1098 Just Done My First Valve Check & Adjustment

Just done my first valve check and adjustment on my 07 plate 1098S at 24k miles. It’s had 2 previously but not by me.

Lots of patience required and hellishly tedious but not complicated and immensely satisfying.

Bought a 4V-7mm shim kit from Mike at EMSDUC along with an engine turning tool, digi micrometer, new belts and JPdiag loaded on my PC to tune them at 110Hz.

Shim kit not cheap but well worth having a wide selection. Despite this, I still needed to lap a few in on sand paper to get the right gaps. But the results were worth it.

But what a feckin pain in the arse job. You can see why people charge so much for doing it.

Hopefully a few pics and a table showing the final clearances and shim sizes used.

Rich.

 

All in all, about 30 hrs of my time !!! Can see why people don’t like doing it. Still, I learnt so much doing it.

 

Clearances before I started ranged from 0.009 to 0.022 thou . Must’ve taken the cams out 12 times !

 

Gotta make sure they’re not too tight (half thou ok with me) otherwise when things heat up and expand, there’s the potential risk that the valve’s might not seat causing massive loss of compression and power loss.

 

Yes mate. My chart are the finished values .

If they’d been that good before I started, it’d have been a couple hrs tops.

I don’t have the previous values but by my reckoning, I don’t think they probably achieved the clearances I’ve got, not when two of the clearances were 22 thou against a 5-7 thou tolerance.

Gotta do the quiet clutch mod next to go with a new EVM Z48 clutch conversion. Should be the quietest Duke out there after all this bollox.

 

Aye.

Interestingly, I did a lot of comparison re-using old half rings compared to using new half rings, with the same closing and opening shims, just to chase down the last 0.0005-0.001 inch of gap. Made feck all difference and doesn’t really support the argument that new half rings help to close wide clearances in the valvetrain. I won’t be buying new half rings again.

The 3 other key things I learnt were:
1) unhooking the springs to help take the closing shims off REALLY does help and is bloody easy to do as part of the process,
2) when you rotate the engine to get the piston in the TDC position it is impossible to drop a valve into the cylinder you’re working on. Even with the valves pushed down to rest on the piston crown, the top of the valve stem is still a good inch above the valve seal,
3) reseating the half rings in their grooves is ESSENTIAL and made really easy by giving the cam followers a ‘ping’ and allowing the spring force to gently ‘tap’ the base of the closing shim to drive it onto the half rings. You do hear a satisfying ‘ding’ when the shim and half rings seat together and bed in. You don’t see this on any of the Youtube videos !

Defo do it again. So much learnt.

 

Got the EVR already fitted. Have to modify the tangs on a couple of old plates to give a small wavy format to the tangs so each falls into two slots but all looks feasible. Bit of machining to do but nowt I can’t sort. Will post up pics when done.

 

Yeah. Agreed. Trouble with this job is I have OCD and hunt down the clearances as close as I can. Reckon its still an 8-10 hr job next time ! Pure pain in the arse.

 

Haven’t done one yet but I guess access is the biggest issue. Space is very tight.