Deck height and head gasket checking

a pontiac · 01-22-2011, 12:19 AM

How does NHRA tech check deck height and v-8 head gasket thickness? I use a depth mic at 12, 3, 6, 9 clock points and take average of 4 points. The head gasket on v-8, i measure 3 points between cylinders then take average. Are either of these correct? Also, should MLS type gaskets be measured different? Thanks for any and all comments or corretions.

Mark Yacavone · 01-22-2011, 12:41 AM

Usually, they'll just check the deck height at the center in conjunction with doing the stroke measurement. Remember, they're just looking for a number that's over the spec.
Also , they will usually measure the gasket at those same three points. Being a Pontiac builder ,you probably torque the middle two bolts an extra five lbs, but if the other two pts are 1-2 thou over, they'll give you that number.
You don't want to cut it that close anyway though.

Alan Roehrich · 01-22-2011, 12:47 AM

What you're doing should be fine. Call or email your division tech director just to be sure you're using the same procedure he does.

And Mark is right, don't go for that last couple of thousandths. It won't make you faster, but it might make you fail tech. Leave a margin for measurement error.

01-22-2011, 12:19 AM	#1
a pontiac Junior Member Join Date: Jan 2011 Posts: 65 Likes: 3 Liked 36 Times in 11 Posts	Deck height and head gasket checking How does NHRA tech check deck height and v-8 head gasket thickness? I use a depth mic at 12, 3, 6, 9 clock points and take average of 4 points. The head gasket on v-8, i measure 3 points between cylinders then take average. Are either of these correct? Also, should MLS type gaskets be measured different? Thanks for any and all comments or corretions.

01-22-2011, 12:41 AM	#2
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,815 Likes: 2,903 Liked 5,120 Times in 1,951 Posts	Re: Deck height and head gasket checking Usually, they'll just check the deck height at the center in conjunction with doing the stroke measurement. Remember, they're just looking for a number that's over the spec. Also , they will usually measure the gasket at those same three points. Being a Pontiac builder ,you probably torque the middle two bolts an extra five lbs, but if the other two pts are 1-2 thou over, they'll give you that number. You don't want to cut it that close anyway though. __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

01-22-2011, 12:47 AM	#3
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,111 Likes: 1,570 Liked 1,816 Times in 413 Posts	Re: Deck height and head gasket checking What you're doing should be fine. Call or email your division tech director just to be sure you're using the same procedure he does. And Mark is right, don't go for that last couple of thousandths. It won't make you faster, but it might make you fail tech. Leave a margin for measurement error. __________________ Alan Roehrich 212A G/S