8BA valve seat grinding

[61Klassic]

Hi. I’m in the process of grinding my valve seats to set the lash as I have non adjustable lifters. Due to the fact the valves aren’t at 90 degrees to the deck, my cutting tool is creating a larger valve seat contact area towards the piston as it is obviously contacting this area first.
Could anyone advise if this is correct or what I need to do to rectify the issue.

Thanks in advance for any help
Kev

[Bored&Stroked]

Sounds like your cutting tool or stone is too wide . . . use a smaller one . . .

[Art Newland]

What tool are you using to grind the seat? What engine? Tool should be referencing from the valve guide.

[JSeery]

The deck is not perpendicular to the valve guides, but the grinding stone has to be. One method uses a valve guide pilot bushing.

[Art Newland]

I have access to a Black and Decker seat grinder, it has a pilot that goes in to the valve guide. It has wedge shapes on both ends, you tighten it up and that centers the pilot.

[Art Newland]

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B and D also has a pilot tool that uses the bore of the guide and the lifter bore to center it, but I haven't had my hands on one.

[derek costello]

The block deck is not at 90degrees to the valves so this is what is giving you a deeper cut on one side! You must use a cutter that uses a pilot rod that fits time in the valve guide to cut the seats correctly or if you are using a block deck mounted machine it must be set at the correct angle as the valves and centered
by the guides.........

[61Klassic]

Hi all, thanks for the replies. As I stated in my original post, I understand that the valve isn’t perpendicular to the deck. I’m also using a cutting tool with a mandrel that fits in both the valve guide and lifter bore.
As has been said in post 2, I could be using a cutting wheel slightly too big, but surely it still shouldn’t cut only one part of the seat more?

[oldford2]

Originally Posted by 61Klassic

Hi. I’m in the process of grinding my valve seats to set the lash as I have non adjustable lifters. Due to the fact the valves aren’t at 90 degrees to the deck, my cutting tool is creating a larger valve seat contact area towards the piston as it is obviously contacting this area first.
Could anyone advise if this is correct or what I need to do to rectify the issue.

Thanks in advance for any help
Kev

Kev
So you are grinding the seats to set the tappet clearance? If the seats are good why not butt grind the valve stems?
Maybe I am missing something which is common for me.
John

[flatjack9]

Were they done correctly initially? What is the history of the engine?

[Pete]

Originally Posted by oldford2

Kev
So you are grinding the seats to set the tappet clearance? If the seats are good why not butt grind the valve stems?
Maybe I am missing something which is common for me.
John

He needs to ADD material, NOT grind it off the valve stem.
Many people adjust the valves that way but it's as wrong as 2 left feet. If you grind the seat, you then have to top and bottom it again. Lots of time.
You grind the valves FIRST. Then you do the SEATS. Then you adjust them by grinding the stem or TIG welding some material to the stem and grinding the clearance. Use 347 stainless rod for filler. Another method is to start out with valves with longer stems. You don't need to weld then.
Once you get familiar with whole process, you can adjust 16 valves faster than with adjustable lifters.

[flatheadmurre]

To me grinding seats for adjusting is not the way to go...maybe if it´s real close i touch up the valve.
You have a big gap to adjust a lashcap is what i use...just my 2c

[Art Newland]

The chevy valves they sell for flatties are extra long and they are inexpensive.
https://www.ebay.com/itm/Ford-flathe...QAAOSwk1haJxX1

[flatrod]

Also check to see if your polite is bent. Turn it 180, touch off again. Does it hit the other side?

[GOSFAST]

Originally Posted by Art Newland

What tool are you using to grind the seat? What engine? Tool should be referencing from the valve guide.

Ans-Absolutely correct, read below!

Originally Posted by Art Newland

I have access to a Black and Decker seat grinder, it has a pilot that goes in to the valve guide. It has wedge shapes on both ends, you tighten it up and that centers the pilot.

Ans-Not the best type pilots for this type work, actually this applies to ANY brand vehicles! For this type adjustable pilot you'd need BOTH ends of ALL the guides to be "squared-off", then it's still a "crap-shoot"!

Originally Posted by Art Newland

The chevy valves they sell for flatties are extra long and they are inexpensive.

Ans-Good luck with getting installed spring hgts correct, this problem may drive you completely "nuts". We use NO Chevy valves any more on any Flathead platform?

Originally Posted by flatrod

Also check to see if your polite is bent. Turn it 180, touch off again. Does it hit the other side?

Ans-Definitely a good area to ALWAYS check, you never know where a pilot's been OR how it's been handled?

(Add) NEVER under any circumstances machine ANY valve seat using ANY pilot that uses the C/L's of the lifter bores AND the guide bores together, you'll never be "happy" with the seats! Use the valve guide bores ONLY for all seat work! The photos below show 2 ways to get it done, the OEM style pilots, (large bottoms) are "Kwik-Ways" with the .437" tops and are "select-fit" for each individual guide bore, they come in -.002", -.001", std., +.001" +,002", etc.

Thanks, Gary in N.Y.

P.S. Am going to try to keep my posts a bit short, still in the middle of a major health issue, half-way out of the woods. Will try to resume working and moving some parts I've gotten asked about from members, mainly the bronze-lined guides. "Kiwi" Tony this is for you and some other members!

[61Klassic]

Originally Posted by flatrod

Also check to see if your polite is bent. Turn it 180, touch off again. Does it hit the other side?

Good shout, I will check.

[61Klassic]

I think I’ve sussed it. Just needed to go a bit deeper with the 30 degree first.
One final question, how far do your valves normally sit above the deck height once set?

[Bored&Stroked]

Couple things to note: Given that the actual vailve to deck angle is different side to side, one side will be higher than the other. The Driver's side will typically be above the deck (on the top edge) - depending on whether it is an intake or exhaust, the type of valve and the seat depths, you might see the Driver's side .030 to .040 above the deck. The passenger side is typically just flush or below the deck a bit. Do NOT attempt to make both sides the same - or you'll screw the pooch! The engine was deliberately designed with the crankshaft offset a bit - causing the valve angles to be different. The 32-41 engines had different valve angles than the later 45 - 53 engines.

If you're new to all this, I hope you have somebody to help mentor you through the process - as I can tell with your initial objective of grinding the seats to set the clearances, that you've not done this before. If your valve lash is too much, then you either use longer valves (not stock Ford), you use lash-caps or you weld up the stems as Pete noted (the original and tried and true way) - then grind back to set the clearance. Best of luck!

[Bored&Stroked]

Also, are you doing the top 30 degree angle first? This is bass-akwards - you do the seat first (typically 45 - depending on interferance angles), then you do the top and bowl cuts second/third - to set the seat location on the valve and finally the seat width. If you're starting with the 30 degree top-cut, then you're going about it all wrong . . .

[40 Deluxe]

Originally Posted by 61Klassic

I think I’ve sussed it. Just needed to go a bit deeper with the 30 degree first.
One final question, how far do your valves normally sit above the deck height once set?

Sinking the seats will somewhat restrict airflow as well as take life out out of the block unless you want the expense of replacing the seats.