Valve guide reamer size
- Thread starter Larry S
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Are they C630 guides ?
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Reaming C630 valve guides
I ordered a new set of 750 valve guides from OldBritts and was sent a set of Kibblewhite's C630 Bronze alloy ones. Looking at Kibblewhite's website, they warn not to use HSS reamers or carbide reamers on C630 alloy. These guides are 0.3105 as received and factory are 0.3135 (nominal) so I'm...
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acadian
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If they are nickle bronze (C630 or similar) You really need a valve guide hone for this, I was lucky enough to pick up a handheld sunnen knock off years ago, works great for triumph tappet blocks too.
If not nickle bronze you find a range of sizes here:
shop.kpmivalvetrain.com
If not nickle bronze you find a range of sizes here:
Tools / Components, Reamers, Solid Carbide Reamers | Kibblewhite Precision Machining, Inc
shop.kpmivalvetrain.com
baz
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Are you sure about 1/2" ?
When I make valve guides I only counter bore them an 1/8"
The counter boring is essential on the exhaust guides IMO
jaydee75
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Yeah, 1/2 is probably too much, but 1/8 seems a little short. It's been 40 years since I stuck a valve on my Mk3 and did it on the repair. I don't remember the details, but I thought the build-up was more than 1/8, maybe a 1/4?
It also helped to replace the OEM cast iron guides with bronze. No problems since.
Jaydee
It also helped to replace the OEM cast iron guides with bronze. No problems since.
Jaydee
Larry S
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Those freaking reamers are expensive. I think I’ll have a local machine shop finish it up for me. I’ll bet they’ll do it for less than the cost of a reamer that I will probably only use once. If I even got lucky enough to get the correct size.If they are nickle bronze (C630 or similar) You really need a valve guide hone for this, I was lucky enough to pick up a handheld sunnen knock off years ago, works great for triumph tappet blocks too.
If not nickle bronze you find a range of sizes here:
Tools / Components, Reamers, Solid Carbide Reamers | Kibblewhite Precision Machining, Inc
acadian
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You need to size the guide to the actual OD of the valve, which can vary, what you're looking for is .001 on intakes and .0015-.002 on exhausts. so you need to first measure the valve and then you may need different sized reamers. You might get away with using HSS on bronze guides depending on the guide. I prefer the hone myself, takes a but more time, but it's adjustable and gets me the size I need without barreling the guide ID. I use different stones for cast iron and bronze.
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