piston to valve clearance

O

oosmytoo

Founding Member

Jun 21, 2002

530

0

16

Portland - Oregon

Nov 17, 2006

#1

• Nov 17, 2006

• #1

hey guys I tried checking piston to valve clearance on my new motor. heres what I have, DSS racing 331 with dish pistons, stg 1 cam, twisted wedge heads.
I went ahead and installed those dummy valve springs, put a piece of clay about 3/8" thick on all pistons, then assembled everything, turned it two revolutions. pulled it all apart and the valves never touched the clay.
so I was wondering if i did something wrong? Or do you think im ok to continue assembling it?

 

94gts

Member

Jul 4, 2004

873

0

16

Carmel, New York

Nov 17, 2006

#2

• Nov 17, 2006

• #2

i have no idea what dummy valves are. i put my heads on with a couple bolts and turned the motor over

 

O

oosmytoo

Founding Member

Jun 21, 2002

530

0

16

Portland - Oregon

Nov 17, 2006

#3

• Nov 17, 2006

• #3

there just springs that have hardly any tension on them, so the dont compress the lifter.

 

K

klapdout

New Member

Mar 7, 2006

15

0

0

Nov 17, 2006

#4

• Nov 17, 2006

• #4

with dish pistons and just a tfstage1 cam, you should have alot of clearance, so that doesent surprise me at all, go on with assembly your good =]

 

BlownFiveLiter

have car, will race....wait, it doesn't run

15 Year Member

Nov 29, 1999

3,133

18

108

Chicagoland

Nov 18, 2006

#5

• Nov 18, 2006

• #5

I agree with klapdout. I'm running the stage 1 with factory pistons, so with dished you probably have a ton of clearance. Planning on turning up the boost on that baby, eh?

 

Zero Signal

Active Member

Feb 24, 2003

2,633

2

46

Tucson, AZ

Nov 18, 2006

#6

• Nov 18, 2006

• #6

I tried the clay method and found it annoying and too much work.

What I finally did was use the dummy springs with a pushrod and rocker, put a dial indicator on the rocker (directly over valve tip) then just pushed the rocker down untill the valve touched the piston and recorded the clearance. I tested it at every crank angle and found the minimum clearance. I liked that way better becuase you can do it after fully torqing the heads on for the most realistic results.

Clearance of more than 3/8" sounds wrong though. I don't want to insult your intellegence, but make sure the rest of the valvetrain is attached. Just the first, simplest check.

 

94CobraPace

Founding Member

Aug 30, 2000

907

1

0

Houston, Tx.

Nov 18, 2006

#7

• Nov 18, 2006

• #7

My 1st thought is are the dummy springs strong enought to put a dent in the clay?