View Full Version : Shim kits
Nudie
27-10-2011, 06:26 PM
Im not a mechanics ring piece, but I own a pliers and id like to have a go at doing my valves. Where do you guys get your shims from? How much should I expect to pay for 'em? If I have to order 'em, will I have 'em in time to butcher and rebuild before NFR (this year)?
I sell full kits just pm me make & model of you bike and I'll shoot you an ASF member price {most dealers want $6 per shim ahahhah)
Cost you a fraction to do it yourself if your confident in having a go ......
Nudie
27-10-2011, 07:28 PM
PM sent
the easyest way mate is to measure all ur clearances and then remove them keep them in order and if you are good at algebra "yes that is the maths s for it "you can then work out wat size shim you need to close the gap,and wat i do is rob pete to pay paul !!
just say no 1 and 2 on ur inlet uses a .230 shim and ur exh 1 and 2 has .235 and ,240
and you need to close the gap on inlet 1 and 2 to a shim value of .240
and you need to open the gap on exh 2 out to .245
then you use the current .240 shim on the exhaust and put in the inlet ! and so forth that way insteed of buying a shim kit you only have to go into a honda shop and buy just a .240 and a .245 shim !!
do that make sence ??
so if youre shim is say (.240) and ur gap is .015 and the spec is (.005-.010) you want to aim for the tighter tolerance for less valve overlap!!
so then you will need a shim value of (.250) this will give you ur clearance of .005.
hope this helps mate "provided i got my maths right lol"
(a+b=c)-d =e !! (.240+.015=.255)-.005=.250 yah i got it i hope !!
(.240 + .015 = .255 ) - .005 = .250
( a + b = c ) - d = e
sorry had to re do to make sure i did it right lol
Hillsy
27-10-2011, 08:37 PM
Albi is right (he's made it complicated, but he's right). You basically swap you shims around so you only have to buy the least amount of shims.
Out of the 16 on my ZX9, 5 were out of spec, but after swapping the 5 shims around I only needed to get 2 new shims.
Just make sure you double check your measurements.
The other thing I would suggest is to go towards the looser side of tolerance as the valves will tend to wear into the seats over time and close up the valve clearance (they rarely go the other way).
Dynomutt
28-10-2011, 03:36 AM
Always set the clearances towards the upper limit as the valves will reccess over time and close the clearances up. If you find you have a zero clearance on a valve then use a shim smaller than the one fitted, by the maximum clearance -0.05, so if you have a zero clearance when it should be 0.15 to 0.20 and a 2.70 shim fitted then fit a 2.45 shim (max clearance -0.05 =2.45) then remeasure.
Make sure the motor is stone cold, measure the clearances and note them, then bring the timing marks to TDC, remove cams and then lift buckets out and measure the shims and work out the required sizes, before reassembling everything. As a tip you can often use cable ties to tie the camchain to the cam sprockets then lift the exhaust cam backwards and do the exhausts shims, then replace the cam and lift the intake forwrds and do those shims, this way the cam timing cannot generally move, as the camchain cannot slip off the crankshaft on 90% of bikes, the FJ/XJR engines are an exception though.
pappas
28-10-2011, 08:57 AM
Wouldn't a tighter tolerence give you more overlap? Not less?
Hillsy
28-10-2011, 10:04 AM
quote:Originally posted by pappas
Wouldn't a tighter tolerence give you more overlap? Not less?
Yes, but it's negligible at these sorts of tolerances.
The main concern is that you don't want the gap closing up and risk burning out the valve, hence you shim on the looser side of tolerance.
A wise old mechanic friend of mine always said "I'd rather hear a tappet make a little noise than not make any noise"
Nudie
28-10-2011, 04:18 PM
Thanks guys. I've been perusing the workshop manual so I actually have an idea what your saying.
I'll fill the fridge and have a go at it soonish
quote:Originally posted by Dynomutt
Always set the clearances towards the upper limit as the valves will reccess over time and close the clearances up. If you find you have a zero clearance on a valve then use a shim smaller than the one fitted, by the maximum clearance -0.05, so if you have a zero clearance when it should be 0.15 to 0.20 and a 2.70 shim fitted then fit a 2.45 shim (max clearance -0.05 =2.45) then remeasure.
Make sure the motor is stone cold, measure the clearances and note them, then bring the timing marks to TDC, remove cams and then lift buckets out and measure the shims and work out the required sizes, before reassembling everything. As a tip you can often use cable ties to tie the camchain to the cam sprockets then lift the exhaust cam backwards and do the exhausts shims, then replace the cam and lift the intake forwrds and do those shims, this way the cam timing cannot generally move, as the camchain cannot slip off the crankshaft on 90% of bikes, the FJ/XJR engines are an exception though.
yeh i spose ur right as i genrally set it up close to spec for better responce ie ;so the duration of the lobe isnt slow ?? if you understand me ,its the way i was taught as an apprentice ,as if you follow the reconmendations for the service intervals and use quality oil and fuel then valve seat resession sholdnt make a difference if all is followed,but that is just me .
then again my tls kinda suffered from a mech owneing her lol
Dynomutt
28-10-2011, 07:34 PM
Valve reccession is mainly due to shite unleaded fuels, the lead in fuel acts as a cushion on the valve seats and valves. The Japanese multivalve heads often suffer because the valve seating width is so small, and the valve diameter is small, which reduces the surface area that absorbs the shock loading of the valves snapping shut, combine this with the lack of leaded fuels, and the problem can get worse. I've stripped heads down and the valve has reccessed so far that the margin has gone completely leaving the edge of the valve sharp enough to cut paper. On my own engines I run a lead substitute through the tank every couple of fills to help protect the valves and seats, especially when I'm running lumpier cams than stock.
As for the effects on cam timing of different clearances, on a road motor the effects are fairly small, on a race motor then the clearances can be set lower as the motor isn't going to be doing the mileage of a road motor. Cams are always dialled in with a zero valve clearance as per the manufacturers specs, so there will always be a very slight discrepancy in terms of set timings and actual timings.
quote:Originally posted by Dynomutt
Valve reccession is mainly due to shite unleaded fuels, the lead in fuel acts as a cushion on the valve seats and valves. The Japanese multivalve heads often suffer because the valve seating width is so small, and the valve diameter is small, which reduces the surface area that absorbs the shock loading of the valves snapping shut, combine this with the lack of leaded fuels, and the problem can get worse. I've stripped heads down and the valve has reccessed so far that the margin has gone completely leaving the edge of the valve sharp enough to cut paper. On my own engines I run a lead substitute through the tank every couple of fills to help protect the valves and seats, especially when I'm running lumpier cams than stock.
As for the effects on cam timing of different clearances, on a road motor the effects are fairly small, on a race motor then the clearances can be set lower as the motor isn't going to be doing the mileage of a road motor. Cams are always dialled in with a zero valve clearance as per the manufacturers specs, so there will always be a very slight discrepancy in terms of set timings and actual timings.
so no margin left ?? ive only seen that when valves machined to their limit!! yeh ive seen some shops do that to save customers money!!
with the multi valve heads on cars oil grade plays a big role aswell ive found , ive pulled some donks down and the carbon build up is profound and when asking owner questions they do their own services and use shite oil ?? thats just wat ive found .
but when i put my TLS donk back together ill set the shims to a bigger gap when dialing in the cams and see how different it makes it!!
Nudie
01-11-2011, 07:08 AM
Pulled the bike apart, checked the valves and you bewdy, all within tolerance after 70,000ks of dragging my fat arse around. You've got to love Honda reliability!
However! During reassembly I broke a valve cover bolt off in the head.
Now I wont have time to fix it before NFR (I leave this morning to go to work interstate and I dont think I'll be back in time).
I've got another bike to ride, but, no whoolies for me
Dynomutt
01-11-2011, 10:30 AM
Get yourself some lefthanded drill bits, and drill the offending bolt out, 9 out of 10 times the lefthanded bit will start to pick up the bolt and start winding it out. If not then try an easy out, but don't snap it. If the thing still won't come out then you'll have to drill it right out an use a thread repair insert. I only use Timeserts rather than helicoils, I've had helicoils pull out, but I've never had a Timesert fail on me.
Gitzy
01-11-2011, 10:49 AM
Nudie not on the psychedelic wheeled VTR???? [:0] Not on I say.. Make it happen Russ :D
Nudie
01-11-2011, 04:28 PM
quote:Originally posted by Gitzy
Nudie not on the psychedelic wheeled VTR???? [:0] Not on I say.. Make it happen Russ :D
I want to bring the Thing, but im not even confident I will be home in time to meet up with you guys, let alone in time to fix it up.
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