Modern engines without hydraulic tappets

[iwaters]

I discovered something which I though was quite odd the other day, wondered if any others had come accross this.

My wife has a 2006 Honda Jazz. I found a workshop manual for it on the web and was looking at the service schedule when I noticed that the valve clearances have to be checked and adjusted every 25K. I thought that all modern cars had hydraulic tappets that required no maintenance.

I know the Jazz is built for economy but was supprised by this.

 

[Burnerman]

Its actually pretty common - the shims that you set the clearance with are beneath the tappet itself......thats the bit the camshaft bears onto.
To set these you need to be good with a micrometer and have a bucket of shims standing by......the better news is that they stay in tolerance pretty well usually and frequent adjustment isn't necessary - which is just as well!
Hydraulic tappets are pretty good though, although they can get a bit rattly after a good few miles.
Superb vehicle, the Jazz. 8 plugs too!
John

 

[KingboyD]

The majority of Honda engines are manual adjustable tappets, no shims required, lock nut and centre screw to adjust

 

[Burnerman]

Is the Jazz like that, then? Bit of a bonus if it is, although this system seems to be less common than before.
Wish the bike engines were!
John

 

[Mursal]

I would be very surprised if you ever have to adjust them. Unless the mileage is well above average.

 

[Burnerman]

I agree - they are much better than they used to be.
I remember the old Fiesta kent series engine was great at rattling them loose...just like the bolts on the rocker cover. Cork gasket indeed!
John

 

[Mursal]

I agree - they are much better than they used to be.
I remember the old Fiesta kent series engine was great at rattling them loose...just like the bolts on the rocker cover. Cork gasket indeed!
John

I remember back in the day setting tappets on a Fiesta and they were worse than when I started! Not a good sign.

 

[Burnerman]

I bet you were using a Haynes manual too.....they got it wrong big time on that one. Different cam profile, if I recall.
John

 

[KingboyD]

Is the Jazz like that, then? Bit of a bonus if it is, although this system seems to be less common than before.
Wish the bike engines were!
John

Yeah I`m sure they are, well 99%! No other Honda engine that I have ever worked on (I`m an ex Honda Tech) had shims, Honda provide a special tool, a T shaped socket with a hole down the middle to fit your flat blade screwdriver down to adjust then hold the tappet while you tighten the lock nut.

I have zero knowledge of bike engines lol! Are they shimmed up??

I would be very surprised if you ever have to adjust them. Unless the mileage is well above average.

TBH I only did if there was a problem/excess noise! There was only 1 occasion I can recall when tappets caused a malfunction, a CRV had the engine management light on, mis-fire on any cylinder was the fault! Engine ran perfect lol!! tried all sorts to get this light out and in the end adjusting the valve clearances sorted it!

 

[Burnerman]

As far as I know, just about all bike engines are shimmed...maybe thats due to them revving in excess of 13000 My Blackbird is about due....
You have to pop the cam out, after measuring whats needed with feeler gauges. Trouble is, when you put it all back together again they're still out
How does a valve clearance issue put the management light on?
John

 

[KingboyD]

How does a valve clearance issue put the management light on?
John

It must have detected a slight mis-fire somehow, no idea how, those clever Japs and there clever ECU`s!!

 

[Burnerman]

You're a better man than me, for cracking that one
John