Modifying Timing Cover To Adjust Camshaft Timing

[bruce]

Has anybody modified a timing cover so that the camshaft timing can be adjusted (advance/retard) without taking the whole timing cover off?

Here are some photos that I found on the net:

 

K engine:

 

 

T engine:

 

 

 

 

 

 

The face of the timing cover is slightly curved, so bolting a plate of aluminium might have issues with oil leaks. From the photos there is a raised edge between the timing cover and the plate. Not sure if it is welded or bolted from the inside of the cover. The raised bit can have a groove so that an o-ring can fit in. Probably the raised edge is so the plate bolts don't stick though to the inside of the timing cover, and hitting the timing gear.

[philbey]

Even if you milled a flat patch on the timing cover, you wont have enough meat for tapping threads in. I suspect they have milled the shape out through the timing cover, machined a matching boss to insert and then welded it into the timing cover from the back. Either way, it's a nice looking setup.

 

That's only half your problem, you still need to produce a vernier cam gear to suit the K engine.

 

What are you doing with this motor? Sounds exciting.

[19914afc]

They sell them for 3t's in the states.

http://brdracing.com/2tc_3tc_timing_componets.htm

[Taz_Rx]

Hmmm, never seen a K timing cover with the timing scale in that position either!

[Evan G]

4K/5K and 7k have the timing stamp in different places on the timing cover. that one shown is a 5k one cause it has aisin stamped in it.

[Taz_Rx]

4K/5K and 7k have the timing stamp in different places on the timing cover. that one shown is a 5k one cause it has aisin stamped in it.

 

I'm in the process of polishing a 5k cover that has the aisin stamp..... but the scale in the usual position just like a 4k!

[bruce]

Even if you milled a flat patch on the timing cover, you wont have enough meat for tapping threads in. I suspect they have milled the shape out through the timing cover, machined a matching boss to insert and then welded it into the timing cover from the back. Either way, it's a nice looking setup.

 

That's only half your problem, you still need to produce a vernier cam gear to suit the K engine.

 

What are you doing with this motor? Sounds exciting.

 

The top photo is for a K engine, and then the rest of the photos are for a 3TC.

Rollmaster make adjustable timing gears for K engines, with up to 4 degree adjustments either advance or retard, in 1 degree increments. Fully adjustable timing gears for K engines can be found here:

 

http://www.esapeltonen.fi/

 

 

I'm modifying a 3TC engine. Nothing extreme. Wadecams 280 duration camshaft with 0.45" lift, twin Dellorto DHLA40, Genie extractors, then head work: stainless steel oversized valves, 3 angle seat angles: 30 45 70 degree (I think?), harder springs from crowcams, pressure test, porting, new seals, and milled.

Couldn't source an adjustable timing gear from Rollmaster, so I'm getting one from Paradiseracing:

 

So I was thinking of modifying the timing cover to make adjustments to the cam timing for finer tuning. Could be useful for dyno tuning, and the rpm power band could be shifted.

[bruce]

They sell them for 3t's in the states.

http://brdracing.com...g_componets.htm

 

I saw that, but they charge over $200 to make the modification. Need to supply a timing cover. Then the postage adds up.

[tojo2]

UK based Kentcams make fully adjutable timing gears for Ks. don't know if anyone sells them in Aus