I'm no machinist but....

[Freddie's Buick]

Well I was a pleasantly surprised when I disassembled my engine today but I was also a little disappointed. I found nothing wrong. That's the good news, bad news is I bought new exhaust valves thinking I was still using the original 'oil-stepped' Buick exhaust valve and I was'nt, (memory loss is attributed to age).

My guide clearances are excellant! 343-341=.002 right in the ball park of much life for my 25506293 heads. No need to change any of my valves, valve seats or guides. As for the stem seals they look used but not brittle.

There'a a lot of confusion when it comes to these heads and their stem seals and I'm hoping to clarify a little of it. First, the various places I looked for info on the guide boss gave me a size of .500 to .531. This is way off and wrong. The oem sizes are .600 for the exhaust boss and .590 for the intake.

The only seal available for purchase that is an easy drop in is the Fel-Pro SS70731. Anything else would mean one would have top rip off the heads and spend a lot of money getting them cut down. But the Fel-Pro kit only comes with six positive stem seals just for the intake valve.

The problem is that the exhaust boss was never machined from the factory for a stem seal. That is why they come with an 'oil-step' on the exhaust valve; to pull down oil and to lubricate the exhaust guide. This keeps manufactoring cost down at the assembly line.

Since I'm already in there my purpose is also to cut the exhaust valve down to .500 and insert a Viton steel jacketed stem seal. Once I'm done with this its on to the timing chain cover mod. :biggrin:

 

[Freddie's Buick]

Pictures tell a thousand words....

To measure valve guide clearances use a 5/16 split-ball gauge, (pictured below the micrometer and above the stem seal).

Measure above, center and bottom of valve guide. Use the micrometer or the digital caliper to get the size of the guide opening. All three measurements should be about the same. If not, it's tapered and must get replaced.

If not tapered, measure the diameter of the valve stem. Subtract this size from the guide opening measurement. The result is the clearance.

For my heads the clearance must be within .0015-.0032.
I'm at .002, so I'm good! :biggrin:

 

[charlief1]

Show a pic of the cutter doing it's work Freddie. This will help the rest of the guys understand how it works. Nice post btw.

 

[dr_frankenstein]

what happened to the umbrealla seal idea?

A.j.

 

[Freddie's Buick]

what happened to the umbrealla seal idea? A.j.

Viton umbrella seals were darn near impossible to find. I gave up. Anyway those steel jacketed viton seals I put in are similiar to umbrellas. Hope my idea works...

 

[Freddie's Buick]

Show a pic of the cutter doing it's work Freddie. This will help the rest of the guys understand how it works. Nice post btw.

Here ya go Charles...

 

[novaderrik]

those valve guides look knurled.. that there is old school stuff..

 

[Freddie's Buick]

These intake valves I installed back in Sept/2000 withstood the test of time. They were purchased from Kenne Bell. They are stainless steel, 1.77". By comparison, the exhaust valve on the right shows typical use, (I got these from Poston's).

 

[charlief1]

What was the part number of the seals Freddie?

 

[Freddie's Buick]

A little Engine Math...

I got myself a burelle and finally C.R.'ed my engine. Volume checked the heads, (28-ccs), and the cylinder, (44.4-ccs), the old gasket was crushed down to .052", with a bore ID of 4.02".

Final results: 8.71.4 compression ratio.
If I were to use .020 stainless head gaskets I can bump her up to 9.35.0.

But I'm good with the above compression ratio. :biggrin:

 

[charlief1]

What kind of fluid is that Freddie? Looks like antifreeze to me.

 

[Freddie's Buick]

those valve guides look knurled.. that there is old school stuff..

Lol!!:biggrin:

Actually I wanted to kill the guy for doing that, (I asked him to replace the guides with bronze inserts). Funny how they lasted so long with little or no usage. I guessed it worked out. But I would never recommend that, (even if I am old skool to the bone). He did a pretty good job of porting too. Kinda reminds me of Charlie's Snot Porting jobs....:biggrin:.

All this was done back in Sept/2000.

 

[Freddie's Buick]

What kind of fluid is that Freddie? Looks like antifreeze to me.

It is. I goofed up so many times you can see the drips all over my garage floor. I finally got it right and the vaseline seal held and did't lose a drop.

 

[Freddie's Buick]

What was the part number of the seals Freddie?

Comp Cams 517-16. They're hard to get because the're flying off of the shelf for $14.99 for 16 of 'em at Jegs. Summit ran dry.

 

[charlief1]

Lol!!:biggrin:

Actually I wanted to kill the guy for doing that, (I asked him to replace the guides with bronze inserts). Funny how they lasted so long with little or no usage. I guessed it worked out. But I would never recommend that, (even if I am old skool to the bone). He did a pretty good job of porting too. Kinda reminds me of Charlie's Snot Porting jobs....:biggrin:.

All this was done back in Sept/2000.

That doesn't look anything like my work Freddie. You still have more guide sticking out than I'd ever leave. Do some cutting on them and you'll get better flow for the engine.:biggrin:

It is. I goofed up so many times you can see the drips all over my garage floor. I finally got it right and the vaseline seal held and did't lose a drop.

I thought you were suposed to use tranny fluid. I'm not sure antifreeze would work the same because it's not as stable as oil at all temps.

 

[Freddie's Buick]

That doesn't look anything like my work Freddie. You still have more guide sticking out than I'd ever leave. Do some cutting on them and you'll get better flow for the engine.:biggrin:.

Nope. I don't think there'll be any significant gain or loss. However, there is if you compare it to a stock port with all the sharp edges and flash. That is the logic behind porting. In your case you maximized the flow area. Only a flow bench will give one an exact measurement. I'm good with what I have.

...I thought you were suposed to use tranny fluid. I'm not sure antifreeze would work the same because it's not as stable as oil at all temps.

Depends on the Burelle. Some cannot handle alcohol, some will lose the miniscule markers from harsh chemicals. Glass ones can handle pretty much anything but are way too fragile for me. Any colored liquid should be fine. Anti-freeze is a good substitute. The object is volume.

 

[dr_frankenstein]

looks very very good freddie!

A.j.

 

[Freddie's Buick]

Final Conclusion.....

These mods are a total success. No oil burning. Plugs are burning super clean. Engine purrs like a kitty cat. Great torque and drivability. Good mileage, (although I have'nt calculated gas consumption yet).

Happy happy!! Joy Joy Joy!! :biggrin:

Super success!

 

[charlief1]

These mods are a total success. No oil burning. Plugs are burning super clean. Engine purrs like a kitty cat. Great torque and drivability. Good mileage, (although I have'nt calculated gas consumption yet).

Happy happy!! Joy Joy Joy!! :biggrin:

Super success!

LOL HOLD YOUR HANDS UP SO WE'RE SURE YOU'RE NOT DOING SOMETHING NAUGHTY WITH THEM FREDDIE!:biggrin:

 

[Freddie's Buick]

Sure you don't wanna shake my hand?

:biggrin: