Hot Rods Question on Spring Shims and Spring Locators - Iron Heads

I'm building a 325 hp or so budget AMC 360 endurance race engine (24 Hours of Lemons) with a mild hydraulic flat tappet cam from Bullet Cams - .491/.494, 224/228 @ .050. I'm using stock 1970 iron heads with some very mild port and bowl cleanup.

The springs are from Bullet Cams as well - they're 110# at 1.82" and 300# at 1.25".

The rev limiter will be set at 5,400 rpm or so.

I had planned to use flat spring shims, but should I be using spring locators or spring cups? I'm thinking not because it's an iron head, mild cam, mild spring pressure, and low rpm build.

Any thoughts?

Thanks

Scott

 

Purpose? Protecting the spring seat on the head? Shims are normally for getting spring pressure or height corrected. The pic doesn't show it, are the seats without an outer or inner step?
This looks like they would be located by the inner area. I don't know what you would gain with a sheet metal outer locator.Pic is AMC 360 result.

 

I used them on my iron bb Mopar heads if I need to shim and it seems like I always do however I haven’t used hydraulic cams for over forty five years.

 

The spring is recessed in the seat; there's a lip that should keep it in place, so I don't think the spring would move around much. With a metal shim under it, I don't think the springs will beat up the spring seats, either.

Here's the best pic that I have right now; heads are at my shop.

 

My machinist always used a .015" harden shim under all the springs, then added from there to get the correct installed hight, that's the way I install them, never had issues or head damage. I've seen two sets of CompCams springs eat the shims and damage the head. The springs had a flat coiled ( third ) spring in between the inner and outer coils. The flat spring cut through the shims and started digging into the heads in a very short time. After the first set did it on dad's Pontiac heads, I ground the flat coil edges smooth and flat hopping they wouldn't damage anything, they still did! These springs were recommended for the cams being used. I will only use Crower springs now.
Pontiac heads look just like yours, they have a machined area for the spring to set with the correct diameters to hold them. Just watch out when adding to many shims, you will use up all your machined area with shims and have nothing holding the spring in place.

 

Check out these guy's for shims and supplies, https://goodson.com. I used to buy through my local shop, but I think you order direct now.
Under head supply, then valve spring work, look for valve spring boosters.

 

Shims need to be 1” ID and maybe 1.437” OD.


I have a bunch of shims but nothing in that size.

 

I have a few of style you may need. I have no idea where they came from or application .

 

Thanks. I’ll check online once I get home from
The shop.

 

If you have a set of calipers, can you please measure the outside and inside diameter on these? Thanks!

 

The closest shims that I'm finding are 1.031" ID and 1.5" OD - lots of companies manufacture these. But there's a small lip on the outside of the valve seat at 1.437" and helps locate the spring, so I don't want to machine that.

Now I'm trying to think of a way that I can trim .063" from the outer edge of these so they will fit.

 

Lathe, or a valve seat cutter.

US Seal B109, A109
Maybe . . .

What is the actual ID/OD of the spring ? If the OD is smaller. And they locate on the ID there are other options. Like a 1.36" OD shim.

 

Love that you're using an AMC engine. I'm ***uming the car is OT, but can you give us a hint?

 

actual OD is 1.475. ID is 1.06.

I saw those 1.36 shims too, but .090 too narrow seems to be too much to me.
Thanks

 

here’s a hint. Mods please delete if not allowed.

 

U.S. Seal B109 should work - these are 1.059" ID, so about .006" loose and 1.438 OD, so about .0037" too narrow, but I don't think I'm going to get any closer. Thanks!

 

Change 1 - There's no valve seat cutter for 1" ID and 1.5" OD, so I'm going to modify one to fit those dimensions, take the seat out to 1.5" and use hardened shims for 1" ID/1.5" OD.

Thanks for all the input!

Scott

 

1.75 OD
1.00 ID

 

Thanks for checking.

 

The name of the company stamped on them is V.S.I. Haven’t checked to see if there still in business.

 

VSI is still in business, but they don't make the correct size for me.

Thanks

 

Google :ALEXSPARTS ....valve stuff

 

I checked their website; they don't have 1.475" x 1".

Thanks

 

Send them a note; I did last year. He called me back(twice) with possible solutions for my application. Not everything is listed on website.

 

Ok, I'll send them a message. Thanks

 

If your spring OD is 1.475" and the seat has an OD of 1.437", then your seat will need to be cut to a larger OD.

What is the OD of the valve guide boss? 1.000"? To use commonly available shims you'd likely need to cut that down (or modify the shims to increase the ID).

You can locate your springs using either their ID or their OD. Your spring ID is close enough to your current boss OD that you can locate off of that - ***uming you don't need to shim for installed height - and machine the seat OD larger to clear your spring OD.

Have you confirmed the stock depth of the spring seat will get you the installed spring height you need with whatever valve and spring retainer you're using?

 

if you are using the shims to set spring pressure you may be able to get valve locks or retainers to vary the retainer height instead of a shim under the spring

 

The spring seat is actually 1.475".

The valve guide boss is .694" but it opens up to 1" at the bottom. The spring locates on the 1" OD of the valve guide boss.

Someone has sent me a valve seat cutter to open up the valve seat to 1.500" so I can use the commonly available 1" x 1.5" shims.

I have only checked the height on one valve and it was 1.845". Installed height on the springs should be 1.82" so I suspect they all will need shims.

Thanks for the input.

 

Yes, but I need to check the height on everything first to see what makes more sense.

Thanks

 

Looks like I got it figured out. Someone sent me a valve spring seat cutter that had a 1.550" OD, but the ID was something like .640" and I needed a 1" ID. However, since no one makes one in that configuration, I just opened up the ID to 1". Not super easy grinding down carbide cutters, but I managed to get it done. Now my bench grinder needs a new wheel.



Anyway, after 45 minutes of grinding to configure the cutter, removing the small lip on the outside of the valve spring seats took about 5 minutes total. Now I can use the 1.5" shims that wouldn't fit my 1.475" valve spring seats.