Valve guide inner dimension

M

madera cruiser

Member
Can anyone tell me that a +.001 oversize valve guide can de found in the tech barn? How realistic is that measurement?
Asking for a fellow racer who got tossed.
 
In terms of performance and longevity a smaller guide ID would be preferred to keep the valve seat and valve head aligned better. A larger guide ID would only be benificial if the guide and seat alignment was less then perfect. It is always beneficial for racers to to be very familiar with not only the rules but the procedures used in determining the legality of a motor. Unless I am missing something I do not even see a reason to check that measurement. It makes more sense to check the diameter of the valve stem to insure that it was not undersized to increase flow.
 
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The only thing I can come up with is that it was the tech of the valve Caps?
717.16.1 valve caps unaltered Briggs Part 3 557016 valve caps required. minimum diameter 0.594". Minimum overall thickness 0.201".
Minimum thickness valve insertion point 0.055"

The valve guide rule only states is that if they are replaced the Briggs 555645 part is allowed.
This is from an old IKF rule book. I can't see being thrown out of tech for having a worn valve guide.
 
madera cruiser said:
The inner dimension of the guide was .001" oversized. WF in a Jr. Sprint.
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I would ask for the tech man to show you in the rules exactly what was violated.
As Freezeman noted, I looked at three separate jr sprint / kid sprint rules and not one spec'd the ID of the valve guide, just that the guide can only be replaced with a Briggs guide. Now, if your builder replaced a guide with something other than the Briggs guides, that would be a violation, but that's not the reason that you/he gave.

.001" larger than what? Larger than what measurement? Larger than a brand new guide? That's not unreasonable due to wear.
Now, did the tech man see something going on that breaks the spirit and intent - undercutting the guide to puddle oil and reduce drag on the valve stem, something along those lines? (It wouldn't be .001, more like .010.") We don't know without seeing the part in question or hearing the tech man's side of the story.


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
34 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
CarlsonMotorsports said:
I would ask for the tech man to show you in the rules exactly what was violated.
As Freezeman noted, I looked at three separate jr sprint / kid sprint rules and not one spec'd the ID of the valve guide, just that the guide can only be replaced with a Briggs guide. Now, if your builder replaced a guide with something other than the Briggs guides, that would be a violation, but that's not the reason that you/he gave.

.001" larger than what? Larger than what measurement? Larger than a brand new guide? That's not unreasonable due to wear.
Now, did the tech man see something going on that breaks the spirit and intent - undercutting the guide to puddle oil and reduce drag on the valve stem, something along those lines? (It wouldn't be .001, more like .010.") We don't know without seeing the part in question or hearing the tech man's side of the story.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
34 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
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Exactly my thought Brian. Appeared to be a targeted tear down. Top two finishers were only checked for fuel.. Third place got complete tear down. Decision for DQ was made two days after the race. From my understanding, the final decision was made by an official who never saw the "illegal" part. Engine was built by a reputable West Coast builder who was on site and disputed the rule.
Politics appeared to be involved.
 
It would help to know the rule set .
Is this a sanctiond race ? If so which organization .
Defanitly seems fishy .
as stated always two sides too every story .
 
CarlsonMotorsports said:
I would ask for the tech man to show you in the rules exactly what was violated.
As Freezeman noted, I looked at three separate jr sprint / kid sprint rules and not one spec'd the ID of the valve guide, just that the guide can only be replaced with a Briggs guide. Now, if your builder replaced a guide with something other than the Briggs guides, that would be a violation, but that's not the reason that you/he gave.

.001" larger than what? Larger than what measurement? Larger than a brand new guide? That's not unreasonable due to wear.
Now, did the tech man see something going on that breaks the spirit and intent - undercutting the guide to puddle oil and reduce drag on the valve stem, something along those lines? (It wouldn't be .001, more like .010.") We don't know without seeing the part in question or hearing the tech man's side of the story.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
34 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
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From the posts I have seen it sounds like this was a grey area violation and must have fallen into spirit and intent like you said Brian. This young man is a helluva wheel man and he will bounce back and be right back on the podium. The engine builder is the best of the best out west and will rectify the issue and come back stronger than before.
 
I will clear this up for everyone. Doesn't appear the OP knows what was looked at or in question in the tech barn.

The valve guide has been pushed up in the head so it doesn't hang out as far and appear like a stock part.

Also the rocker side of the head has been cut to lower the rocker arms.

I believe they had a third issue with the head as well but i cannot speak to what that was.

From what I've read/been told nothing about the measurement on the valve guide ID/OD was/were in question.
 
racinnut15xm said:
I will clear this up for everyone. Doesn't appear the OP knows what was looked at or in question in the tech barn.

The valve guide has been pushed up in the head so it doesn't hang out as far and appear like a stock part.

Also the rocker side of the head has been cut to lower the rocker arms.

I believe they had a third issue with the head as well but i cannot speak to what that was.

From what I've read/been told nothing about the measurement on the valve guide ID/OD was/were in question.
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After gathering further information, the problem was with the installed height of the guide. Nothing else was mentioned about mods anywhere else on the head. Tech man agreed that there is no specification on the guide. Grey area that will be addressed in the rules.
After being threatened with a lawsuit, the promoter decided on the DQ. Prize money was lost but the finish and points stand.
 
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