[Dr.Dee]

How not to set valve lash .......... 101:shocked:

Hello i've seen these methods on setting valve lash in 30 + years in print & posted 1,000,000+ times..

Do your self a huge favour and never set valve lash with this methods..

Method # 1 ............ On setting valve lash.

Turn engine to #1 TDC COMPRESSION stroke (ie. rotor arm pointing at #1 plug), then adjust the following rockers...

Adjust the #1 exhaust valve

Adjust the #1 intake valve

Adjust the #3 exhaust valve

Adjust the #5 intake valve

Adjust the #7 intake valve

Adjust the #2 intake valve

Adjust the #4 exhaust valve

Adjust the #8 exhaust valve

Now, rotate the engine 360 degrees (the TDC mark on the crank balancer will be back at the top, but #1 piston will now be on the EXHAUST stroke and the rotor arm will be pointing at #6 plug). Adjust the following rockers...

Adjust the #3 intake valve

Adjust the #5 exhaust valve

Adjust the #7 exhaust valve

Adjust the #2 exhaust valve

Adjust the #4 intake valve

Adjust the #6 exhaust valve

Adjust the #6 intake valve

Adjust the #8 intake valve

The process you should use to adjust each rocker is as follows...

Grasp the pushrod between thumb and index finger and jiggle it up and down. Tighten the polylock until there is no more slack in the pushrod (do NOT tighten it anymore than is necessary to eliminate the slack). THEN, tighten the polylock another 1/2 a turn and lock it. Do this for each rocker following the sequence above.

NEXT:

WRONG & OVER COMPLICATED METHOD # 2 ....Gee i think launch'n the space shuttle is'nt as complicated..:shocked:

NEXT WEB POSTED WAY:

the order I have is;

crank TDC (rotor pointing to no 1) adjust no 8 exhaust

TDC + 45degrees no 2 intake

TD + 90, no 4 exhaust

TDC + 135, no 1 intake

BDC + 180, no 3 exhaust

BDC + 45, no 8 intake

BDC + 90, no 6 exhaust

BDC + 135 no 4 intake

TDC, no 5 exhaust

TDC + 45, no 3 intake

TDC + 90, no 7 exhaust

TDC + 135, no 6 intake

BDC, no 2 exhaust

BDC + 45, no 5 intake

BDC + 90, no 1 exhaust

BDC + 135, no 7 intake

TDC done

Job done...BIG TIME :roll::S:sniff::shake:

I'm not try'n to be a smart A or knock / shag anyone here... the posters of this info i'm sure have the best of intentions

These above methods are okay @ best for your BONE stock American V-8 engine....never use it with modern high output performance engines .

I will cover setting valve lash on hyd & solid cams & ant-pump up lifters & hyd & solid roller cam.'d engines.. no matter what grind profile... or advance or retard ground into cam by manufactor or via crank gear keyway positions or cam gear offset bushing ect ect.

_______________________________________________________________________________________________

Here is why the above methods CAN get you into serious trouble & even cause severe engine damage..... First problem is your using the dizzys position as a refferance point for TDC # 1 buy pointing dizzy rotor to # 1 & # 6 cyln on dizzy and proceeding to set valve lash on various cylinders as listed in above method....there are a few MAJOR problems with this method... IE: What if your dizzy when loaded into engine is NOT in phase with #1 TDC... if so using it as a refferance point to cyln TDC is useless and you would be setting valve whlle most lifters are NOT on the base circle of the camshaft lobes.

Also as we all know the dizzy is able to rotate in block advancing & retarding ignition timing.... this moves the dizzy's rotor

away from # 1 cyln & # 6 cyln terminal on cap & you are NOT on TDC.... now when you try to line up rotor to the terminals on the cap it is way off the TDC of those cyln's and your trying to adjust & the lifters may NOT be on the base circle of the cam on ALL cylinder's....causing you to set improper valve lash....

Using the TDC method also opens you up to making the mistake of adjusting the wrong valve if you mistake the intake for the exhaust valve & possibly mix'n up cyln #'s thiis is very possible... ive seen pro's do it... by being distracked by a hot looking blonde strolling by the shop in pump heels & hot pants ... point is your prone to error & mistakes here big time with this method.

Another major problem with this method is with 1,000's of differant cam profiles used by all differant cam manufactors when designing high performance cams they greatly change cam lobe centers & lobe seperation and lobe flanks & ramp profiles to increase cam lift durations...that are no where near STOCK cam profiles .

And when you set your lash on lifters using TDC method could be no where near the cams base circle of that cyln your adjusting.

Also many aftermarket cam manufactors grind adavance into there cams.... this is to compensate for chain stretch as chain & gears wear.... they also play with adavance & retarding cam grinds to produce more power @ differant RPM ranges & engine combonations............ when this is done.

You may again not be on lobe base circle of ALL lobes when you set lash using TDC method.

An other possiblity for error here is if your cam is ADVANCED OR RETARDED via crank gear key or offset cam gear bushing this could leed to lifters NOT being on base circle of cam when using TDC method

One more recent trick cam manufactors is cam lobe swaping IE 4/ 7 cam lobe switching..where you swiitch cyln's # 4 & 7 around changing the firing order.... now 99% of you will never have this cam in your engine... BUT i've seen fellows @ race tracks set valve lash on engines and the dam thing will not run right.... they used the TDC method and made a major error forgetting they had a 4/7 swap cam in the engine.....bottom line here is to be 100% sure you've got valve lash set correct DO NOT USE THE TDC METHOD

On the rotate engine & stop on degrees marked on damper @ BTDC ATDC / INTAKE & EXHAUST valves ect............way confusing and same reasons above apply.

*On the pushrod GIGGLE method to see if all slack is out of valve train....NEVER use this method it is dead wrong way of checking again due to possible error or judgement IE differant types of rocker arms used on engine & access to pushrod & your finger grip tech and ability to call a giggle or is it a wiggle IE: 140 Kg weight Rugby player checks pushrod giggle VS 60 Kg Horse jockey checks giggle............

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Okay here is the fail safe method to adjust your valve lash on any engine & with any type cam profile hyd, or solid or roller cammed.

Remove ALL spark plugs from engine..........load socket on crank damper bolt use 1/2 drive socket is best... bumping engine over with starter motor is NOT recommended to turn engine over... better done by hand

Remove both rocker covers... back off ALL rocker jam nuts or poly locks. Now start @ any cyln you wish.. rotate engine clockwise watch that cyln's only pushrods or lifters rotate engine over till you see the EXHAUST lifter or pushrod of that cyln just start to rise STOP[Now you are ready to set valve lash of the INTAKE on that cyln.. Take a feeler gauge .002 th( FOR HYD CAMMED ENGINES) slide the blade between the rocker arm tip & the valve stem tip now tighten down jam nut till you feel a SLIGHT drag on your feeler gauge & STOP there..now take a 12 point socket or box end wrench load onto jam nut @ 12:00 o'clock postion turn nut clockwise 3/4 turn & STOP valve lash is set on INTAKE valve

Now we are ready to set EXHAUST valve lash of the same cylinder....Rotate engine over till you see the INTAKE valve lifter rise / open all the way up and then start to go down ...when the lifter or valve is ALMOST all the way down or valve is almost closed STOP... you are now ready to set EXHAUST lash.... again load socket on jam nut , load feeler gauge and turn nut till SLIGHT drag is felt on gauge........load socker @ 12:00 O'clock and turn nut 3/4 of a turn STOP ...EXHAUST lash is now set .. now proceed to next cyln & repeat till all cyln's are done.

For engines with ROLLER ROCKERS & POLY LOCKS & hyd cams.. load wrench 12:00 Oclock turn nut to 7:00 postion leave wrench on nut & hold it from moving ... take allen wrench and tighten screw DO NOT let nut move... now tighten nut it will move from 7:00 Oclock to 9:00 Oclock postion = 3/4 of a turn and poly nut WILL BE LOCKED to stud

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Now for SOLID CAM ENGINES take your feeler gauge .016 to .028 th ( check your cam spec card for lash spec) and slide between rocker arm & valve tip lock nuts and check for proper clearance after nut is locked.....TIP with COLD engines REDUCE gap by .002 to .003 ths this will allow for engine cyln head expansion when heated up and put your lash / clearance very close toi HOT running lash spec's.

After engine has been run to operating temp stop engine & check HOT VALVE LASH to be sure its spot on

Fee for this lesson mate's 1 pint local brew next UK tour:tup:

Regards Dr.Dee
[email protected]

 

[605 heavy]

Good post & i agree you're lash setting method to be the most accurate....................however ...............Ex lifter starting to rise adjust intake valve , intake valve full lift & just starting down adjust Ex valve , this ensures valve being adjusted is on base circle of lobe , this is the only accurate method when dealing with long duration cams , wide lobe seps & assymetrical grinds.


Cold lash setting on iron head/iron block should be set .002" LOOSER , where as iron block/alu head cold lash should be set ,006" TIGHTER , setting lash .004" to loose on cam profiles with aggresive lash ramps will hammer the valve train.

Great post BTW.:smoke:

 

[Dr.Dee]

Valve lash settings... 101

:tup:

Good post & i agree you're lash setting method to be the most accurate....................however ...............Ex lifter starting to rise adjust intake valve , intake valve full lift & just starting down adjust Ex valve , this ensures valve being adjusted is on base circle of lobe , this is the only accurate method when dealing with long duration cams , wide lobe seps & assymetrical grinds.

Cold lash setting on iron head/iron block should be set .002" LOOSER , where as iron block/alu head cold lash should be set ,006" TIGHTER , setting lash .004" to loose on cam profiles with aggresive lash ramps will hammer the valve train.

Great post BTW.:smoke:

Hello sir... thanks for the kind words..:tup:... You may have slightly miss read setting prodcedure... to set EXHAUST valve lash... rotate engine till INTAKE valve or pushrod travels up all the way and then starts on its way down when intake valve or pushrod is ALMOST all the way down /or valve is ALMOST closed/ VERY close to closed (STOP).. set EXHAUST valve lash on that same cylinder.

To set INTAKE valve rotate engine till EXHAUST valve just starts to open ever so slighly or pushrod just starts to rise (STOP) now set INTAKE valve lash on that same cylinder..... This procedure can be used on bone stock ground cams symetrical or assymetrical cam grinds...flat tappet or roller cams

I was taught this method by Ed Iskenderian / The Cam Father..8)
ohhhhhhhhhhhhhh 30 years ago now... with 0 issure to date on all types of engines and cam grind types & profiles.
8):tup:
Excellent info on COLD valve lash setting with iron heads to iron blocks and ally heads to iron blocks... ohhhhhh how those ally heads grow when they get hot! :shock:

SHOULD HAVE USED THE WORD (TIGHTER)... not reduce.... Thanx!
My quote .......TIP with COLD engines REDUCE gap by .002 to .003 ths this will allow for engine cyln head expansion when heated up and put your lash / clearance very close toi HOT running lash spec's.

Cheers! Dr.Dee

 

[605 heavy]

Thanks Dr Dee , was worried you may of posted back giving me a scolding.

 

[cren514]

Nice post Daryl and 605 :tup:,didn,t know how much difference ally heads make will check mine before next outing.
Rick's cleveland nearly ready to go in the cob now Daryl,changed sump and oil pickup weekend so allmost there. :smoke:
Dave

 

[Kustom Jim]

Great timing!

no pun intended! msl:

Even I can understand the logic on this one :tup:

Going to adjust my sbc using this method next week!

cheers
KJ

 

[cren514]

Had a Thought today(the one and only)the cam I have is a ford racing item and they use this in their crate engine which has ally heads fitted so I guess that the spec for the cold lash on the cam(14 thou) takes this in to account allready :?:

 

[605 heavy]

Had a Thought today(the one and only)the cam I have is a ford racing item and they use this in their crate engine which has ally heads fitted so I guess that the spec for the cold lash on the cam(14 thou) takes this in to account allready :?:

Mostly the cam grinder will express hot lash settings on the card , in saying this i had a custom grind delivered from the states a couple of months ago , the lash settings stated on the card were .018" cold , i had a feeling this was'nt right , so i measured lash ramp X rocker ratio & it came out to .019" hot setting , got in contact with the cam grinder to which he told me a typo error was made on the card & to set lash hot @ .018" , so mistakes can be made , i set cold lash to .012" , checked hot which gave me .018".

Hope this helps.

 

[cren514]

Hi 605,this is the cam spec and the 14 thou is cold lash and I guess the bit about other heads relates to iron heads :?:

 

[605 heavy]

514 , this is for the alu head as you pointed out , also what the cam card states , notice hot lash is .020" , this is .006" growth , iron head lash would probably be .022" cold/.020" hot.

I notice they are asking for the cam to be advanced 5* from straight up.

 

[cren514]

Hi 605,have intalled this cam straight up didnt know it should be 5deg advanced :?:

 

[605 heavy]

Was this cam installed with a degree wheel? , the card calls for it to be installed on a 107 ICL , straight up would be 112 inatalled ICL.

If this cam was speced for you're motor i would say it's gonna leave some torque on the table as cyl pressure will be down , the wider lobe sep just adds to the problem, also if street driven temps could rise due to the later closing ex valve , is this already up & running? , if so back the lash off (max .004") & see if she picks up...............my guess it will.

 

[Dr.Dee]

Darn those WIDE center line cam's

Hey Dave heed # 605 advice on cam install/ degrees advanced...engines with higher comp's & cams with wide center lines / lobe seperation = engines that produce more top end HP & are more prone to ping ping ....& rattle rattle. @ low RPM loads..:tdown: not good.
Cheers! Dr.Dee

 

[cren514]

Hi 605,Daryl,engines been in for 4 years with no problems other than destroying clutches (this is the forth one)Mc cloud twin plate at precent.
Oh did have prob with pushrods 3 piece crane items destroyed 3 of em now one piece items installed.
it's producing over 500lbs and the big problem at the mo is traction on the track,and the cars driven on the road.
next time I hoist the engine out Ill double check the timing with the wheel again but im sure I installed it straight up,but as i said my main problem is traction so looking at that,probably change front dampers for 90/10 to see if that will help.
cheers
Dave

 

[605 heavy]

Well , if you got traction problems with that cam installed straight up (112icl)then installing as the card suggests (107icl) will make it worse , so a good move on you're part , should also help top end , maybe leave it as it is then.

You could tighten lash to bleed some cyl pressure off which might help regards you're traction issues , if you got enough piston to valve clearance maybe retard the cam a few degrees.

:tup:

 

[cren514]

Well theirs food for thought.
Cheers 605. :tup:
Dave