Valve shims available?

[98SF19]

I'm pretty sure these were addressed at 60k service, which was probably around 2009, but as I have things opened up now, I'd like to check and possibly replace shims if needed. I came across a thread that mentioned that they come in varying thickness, but I haven't yet measured clearances yet. I believe intake clearance spec is 0.006-0.010 and exhaust are 0.010-0.014. Before I get ahead of myself are there even shims for the 3.4 v8 still available? Looks like shosource only has Gen 1 & 2.

 

[gamefanatic]

Well, I believe Gen2 shims are the same radius. I haven't seen one to know if the surface is the same, but would imagine it was. Wity the exception that they do not have the easy removal blow hole. Though, I was able to remove most with my fingernails, and they weren't all that long.

I have seen some for sale at ShoNutPerformance.
http://www.shonutperformance.com/E9DZ-6515-***.HTM

One thing you could do is check the clearance / condition of the shims and see if you even need replacement first. Usually they should be just fine, maybe just need to move them around.

One other thought is to reach out to shoheaven and see if they have any not already scavenged up with their heads...

https://shoforum.com/index.php?threads/sho-csvt-junkyard-what-do-you-need-20-shos.103080/

 

[98SF19]

Looks like I'm just a smidge out of spec for a few valves. Does 0.001" out of tolerance for exhaust valves warrant replacement of shims?

Here's what I measured: https://www.dropbox.com/s/gl31ckex72iir2n/vavle clearances 5-2-18.pdf?dl=0

(I have s few intake valve clearances highlighted here, but they are actually fine)

 

[GEN 3 SHO FAN]

IIRC, I have rode something on V8SHO saying that some shims of big motos can be used too (Kawasaki maybe ?).

 

[E1]

They have been said to actually be available through Yamaha dealers. Your 0.001 does not warrant replacement in my opinion.

I might have, oh....one or two around here somewhere...

Oh yeah - if in the event you actually have one that is worn, flip it over. Measure it now and see what you get.

For the record, I've been in hundreds of these motors and in my experiences it is very rare to see them need shims even over 150,000 miles with even average upkeep. The babied engines are virtually never.

 

[stephen newberg]

Mine is at well over 200K now and at the 200K check the shims were still fine.

pax, smn

 

[AREA 91]

You can use valve shims from the Yamaha motorcycle dealership. 89-99 V6 and V8 shims are compatible as well.

 

[gamefanatic]

Looks like I'm just a smidge out of spec for a few valves. Does 0.001" out of tolerance for exhaust valves warrant replacement of shims?

Ultimately this just comes down to how important it is to be within spec to you, or if you are having any issues. Most of the time this just means a little loss in power is all.

I'd say it would be worth investing if you can find the parts. Though you want each valve to be as close to each other as realistically possible. Keep in mind your measurements may differ from the book based on differences in your tools spec fron the manufacturers. If you are going for the closest to the bottom end of the specs, you may want to physically check each valve after you put the new shim in to ensure clearance to the piston. You really only need to do this for one valve, but you may want to do that for all of them.

While I have not done this yet on mine, it is recommended, after putting new shims in, to recheck your clearances after 300 or so miles. I am too lazy, but this is just to make sure after the system has hammered everything a while and has had several heat exchanges ehat everything is where you expected it to be...

 

[98SF19]

I know 0.001 really isn't anything to worry about, but my thinking is that the rate of wear on shims would sloooowly accelerate the larger the gap gets. I think it's relevant to say that this is all in the context of keeping the car running normally many years from now. Preparing ahead of time to address normal wear/tear, fatigue, creep of materials (IE stockpiling new or used parts soon to be extinct) behooves anybody wanting to hit and surpass the 30 year mark. Sounds like there are alternative with the v6 shims and the Yamaha shops.

Another question I meant to ask earlier - the shonutperformance link above lists the v8 shim thicknesses from 2.2 mm to 3.25 mm. What is the stock thickness?

 

[zak]

You can pull the shim and check the wear pattern on it (or look very carefully with the shim n place). Sometimes the shims get pitted - those you want to replace.

When I autocrossed a V6 I always carefully shimmed the intakes at the tightest (smallest) end of the spec, and tried to get the exhausts to near but not at the minimum spec.

There is no "stock" thickness, because of machining tolerance stackups between the seat and the head, and the angle of the valve seat to the angle cut on the valve.

 

[E1]

Each shim has a thickness number etched on it. Some are easy to read, some are impossible.

So then, you read the feeler gauges and find the shim gap out of spec by .2 mm. You remove the shim and read the number on the back as 2.50. Then you know you want to obtain a 2.70 shim. It literally IS written right on them.

There is NO rhyme or reason to the pattern of shim sizes, they are all individual to each cam lobe.

 

[GEN 3 SHO FAN]

IIRC, I have rode something on V8SHO saying that some shims of big motos can be used too (Kawasaki maybe ?).

I'm not completely fool already...
http://www.v8sho.com/SHO/ReplacementValveShims.htm

Kawasaki was mentionned by Paul and Eric in 2008 (KLR650 model). But stay with Yamaha if you're able.

 

[98SF19]

I did a search on that site but musta skimmed too quickly cuz I don't remember seeing it . . .
I like Scott's suggestion of the magnet - I'd though of using one of the little magnets from the electric toothbrush heads (Phillips). They are small but very strong. I'd recommended them on here somewhere for holding wiring down.

Whatever happened to Scott K? I guess he's not in the sho game anymore.

 

[GEN 3 SHO FAN]

Other idea for magnets :

Repairing a door on a computer case, one of my friends give me magnets coming from small cloth pin. These magnet are really strong too and small (for restricted place app.).

For Scott, I haven't seen a recent post of that guy sadly. He gave very usefull infos over years.

 

[E1]

Scott's around. You should join the V8SHO.com email list if you want to get in touch with him.

He hasn't posted there since, ohhhh....yesterday?

 

[GEN 3 SHO FAN]

Ok, ok, I don't want to misleading any people here... sorry. We are out of the thread anyway. :S

 

[98SF19]

That's ok - I've steered too many a thread off course to have an issue with it. It was I who steered off topic to begin with! lol
Ok back on . . .

There is NO rhyme or reason to the pattern of shim sizes, they are all individual to each cam lobe.

So when the motors were assembled, did they start with one nominal size shim and then measure gap, then replace with larger or smaller as needed?
I think I'll kick any shim adjustment down the road for now, but will keep the Yamaha KLR650 shims in mind for the future.

 

[Qshiplvr]

I think I need at least one new shim...posted new post in V8 Emergency Issues.

https://shoforum.com/index.php?threads/v8-sho-catastrophic-shim-failure.138715/

 

[stephen newberg]

You should try Paul Nimtz, here as SHO123. He is a repository for knowledge on the car and spare parts.

Best of luck with your problem.

pax, smn