Tech:Engine/K Series/Camshaft

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Camshaft

There are two stock camshaft profiles. The first is found in Sprinter motors with twincarbs (K-B, 3K-B), it's an 18-58 (256 degrees). The second is found in all other K motors with solid lifters, and is a 16-50 (246 degrees) with 0.338" intake valve lift and 0.356" exhaust valve lift.


The camshaft is modified by grinding the lobes, you don't have to buy a new cam when you want different valve openings.


There are many, many aftermarket cam grinds available for these motors. Here are some popular ones:

Tighe 112: 20-60, 260 degrees, 0.423" valvelift (best for 3K engine, most torque in 4k/5k, 6500rpm peak power)

Tighe 104: 25-65, 270 degrees, 0.423" valvelift (best for powerful 4K/5K, alot of torque, 7500rpm peak power)

Wade 169x: 30-70, 280 degrees, 0.405" valvelift (custom cam in Doug's rally car, slightly more top end, slightly less torque than above)

Camtech 609: 33-64/72-32, 277/284 degrees, 0.435" valvelift (this is Stewart's cam, peak power 8000+rpm)

Waggott 605: 21-61/63-19, 262 degrees, 0.347"/0.343" valvelift (stage 1 grind, Alex uses this one, peak power 6500rpm)


Note: Tighe 104 cam does not appear to have an aggressive/lumpy idle (Camshaft supplied, They charge you $110 to grind a standard cam to spec) - Justin...



Article by Superjamie / Medicine_Man



Camshaft Replacement for K Series motors.

When you do the cam,

Degrease engine before hand.

I always set the engine with cylinder 1 on TDC on the firing stroke. Set the engine with the timing mark on the pulley on the TDC mark. Look at the cap note where no1 lead goes. Should be inline with the second spark plug hole in the head. Pull off the cap, if the rotor button points to where no1 lead was your set. If it points to four, turn the engine over 360degrees.

Once you have the radiator out loosen the crank pully bolt before you rip into the engine. A bit of compression helps here, put in gear with the handbrake on. Get a big spanner or breaker bar and your favourite big hammer, and belt the shit out of it until it undoes. Cheaper than an impact wrench :) Watch the spanner or socket doesn't slip, or you may strip the head.

Most of the time you can pry the crank pulley off with a couple of big flatheads. Some pull off, usually ones out of the car. :( A couple of long bolts through the 2 threaded holes in the pulley will move a stubborn one.

Open the engine up, take out the rocker setup remove bolts outside in, remove pushrods and fishout the lifters, maintaining the order. About this time you will be cursing if you haven't maintained frequent oil changes.

raise the car on stands and drop the engine mounts on the xmember and raise the engine for working room. I'd loosen right off the back 3 or so sump nuts on each side (may need to loosen off block to gearbox strengthening brackets if fitted for access), and take off all the nuts forward of this. Carefully drop the front of the sump, pull off the timing cover, remove the tensioner, undo the cam gear, remove the gear and screw the bolt back into the cam a few turns. Remove the cam thrustbearing and carefully slide out the cam.

Lube up the lobes of the cam with camlube or moly grease. Slide in the new cam, reassemble, double checking the timing marks. Before you put the timing cover back on, remove the studs for the sump attachment and replace with bolts. Make things easier next time, as you dont need to drop the sump anywhere near as much.

Use locktite no3 non hardening aviation goop, and give the sump gasket a good coating. Tighten the sump nuts up evenly. If you do it right it will never leak.

No big deal to put back together, just watch distrubutor timing. Sometimes the oil pumpdrive can throw you out a tooth when you drop in the dizzy if not aligned properly.

Before you start it, pull the coil lead and crank over to build up oil pressure. Connect coil lead and start. Run at fast idle over 2000 rpm for half an hour to break in cam. Recheck valve clearances after a few days running.

It's not too bad a job. If the engine is clean and you raise everything for access it makes things a lot smoother.



Article by Felix


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