Easiest way to set valve lash.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

omillan99

omillan99

Full Access Member
Joined
Jan 22, 2015
Posts
85
Reaction score
25
Location
El Paso, TX
First Name
Oscar
Truck Year
1978
Truck Model
K20 Scottsdale
Engine Size
350 4 Bolt
I recall a method where you can put the motor in one of two positions and you could set half of the push rods with each position for a SBC. I can't seem to find it anymore however. I found a quarter turn method but it got me confused and since I'm doing this with the motor in a tall truck, without the balancer installed, in the summer heat, I'd like to reduce the number of times I have to climb in and out of the engine bay and crawl under the truck to turn the flexplate. Since usually by 10 am it is usually hot the fastest method would be best. Or if I'm making an issue of a non-issue feel free to let me know to suck it up lol
 
DoubleDingo

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,165
Reaction score
14,453
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
The two-roll method is easy. Let me find where I have it.
 
DoubleDingo

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,165
Reaction score
14,453
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
https://www.gmsquarebody.com/posts/342268/

#225....

I use 1/2 turn on the lifters, not 1 turn like the manual says. A little easier on the valve train. This method really is easy, and once you've set them, you won't have to worry about it.
 
omillan99

omillan99

Full Access Member
Joined
Jan 22, 2015
Posts
85
Reaction score
25
Location
El Paso, TX
First Name
Oscar
Truck Year
1978
Truck Model
K20 Scottsdale
Engine Size
350 4 Bolt
DoubleDingo said:
https://www.gmsquarebody.com/posts/342268/

#225....

I use 1/2 turn on the lifters, not 1 turn like the manual says. A little easier on the valve train. This method really is easy, and once you've set them, you won't have to worry about it.
Click to expand...


Thank you!! That's the one I was looking for but I saw it in a video format. BTW if I have the Timing marks lined up on the gears does that mean I'm on the 6 firing position?
 
DoubleDingo

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,165
Reaction score
14,453
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
Timing marks both at 12 o'clock is #1 tdc, crank at 12 o'clock, cam at 6 o'clock is #6 tdc
 
Last edited:
DoubleDingo

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,165
Reaction score
14,453
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
omillan99 said:
Thank you!! That's the one I was looking for but I saw it in a video format. BTW if I have the Timing marks lined up on the gears does that mean I'm on the 6 firing position?
Click to expand...
I like having the printed version next to me as I do it, that way I can see what I've adjusted and what is left to adjust. A video would have to started and stopped too many times for my liking.
 
omillan99

omillan99

Full Access Member
Joined
Jan 22, 2015
Posts
85
Reaction score
25
Location
El Paso, TX
First Name
Oscar
Truck Year
1978
Truck Model
K20 Scottsdale
Engine Size
350 4 Bolt
DoubleDingo said:
Timing marks both at 12 o'clock is #1 tdc, crank at 12 o'clock, cam at 12 o'clock is #6 tdc
Click to expand...
I think you just said the same thing here lol

I did the video last time since i only swapped rockers to Full rollers so it helped a lot.
 
DoubleDingo

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,165
Reaction score
14,453
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
omillan99 said:
I think you just said the same thing here lol

I did the video last time since i only swapped rockers to Full rollers so it helped a lot.
Click to expand...

Fixed it, thanks for catching that.

That's what happens when one gets distracted midthought
 
omillan99

omillan99

Full Access Member
Joined
Jan 22, 2015
Posts
85
Reaction score
25
Location
El Paso, TX
First Name
Oscar
Truck Year
1978
Truck Model
K20 Scottsdale
Engine Size
350 4 Bolt
DoubleDingo said:
Fixed it, thanks for catching that.

That's what happens when one gets distracted midthought
Click to expand...
Sweet thank you very much, this weekend or maybe this week I'll get on it. Since I already have it on #6 TDC
 
Matt69olds

Matt69olds

Full Access Member
Joined
Jan 8, 2018
Posts
2,350
Reaction score
3,597
Location
Central Indiana
First Name
Matt
Truck Year
81
Truck Model
GMC 1/2 ton
Engine Size
455 Olds
Take the firing order of any engine, spilt it in half. In the case of GM it will look like this.

1843
6572

Put the engine with number one at TDC, set the lash on cylinders 1 and 6. Turn the engine 90*, lash cylinder 85, turn another 90*, cylinder 4 and 7, turn 90*, then cylinder 3 and 2. This is much easier with a degrees balancer, but you can eyeball it pretty close, especially with a hydraulic cam.
 
Matt69olds

Matt69olds

Full Access Member
Joined
Jan 8, 2018
Posts
2,350
Reaction score
3,597
Location
Central Indiana
First Name
Matt
Truck Year
81
Truck Model
GMC 1/2 ton
Engine Size
455 Olds
I forgot to mention, make sure you turn the engine in the direction it normally rotates.

And half a turn past zero lash will position the lifter plunger in about the middle of its travel.
 
shiftpro

shiftpro

Full Access Member
Joined
Aug 31, 2012
Posts
4,855
Reaction score
6,086
Location
BC Canada
First Name
shiftpro
Truck Year
73-87
Truck Model
1500, 2500, 3500
Engine Size
350, 383, 454, 496!
If it's a BB and the intake is off, you can see the cam lobes. Turn engine over (with 3/4 socket and bar on crank pulley) and watch any valve closing, you see the lobe disappear after the valve closes and then the lifter is sitting on the heel of the cam. Without any oil in your new lifters (assuming new lifters) tighten until you feel the smallest drag spinning the pushrod. This is zero clearance then crank down your desired preload. I like 3/4 turn in for preload. Done.
 
shiftpro

shiftpro

Full Access Member
Joined
Aug 31, 2012
Posts
4,855
Reaction score
6,086
Location
BC Canada
First Name
shiftpro
Truck Year
73-87
Truck Model
1500, 2500, 3500
Engine Size
350, 383, 454, 496!
shiftpro said:
If it's a BB and the intake is off, you can see the cam lobes. Turn engine over (with 3/4 socket and bar on crank pulley) and watch any valve closing, you see the lobe disappear after the valve closes and then the lifter is sitting on the heel of the cam. Without any oil in your new lifters (assuming new lifters) tighten until you feel the smallest drag spinning the pushrod. This is zero clearance then crank down your desired preload. I like 3/4 turn in for preload. Done.
Click to expand...

Installing new hydro lifters 'dry' also has the benefit of reduced spring pressure on the new cam (if you are in fact breaking in a new cam).
 
You must log in or register to reply here.

Similar threads

ChuckN
How do YOU set timing?
2 3
Replies
32
Views
3K
ChuckN
ChuckN
mxer147
Another fuel selector valve question
Replies
2
Views
1K
mxer147
mxer147
AuroraGirl
Need a 1987 R10 350 valve cover grommet set
Replies
2
Views
337
AuroraGirl
AuroraGirl
JACK34
Timing is way advanced
2
Replies
15
Views
2K
JACK34
JACK34
chevytech87
Proportioning valve problems
Replies
2
Views
633
fast 99
fast 99

Latest posts

Forum statistics

Threads
42,110
Posts
909,308
Members
33,596
Latest member
LeBeepBeep
Top