For those who have ordered stainless steel valves...

[Marshall V. Daut]

Were they already cut at a 45 degree angle or did you have to reface them upon delivery? I ask because it turns out that the valves in my friend's Victoria engine are too worn, rust-pitted from heat and minus any margins to be reused. So, new stainless steel valves will be ordered Monday. I just need to know if they come already to be installed or whether I'll have to find someplace to true them to a 45-degree angle. I am using a 46-degree Nuway seat cutter and must have a 45-degree cut on the valve heads.
Thanks!
Marshall
Added: For what it's worth, we are using the original style valves with the mushroom stem, not the "modern" straight-stem valve also available from vendors.

[JayJay]

Originally Posted by Marshall V. Daut

Were they already cut at a 45 degree angle or did you have to reface them upon delivery? I ask because it turns out that the valves in my friend's Victoria engine are too worn, rust-pitted from heat and minus any margins to be reused. So, new stainless steel valves will be ordered Monday. I just need to know if they come already to be installed or whether I'll have to find someplace to true them to a 45-degree angle. I am using a 46-degree Nuway seat cutter and must have a 45-degree cut on the valve heads.
Thanks!
Marshall
Added: For what it's worth, we are using the original style valves with the mushroom stem, not the "modern" straight-stem valve also available from vendors.

M - As a matter of practice I always reface new valves if for no other reason than to minimize runout. It’s relatively easy for me because I have access to a valve cutting machine. Measure the runout on your new valves, you might be (unpleasantly) surprised. You can hear it when you run through the grinder.

[BButturff]

Originally Posted by JayJay

M - As a matter of practice I always reface new valves if for no other reason than to minimize runout. It’s relatively easy for me because I have access to a valve cutting machine. Measure the runout on your new valves, you might be (unpleasantly) surprised. You can hear it when you run through the grinder.

I agree. I've built, drag raced and rebuilt many V-8 engines and always "touched up" new valves before installing. My OCD and trust issues wouldn't have it any other way. "Trust but verify" - Ronald Reagan

[ThirstyThirty]

Originally Posted by BButturff

I agree. I've built, drag raced and rebuilt many V-8 engines and always "touched up" new valves before installing. My OCD and trust issues wouldn't have it any other way. "Trust but verify" - Ronald Reagan

I would not want new valves just 'dropped' into the head... block and/or onto the seat without a kiss in the valve grinding machine first. center up to the stem, then center up to the guide... ie, seat to face concentricity.

[Joe K]

If you really want to hear the "touch touch touch" of the grinder on the valve, just take them out of the chuck, turn them 180 degrees, and chuck and grind them again.

Repeatability is an issue in the real world. There are machines of better repeatability - but there is no PERFECT repeatability.

The real question is how far out of concentric can you truly tolerate.

Joe K
Who does um, ok in a lathe made in 1871. Flather Serial Number "1."

[ThirstyThirty]

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Originally Posted by Joe K

If you really want to hear the "touch touch touch" of the grinder on the valve, just take them out of the chuck, turn them 180 degrees, and chuck and grind them again.

Repeatability is an issue in the real world. There are machines of better repeatability - but there is no PERFECT repeatability.

The real question is how far out of concentric can you truly tolerate.

Joe K
Who does um, ok in a lathe made in 1871. Flather Serial Number "1."

I am not a valve grinder/cyl head guy... but have done my share of clean up work. have my own hand tools, lapping compounds, etc. I always thot the final work, prior to parts clean up was hand lapping in the seat and face... to ensure best possible concentricity and sealed setting seat.

[Joe K]

Originally Posted by ThirstyThirty

I am not a valve grinder/cyl head guy... but have done my share of clean up work. have my own hand tools, lapping compounds, etc. I always thot the final work, prior to parts clean up was hand lapping in the seat and face... to ensure best possible concentricity and sealed setting seat.

What you say is VERY true for those two pieces.

Look up on the Internet "generation of a surface plate." It takes three plates to get it NEARLY perfect.

And even this is more a matter of your endurance and how much out of perfect you can tolerate.

And you kind of learn the limit of practicality when the heat of your hand changes the "rub."

Those who do this for a living wear gloves.

Joe K

[JayJay]

Originally Posted by ThirstyThirty

I am not a valve grinder/cyl head guy... but have done my share of clean up work. have my own hand tools, lapping compounds, etc. I always thot the final work, prior to parts clean up was hand lapping in the seat and face... to ensure best possible concentricity and sealed setting seat.

Yes, hand lapping following a quick touchup of the new valve in the valve grinding machine. On old valves I clean them up in the machine and look at where the surface is in relation to the top of the valve, replacing if necessary. Nothing exotic, this is kinda Valve Grind 101...

[Marshall V. Daut]

Thanks for sharing the benefit of your experience with valves, Guys. 'Just needed confirmation. I was afraid I'd end up taking these new ones to a machine shop to have them re-faced. My luck with local shops has not been all that satisfying, so I cringe every time I am forced to avail myself of their services = $$$$$$$$$$$$$$$$. 'Looks like once again I have no choice. I wish I had bought a valve facing/stem grinding machine years ago for a couple hundred bucks. Counting up the number of times I have had to pay for this service over the years, the machine would have paid for itself!
Marshall

[nkaminar]

I would not regrind the valves. It sounds like you have the seats under control. I always do a light lap with the new valves. Just enough to get a uniform grey on the valve and seat. Of course this will destroy the one degree difference you have between the valves and seats.

[Marshall V. Daut]

nkaminar -
In Nuway's instruction booklet, it states that lapping after cutting new seats is not recommended, presumably because that one degree difference will be lost, as you wrote. Supposedly upon initial start up, the closing valve will cancel out that one degree difference anyway. I guess Nuway considers this 46 seat-45 degree valve relationship will give a tighter seal than going 45-45 degrees.
Marshall

[noboD]

I would lap to get a 1/16 wide surface of contact. It only takes a few seconds. And I've found many stems to be a little over sized. Make sure you check the clearance.

[old31]

I don't understand. Why do you need this 1 degree difference?

[Afordman31]

Originally Posted by old31

I don't understand. Why do you need this 1 degree difference?

It is called a interference fit!

[Joe K]

Originally Posted by Afordman31

It is call a interference fit!

Um. You have the thought, but it actually results in a "near line" seal. The valve disk is thus brought to contact the "outermost" radii of the bevel in the block, and holding this small angular difference increases the "contact pressure" in that annular seal area.

Forcing the seal to the outer edge of the valve bevel helps prevent "burning" of the valve disk edge, erosion of the block seal area, and makes for "better seal," all of which makes it work correctly "longer."

One of my critiques on valve seat inserts is they introduce an additional "joint" - which impedes heat transfer to the block. But valve seat inserts are also much more durable than the cast iron under this duty - and generally seat inserts are considered "state of the art" because of this.

Joe K

[ModelA29]

Put em in the hole and run them. Lap em if you'll feel better. New as manufactured valves are dropped into engines by manufacturers everyday without problems. Hardened seats are a waste of money. As don't have enough spring pressure to cause excessive wear. Our engines are far from state of the art.

[ThirstyThirty]

Originally Posted by Marshall V. Daut

Thanks for sharing the benefit of your experience with valves, Guys. 'Just needed confirmation. I was afraid I'd end up taking these new ones to a machine shop to have them re-faced. My luck with local shops has not been all that satisfying, so I cringe every time I am forced to avail myself of their services = $$$$$$$$$$$$$$$$. 'Looks like once again I have no choice. I wish I had bought a valve facing/stem grinding machine years ago for a couple hundred bucks. Counting up the number of times I have had to pay for this service over the years, the machine would have paid for itself!
Marshall

call around! redoing cyl heads is not backyard shade tree typical! can be done as such. but best results calls for disassembly. vat cleaning. parts inspections. guide inspections. ck spring pressures. etc. most shops do surface, fly cut or table belt kiss. each valve is a bit of a project, done correctly. i see one shop says they charge .1 labor just to grind 1 valve. don't know if that includes seat. prob does. ie, V8, 1 valve x 8 (1 head) rate $100... $10 per valve. 80/head. 160 pr, maybe set price for two. then any parts. basic cost OHV cyl head 160/175 ($200) and up. to ck just where one is... call O'Rielly, NAPA, PepBoys, etc.... and inquire as to cyl's on exchange basis. usually will include core charge to ensure ur head not cracked. all that and besides... prior to the machine work... dirty, greasy, heavy... etc, well, you git the idea!

and if handy with the grinder, good time to kiss & clean up the under seat mill ridges in the head casting (OHV). go OH cam heads... and quite another story! a cyl head done by a custom pro grinder cyl head porting guy is a nice 'precision' piece of engine artwork!

the days of $85.00 V8 pair of cyl head valve jobs... long gone!

[ThirstyThirty]

Originally Posted by ModelA29

Put em in the hole and run them. Lap em if you'll feel better. New as manufactured valves are dropped into engines by manufacturers everyday without problems. Hardened seats are a waste of money. As don't have enough spring pressure to cause excessive wear. Our engines are far from state of the art.

might get by like that, then again might not seat perfectly. if was 'gunna run what ya brung!' out of the box, the least i would do is to perfectly clean and freshened up seats... if not 'fresh face" i say... why bother!! ?

...the least i would do is check both circles (seats) with some Precision Blue. if rings perfect then can't do better than that! however, that does not control the valve's sitting heigth in the port once on seat. ie, new valves thick sides, reground over the yrs, thinner... so each sits in hole dif... depths

[ThirstyThirty]

Originally Posted by Joe K

Um. You have the thought, but it actually results in a "near line" seal. The valve disk is thus brought to contact the "outermost" radii of the bevel in the block, and holding this small angular difference increases the "contact pressure" in that annular seal area.

Forcing the seal to the outer edge of the valve bevel helps prevent "burning" of the valve disk edge, erosion of the block seal area, and makes for "better seal," all of which makes it work correctly "longer."

One of my critiques on valve seat inserts is they introduce an additional "joint" - which impedes heat transfer to the block. But valve seat inserts are also much more durable than the cast iron under this duty - and generally seat inserts are considered "state of the art" because of this.

Joe K

in talking with the guys at one engine shop i use(d) over the years, the cyl head guy told me that the valve only cools when the valve is seated. (esp important on exhaust valve) these guys used to drag race... and after every event... they popped off their heads and re-kissed the seats!

they were hard to beat!

[Big hammer]

Originally Posted by nkaminar

I would not regrind the valves. It sounds like you have the seats under control. I always do a light lap with the new valves. Just enough to get a uniform grey on the valve and seat. Of course this will destroy the one degree difference you have between the valves and seats.

This is what we did for A/C engines, new valves did require grinding, the light gray color seals very well, shiny leaks like a sieve ! same for gas valves !

We had two 8 cylinder engines come through at one time, I got pretty good grinding seats and lapping valves set up an assembly line