The Cal-look Lounge

Cal-look/High Performance => Technical stuff => Topic started by: Mike Cott on May 17, 2020, 20:51:53 pm



Title: Valve guide advise
Post by: Mike Cott on May 17, 2020, 20:51:53 pm
I bought some used heads and upon strip down I’ve found a tip on an intake valve guide has a little damage right on the tip of it. The valves slide nicely with no indication of miss shape, does this matter???
(https://uploads.tapatalk-cdn.com/20200517/29f868c9613c38114550f245ac9fa66c.jpg)
 


Sent from my iPhone using Tapatalk


Title: Re: Valve guide advise
Post by: Mike Cott on May 20, 2020, 18:56:49 pm
Any advice would be great!!! 😂😂


Sent from my iPhone using Tapatalk


Title: Re: Valve guide advise
Post by: Martin S. on May 20, 2020, 23:09:07 pm
I thought trimming guides back was done on purpose for some reason, turbo maybe?
Some think it's a good idea to trim it, while some say leave it protrude to support the valve better so probably doesn't matter much.
Just giving some seat of the pants bs here since nobody else has an opinion.  ::)


Title: Re: Valve guide advise
Post by: Neil Davies on May 21, 2020, 10:47:53 am
Mike, I'm no expert, but my gut feeling is that it'll be OK, however if it was me I'd do a little bit of work deburring it and making sure there are no cracks or stress risers in it.
Next thing to consider is if the others would need shaping to match. I'm sure someone who actually knows what they're talking about will tell you if I'm talking rubbish or not!
You might find a local cylinder head place who can replace the guides though - I had my Superflow heads done many years ago.


Title: Re: Valve guide advise
Post by: samotorsport on May 21, 2020, 12:02:56 pm
I am one of those guys , in case of doubt ....
You ve got it apart, you never get a better chance to get it done . Just imagine you have to take the engine out again and start from scratch .
I would replace it .
Ok maybe thats because i am fixing airplanes for living and have a different approach to stuff like this .
But as it is in aviation : Better safe than sorry !


Sent from my iPhone using Tapatalk


Title: Re: Valve guide advise
Post by: Garrick Clark on May 21, 2020, 19:07:41 pm
 A machine shop would spot face that in 15 mins


Title: Re: Valve guide advise
Post by: Martin S. on May 21, 2020, 21:17:31 pm
Here's a pic of mine before the guides were pushed in to get them out of the way for porting.
Doesn't look much different than yours. Note the unshrouding of the intake valve is very similar to mine, at least at this point of the headwork.


Title: Re: Valve guide advise
Post by: Mike Cott on May 27, 2020, 22:33:47 pm
I thought trimming guides back was done on purpose for some reason, turbo maybe?
Some think it's a good idea to trim it, while some say leave it protrude to support the valve better so probably doesn't matter much.
Just giving some seat of the pants bs here since nobody else has an opinion.  ::)
Thanks for the advice Martin 👍


Sent from my iPhone using Tapatalk


Title: Re: Valve guide advise
Post by: Mike Cott on May 27, 2020, 22:35:18 pm
Mike, I'm no expert, but my gut feeling is that it'll be OK, however if it was me I'd do a little bit of work deburring it and making sure there are no cracks or stress risers in it.
Next thing to consider is if the others would need shaping to match. I'm sure someone who actually knows what they're talking about will tell you if I'm talking rubbish or not!
You might find a local cylinder head place who can replace the guides though - I had my Superflow heads done many years ago.
Yeh I reckon they’d be fine may as well send them to be checked over by someone in the know you know 😉


Sent from my iPhone using Tapatalk