knurled valve guide ?
Thread Starter
Racer
Joined: Mar 2005
Posts: 263
Likes: 0
From: Creswell OR
knurled valve guide ?
Hi,
I have been looking at a set of remanufactured heads.They have been cut for bigger valves,and have knurled valve guides.It's been a long time since I heard that term.Can someone tell me what this means,and if this is a good thing?Also,do you still put in like bronze valve guides with this also?Thanks much.......
I have been looking at a set of remanufactured heads.They have been cut for bigger valves,and have knurled valve guides.It's been a long time since I heard that term.Can someone tell me what this means,and if this is a good thing?Also,do you still put in like bronze valve guides with this also?Thanks much.......
Instructor
Joined: Jan 2006
Posts: 128
Likes: 0
Knurling valve guides is a cheap, quickie way to pass off worn out cylinder heads on an unsuspecting buyer.
The process involves running an expandable knurling tool through the ID of a worn out valve guide, upsetting some guide material to expand into the ID of the guide, thus taking up space and hopefully reducing oil burning and valve stem play. This process DOESN"T solve the problem of worn out valve guides - it only camoflages it.
The ONLY way to repair wornout valve guides is to install new guides, hone them to size and then recut/grind valve to valve seat concentricity.
Look for another set of cylinder heads with REPLACED GUIDES.
The only thing these heads are good for is boat anchors - or the trash.
The process involves running an expandable knurling tool through the ID of a worn out valve guide, upsetting some guide material to expand into the ID of the guide, thus taking up space and hopefully reducing oil burning and valve stem play. This process DOESN"T solve the problem of worn out valve guides - it only camoflages it.
The ONLY way to repair wornout valve guides is to install new guides, hone them to size and then recut/grind valve to valve seat concentricity.
Look for another set of cylinder heads with REPLACED GUIDES.
The only thing these heads are good for is boat anchors - or the trash.
Last edited by MrEldo; Feb 4, 2006 at 01:32 PM.
Thread Starter
Racer
Joined: Mar 2005
Posts: 263
Likes: 0
From: Creswell OR
Originally Posted by MrEldo
Knurling valve guides is a cheap, quickie way to pass off worn out cylinder heads on an unsuspecting buyer.
The process involves running an expandable knurling tool through the ID of a worn out valve guide, upsetting some guide material to expand into the ID of the guide, thus taking up space and hopefully reducing oil burning and valve stem play. This process DOESN"T solve the problem of worn out valve guides - it only camoflages it.
The ONLY way to repair wornout valve guides is to install new guides, hone them to size and then recut/grind valve to valve seat concentricity.
Look for another set of cylinder heads with REPLACED GUIDES.
The only thing these heads are good for is boat anchors - or the trash.
The process involves running an expandable knurling tool through the ID of a worn out valve guide, upsetting some guide material to expand into the ID of the guide, thus taking up space and hopefully reducing oil burning and valve stem play. This process DOESN"T solve the problem of worn out valve guides - it only camoflages it.
The ONLY way to repair wornout valve guides is to install new guides, hone them to size and then recut/grind valve to valve seat concentricity.
Look for another set of cylinder heads with REPLACED GUIDES.
The only thing these heads are good for is boat anchors - or the trash.
Thank you very much.I will take your advice,and forgetaboutem..........
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Originally Posted by MrEldo
Knurling valve guides is a cheap, quickie way to pass off worn out cylinder heads on an unsuspecting buyer.
The process involves running an expandable knurling tool through the ID of a worn out valve guide, upsetting some guide material to expand into the ID of the guide, thus taking up space and hopefully reducing oil burning and valve stem play. This process DOESN"T solve the problem of worn out valve guides - it only camoflages it..
The process involves running an expandable knurling tool through the ID of a worn out valve guide, upsetting some guide material to expand into the ID of the guide, thus taking up space and hopefully reducing oil burning and valve stem play. This process DOESN"T solve the problem of worn out valve guides - it only camoflages it..
... for the most part. Knurled guide works & lasts marginally. If the heads are iron & have OE iron guides ... here are two other pretty good ways to RECONDITION OE guides ... one is installing a helical bronze "insert" in guide; works & lasts pretty well ... the other is installing a thin-wall bronze "liner" in guide; works & lasts VERY well. Liner is my preferred method for iron heads; race-proven too.Both methods reasonably priced at machine shop.
Lastly, shop can cut the entire OE guide out of an iron head & then REPLACE w/ a new guide ... works OK & lasts very well ... but it's expensive ... the working drawback is that the tip of new guide usually ends up extending into port too far and interferes with flow.
Last edited by jackson; Feb 4, 2006 at 01:56 PM.
