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  #61 (permalink)  
Old 09-21-2021, 08:17 AM
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Quote:
Originally Posted by eschaider View Post
This looks like an 11/32 valve stem in a ⅜ guide.
That's what I thought. But the out-of-the-box inside diameter of the Edelbrock valve guides, which are designed for 3/8" valve stems, is .365". Even if you did no diamond honing at all, and just blindly dropped an 11/32" stem in there you would spot a wiggle of over .02" as you did it.
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  #62 (permalink)  
Old 09-21-2021, 10:39 AM
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Quote:
Originally Posted by eschaider View Post
+1 on what Brent said. This looks like an 11/32 valve stem in a ⅜ guide. This is very likely not a wear problem as much as it is a parts mismatch problem.


Ed
That is not what I'm saying at all.

It is indeed a wear problem.

These heads do not come with 3/8" guides because *they are NOT out of the box Edelbrock heads*. These were CNC ported, guides installed, and valves supplied by Craft Racing.
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  #63 (permalink)  
Old 09-21-2021, 11:51 AM
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Quote:
Originally Posted by patrickt View Post
Oliver, is there a stamping on the outside of the valve guide that is visible? For instance, the Edelbrock guides (which it is said you do not have) often have the number 39-1119 on the outside. Of course the inside diameter of that particular Edelbrock guide is already too big for an 11/32" valve. But it would be interesting to know if your guides have an identifying stamp.
Patrick, I have absolutly no stamps on the guides.

Brent knows what he speaks about: I have 11/32 guides not factory 3/8.
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  #64 (permalink)  
Old 09-21-2021, 11:53 AM
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Quote:
Originally Posted by blykins View Post
That is not what I'm saying at all.

It is indeed a wear problem.

These heads do not come with 3/8" guides because *they are NOT out of the box Edelbrock heads*. These were CNC ported, guides installed, and valves supplied by Craft Racing.
OK Brent but can you give me #guide reference I would need to order to keep my valves ? guides for 11/32 valves of course.

Thanks, OliveR
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  #65 (permalink)  
Old 09-21-2021, 12:07 PM
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Call Lance at Craft Racing and ask for some guides.
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  #66 (permalink)  
Old 09-21-2021, 12:27 PM
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Quote:
Originally Posted by blykins View Post
Call Lance at Craft Racing and ask for some guides.
Sorry Brent but I don't know "Craft Racing".

If you have a web site / phone number / email address for me please ??

Thanks, OliveR
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  #67 (permalink)  
Old 09-21-2021, 12:38 PM
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Lance at Craft Racing is taking off where Keith Craft left. They still do the same CNC ported Edelbrock heads and will have parts on the shelf.

https://www.craftperformanceengines.com/
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  #68 (permalink)  
Old 09-21-2021, 01:35 PM
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Quote:
Originally Posted by blykins View Post
That is not what I'm saying at all.

It is indeed a wear problem.

These heads do not come with 3/8" guides because *they are NOT out of the box Edelbrock heads*. These were CNC ported, guides installed, and valves supplied by Craft Racing.

Poor sentence structure on my part, Brent. I was agreeing with what you said, and then observing (my opinion, not yours) that an 11/32" stem in a ⅜" guide could produce a significant wobbling of the valve in the guide — similar to what he was experiencing.


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  #69 (permalink)  
Old 09-21-2021, 02:03 PM
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Quote:
Originally Posted by blykins View Post
Lance at Craft Racing is taking off where Keith Craft left. They still do the same CNC ported Edelbrock heads and will have parts on the shelf.

https://www.craftperformanceengines.com/
Thank you very much.
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  #70 (permalink)  
Old 09-21-2021, 03:18 PM
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If it was me, I'd replace the valves too.
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  #71 (permalink)  
Old 09-21-2021, 05:11 PM
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Quote:
Originally Posted by Chaplin View Post
If it was me, I'd replace the valves too.
With that much clearance, he could just hone it up a bit and go with 3/8" stems. A half hour of lapping and badda boom badda bing we're done.
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  #72 (permalink)  
Old 09-21-2021, 06:26 PM
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Or why not hone for a K-line guide insert to bring back 11/32, and run a tight clearance, since they claim to have better life.

I am still dubious about the Edelbrock guides.
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  #73 (permalink)  
Old 09-22-2021, 04:47 AM
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Keith Craft seemed to do a fair amount of international sales when they built my engine so unless they have changed under Lance, it should not be a stretch for them to get parts to you.
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  #74 (permalink)  
Old 09-25-2021, 01:38 AM
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Well I've done a partial test which should required a full engine reassembly but here is what I did:
I've resinstalled rockers assembly on one of my head without valve springs. As there is a "line" on each valve showing where valve stop when full opening I make pictures of rocker when valve is closed and when valve is open (stopping rocker when "line" on valve reachs the top of the valve seal).
OK this test should be done with head installed on block, pushrods, etc... BUT does my test doesn't show a rocker pivot issue / pushrod lenght issue ? which could have caused my valve wear premature failure ?
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  #75 (permalink)  
Old 09-25-2021, 01:39 AM
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valve full lift

Last edited by CLV8; 09-25-2021 at 01:44 AM..
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  #76 (permalink)  
Old 09-26-2021, 02:48 PM
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A rocker, roller or otherwise, will not remain centered on the valve stem. The reason is the roller or (rocker wear pad) traces out an arc that is determined by the distance from the center of the roller to the center of the pivot on the rocker shaft.

If you use the valve lift to establish the length of a chord describing the valve motion in the guide you can position the rocker to center the motion of the roller across the middle of the valve stem, favor the portion of the valve stem closest to the exhaust side of the head or favor the portion of the valve stem closest to the intake side of the head.

My personal preference, when building pushrod engines, is to center the motion of the roller across the middle of the valve stem. When you go to either of the exhaust or intake positioning models you place unnecessary side loading on the valve stem and the guide, resulting in premature wear of the guide.


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Old 09-26-2021, 10:52 PM
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The roller should start from the rocker shaft side of valve stem centre, roll ACROSS centre at half lift, then be at back to the start point at full lift.

Yours appears to start at centre, and by full lift is coming to far away from centre at full lift.

So your valve stem height needs to be increased, longer valves, a lash cap, or lower the rockers. Lash cap is by far the easiest way.

Your roller moves too far, especially since this happens at the highest load at max valve lift.

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Last edited by Gaz64; 09-27-2021 at 08:47 PM..
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  #78 (permalink)  
Old 09-27-2021, 01:57 AM
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It’s because on the “full lift” picture he has “input” way more lift than what he has. He is trying to go to whatever mark that is on the valve and that’s not accurate. When the valve lock groove is almost touching the valve seal, that should be an indicator that somethings not right with the experiment. If you try to open the valve an inch, you’re gonna see something like that.

There is nothing wrong at all with that first picture. T&D rockers are some of the easiest to set up and I’m probably the most anal about setting up valvetrain geometry.

In addition, pushrod length has nothing to do at all with geometry on a shaft mounted rocker.
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  #79 (permalink)  
Old 09-27-2021, 06:23 AM
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I was thinking that looks like a lot of camshaft lift.
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  #80 (permalink)  
Old 09-27-2021, 09:47 AM
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what caused those marks on the valve stem just below the keeper lock grove??
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