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Author
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Topic: What to use when checking piston to valve clearance
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Dizzy
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Member # 884
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posted
 
 
I did a search but didnt come up with anything...
Questions:
what kind of clay to use on the heads that will come up easy and yet be hard enough to measure when pulled off. where to find it.
What kind of paint to pain the bottom of the valves that will also come off easily.
thanks
Posts: 344 | From: South Bay | Registered: Feb 2002
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JohnB
Tech Moderator
Member # 969
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posted
I've always used kids modeling clay. Stays soft enough to fill the voids, but will retain an impression very well. As for paint, I use a black magic marker. ![[Big Grin]](biggrin.gif)
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1965 Shelby Cobra
1993 Cobra
2012 F150 Raptor
2020 GT500
Posts: 6523 | From: Orlando FL/Redding CA | Registered: Mar 2002
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Dizzy
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Member # 884
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posted
cool thanks.. i didnt think about the marker... good idea
Posts: 344 | From: South Bay | Registered: Feb 2002
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2stangs69-91
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Member # 1951
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posted
why do you paint the bottom of the valves? They leave a indention in the clay that is very easy to see. I use modeling clay put it on the piston and smoth out the top, spray a little WD-40 on the clay so it won't stick to the valves if they hit it. Then bolt the head on and check it.
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69 Mustang on hold
1991 LX hatch getting a make over
1994 F150 4X4 351
2006 Yamaha V-max 1200 Modded
Posts: 3711 | From: Redding | Registered: Oct 2002
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Dizzy
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Member # 884
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posted
i wont paint the valves and use the clay at the same time
but thanks for the wd-40 tip
the paint is for if i have to notch the pistons... got that from fordmuscle
[ September 01, 2004, 12:33 AM: Message edited by: Dizzy ]
Posts: 344 | From: South Bay | Registered: Feb 2002
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Blind
2.3L
CAFords OG
Member # 3052
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posted
personally, I would use Joe ![[worship]](graemlins/worship.gif) ![[patriot]](graemlins/patriot.gif)
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89 LX Notchback ex 4cyl, 14psi
02 Harley F150, 15psi
Posts: 8521 | From: Fairfield | Registered: Jul 2003
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HaulinAss Motorsports
Its a STREETRaceCar!
Member # 541
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posted
quote:
Originally posted by 2stangs69-91:
why do you paint the bottom of the valves? They leave a indention in the clay that is very easy to see. I use modeling clay put it on the piston and smoth out the top, spray a little WD-40 on the clay so it won't stick to the valves if they hit it. Then bolt the head on and check it.
ditto
Posts: 22469 | From: Sacramento | Registered: Nov 2001
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93PONY
Mr. Valve Events
Member # 60
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posted
Depends on how accurate you want your test to be. The most accurate test is the 'drop valve' method. You setup a dial indicator on top of your valve with a checking spring, setup a degree wheel on the crank snout, & move through the overlap phase of the camshaft while 'dropping' the valve & taking measurements off the dial indicator every few degrees.
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www.advancedenginedevelopment.com
SCT dealer
Dynotuning
(916)715-7569
Posts: 4265 | From: Fair Oaks, CA | Registered: Nov 2000
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2stangs69-91
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Member # 1951
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posted
The drop method won't give you side clearence. Most of the times when valves won't clear it is becuase the valve reliefs are not in the correct place not the depth of them. Plus the clay will give you exactly were you have to cut the reliefs if they need to be cut. Using the other method you still wouldn't know were the valve is hitting unless you clayed it after you found a problem. JMO
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69 Mustang on hold
1991 LX hatch getting a make over
1994 F150 4X4 351
2006 Yamaha V-max 1200 Modded
Posts: 3711 | From: Redding | Registered: Oct 2002
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JoeT
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Member # 298
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posted
true, but valve-drop will tell you the peak clearance needed, it's up to you to create the proper valve relief shape, which on a TFS car can be a bit odd.
got eyebrows on your stock pistons? don't remember seeing any there?
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1984 Ford Tempo AOD--- RIP
Posts: 6785 | From: San Jose | Registered: Jun 2001
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2stangs69-91
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Member # 1951
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posted
yes my stock pistons have eyebrows just like everybody elses after 86 or so ![[Wink]](wink.gif) I am sure measuring clerance with a dail indicator is more acurate buy far.LOL thats why I have hundreds of dollars in mic's and dial indicators (probably even over a thousand). But piston to valve clerance is easily checked with 2 dollar clay and a caliper
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69 Mustang on hold
1991 LX hatch getting a make over
1994 F150 4X4 351
2006 Yamaha V-max 1200 Modded
Posts: 3711 | From: Redding | Registered: Oct 2002
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AaronC
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Member # 86
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posted
The isky piston notching tools will create the perfect angle, width, and depth needed for whatever head you run. As well as consistent perfect cuts. The cutters are like oversize valves that attach to a stem that goes through the valve guide. They work really well. All you need to know is how much to cut, and either clay or drop valve method should get you the #'s you need to know.
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1991 GT Convertible: Stock 157k mile shortblock, HiTech cam, AFR 165 heads, Edelbrock RPM intake, 1 3/4 headers
12.23 at 112.99
Best MPH 113.97
Posts: 776 | From: woodland | Registered: Dec 2000
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JoeT
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Member # 298
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posted
quote:
Originally posted by 2stangs69-91:
yes my stock pistons have eyebrows just like everybody elses after 86 or so
I am using 'eyebrow' to mean an impression above the stock valve relief, e.g. the 'eyebrow' to an 'eye', this can happen on a TFS car for instance that has a cam with a bit much duration.
What this means is the valve relief is in the wrong place under certain conditions (e.g. missed shift, valve float)
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1984 Ford Tempo AOD--- RIP
Posts: 6785 | From: San Jose | Registered: Jun 2001
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PunkINa5.SLOW
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Member # 10
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posted
Go to Michaels or some sort of craft store and buy some silly pudy. They always have it. You know the kind you used to chew on when you were a kid. This eliminates the WD-40 need. Use this to catch the relief mold. Make sure you have a dial caliper so you can measure the thickness without cutting the mold all apart cause that proves to be a pain the booty. While you are at the artsy craftsy store, skip the flower isle, and go get some ink pad stamp refills. You know the kind they used to mark your overdue library books back in the day? Coat the bottom of the valves with this. Mock up the rest of the head and valve train and rotate it through.
This gives a good idea of the clearance and just to be safe borrow or rent a dial bore indicator and set it up on your valves with either test springs or no springs and measure at TDC
[ September 03, 2004, 08:28 PM: Message edited by: PunkINa5.SLOW ]
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OUTTA THA DRAMA
R.I.P. MIKE STARKEY MY BABY BROTHER
12/8/77-5/17/03
Posts: 2495 | From: MTZ | Registered: Sep 2000
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MustangNate
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Member # 4559
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posted
Something that no one has asked that I'm personally curious about, how much clay do you use? What's the best P to V clearance to have? And anything else that deals with that. ![[Smile]](smile.gif)
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1989 Mustang LX Vert, 5.0 Auto
Posts: 1032 | From: Chico | Registered: May 2004
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kwikrob
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Member # 835
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posted
quote:
Originally posted by 2stangs69-91:
The drop method won't give you side clearence. Most of the times when valves won't clear it is becuase the valve reliefs are not in the correct place not the depth of them. Plus the clay will give you exactly were you have to cut the reliefs if they need to be cut. Using the other method you still wouldn't know were the valve is hitting unless you clayed it after you found a problem. JMO
Exactly!! I used a dial indicator and had my 100 thousandths clearance but not checking side to side cost me 6 valves, plus pulling the motor back apart to flycut pistons.
Posts: 382 | From: Bay Area | Registered: Feb 2002
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Dizzy
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Member # 884
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posted
quote:
Originally posted by MustangNate:
Something that no one has asked that I'm personally curious about, how much clay do you use? What's the best P to V clearance to have? And anything else that deals with that.
1. 1/4" thick strip of clay
2. Minimum clearances between the valve and piston should be 0.080" on the intake valve, and 0.100" on the exhaust valve.
courtesy of fordmuscle.com
[ September 04, 2004, 12:08 AM: Message edited by: Dizzy ]
Posts: 344 | From: South Bay | Registered: Feb 2002
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MustangNate
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Member # 4559
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posted
Thank you!!
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1989 Mustang LX Vert, 5.0 Auto
Posts: 1032 | From: Chico | Registered: May 2004
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