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Maddog
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394 Posts
Discussion Starter #1
Can anyone help me find the outside diameter of stock twin cam
valve seats?

I don't want to take them out to find out.

thanks in advance
 

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nitro freak
Joined
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1,264 Posts
just measure it in the head,if your wondering what to put in for 1.940+ valves,you use a OS seat anyway (i can get you GOODSON/AV&V #`s when i get in the shop)
 

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Maddog
Joined
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394 Posts
Discussion Starter #3
Thanks PD. I did measure them in the head, I got close, but no cigar. I need the exact
size(s) and nobody seems to be able to tell me what they actually are.

I have an account at Goodson, I buy (AV&V) guides from them. I was just wanting to
put stock seats back in these heads b/c I cut them so many times, they're sunk a little
too low now.

I called Goodson's tech line and they said they don't carry the exact replacement size.

Also tried to contact Rowe. They must have gone out of business, I get no answer at
all. :(

As always, I appreciate your help!
 

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nitro freak
Joined
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1,264 Posts
you cant put in the same size.without a interfit,they`ll fall out (we use a .005 interfit)just get OS sets and counterbore the head,heat the head,press the seat in and open up the ID the the stock size
 

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Maddog
Joined
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394 Posts
Discussion Starter #7
Plan A was machine the seat until it's almost all gone (with a Serdi cutter), weld an old
valve to it and knock it out then replace with the same size. Heat the head, freeze the
seat with nitrogen and knock it in with a piloted driver.

yes? no?

kinda wanted to keep the stock size seats
 

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nitro freak
Joined
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1,264 Posts
if you take out the seat & replace it with the same size,theres no press fit,no need to heat or freeze,it`ll go right in (and fall right out)just like a valve guide.you wouldnt take out a std guide & replace it with a std guide (i HOPE not anyway)you dont have to put a seat in for a bigger valve,just a OS seat with the same ID,then cut the seat for a stock size valve
 

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Maddog
Joined
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394 Posts
Discussion Starter #9
When I used to replace seats on Alloy BBC heads that's how we did it. The replacement
seats were always .005" larger then the existing counterbore. We replaced lots of em, never
had one fall out. knock on wood.

For the harley guides, I put STD ones back in all the time (not always but most of them).
I measure the new guide O.D, then set a dial bore guage to it and then check the guide
bore against that. Usually the STD O.D. guide has enough interference fit as is.

Someone told me a long time ago not to assume you need an OS guide just because you
have them out. You have to measure them to be sure.

I'm sure they're differing opinions but that's how we've always done em.
 

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Maddog
Joined
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394 Posts
Discussion Starter #10
Found the answer to my origional question too. Mario at Tucker was kind enough to look it up.
(Not that anyone besides me really cares)

STD Seat outside diameters:
I 1.958"
E 1.723"
 

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nitro freak
Joined
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1,264 Posts
if the replacement seat for the BBC`s is .005 bigger,then its not the same size (like i said earlier,we use a .005 interfit on seats).i gaurantee if you cut out a 1.958" seat and replace it with a 1.958" seat,it aint going stay in.and we go +.001 on guides,not sure about car heads,but i wouldnt get in the habit of replacing STD guides with STD guides on HD heads,especially `06 up,7mm valve heads
 
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