cc-ing heads

[ruckman101]

So I was checking the heads, cc-ing them and seeing how close they were, 1600 dp, new. Like within a ml of volume across the board. Woohoo!

But, the intake valves on one head seep water. Should I be concerned?



neal

[hambone]

Mine didn't leak. Not sure if it's an issue or not.

[satchmo]

If it leaks water, it will probably leak compressed air at 120psi, don't you think?

I'd get the spring off, check the seat, and see if there is a major problem. If things don't look too bad, get out the valve grinding compound and lap the valve to the seat.

I don't recall exactly, but I think you want the contact surface between the valve and the seat to be ~2mm in width all the way around the circumference (you should check the Bentley on that). Less than 2mm and there isn't sufficient transfer of heat from the valve to the head and the valve gets too hot. Too much contact between the valve and the head isn't good either (I forget why but I have a feeling a higher authority will weigh in on that).

Tim

[ruckman101]

I got's no tool for expedient release of spring on the valve assembly in a head. There's the rub. Well, another bit of detail that should surely be addressed. Anyone got a valve spring release tool? Or is there an alternative that doesn't risk fingers. More new territory? Sigh.


neal

[satchmo]

I got's no tool for expedient release of spring on the valve assembly in a head. There's the rub. Well, another bit of detail that should surely be addressed. Anyone got a valve spring release tool? Or is there an alternative that doesn't risk fingers. More new territory? Sigh.


neal

The big auto parts places (Schucks, Autozone, O'Reilly, Carquest, maybe NAPA) usually have a valve spring compressor tool you can rent. They aren't VW specific, but they will work. Maybe DJEep has one you can borrow.

Good Luck, Tim

[ruckman101]

Thanks Tim!


neal

[Amskeptic]

Thanks Tim!


neal

The intakes want a skinnier seat than the exhausts.
If this were a Type 4 new head, intake seepage would not be unexpected if it were machined according to the factory. They call for a 1* interference so that the valve will actively seat in operation (off the top of my head, a 22* seat angle and a 23* valve face angle).
Colin

[ruckman101]

Woohoo! Cheryle's Dad has a valve spring compressor that will work on the heads, yes, 1600 dp heads.


neal

[ruckman101]

Cheryle's Dad has some great tools. He's turned me onto a dandy hand valve grinding tool. Old school tool. Along with the vintage valve grinding compounds. Although he did suggest cigarette ash and oil is optimum. I'm going to have to corner him on that one and ask him what the ratio of each should be.


neal

[Amskeptic]

Cheryle's Dad has some great tools. He's turned me onto a dandy hand valve grinding tool. Old school tool. Along with the vintage valve grinding compounds. Although he did suggest cigarette ash and oil is optimum. I'm going to have to corner him on that one and ask him what the ratio of each should be.
neal

Cigarette ash is no match for "today's" hardened valve seats.
Just shoot for a nice skinny ring 1-1.5mm and clean it like you mean it.
Colin

[ruckman101]

Cheryle's Dad has some great tools. He's turned me onto a dandy hand valve grinding tool. Old school tool. Along with the vintage valve grinding compounds. Although he did suggest cigarette ash and oil is optimum. I'm going to have to corner him on that one and ask him what the ratio of each should be.
neal

Cigarette ash is no match for "today's" hardened valve seats.
Just shoot for a nice skinny ring 1-1.5mm and clean it like you mean it.
Colin

Ahh the simplicity of days gone by. And apparently much more frequent valve grinding.


neal

[ruckman101]

Actually my thoughts along those lines was that after application and work with a modern valve grinding compound, cleaning cleaning cleaning and more cleaning, to give it a final buff of old school with the cigarette ash/oil concoction. There are other questions. Why cigarette ash? What about wood stove ash? Old school hand crank tool, or rubber tubing and a power drill? Brand new head, I was ready to pull and spin that valve into a happier, closer relationship with it's seat by hand.

So many quandries when striving to get it just exactly perfect.



neal

[hambone]

Don't fret, it's only perfect for the first 100 miles.

[Amskeptic]

So many quandries when striving to get it just exactly perfect.

You actually want the engine to make it perfect for itself. That is what breaking in is all about. The best fit is the fit between two parts that had to specifically get to know each other. The Barbie/Ken Doll perfection does not exist. If you try to over-polish parts, it actually hampers the break-in. Ask any Hollywood marriage . . .
Colin

[ruckman101]

So many quandries when striving to get it just exactly perfect.

You actually want the engine to make it perfect for itself. That is what breaking in is all about. The best fit is the fit between two parts that had to specifically get to know each other. The Barbie/Ken Doll perfection does not exist. If you try to over-polish parts, it actually hampers the break-in. Ask any Hollywood marriage . . .
Colin

I'm hearing a little "tooth" should be there for the parts to build some integrated molars between themselves with. That last bit of perfection built breaking in and introducing parts to connected other parts.

And I am well aware that perfection is a physics impossibility when faced with reality. That dern devil time. Much like normal, if you mean average, is a mathmatical formula that only gives you the median to base quantitatively measureable deviations from.

I'm gonna use the old school hand tool, not get carried away, I mean, new heads, should be cut pretty close to spec to begin with, just give those two intakes a little dusting off.

Or should I get all anal and give every valve a quick dusting off despite leakage detection at only the intakes of one head? Having the tools is intoxicating.


fret, stew, overthink,
neal