vn 1988 series 1 auto, valve clearance for tappet adjustment

[Mattyg]

Hey,

I want to adjust my tappets. 1988 vn series 1 V6 auto

Is it with the engine hot or cold?

intake = tappet clearance? tho or mm both preferable
exhaust = " "

have gap guages and rocker gaskets all ready to go. should be all i need to do the operation?

thanks,

Matt

[noah_73]

Can't adjust them and don't need to! They have hydraulic lifters which self adjust so to speak. If anyone says you can don't take anymore advice from them.

[Hairy Eater]

noah_73.... sometimes cam lobes or the face of the tappet wears and they wont adjust fully and make tapping noise... you can unbolt the mounting block and grind some off the bottom.... the is a cheat way some car yards do..

[Frd_thmsn]

noah_73.... sometimes cam lobes or the face of the tappet wears and they wont adjust fully and make tapping noise... you can unbolt the mounting block and grind some off the bottom.... the is a cheat way some car yards do..

I don't understand where they would grind, don't forget the lifters in these
motors have a roller on them and don't look like normal tappets. I would hate to be grinding a roller.

[noah_73]

noah_73.... sometimes cam lobes or the face of the tappet wears and they wont adjust fully and make tapping noise... you can unbolt the mounting block and grind some off the bottom.... the is a cheat way some car yards do..

Strictly speaking they don't have tappets, they have rockers. And why on earth would you want to do something so butcherous to what is probably a perfectly good engine is beyond me. On top of that it is good way to introduce metal contamination to your engine, no amount of covering oil drain ports is going to stop it.

[NOGEN 3]

noah_73.... sometimes cam lobes or the face of the tappet wears and they wont adjust fully and make tapping noise... you can unbolt the mounting block and grind some off the bottom.... the is a cheat way some car yards do..

Did this with a friends 202 engine when we put a regrind cam in-stopped it rattling like a deisel. just ground the bridges down a bit to take up the slop in the drivetrain. Dodgy, but it did the job...
Does the V6 have the same sort of setup?

[noah_73]

Very similar but it changed in the VR I think it was, if not definitely the VS. More of a roller rocker type set up.

[Dayvo]

Grinding them is a bit severe . i'd use a file

[Frd_thmsn]

There's a bit of confusion in this thread as to what a tappet is.

A tappet a.k.a lifter, cam follower, hydraulic lifter is the small cylindrical object that rides over the cam lobes inside the engine . In the VN /VP and probably later models this has a roller on the bottom that rolls around the cam lobes.
You do not want to grind this roller.In flat face tappets there is no roller just the face of the lifter rides on the cam lobe.

The arms at the top that you see when looking inside the rocker cover is a rocker that connects between the valve and the pushrod, this is called the rocker or rocker arm, this is the bit that some have ground.

You may have heard of solid lifters, these are tappets that are not hydraulically pumped up by oil, their main use is in high revving engines to prevent pump up , where the lifter can keep the valve open.Earlier engines had solid lifters and it was necessary in these to adjust them with a clearance. Overhead cams where there is no lifter and the rocker arm rides directly on the cam also needed adjustment.

The disadvantage of the roller lifters as used in the commodore engines is the weak point at the pin axle for the roller , especially when stronger valve springs are used.

The early holdens all had flat faced tappets , the VN and probably later had roller faced tappets.