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View Full Version : LS/Vtec valve clearence help



Timinater
11-30-2007, 02:42 PM
I am building an all motor b18a1/b18c1 with cams, valvesprings, stock valves, and b16 pistons. I was trying to figure out how to check the valve to piston clearence. if anyone can tell me how to do this and what to do it with or give me a good resource i can pull this info from that would be awesome. thanks in advance.

Vteckidd
11-30-2007, 02:47 PM
Best way to do it is to clay the engine

http://www.c-speedracing.com/howto/claymotor/clay.php

http://www.c-speedracing.com/howto/claymotor/pics/dsc00038.jpg

Init2winit
11-30-2007, 02:53 PM
I am building an all motor b18a1/b18c1 with cams, valvesprings, stock valves, and b16 pistons. I was trying to figure out how to check the valve to piston clearence. if anyone can tell me how to do this and what to do it with or give me a good resource i can pull this info from that would be awesome. thanks in advance.There are a few ways to check. If you don't have the engine assembled yet, you can use putty on top of the piston, bolt the head on with a gasket (use an old gasket that is compressed), and roll the engine over slowly. It doesn't take much putty. Take the head back off, take a razor and cut through the middle of the patch, and measure how thick the putty is.

Or, you can put a dummy spring (very light tension spring)on one intake, and one exhaust valve, get a dial indicator and set it square on top of the retainer, and roll the engine through and measure the clearance of the tightest spot.

Either way will be suffecient. Just make sure you use a gasket, and bolt the head down with a few bolts. Be sure to put the timing belt on too.

You want no less than .080 on the exhaust, and .060 on the intake. That is an absolute minimum, and really wouldn't hurt to be more than that.

Timinater
11-30-2007, 02:57 PM
thanks yall, i appreciate it, but what if there isnt enough clearence? what should i do then?

Init2winit
11-30-2007, 03:02 PM
thanks yall, i appreciate it, but what if there isnt enough clearence? what should i do then?You can always move the timing gears, but the logical thing would be to fly-cut the pistons.

Vteckidd
11-30-2007, 03:03 PM
get adjustable cam gears or enlarge the valve reliefs

What cams are you running, ill know if you have enough clearance or not

Timinater
11-30-2007, 03:07 PM
crower 402a's

Vteckidd
11-30-2007, 03:20 PM
402as youll be fine with a b16 head at 0,0 as lon as the block/head isnt milled alot.

If your trying to degree them in, your better off with a Degree wheel than claying the motor.

For your setup, and such small cams, its not going to be a huge power difference, i would just set them up at -2 on the exhaust an +1 on the intake

Init2winit
11-30-2007, 03:36 PM
402as youll be fine with a b16 head at 0,0 as lon as the block/head isnt milled alot.

If your trying to degree them in, your better off with a Degree wheel than claying the motor.

For your setup, and such small cams, its not going to be a huge power difference, i would just set them up at -2 on the exhaust an +1 on the intakeThat would tighten up the piston to valve clearances.

Vteckidd
11-30-2007, 03:39 PM
No you missed my point, he would have to go -20 or +20 to see any contact on cams that small.

usually, thats where ive seen best results on mild cams

Init2winit
11-30-2007, 03:59 PM
No you missed my point, he would have to go -20 or +20 to see any contact on cams that small.

usually, thats where ive seen best results on mild camsAhh, ok. Just makin sure.

Timinater
11-30-2007, 06:20 PM
you said the b16 head it would be fine, but i have the b18c1 head with theb 16 pistons