How to: SOHC V6 Camshaft Timing

[mrb09c]

That's what I was thinking too, I made sure the traction side was tight.

 

[2000StreetRod]

The spring in the tensioner is too weak to overcome the slack on the traction side of the chain resulting from valve springs. When there is oil pressure in the tensioner the slack is overcome and the chain on the traction side is taught. Timing the camshaft without using the tensioner tool or an equivalent procedure resulting in a taught chain on the traction side will result in the timing being a few degrees off. It probably would not be detectable for normal driving but could affect peak performance. Many Mustang owners time the camshaft to advance the timing about 5 degrees to improve max rev performance at the expense of idle smoothness and low rpm performance.

 

[CDW6212R]

Ditto, the process of setting the timing is based on the intended chain conditions, the length of the chain given known tensioner length. The stock tensioners change length given chain tension, the tool(dummy tensioner) does not change length, thus maintains chain tension expected to set the timing.

Thanks Dale for the Mustang reference. I'm planning to set mine soon after locking TDC by a proper TDC piston stop tool. I hadn't yet searched to see if there is a best timing to use, such as 5 BTDC. I don't want any loss of bottom or mid range power, I don't need 5500rpm power.

 

[allmyEXes]

So what is the length of the dummy tensioner? From the point that it contacts the head to the end of the plunger?

 

[ICoull]

So what is the length of the dummy tensioner? From the point that it contacts the head to the end of the plunger?

It is 2 5/8” from point of contact to the end of the tool. Remember there is no (spring loaded) plunger involved, it is solid for its entire length.
Corrected below... there is a heavier spring (relative to the real tensioner’s) inside this install tool, that preloads the traction side of the chain when setting timing. Thnx for the correcting info. Ian

 

[allmyEXes]

Thanks ! that translates to 66.675 mm. I have been wondering what it was for a few days now. I installed an adjustable tensioner meant for a RZR a few months back in the right head and it has been working well.

 

[2000StreetRod]

The compression ring is 0.060 inches thick so the distance is 2.687 - 0.060 = 2.627 inches. Before I purchased my OTC 6488 timing tool kit I made my own "precision" tensioner using an old spring/hydraulic tensioner.

I cleaned the oil off and then applied epoxy to the area between the arrows.

 

[donalds]

The dummy tensioner has a heavy spring in it

Install it at full length you will break your guide

 

[2000StreetRod]

The dummy tensioner has a heavy spring in it. Install it at full length you will break your guide

Good point! When I used my improvised "precision" tensioner (with no piston movement) I torqued it to 20 in-lbs. That was sufficient to make the chain taught on the traction side but not break the cassette guide. See the following posts: Post #280 SOHC V6 Timing Chain Saga, Post #290 SOHC V6 Timing Chain Saga, Post #301 SOHC V6 Timing Chain Saga