My Community

Grass Roots Tech => Grass Roots Small Block Windsor => Topic started by: dads67coupe on April 05, 2017, 11:31:15 am



Title: headgasket use, checking piston to valve clearance
Post by: dads67coupe on April 05, 2017, 11:31:15 am
using felpro 1011-1 high performance gaskets, gonna bolt the head down with arp bolts. Can I re-use the gasket after i check clearances?, or do I need to replace it?


Title: Re: headgasket use, checking piston to valve clearance
Post by: Bam54 on April 05, 2017, 11:49:59 am
Yes you can reuse it actually most of the time I won't use one at all unless the piston is above the deck or I actually have PTV issues then I will sick a gasket in there and check it again.

Bam


Title: Re: headgasket use, checking piston to valve clearance
Post by: dennis112 on April 05, 2017, 12:18:58 pm
You don't have to fully torque the head to check PTV.  30-40lbs will be snug enough.  That will allow a little more crush when you do the final torqueing and yet the PTV clearance difference will be negligible.


Title: Re: headgasket use, checking piston to valve clearance
Post by: dads67coupe on April 05, 2017, 12:28:36 pm
ok, thats great info guys thanks again!
what should I be shooting for for intake and exhaust clearances?


Title: Re: headgasket use, checking piston to valve clearance
Post by: Bam54 on April 05, 2017, 03:44:30 pm
.100 exhaust and .070 intake is the excepted rule they can be run closer in some cases.

Bam


Title: Re: headgasket use, checking piston to valve clearance
Post by: dads67coupe on April 08, 2017, 10:22:07 am
Looks like I have over 250 thousandths on both valves at a minimum (the way I set my dial indicator up it stopped touching the valve retainer with any more clearance than that)

Looks like my best pattern on pushrod length comes in a 7.800, pattern just barely to the intake side and about .045 wide the valve tip using chevy roller rockers. does this sound reasonable?

Thanks for all the help guys


Title: Re: headgasket use, checking piston to valve clearance
Post by: juiced coupe on April 08, 2017, 12:19:25 pm
Use clay. The dial indicator doesn't allow you to check radial clearance.


Title: Re: headgasket use, checking piston to valve clearance
Post by: quickshift on April 09, 2017, 01:02:42 pm
On occasion, I used clay and NO gasket and head finger tight. If the findings were questionable, I used a gasket and fully torque to spec. Just me.


Title: Re: headgasket use, checking piston to valve clearance
Post by: quickshift on April 09, 2017, 01:04:37 pm
.100 exhaust and .070 intake is the excepted rule they can be run closer in some cases.

Bam
...on steel rods.....more on aluminum.


Title: Re: headgasket use, checking piston to valve clearance
Post by: dads67coupe on April 10, 2017, 07:20:32 am
Looks like came out with 165 thousandths radial on intake and 248-250 valve clearance for intake in the clay. Exhaust never touched the clay so I must have a mile of space.

they are 25.8 cc dished pistons with huge valve reliefs.

How does the 7.800 pushrods sound? 91 351 block, AFR heads and chevy (1.6) chromolly comp full roller rockers with lunati link bar lifters. Pattern came out just slightly to intake side with .045 or so pattern width



Title: Re: headgasket use, checking piston to valve clearance
Post by: rodbolt on December 06, 2017, 09:32:13 am
I know this is an old topic....BUT, has anyone given thought to the clay pulling apart a little when the piston moves away from the valve and/or vice versa?


Title: Re: headgasket use, checking piston to valve clearance
Post by: woody on December 06, 2017, 09:55:08 am
I know this is an old topic....BUT, has anyone given thought to the clay pulling apart a little when the piston moves away from the valve and/or vice versa?
You just put a very thin amount of oil on the valve face.