Anyone actually find valve shims that needed replacing?

[SHOmont]

I worked at a Ford dealer in the 1990s, the service manager had a 1989 SHO and did his due diligence for his 60k and then 120k service. His advice when I had my first SHO was to use a quality oil and not bother with the checking for clearance and use shims unless you hear clattering. The wear was so negligible it’s not worth the effort. Might have been true 30 years ago+ but as these engine age and are not used daily, I could see increased wear. But yet again, motor oils are so much better now too. Interesting to think about.

 

[RonPorter]

Back in the day, on my original 89, I wasted money twice getting it done. I've been telling people for years that, on a stock SHO with stock cams, don't even bother. If it concerns you, plan on checking at maybe 250k!

And same with the timing belt. Consider it at 150k. Or, if sometime after 100k, if you have to go in for the crank sensor and/or water pump, do it while you're in there.

 

[Irish Pride]

I have only ever done valve shims when changing cams. Either when upgrading or when doing a head swap. Other than that, I've never bothered with it on any of my drivers and I've owned over 40 SHOs over the last 15 or so years.

-Chad

 

[rubydist]

I have had well over a dozen of these cars and would always check valve clearances when I changed out the valve cover gaskets. I had to change shims on 2 of the cars - 1 because I had changed to 3.0 cams and 1 because one or two of the valves were just out of spec. 1 of those had a shim that had some pitting. Even when changing cams I only had to change shims on a few of the valves.

 

[BaySHO Performance]

I've adjusted the valve clearances on over 90 cars. While I've rarely found a clearance that was higher than the max, I've found plenty that were close to it. I only adjust clearances at around 120K, despite the Ford recommendation of 60K.

I change all 24 shims, setting the clearances at the bottom end of the range. Now the valves are fully bedded in, the gap can only get bigger, not smaller. Gives an unnoticeable increase in power, and prolongs the service interval. But on a new engine, or after valve work, the clearances should be set in the middle of the range (6-10 thou intake, 10-14 thou exhaust). One has to allow for the gaps to reduce a little as the valves bed in, as well as them to increase through normal wear.

I follow the normal practice of flipping shims over and using the pristine underside as long as there are no scratches in which case the shim shouldn't be used. Shims I take out invariably have a one thou cup in their old working surface, so if I need to reduce the gap by, say, three thou, I choose a shim that will only reduce it by two thou.

Problem with flipping shims is that the shim size stamped on the underside gets erased. So it's important to keep a record of all the shim sizes. Here's a handy spreadsheet to do that:

https://www.dropbox.com/.../Valve%20clearance%20template...

Wait for the sign in box to appear, then close it. Use the down arrow top right to download it.

Although Ford shims are no longer obtainable, shims for BMW bikes work great. Here's a spreadsheet with a parts cross reference for the V6 and V8 engines. The one caveat is that they are only available in two thou increments vs. Ford one:

Dropbox

www.dropbox.com

Shim tools and kits here:

https://shosource.com/products/ols/products/sho-source-shim-kit-rental-deposit-89-95

 

[RonPorter]

Do Yamaha shims from a motorcycle work?

 

[luigisho]

I think they do. I know I was considering going to a local shop to see what they had years ago. Then I blew it off because I haven't had to change any ever

 

[BaySHO Performance]

Do Yamaha shims from a motorcycle work?

Yes. This is the info I have. No idea whether the Yamaha shims are still available. Key is they have to be 29mm diameter. https://www.dropbox.com/s/iecidrd8h3sc9gr/Shims - Yamaha.xlsx?dl=0

 

[TimboSHO]

Do Yamaha shims from a motorcycle work?

I think I had to use Kawasaki shims when I put stage 1 cams in my 89

To answer the OP, I usually find 1 or 2 out of spec when I check. I recently swapped 3.0 cams into 3.2 heads and I changed 3 of them, not because they were out of spec, but because they weren't in the middle of the spec like all of the others.

 

[LOUDSHO92]

From doing multiple valve adjustments it has ranged from no shims to almost all needing to be adjusted. I also handle the SHO Source shim kits and yes people have replaced shims.

 

[Toolman]

It’s so quick and easy to check, I don’t know why you wouldn’t when you have the valve covers off. And yes, I have seen plenty out of spec.

 

[JRA2000TL]

I've only had a couple barely out of spec. I didn't have the numbers I needed to swap them, so I left them as-is. Never been an issue.

 

[SHOMON]

So set them with as little gap as possible??? Or get them all to match even if they are low but within range???.....

 

[NoSlo]

So set them with as little gap as possible??? Or get them all to match even if they are low but within range???.....

Measure the current gap of all, then find the current thickness value of all from the number underneath, and come up with a plan that achieves both as well as possible including your replacement shim collection.