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The mkiv Supra Owners Club

Cam degree kits


pedrosixfour
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I'm looking around for a kit to dial my new BC 264 cams in properly before the car ever sees a rolling road for fine tuning.

 

The majority of what's on the market seems to cater more for the American V8 engines and as such would be designed around imperial fasteners, tolerances & such, as opposed to what I would perceive as the metric items/systems used in the 1JZ & 2JZ.

 

I was about to order this kit so it would arrive as soon as possible in the new year

 

http://www.summitracing.com/parts/sum-g1056

 

But before I do I thought I'd just ask here if anyone would see any reason why it might not be the most suitable kit to assist in my 1JZ camshaft upgrade or if there is a kit more suited to Japanese in-lines?

 

Thanks,

Damien.

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I just buy cheap plastic degree wheels off Ebay and Blue Tack or double sided tape them to the crank dampers or crank pulleys. On a 2JZ I bolt a 3mm steel plate across the plug well valley and mount a magnetic stand there, with a DTI on it. You need to buy / make a thin extension for the DTI plunger to go down onto the tappet buckets. DO NOT bother trying to find TDC with a DTI, piston rock will adulterate the reading.

Carefully use a piston stop down a plug hole and divide the degree wheel readings in half.

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Thanks for the tips Chris.

 

I will need to pick up a dial indicator as well as the degree wheel anyway so I thought a cased kit with a few extra items would be the easiest way of keeping it useful for other (paying) jobs for years to come and if I'm not on the complete wrong track with the kit I linked to I'm happy to order it.

 

I did think the piston stop and degree wheel method would be the most accurate way of finding TDC, I assumed there would be a few degrees of crank rotation where the piston would be virtually static.

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Correct, you get a few degrees of rock. Put in a modified old plug body with a rounded end protrusion welded in that can contact a piston top about an inch BTDC. Turn clockwise to the stop (slowly....!) and read the degree wheel. Turn the crank in the opposite direction until it hits again. Read the degree wheel. Divide by two, set the engine to that figure you got from division. Remove wheel and reattach so the pointer is dead on zero degrees TDC. Voila, spot on TDC. You can do something similar to find full valve lift, reading a few thou either side, of full lift with the DTI, and dividing, but BIG CAVEAT, some cams have asymmetric lobes which will catch you out with that method, check the cam specs or put it on a Cam Doctor machine and check it out yourself if you have access to one. Be prepared to be amazed how dire the grinding is on some US cams and most Chinese ones . HKS ones, and Tomei ones have always checked out admirably on the ones I have bothered testing.

Edited by Chris Wilson (see edit history)
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Ah don't start bringing me down Chris, I'm cheap, that is all there is to it!:D

 

But I did notice the real edge of each cam lobe is far from what I would class as finished.

 

Is it alright to "de-burr" the profile edges with a small grinding stone so there is nothing on the cams in the line of debris to detach and cause scoring or foul an oil way?

 

I've just purchased the degree kit and a pair of these to complete the upgrade.

 

http://works-engineering.com/wp-content/uploads/2012/04/ADJUSTABLE-CAM-GEAR.jpg

 

http://works-engineering.com/?product=3-cam-pulley

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  • 4 weeks later...

This is a pretty good explanation of the process. Of course it's FAR easier with the engine on a stand and with it in the chassis you'd have to use a smaller degree wheel. I tend to use throw away plastic ones, so I don't worry about butchering them to fit a specific application. You can stick them to the face of the damper with double sided adhesive pads, or even use silicone sealant.

 

 

http://www.enginelogics.com/degree-dual-overhead-camshafts/

 

 

NOTE!! This method of finding the cam lobe centreline only works for symmetric cam profiles. I have yet to see a commercially available asymmetric one, but they may be out there!

Edited by Chris Wilson (see edit history)
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  • 3 weeks later...
Do you need a Degree wheel? Can you not just set them to OEM TDC ?

 

Not accurate enough mate, too many variables when dealing with degree increments.

 

I saw one article where a cam was off by 26° when valve lift in relation to recommended crankshaft rotation was measured on an engine where the block and head had been previously skimmed.

Edited by pedrosixfour (see edit history)
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