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ASEMaster35yrs
ASEMaster35yrs, Master Auto Tech
Category: Classic Car
Satisfied Customers: 2095
Experience:  Master Auto tech since 1972,I own a 65 mustang and have built a 57 ford race car from the bottom up
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Chevrolet Corvette: I need to replace the valve stem seals

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I need to replace the valve stem seals on a 1994 ZZ3 crate engine. In order to order the correct seals, I need to know the valve guide o.d. that the seal presses onto. Can you help?

Purchase an inexpensive micrometer and measure it. I'll see if a manual lists the diameter though.

Do you have the number off the heads?
Customer: replied 3 years ago.


No; but they are aluminum, angle plug heads.

Customer: replied 3 years ago.

I do have the head part number. It is 10185086

The specs for the 1965 350 are for the stem diameter int .3404-.3417", ext .3410-.3417"

Summit only sells 1 seal for that and they list it for Valve Stem Diameter:0.341 in.

Valve Guide Diameter (in):0.443 in.

Valve Stem Seal Outside Diameter (in):0.625 in.

http://www.summitracing.com/parts/slp-mv1903/overview/make/chevrolet

Customer: replied 3 years ago.


Your answer is not satisfactory for the following reasons:


1. There is no such thing as a 1965 350 cid Chevy engine. In 1965 the small block was 327 cid.


2. My question is about a 1994 ZZ3 with head #10185086.


3. Summit lists two seals for the 11/32 dia. (.344 in.) stem; neither


of which is for a .443 in. dia. valve guide.

That is not fair when you go back and edit your post. You never said 1994 the first time.

They were all the same back then.

Customer: replied 3 years ago.


The first sentence of my original post said "I need to replace the valve stem seals on a 1994 ZZ3 crate engine."


If you don't have an answer for me, just say so; and we can forget about it.

These are the seals to use on your ZZ3 engine.

460483 *SEAL, INTAKE STEM

10147883 *SEAL, EXHAUST STEM

http://www.gmpartsdirect.com/performance_parts/store/catalog/Product.jhtmlPRODID=751&CATID=749.html

You can get them here:

http://www.gmpartsdirect.com

Back in the day we used the seals from a chevy vega which fit & worked perfectly inside the spring and was a tight fit. The seals at this link look just like the old vega seals. Umbrella type seals are recomended for your engine.

 

Valve stem size is 11/32" see: http://www.gmpartsdirect.com/performance_parts/2012/ChevroletPerformance_Catalog_2012185.html

 

See: zz engines - CrateEngineDepot.com

You can use the 460483 *SEAL, INTAKE STEM on both intake & exhaust valves.
Customer: replied 3 years ago.

I appreciate the links to Summit and GM parts, but none of that answers my question: What is the valve guide o.d. on a 1994 ZZ3.


I need the guide o.d. in order to select the proper seal.


I don't want the factory seals, because the originals only lasted 38,000 miles. I would prefer some good after-market Teflon or Viton seals.

It's a .558" OD guide. If your going to use aftermarket seals, I would suggest having the heads machined for Perfect Circle All Teflon Valve Seals - 11/32" stem / .530 OD guide.

If you decide to have the heads machined, the machine shop can do all the work and fit the seals properly and will supply the parts, or you can get them here:

http://store.440source.com/All-Teflon-Valve-Seals-11_32-stem-_-530-OD-guide/productinfo/101-1049/

Customer: replied 3 years ago.


Can you recommend a Teflon or viton seal that will fit without having the guides machined?

ASEMaster35yrs, Master Auto Tech
Category: Classic Car
Satisfied Customers: 2095
Experience: Master Auto tech since 1972,I own a 65 mustang and have built a 57 ford race car from the bottom up
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