Valve Spring Shim Question

D

Daveyjonez

Member
Any problems adding valve spring shims to the retainer side?

I don't want to stack too many on the guide and lose the spring register.

Thanks!

Dave
 
Daveyjonez said:
Any problems adding valve spring shims to the retainer side?

I don't want to stack too many on the guide and lose the spring register.

Thanks!

Dave
Click to expand...

You´re adding weight to the moving side...not preferd.
Offset valv locks can compensate a bit to avoid to many shims.
 
Daveyjonez said:
Any problems adding valve spring shims to the retainer side?

I don't want to stack too many on the guide and lose the spring register.

Thanks!

Dave
Click to expand...

Hi Dave, that's a "band-aid" fix, not recommended, really.

We have bronze-lined guides that will accept up to 6 shims and where they belong, at the bottoms!

Thanks, Gary in N.Y.

P.S. Here's a shot of the entire setup including new "custom" spring locators.
 

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Valve spring shims go up against the block surface, correctly selected valve springs, pretested at the installed height for the given pressure should minimize the number of shims to 1 or 2.
 
Up against the block? I don’t understand. I’ve carefully selected valve springs and meticulously measured each assemblies installed height, and corresponding seat pressure. Given my cam grinders recommended pressure, I need more than “1 or 2” in certain cases. (1 or 2 of what thickness shim?). My shims fit the guide, you are saying I need shims between the guide and the block?

I’m new to flatheads, maybe I’m missing something.
 
Daveyjonez said:
Those look like what I need- could you give information on ordering??

Best from Texas,
Dave
Click to expand...

Hi Dave, the adjustable locators are really your best option, but, it isn't an inexpensive setup.

I have the package available for $300.00, this comes with 16 Comp Cams (machined) locators, 16 guides machined to accept the locators. The guides are bronzed-lined and machined for 8 Viton intake stem seals if desired??

The guide cores are on an exchange basis, in other words I would need 16 old guides as cores OR I can do those and return them to you ready to go!

Shims aren't included but I can supply them also!

Thanks, Gary in N.Y.

P.S. I have 2 sets of the bronze-lined/adjustable locators on the shelf as of tonight!
 
How much do you need to shim? Usually you can use 2 - .060 shims without a problem. You could also use .060 offset valve keepers in addition. What are you looking to get for seat pressure? Seldom need more than 50 lbs.
 
Pete (ground my cam) says 70, 2 x .60 leaves very little register for the spring on the guide. Maybe I am overthinking this?
 
I've used 50 Lbs on most of my street engines, even with the L-100. Most street engines never see 4K. I use 60 on the 400 jr . it has a higher lift rate. Your problem might be the wrong springs, I use the stock long ones. however with a cam with 350 or less I prefer to use the rotators for street and the short springs. The big issue is when using chevy valves, they are .050" longer.
 
Hi Dave, if it would help with the budget I could supply the seat locators alone, but the guides need some minor machining to make it all fit!

(Ron-heads up) Posted above the valve sizes for the Chev is closer to +.100" long? Typical Chev:4.920", Flathead (OEM):4.820"!

(Add) I would also add about 5# to the spring pressure for a Chevy valve if this is what you're using, the valves are about 10 grms heavier than the OEM's!

Thanks, Gary in N.Y.

P.S. The locators alone would run $128.00 ($8.00/ea). Have over 150 "loose" in stock ready to go.
 
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Thanks for the input guys- I am using the Isky 185g springs. Just a street setup, I just want to make sure I set it up right. I am going to go back through and see exactly where I am and I will reach out if it looks like I need to take the plunge with your trick setup Gary.

Thanks Again,
Dave
 
Before you do anything, you need to figure out the desired spring height that you need to get to 70 lbs on the seat (do what the cam manufacturer recommends). Then decide how best to get there . . .

Sometimes I machine the tops of the guides (where the shims go) and make a custom aluminum shim to take up some of the 'extra slack' that happens when you're using typical SBC .100 longer valves. Also, I cut down thicker steel retainers (made for SBCs with dual springs) to take up some length at the bottom as well. Examples of both are shown below.

Lots of ways to skin the cat if you have a small lathe.

Are you able to make simple parts (have a lathe and know how to use it) - or do you need to "buy stuff" to solve the problem?

Also, I put a small knurl on the outside of the guides - to tighten them up just a bit.

Below are some pictures of what I do on most of my engines. Note, one photo shows the package the retainers come in (part number), then I modify them as shown.

FinishedGuides1 copy.jpg

ExhaustValveComponents copy.jpg

Retainer1 copy.jpg

Retainer2 copy.jpg

StockAndModified2 copy.jpg

This sample assembly didn't need the aluminum spacer at the top - but does have my custom lower retainer:

ValveSetup copy.jpg

This sample needed both - as it was a cam that lifts .420 and has a smaller base circle - so more valve length was needed:

ExhaustValveSetup copy.jpg
 
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Thanks Bored n Stroked- I have measured each installed height, and have been trying to get to 70 lbs. I do have and can operate a lathe, I appreciate the pics- great stuff. I also have the chromoly retainers from Red's that look marginally thicker. Thanks for the help.
 
Daveyjonez said:
Thanks Bored n Stroked- I have measured each installed height, and have been trying to get to 70 lbs. I do have and can operate a lathe, I appreciate the pics- great stuff. I also have the chromoly retainers from Red's that look marginally thicker. Thanks for the help.
Click to expand...

I make the aluminum top pieces out of 6061 or 7075 and they do have a little 'collar' on the bottom side to center the spring. Also, I take every guide and turn/true it down a little bit - where the aluminum spacer slides over - you can see that in one of the pictures. I do like the very slight knurl on the guides (especially the intake side) as in almost every case they are a bit looser in the guide bores than I like.

On the exhausts, I prefer to use no knurl or a very light knurl - as you want as much heat transfer as possible from the guide to the block. I also like to use guides on the exhaust side that do NOT have the seal groove cut into them (it is not needed) - gives more heat transfer from the hot exhaust valve.

I prefer to have them just take a very slight tap fit (usually have to smooth some of the knurl down). I do this fitment and I mark with a felt pin their location in each bore. I then do a slight valve lapping with fine compound - to make darn sure I'm seeing a nice seal on the valve. All these little things matter in the end - as the top-end is the area where many shops screw it up.
 
Real nice work! I always dycem and lap in my valves- I was just able to try the chromoly retainers I have and I am very close to the 70lbs that my cam grinder recommended with a .060 and a .015 at my measured installed height. I think I am on the right track now- the retainers are definitely a bit thicker.
 
if the valve seats are cut too far down, makes everything else lots harder to do. it the block needs new seats, better to do it.
 
Daveyjonez said:
Real nice work! I always dycem and lap in my valves- I was just able to try the chromoly retainers I have and I am very close to the 70lbs that my cam grinder recommended with a .060 and a .015 at my measured installed height. I think I am on the right track now- the retainers are definitely a bit thicker.
Click to expand...

You can also purchase offset valve keepers - that move the retainer position further up the valve stem. They are cheap and can help your situation.
 
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