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valve clearance/ adjustment b230F formula?

durk80

Member
Joined
Nov 17, 2015
Location
South GA
Both of my Haynes' manuals gives a formula for calculating the correct valve shim for hot and cold engines.

T= Thickness of old shim
A= Valve clearance measured
N= Thickness of new shim required

If measured on a cold engine the formula is: N= T+(A-0.018 inch)

If measured on a hot engine the formula is: N= T+(A-0.016 inch)

The Haynes manual did not say anything more about what the measured clearance range should be.

In my Chilton's manual, although it doesn't give a precise formula it does say that valve clearance should be set between 0.014 to 0.016" for a cold engine and 0.016-0.018 inch for a hot engine (above 176 degrees)

My question is: Is this the correct formula to use that is in the Haynes manual? I used the cold formula when I computed the new valve thickness, and was wondering if the Bentley manual said the same thing for calculating valve shim thickness.

Thanks for any clarification as it is greatly needed!
 
The Bentley manual has the following info:

Cold Engine
Checking: 0.3mm - 0.4mm (0.012" - 0.016")
Adjusting: 0.35mm - 0.4mm (0.014" - 0.016")

Hot Engine
Checking: 0.35mm - 0.45mm (0.014" - 0.018")
Adjusting: 0.4mm - 0.45mm (0.016" - 0.018")


I don't see an equation in that section, but there are a couple examples.

I believe the equation is basically correct, although the clearances in the Bentley manual and Chilton's are a little different. As a quick check:
If the valve clearance is correct on a cold engine then (A - 0.018") = 0, therefore N=T and the shim doesn't need to be adjusted.

If the valve clearance is a little too big, then (A - 0.018") = DeltaThickness > 0, therefore the new shim is bigger than the old one by DeltaThickness.


I think better equations are:
Cold Engine
Nmin = T+(A-0.016 inch)
Nmax = T+(A-0.014 inch)

Hot Engine
Nmin = T+(A-0.018 inch)
Nmax = T+(A-0.016 inch)

These equations give you a range that you need the new shim to lie within.

A spreadsheet is helpful for this as it can be used to automate the calculation and keep track of the numbers.
 
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Wow, it's not that complicated guys.

Spec is .014-.018.
If your clearance is too tight, figure out how many thou too tight and go with a shim that is that amount thinner than what you took out. If it's too loose, go with a shim that much thicker than what you took out.

If you're at .010" and are shooting for .015", with a .160" shim, go down to a .155 shim. If you're at .020", go to a .165" shim.
 
Get a piece of paper and diagram intake or exhaust valve, then seat each cylinder to tits up, then measure your clearance with the feeler gauge. Log each clearance on the paper. Then, use whatever shim size necessary to get the clearance to spec.

Get the J tool for depressing the buckets and a shim kit
 
Rusty_ratchet, thank you for providing the correct specifications as my Haynes manual was not correct. hessam69, thank you for creating a simple formula ready to go into the spreadsheet. gottarollwithit, what an excellent idea to make a paper copy. And gsellstr, I have much respect for your expertise--hopefully I can get the hang of it eventually!

After taking everyone's suggestions into to consideration, I created an English and Metric spreadsheet with printable copies made for each.
If there are any mistakes, please feel free to correct it. I have a separate copy, so you can edit directly on the sheets.
https://docs.google.com/spreadsheets/d/18m39H33UJTVEaYaT7Yvs_-Mh0hIV9Eyme2deOXM3kL0/edit?usp=sharing
 
Hello,

Copies of the original Volvo tool are available and I have 1 in stock for sale and I have original Volvo tools for rent.

The main advantage with this tool is it doesn't rotate the buckets while depressing them. The J hook tool spins the buckets so you have to position each bucket so the shim removal slots will be accessible after you rotate them. With the original tool, you set the buckets so you can get to the slots and then use the tool and it depresses the 2 buckets without spinning them.

1052149.jpg
 
Hushers during clearance check or no?

For me I don't like using the tools with the cam in, it took me forever to get them to not spin or get the pliers to grab the shim.

I measure them all, take out the cam, take out the buckets, dig out the husher pieces, measure the shims, change the shims, put the cam back on and re-check without the hushers.

If the clearance is good, then put in the new hushers and put it all back together.

Now that's not how the shop guys do it for sure, I've seen Bob Workman do the whole thing in like 4-5 minutes. Head on a work bench, J hook and pliers and the plastic case full of shims, but he's been at this kinda stuff for a while.
 
I've done them far too many times, my heads and locals. Takes me about 30 minutes start to finish including removing the valve cover. Not pulling the cam means no messing with the timing belt, no chance of damaging seals, less chance of having the bearing caps start leaking, etc. As for the followers spinning, that's easy...spin them until you can get the pliers into the notches, grab them lightly to keep from spinning, compress with the j-hook while holding the pliers. Once the hook is down, squeeze the pliers to release the shim, walk it out, measure, install new shim, seat new shim, release hook, verify measurement, move to next hole.
 
Not exactly related to this thread, but why not.
Anyone dealt with noisier valvetrain after shimming (especially with aftermarket shims)?
I don't remember my B230 this loud at higher rpms with stock shimmed M cam and hushers. I put in an A cam and had to buy aftermarket shims in various sizes. I've thrown away the hushers as a few of them were already gone.
Gaps are in specs, exhausts are a bit on the looser side, intakes are on the tighter side.

I've heard it could be silent with good shimming even without hushers...
That leaves me with three suspects:
-Aftermarket shims have rougher cylindrical surface and a tad bit looser fit in the buckets :roll:
-Aftermarket shims does not have that nice and shiny (grinded) frictional surface
-Its really just the hushers

Thoughts?
 
you guys never said if you check it with hushers out then put them in and leave it? Or check them with the hushers in and leave it? Just curious which way is better or more accurate. I should probably ask kyle.


"I measure them all, take out the cam, take out the buckets, dig out the husher pieces, measure the shims, change the shims, put the cam back on and re-check without the hushers.

If the clearance is good, then put in the new hushers and put it all back together"

You can check with the old ones in and can adjust with the old ones in. The old ones are all squished flat. You don't want to check or adjust with new ones installed.
 
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