc With a screw driver but want a 100 percent way to find tdc so i can mark cover and pulley.

Cheers
Dave

 

[roaldin]

Replace the screwdriver with a dial gauge.

Tim.

 

[Dave]

How do i mount the gauge? Does summit have a tool?

 

[Jon Briggs]

The best way I know is to take the head off and use a positive stop to find TDC. The problem is there is about 30deg of rotation where the piston doesn't move at the top or bottom of its stroke.

Try this: COMP Cams 4933 - COMP Cams Top Dead Center Tools - Overview - SummitRacing.com

Or make your own with 3 bolts and a bit of scrap metal.

 

[Ian Anderson]

Heard a good method elsewhere

Knock out the ceramic in a spark plug and weld a bolt in it
Screw into no 1 spark plug hole
Turn engine by hand until it hits the stop (bolt)
Mark pulley
Turn engine backwards till it hits the stop (bolt)
Mark pulley

The mid point between the 2 marks is TDC

It has to work!

Ian

 

[roaldin]

Years ago, in those days when I actually got my hands dirty, I had a magnetic block that the gauge mounted on.
I remember using it for just this purpose. Bolt on a steel rocker cover and it should stick and be stable enough for your purpose.

Tim.

 

[David]

Heard a good method elsewhere

Knock out the ceramic in a spark plug and weld a bolt in it
Screw into no 1 spark plug hole
Turn engine by hand until it hits the stop (bolt)
Mark pulley
Turn engine backwards till it hits the stop (bolt)
Mark pulley

The mid point between the 2 marks is TDC

It has to work!

That should work, although for best accuracy would be best if you preloaded the crank by the same amount both ways to remove any slack (small though it should be).

For the same reason the picking TDC with a dial gauge can be a little bit out if you have knackered shells (which might be an issue if you are doing it prior to a rebuild, shouldn't be afterwards!)

 

[Dave]

Yes will use a positive stop method and split difference.
Will get a spark plug and modify it.

 

[roaldin]

If bore is offset then before and after will be slightly different (more or less depending on the distance you choose to measure at). To be honest I can't remember if it is or not in a conventional Windsor.

Tim.

 

[EGLITOM]

Positiv stop tool works great.

I use a bored and threaded spark plug. This way i can adjust the lengt of the threaded rod into the burning chamber. I like to do the rod as long as possible. The more before and after you stop the more exact it will be, because of the move of the piston per degree of rotation.
to protect the piston from beeing damaged , i machined a recess in the front of the stop rod and insertet a hard PU piece, which actualy makes contact with the piston.

TOM

 

[Dave]

Hi Tom
Any chance of a pic of the tool you made?

 

[Jac Mac]

Toms method with the longer positive stop gets the contact point closer to the centerline of the piston which helps eliminate any pin offset issues, just make sure your on the fireing cycle, not overlap while doing the check, so it cannot tangle with the exhaust valve. Pin offset in most ford production pistons is around 0.060", Toms motor probably has pins on centerline.