#1  
Old 04-28-2022, 05:38 PM
prostreet64's Avatar
prostreet64 prostreet64 is offline
Ultimate Warrior
 
Join Date: Jul 2007
Location: Gainesville, Fl.
Posts: 1,324
Default solid roller valve lash

Did a search for this topic and found a good thread back from Jan. 2019. So I called lunati about my cam which according to the cam card calls for .020/.022 lash I/E. I assumed incorrectly that their #s were for cold. The tech said they were for hot setting and he suggested since I have aluminum heads to set the I/E at .012/.014 cold and then check hot to see how much increase. He gave a range of .007-.010 increase when hot for the aluminum heads. This seems to square pretty much with the #s I was seeing from the past thread although a little on the high side.

__________________
69 Bird w/1970 400 block(409 cubes), #64 heads, hyd. roller, Q-jet by Jeff E., original interior, ps, pdb, th350, and 3.73 gears. Pump gas, street driven muscle. 3800 lbs. race weight. Best, 11.39 @118, my son's car.

79 T/A w/463, Scat crank, Eagle rods, Icon pistons, Lunati solid roller, 262/270, KRE 325 heads,Northwind intake, QF950 carb, full interior, ps, pdb, th350, and 3.73 gears. Pump gas, 3650 lbs. race weight. 10.72 @ 126 so far... no tuning yet.
  #2  
Old 04-28-2022, 06:00 PM
25stevem's Avatar
25stevem 25stevem is offline
Ultimate Warrior
 
Join Date: Jan 2022
Posts: 1,744
Default

That cold setting works, I have on average seen the hot lash grow by .009”.
This however was with the Added X cooling lines under the intake on a drag motor.
On the street depending on your cooling system and or on a hot day you might see more growth in lash.

__________________
I do stuff for reasons.
  #3  
Old 04-29-2022, 06:54 AM
krisr's Avatar
krisr krisr is offline
Ultimate Warrior
 
Join Date: Sep 2003
Location: Sydney, OZ
Posts: 1,433
Default

I lash my 400 with eddy heads at 0.014" both sides cold. Mine grows around 0.006" between hot/cold -- street driven.

__________________
'71 Holden HQ Monaro - 3850lbs race weight, 400c/i - 11.4 @ 120
'66 Pontiac GTO - 389, 4 speed street cruiser
  #4  
Old 04-29-2022, 08:34 AM
Bill Eveland's Avatar
Bill Eveland Bill Eveland is offline
Ultimate Warrior
 
Join Date: Apr 2004
Location: Glasford Il
Posts: 3,650
Default

I figure .006 on mine , ia2 block and high ports

__________________
Illinois Outlaw Gassers

6.27@107
9.97@131
  #5  
Old 04-29-2022, 11:35 AM
mgarblik mgarblik is offline
Ultimate Warrior
 
Join Date: Mar 2005
Posts: 6,035
Default

Interesting Tidbit about aluminum engines and valve lash. Extreme example of lash growth. Current Top Fuel and Funny Car engines are lashed at 0.00" cold. They just take the adjuster down until zero is reached and stop. When the engine is run, the heat creates the lash they use. After a pass, engine hot, the lash will be around .020". If you ever wondered why these cars seem to miss pretty badly the first 2-3 minutes of a warm-up, it's partly due to valve leakage from zero lash until they warm up.

The Following User Says Thank You to mgarblik For This Useful Post:
  #6  
Old 04-29-2022, 12:41 PM
PAUL K's Avatar
PAUL K PAUL K is offline
Ultimate Warrior
 
Join Date: Feb 2004
Location: Sugar Grove IL USA
Posts: 6,283
Default

We find about .006 growth with iron blocks and aluminum heads. About .014 with aluminum block and aluminum heads. I recall a friend trying to run solid roller lifters with a hydraulic roller cam and he had aluminum heads and aluminum block. He had to preload the valves about an 1/8 turn to get .004 lash hot.

__________________
Go fast, see Elvis!
www.facebook.com/PaulKnippensMuscleMotors
  #7  
Old 04-29-2022, 06:52 PM
chuckies76ta's Avatar
chuckies76ta chuckies76ta is offline
Ultimate Warrior
 
Join Date: Jun 2004
Location: Canada
Posts: 3,078
Default

Ours also IA2 block and Aluminum heads. .006 growth. Set at .010- .011 cold. Requires .016 hot.

__________________
68 Firebird. IA2 block, 505 cu in, E-head, Solid roller 3650 weight. Reid TH400 4:11 gear. 29" slick.
Best so far 10.12@133 mph. 1.43 60 ft.
76 Trans am, TKX .81 o/d, 3.73 Moser rearend,
468 with KRE D-ports, Doug headers, 3" Exh.
  #8  
Old 05-01-2022, 12:06 PM
Bnick166's Avatar
Bnick166 Bnick166 is offline
Chief Ponti-yacker
 
Join Date: Sep 2006
Posts: 875
Default

I did mine on an engine run in stand. Immediately after reaching full temp, I adjusted the valve last as per Comp Cams cam card (Intake .020 hot / Exhaust .022 hot). Let engine set and checked the lash the next day.
Intake .011 cold / Exhaust .013 cold.
I asked a good friend that worked for Crane Cams as a Tech advisor, and he stated that it sounds about right to him.

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 11:01 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017