The Ford Barn

Scottyboy · 10-29-2014, 04:20 PM

Are seals used and or needed for the exhaust valves on the 8BA engine?

Thanks

oldford2 · 10-29-2014, 04:31 PM

Intakes only. And then use the O'ring type rather than the square ones which are a bear to install without them shearing.

Ol' Ron · 10-29-2014, 06:35 PM

I use never seize on the exhaust and RTV on the intakes

oldford2 · 10-29-2014, 06:44 PM

Ol Ron,
No seals on either? John

flatjack9 · 10-29-2014, 08:13 PM

I'm with Ron on no seals in either. I use a little hi temp RTV on the intakes.

Ol' Ron · 10-29-2014, 10:24 PM

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This is a logical decision I made because the Hi Temp RTV was not available back when Hank designed the flathead. AND, that's a big and, from 32 to 48 Ford never used any seals. Now what you should be concerned with is the valve stem ti guide clearance. THIS, is where the oil is pulled under hi vacuum. I Knurl the guides and ream them for a .0005/.001 fit. The knurel will keep the guide well lubricated. AND yes Knurel the new guides you bought and ream them as well. I've done this to every engine I've build over the past 30 years.

Shu47 · 10-30-2014, 02:33 PM

Ol' Ron - The knurling makes sense to me but being an electrical engineer I don't know how it is done. Do you have to take the guides to a shop or can you do it yourself?

Ol' Ron · 10-30-2014, 03:43 PM

I do mine in a lathe now, however I did them in a vice with a fixture I made out of wood to hold the guide while I ran the knurling tool, and the reamer. Most auto machine shops should have the tools

Bored&Stroked · 06-01-2015, 10:26 PM

BTTT: Here is how I just did it:

Here is the problem - all the guides I've ever used are fairly loose in the guide bore. This is something that I 'fix' with knurling. When Ron talks about knurling, he is talking about the traditional knurling of the valve guide bore to tighten up guide bore to valve stem clearances. I know some experienced racers that won't knurl flathead valve guides (especially the exhaust), they install bronze liners. The reason is that they want better heat transfer from the valve stem to the guide and tightly fitting bronze liners do this supposedly better than a knurled cast iron one.

Video: The problem with loose fitting guides (in the block):

https://www.youtube.com/watch?v=qZBXFMqHs-c

Here is the knurling process and final result:

Video: Knurling:

https://www.youtube.com/watch?v=UqYqBIy1BAI

Here are some final guide pictures - you can see my spring spacers for the Isky 185-G springs as well as the cut-back section I do on the top of the valve guides (so they don't obstruct the port).

Enjoy:

KnurledIntakeGuide copy.jpg

FinishedGuides1 copy.jpg

Keystone 34 3w · 06-01-2015, 11:14 PM

Knurel is a good friend of mine!

Ol' Ron · 06-02-2015, 07:24 AM

I don't bother to Knurell the outside of the guide the RTV takes up the room between the guide and block. However, doilg this will probably center the guide and grinding the seat with the knurelled guide in place will make a true seat. My valve grinding fixture locates on the guide bore.
BUT, we haven't addressed the stem to guide clearance here.

GB SISSON · 04-22-2024, 08:40 AM

I'm still wondering what is considered proper stem to guide clearance for 8ba? Not showing up in a search.

petehoovie · 04-22-2024, 10:55 AM

Quote:

Originally Posted by Bored&Stroked

BTTT: Here is how I just did it:

Here is the problem - all the guides I've ever used are fairly loose in the guide bore. This is something that I 'fix' with knurling. When Ron talks about knurling, he is talking about the traditional knurling of the valve guide bore to tighten up guide bore to valve stem clearances. I know some experienced racers that won't knurl flathead valve guides (especially the exhaust), they install bronze liners. The reason is that they want better heat transfer from the valve stem to the guide and tightly fitting bronze liners do this supposedly better than a knurled cast iron one.

Video: The problem with loose fitting guides (in the block):

https://www.youtube.com/watch?v=qZBXFMqHs-c

Here is the knurling process and final result:

Video: Knurling:

https://www.youtube.com/watch?v=UqYqBIy1BAI

Here are some final guide pictures - you can see my spring spacers for the Isky 185-G springs as well as the cut-back section I do on the top of the valve guides (so they don't obstruct the port).

Enjoy:
]

Pete · 04-22-2024, 02:51 PM

On one hand knurling the outside is good because it makes the guide tight in the block so the valve seat remains solid in place but you also lose about 30% contact area which relates to a LOT of heat transfer capability.
In a street engine you may not notice the shorter life.

10-29-2014, 04:20 PM	#1
Scottyboy Member Join Date: Apr 2014 Location: Salt Lake City, Utah Posts: 39	Flathead exhaust valve guide seals Are seals used and or needed for the exhaust valves on the 8BA engine? Thanks __________________ "This thing better run when I get done!"

10-29-2014, 04:31 PM	#2
oldford2 Senior Member Join Date: May 2010 Location: pittsfield, MA Posts: 2,087	Re: Flathead exhaust valve guide seals Intakes only. And then use the O'ring type rather than the square ones which are a bear to install without them shearing.

10-29-2014, 06:35 PM	#3
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,985	Re: Flathead exhaust valve guide seals I use never seize on the exhaust and RTV on the intakes

10-29-2014, 06:44 PM	#4
oldford2 Senior Member Join Date: May 2010 Location: pittsfield, MA Posts: 2,087	Re: Flathead exhaust valve guide seals Ol Ron, No seals on either? John

10-29-2014, 08:13 PM	#5
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,608	Re: Flathead exhaust valve guide seals I'm with Ron on no seals in either. I use a little hi temp RTV on the intakes.

10-29-2014, 10:24 PM	#6
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,985	Re: Flathead exhaust valve guide seals Sponsored Links (Register now to hide all advertisements) This is a logical decision I made because the Hi Temp RTV was not available back when Hank designed the flathead. AND, that's a big and, from 32 to 48 Ford never used any seals. Now what you should be concerned with is the valve stem ti guide clearance. THIS, is where the oil is pulled under hi vacuum. I Knurl the guides and ream them for a .0005/.001 fit. The knurel will keep the guide well lubricated. AND yes Knurel the new guides you bought and ream them as well. I've done this to every engine I've build over the past 30 years.

10-30-2014, 02:33 PM	#7
Shu47 Senior Member Join Date: Feb 2011 Location: Maltby, Washington Posts: 187	Re: Flathead exhaust valve guide seals Ol' Ron - The knurling makes sense to me but being an electrical engineer I don't know how it is done. Do you have to take the guides to a shop or can you do it yourself?

10-30-2014, 03:43 PM	#8
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,985	Re: Flathead exhaust valve guide seals I do mine in a lathe now, however I did them in a vice with a fixture I made out of wood to hold the guide while I ran the knurling tool, and the reamer. Most auto machine shops should have the tools

06-01-2015, 10:26 PM	#9
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,906	Re: Flathead exhaust valve guide seals BTTT: Here is how I just did it: Here is the problem - all the guides I've ever used are fairly loose in the guide bore. This is something that I 'fix' with knurling. When Ron talks about knurling, he is talking about the traditional knurling of the valve guide bore to tighten up guide bore to valve stem clearances. I know some experienced racers that won't knurl flathead valve guides (especially the exhaust), they install bronze liners. The reason is that they want better heat transfer from the valve stem to the guide and tightly fitting bronze liners do this supposedly better than a knurled cast iron one. Video: The problem with loose fitting guides (in the block): https://www.youtube.com/watch?v=qZBXFMqHs-c Here is the knurling process and final result: Video: Knurling: https://www.youtube.com/watch?v=UqYqBIy1BAI Here are some final guide pictures - you can see my spring spacers for the Isky 185-G springs as well as the cut-back section I do on the top of the valve guides (so they don't obstruct the port). Enjoy: KnurledIntakeGuide copy.jpg FinishedGuides1 copy.jpg Last edited by Bored&Stroked; 06-02-2015 at 07:48 AM.

06-01-2015, 11:14 PM	#10
Keystone 34 3w Senior Member Join Date: May 2010 Location: Manitoba Posts: 105	Re: Flathead exhaust valve guide seals Knurel is a good friend of mine! __________________

06-02-2015, 07:24 AM	#11
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,985	Re: Flathead exhaust valve guide seals I don't bother to Knurell the outside of the guide the RTV takes up the room between the guide and block. However, doilg this will probably center the guide and grinding the seat with the knurelled guide in place will make a true seat. My valve grinding fixture locates on the guide bore. BUT, we haven't addressed the stem to guide clearance here.

04-22-2024, 08:40 AM	#12
GB SISSON Senior Member Join Date: Jan 2014 Location: Orcas Island Washington Posts: 6,202	Re: Flathead exhaust valve guide seals I'm still wondering what is considered proper stem to guide clearance for 8ba? Not showing up in a search. __________________ Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1946 Tonner Pickup with 226 H six, 1979 Toyota landcruiser wagon, now wearing 1947 Ford Jailbar sheet metal. 'Rusty ol' floorboards, hot on their feet' (Alan Jackson)

04-22-2024, 02:51 PM	#14
Pete BANNED Join Date: May 2010 Location: Wa. Posts: 5,423	Re: Flathead exhaust valve guide seals On one hand knurling the outside is good because it makes the guide tight in the block so the valve seat remains solid in place but you also lose about 30% contact area which relates to a LOT of heat transfer capability. In a street engine you may not notice the shorter life.