What does the stock cam measure to?

[grainofsalt]

I'm checking out parts to make sure that they are all in spec, But I cannot find any measurement for the cam. I am looking for the bearing sizes AND the height and width of the lobes.

Also, The preferred KB 944 cylinder wall clearance, For a daily driver, With occasional light towing, Is .004" Correct? Or should I do .0035"

Thanks!!

[Retlaw01XJ]

Also, The preferred KB 944 cylinder wall clearance, For a daily driver, With occasional light towing, Is .004" Correct? Or should I do .0035"

Thanks!!

The spec from KB is 0.0025 to 0.0035" for normally aspirated, and 0.0030 to 0.0040" for street towing.
0.0030 to 0.0035" would fit both categories. The real issue is HEAT. If it's going to be running hot and under load for long periods, more clearance is preferred. Factors such as climate, terrain, gearing, and trailer weight should be considered.

[SilverXJ]

You can't accurately measure the lobes with out the cam installed in the engine and with lifters on it.

The journals:
Bearing Journal Diameter
No. 1: 2.029 to 2.030 in.
No. 2: 2.019 to 2.020 in.
No. 3: 2.009 to 2.010 in.
No. 4: 1.999 to 2.000 in.

Bearing clearance is 0.001 to 0.003 in.

According to KB 3.5 thou will be fine for the pistons.

[fannman]

im running the kb944 pistons in my stroker right now with a tight 3 thou clearance and have not noticed any problems yet,i have around 400 miles on it so time will tell.

[IH 392]

You can't accurately measure the lobes with out the cam installed in the engine and with lifters on it.

You can put a cam on centers in a lathe and measure it.

[grainofsalt]

You can put a cam on centers in a lathe and measure it.

So would I use a dial style caliper and check for the correct lift, Right? My bearing journals are about 2.027", 2.127", 2.008", And And 1.998" at the thin side, They do measure within spec 90 degrees from this measurement. This cam has less than 180k on it.

I'll shoot for .003"-.0035" piston to wall clearance then.

[SilverXJ]

You can put a cam on centers in a lathe and measure it.

How would you take into account the taper on the lobe?

[5-90]

You can't accurately measure the lobes with out the cam installed in the engine and with lifters on it.

The journals:
Bearing Journal Diameter
No. 1: 2.029 to 2.030 in.
No. 2: 2.019 to 2.020 in.
No. 3: 2.009 to 2.010 in.
No. 4: 1.999 to 2.000 in.

Bearing clearance is 0.001 to 0.003 in.

According to KB 3.5 thou will be fine for the pistons.

Sure you can - it just takes a special jig for the dial indicator and camshaft to ride in, or you can get a full setup to measure everything with the aid of a computer (lobe lift, ramps, centrelines, overlap, LSA, ...)

Apart from measuring the bearing journals, it's out of reach of the hobbyist, tho. And if you do end up building your own measuring jig, you're just going to be able to measure lift (unless you get creative, then you can measure duration as well.)

[grainofsalt]

You can't accurately measure the lobes with out the cam installed in the engine and with lifters on it.

The journals:
Bearing Journal Diameter
No. 1: 2.029 to 2.030 in.
No. 2: 2.019 to 2.020 in.
No. 3: 2.009 to 2.010 in.
No. 4: 1.999 to 2.000 in.

Bearing clearance is 0.001 to 0.003 in.

According to KB 3.5 thou will be fine for the pistons.

Sure you can - it just takes a special jig for the dial indicator and camshaft to ride in, or you can get a full setup to measure everything with the aid of a computer (lobe lift, ramps, centrelines, overlap, LSA, ...)

Apart from measuring the bearing journals, it's out of reach of the hobbyist, tho. And if you do end up building your own measuring jig, you're just going to be able to measure lift (unless you get creative, then you can measure duration as well.)

And the cost to build such a accurate jig would take more time and money than buying a new cam!

Thanks 5-90!

[IH 392]

You can put a cam on centers in a lathe and measure it.

How would you take into account the taper on the lobe?

Put your dial indicator on the high side.

[grainofsalt]

You can put a cam on centers in a lathe and measure it.

How would you take into account the taper on the lobe?

Put your dial indicator on the high side.

just for kicks: Would I be measuring the same number as advertised lift? Or would I multiply by 1.6, Or whatever the stock ratio is?

[SilverXJ]

Put your dial indicator on the high side.

The lifter is domed, how are you accounting for that?

just for kicks: Would I be measuring the same number as advertised lift? Or would I multiply by 1.6, Or whatever the stock ratio is?

You would be measuring lift at the cam. Multiply by 1.6 and you will get valve lift. Of course it won't be correct.

[grainofsalt]

Camshaft is PN: 53020436 , Lift is approximately .260" Exhaust and .365"Intake, Multiplied by 1.6 is .416" and .584"

Does this sound about right?

[Retlaw01XJ]

No, it sounds wrong At least the exhaust does.
My 2001 cam measured at 0.2426" on the intake and 0.246" on the exhaust. That's lobe lift. Cam in block, dial indicator on end of pushrod at head surface.
About 0.388" at the intake valve and 0.393" at the exhaust valve.

[SilverXJ]

That definitely isn't right. .584" is 100% error.

Exactly how are you measuring this?