Tappet Adjusting

[powerlord]

Dunno about you, but I always wondered what exactly this was.. do the valves wear ? what are shims for ? what do folk talk about 'tappety noise'..

found this excellent article:

www.cybersteering.com/cruise/feature/bullet/adj_pushrod.html#

Assume it is generally applicable to most engines ?

stu

[TT Tim]

But of course you don't have pushrods on the VG30DETT engine, just small hydraulic lifters between cam and valve top, and the RV8, unless highly modified with solid lifters, doesn't need the tappets adjusting as it has pushrods but also hydraulic cam followers (buckets).

Just thought I'd confuse the issue.

Tim

PS: Nice to see another 300zx driver.

[rev-erend]

Powerlord - if you are refering to a Speed 6 engine (Tuscan etc..) then yes them have tappets that need adjusting.

They use bucket and shim's - before 16 valve car engines came along - used to be used in motorbike engines.

Why need adjustment - well they don't use hydraulics due to the high reving nature of the S6 engine - so
parts do ware slightly and need adjustment.

[TT Tim]

rev-erend said:

Powerlord - if you are refering to a Speed 6 engine (Tuscan etc..) then yes them have tappets that need adjusting. They use bucket and shim's - before 16 valve car engines came along - used to be used in motorbike engines. Why need adjustment - well they don't use hydraulics due to the high reving nature of the S6 engine - so parts do ware slightly and need adjustment.

I know that solid lifters were/are used to eliminate valve bounce but what sort of revs is the S6 engine hitting?

Tim

[blueyes]

Somewhere between 7500 and 8000... but I'm a bit busy when it gets there to be very precise.

[rev-erend]

With this system - the cam pushes the bucket which sits on top of the valve - very direct .. allows very high revs.

[powerlord]

aha. yup, was referring to the tuscan.

Yeh, figured it was similar, but with the shims, etc (like my fireblade uses I think ?).

obviously hydraulic ones self adjust.

tt tim, yup 300zx owner still... though it's advertised on PH and goes into autotrader this week, so hopefully not for much longer with the tuscan soon to be aquired. :-)

stu

[TT Tim]

Should keep both, I have

I've posted your ad on www.300zx.co.uk hope that's okay, you might get some interest.

Tim

[Buster4.2]

I think the main reason for adjusting solid valve clearances on TVR's is because of valve stretch. As the mileage gets higher (>30000), the need to adjust them should become less.

[SXS]

Dont forget to get this done on your cars fellas, if you havent already.

Cos when they go, the whole thing goes!

And anyway, once done (correctly), the engine note and response noticeably sounds and feels better! Maybe just mental, but it does show.

[powerlord]

TT Tim said:

Should keep both, I have I've posted your ad on www.300zx.co.uk hope that's okay, you might get some interest. Tim

erm.. thanks Tim, but it was on there already. Posted it a couple of weeks ago.

stu

[TT Tim]

LOL - Sorry about that then. Don't often look in the for sale section, and tbh yellow is not my colour.

Good luck

Tim