Olgawld Posted November 16, 2019 Share Posted November 16, 2019 Hi. I've been given a nicely ported and big valve cylinder head for a xflow. Looks quite tidy but when I tried taking an inlet valve out to check it was heavily coked around head, which hopefully will clean but also the guide came out with it. Is this ok, will it just pop back in the valve or should it be firm and not pop out? Taken exhaust valve out too next and that stayed in ok. also how can you check to see if it's had hardened exhaust seats for unleaded, hard to see? Thanks Link to comment Share on other sites More sharing options...
ECR Posted November 16, 2019 Share Posted November 16, 2019 Valve guides should be fixed firm in the head ! Link to comment Share on other sites More sharing options...
7 wonders of the world Posted November 16, 2019 Share Posted November 16, 2019 Time to pop all the valves out and have them all checked by someone familiar with the head, you may end up having some new ones machined and the seats recut etc. Link to comment Share on other sites More sharing options...
Olgawld Posted November 17, 2019 Author Share Posted November 17, 2019 Thanks for your replies. I've tapped the guide back in carefully and is now tight, but can't now push the valve through. Also the guide just seemed like a basic uniform shape not tapered at ends like the ones I've seen in Burton's etc. Link to comment Share on other sites More sharing options...
Olgawld Posted November 17, 2019 Author Share Posted November 17, 2019 Hands up time, realised i've made a school boy error...i've had man flu last week which im putting it down to.Its one of the liners/guide inserts which came out with the valve, not the actually guide. I tapped it back in and the valve will move up and down but very tight to actually get it all the way out. Should i have lubed it or will it be ok, or new insert needed? Cheers. I'll do no more to the engine till this obviously serious illness has passed! Link to comment Share on other sites More sharing options...
oilyhands Posted November 18, 2019 Share Posted November 18, 2019 The inserts should be an interference fit in the guide , there are various types , the most popular being K-line inserts, the insert on that guide will need re-doing and the others checking, if they move in service all manner of carnage can result.Oily Link to comment Share on other sites More sharing options...
Roger King Posted November 19, 2019 Share Posted November 19, 2019 Seconded Although I would amend "carnage" to read "catastrophic carnage". Link to comment Share on other sites More sharing options...
elie boone Posted November 23, 2019 Share Posted November 23, 2019 A hardened seat will show direct as it's another colour than the cast head, likely it's about 1 mm bigger than the valve dia. and will go about 5 mm deep into the port. Most valve stem problems are due to the valve wander around in the soft valve seat. Link to comment Share on other sites More sharing options...
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