roule

Active Member
I v'e just put my new lifters and cam and keep the old pushrods that are in good shape. I notice the top of the new lifters is a little larger and deeper than the old one , about 1 mm, and my composite head gasket is thicker than the tin one. The result should be not enough preload for my lifters...
 
Possibilité de mettre des entretoises, oui ;)
Je viens de vérifier la précharge des poussoirs, ils sont dans la tolérance de 0,5 à 1,5 mm entre le circlip et le dessus du piston. Finalement entre l'épaisseur de mon joint composite et la forme de mes nouveaux poussoirs avec leur gorge un peu plus profonde que les autres, les jeux s'annulent et je me retrouve à la situation initiale (simple joint métallique et poussoirs d'origine).Je revérifie encore une fois avant de serrer au couple mes bras de culbuteurs.
Quelques tours de manivelle, tout à l'air d'être à sa place, même si j'ai encore cet air qui s'échappe avec des "bulles" ...peut être le mélange d'air et d'huile au niveau des pistons ...
 
You cannot adjust the standard rocker arms. The cam followers are hydraulic & do this automatically.

You can adjust the height of the pillars (pedestals) that the rocker shafts are in.
You need to take measurements & then work out the thickness of shims required.
One shim goes under each pedestal & the shims must all be of the same thickness for each shaft.
Read 'checking tappet preload' in this link: http://www.v8engines.com/faq-gen.htm#preload

Alternatively you can buy pushrods that are adjustable. But you're really just overcomplicating things.

I used Elring composite head gaskets when I overhauled the top end on my 3.5EFi. Very light skim on the heads, less than 10 thou IIRC & no adjustment was required.
 
You cannot adjust the standard rocker arms. The cam followers are hydraulic & do this automatically.

You can adjust the height of the pillars (pedestals) that the rocker shafts are in.
You need to take measurements & then work out the thickness of shims required.
One shim goes under each pedestal & the shims must all be of the same thickness for each shaft.
Read 'checking tappet preload' in this link: http://www.v8engines.com/faq-gen.htm#preload

Alternatively you can buy pushrods that are adjustable. But you're really just overcomplicating things.

I used Elring composite head gaskets when I overhauled the top end on my 3.5EFi. Very light skim on the heads, less than 10 thou IIRC & no adjustment was required.
same for me !
 
Finally i have a 2mm (0,08") preload on almost my lifters. So a little above the tolerance.
I should buy a shim kit...i need only the 0,03" set...if someone doesn't use this set , i'm very interested ;)
 
Something upset me about lifters : they should be primed with oil after 2 weeks in the oil, and some have much less resistance than others when i push the piston ...they dont have the same quantity of oil inside as they should.
how ca i be sure the all have enough oil inside to be perfectly efficient ?
 
The link I gave you says the lifters should be empty.
They are hydraulic & the engine running (which drives the oil pump) will fill them with oil under pressure.
If the oil is not under pressure then you will have no resistance when you press them as you are emptying any oil that's in them out.
Priming them in a bath of oil only ensures they aren't completely dry when you start the engine for the first time so avoiding unlubricated metal to metal contact.

Shims under the pillars will lift the rocker shaft & consequently the rockers away from the heads & increase the gaps.
In your case the clearance is too large & you would need to have the pillar bases machined to shorten them, not add shims.
Adding a 0.03 shim to a 0.08 gap will give you a 0.11 high clearance.
 
When you have finished the build, keep the ignition disconnected and crank the engine for a few seconds this will help charge the hydraulic lifters. 👍
 
The link I gave you says the lifters should be empty.
They are hydraulic & the engine running (which drives the oil pump) will fill them with oil under pressure.
If the oil is not under pressure then you will have no resistance when you press them as you are emptying any oil that's in them out.
Priming them in a bath of oil only ensures they aren't completely dry when you start the engine for the first time so avoiding unlubricated metal to metal contact.

Shims under the pillars will lift the rocker shaft & consequently the rockers away from the heads & increase the gaps.
In your case the clearance is too large & you would need to have the pillar bases machined to shorten them, not add shims.
Adding a 0.03 shim to a 0.08 gap will give you a 0.11 high clearance.
Are you sure ? if i put shim under the arm the push rod will raise a little and the piston in the lifter too, so the gap decrease...
 
i chek a third time the preload : half the lifter have 1,5 mm (ok) and the others 2 mm (slightly above tolerance)
 

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