cometic head gaskets

BillK · 06-22-2017, 03:42 PM

Quote:

Originally Posted by RonP

A torque wrench measures torque, not friction as someone stated earlier.

Ron,
That is correct and what I was trying to get at was the fact that the friction will significantly affect the preload on the fastener for a given torque. My choice of words were not the best

Rich Biebel · 06-22-2017, 08:22 PM

I have used Cometics with zero issues for at least 5 years. I have reused the same gaskets 3 times with no additional coatings and also another set 2 times with copper coat spray. This is a 15-1 compression engine and with or without the copper coat there was no leaks. Pretty smooth finished block and heads. I generally block sand the heads if they are off with wet 400 paper in a wash tank. Cometics work very well for me.

RICK W · 06-22-2017, 10:18 PM

Thanks for all your comments guys, the block is just machined too rough for those gaskets

Ed Wright · 06-23-2017, 02:18 PM

Listen to Rich.

Greg West · 07-05-2017, 08:29 PM

Something else to consider on a SBC is the size of the dowel pins. The OE dowel pins are .309" diameter. If .3125" (5/16") pins are used the head can bind on the pins. This will prevent the head from clamping properly to the block in the lower corners. Several companies sell SB dowel pins that are actually 5/16" roll pins.

06-22-2017, 08:22 PM	#2
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,314 Likes: 25 Liked 544 Times in 213 Posts	Re: cometic head gaskets I have used Cometics with zero issues for at least 5 years. I have reused the same gaskets 3 times with no additional coatings and also another set 2 times with copper coat spray. This is a 15-1 compression engine and with or without the copper coat there was no leaks. Pretty smooth finished block and heads. I generally block sand the heads if they are off with wet 400 paper in a wash tank. Cometics work very well for me. __________________ Rich Biebel S/C 1479 Stock 147R

06-22-2017, 10:18 PM	#3
RICK W Junior Member Join Date: Jun 2007 Posts: 64 Likes: 0 Liked 0 Times in 0 Posts	Re: cometic head gaskets Thanks for all your comments guys, the block is just machined too rough for those gaskets

06-23-2017, 02:18 PM	#4
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: cometic head gaskets Listen to Rich. __________________ Ed Wright 4156 SS/JA

07-05-2017, 08:29 PM	#5
Greg West Junior Member Join Date: Jul 2016 Posts: 63 Likes: 26 Liked 52 Times in 22 Posts	Re: cometic head gaskets Something else to consider on a SBC is the size of the dowel pins. The OE dowel pins are .309" diameter. If .3125" (5/16") pins are used the head can bind on the pins. This will prevent the head from clamping properly to the block in the lower corners. Several companies sell SB dowel pins that are actually 5/16" roll pins.