Didn't you just ask this question? Anyway, toward the beginning of this thread you said: "All the racing head valve seats I saw being done were cut and then lapped."
My response was: "I've been of the opinion for decades that lapping valves/seats is an ancient process that is not necessary if the valves and seats are reconditioned/modified properly, and lapping if carried to extremes, can actually be harmful. Besides, the cold lapped line contact may not be the contact point after the engine/combustion chamber/valves/seats heat up under power."
My point was concerned about "lapping" valves/seats. NOT about which was better, grinding or cutting.
"In my experience many race engine builders do a lot of shit that they can't really justify so this whole argument is going to be very hard to pin down. When I worked in Tucson, Arizona in a race engine shop we cut all our cylinder seats. We never ground them. We sometimes lapped the values in."
What thread did I post this in?
Does it mean that I think valves should be lapped in?
Does it imply that I think valves should be lapped in?
OK, we've come full circle, twice. Like I said, there's not much more to be made out of this. I fail to see why you wanted to go through all this again. Are we done with this issue now?
"Anyway, toward the beginning of this thread you said: "All the racing head valve seats I saw being done were cut and then lapped."
Where did I say they were *all* lapped in? I said all were *cut*. I didn't say all were lapped in.
I said *sometimes* they were lapped in.
This look familiar?
"In my experience many race engine builders do a lot of shit that they can't really justify so this whole argument is going to be very hard to pin down. When I worked in Tucson, Arizona in a race engine shop we cut all our cylinder seats. We never ground them. We sometimes lapped the values in."
I guess we'll have to go over this yet again. First, I DIDN'T misquote you. I quoted EXACTLY what you said in your post of Jan 27 1:22 PM where you said: "All the racing head valve seats I saw being done were cut and then lapped." In THAT post you never mentioned anything about "sometimes" they were lapped. I then responded on Jan 27 at 5:29 PM with my opinion that lapping was unnecessary and linked some sites to support my position.
YOUR response to my post that you made on Jan 27 at 6:19 PM was where you THEN changed your story slightly and mentioned the word "sometimes" in reference to lapping.
Show me where I misquoted you and I'll profusely apologize.
"I quoted EXACTLY what you said in your post of Jan 27 1:22 PM where you said: "All the racing head valve seats I saw being done were cut and then lapped."
Okay. I went back and found it. That's a mistake on my part. It should have been sometimes lapped as I correctly stated later on.
"In THAT post you never mentioned anything about "sometimes" they were lapped."
Correct. It should have stated sometimes lapped
I didn't change my story. I left out some information by accident. Thank you for bringing this oversight to my attention so that I could correct it.
I made a mistake in that post by leaving out the word sometimes. As soon as you brought the *specific post and when I made it* to my attention and I could go back and look at what I wrote I saw that I had made a mistake and promptly admitted my mistake.
What this thread never really covered and I feel is very important is...
Do you really have to use a Serdi to get the same results?
Can you get the same result as a Serdi using a single point tool and a CNC and a very good fixture?
formatting link
Perhaps I should call / pay them a visit:
NEWEN INC - 8320 MIRAMAR MALL - SAN DIEGO, CA 92121 - USA
What happens to the actual seat and valve seal when it's up to temperature?
What measurable real world benefits do you gain when using using an expensive piece of equipment like a Serdi vs other seat cutting methods?
What are the viable alternatives?
Is this subject covered in a new book like the Rehr-Morrison book on engine building? I have already stated that Vogelin's book and others that I know of (Sunnen the one you linked to) are very badly out of date or are much too basic.
"Jon, I never forgot any of your postings about SDRC I made the wrong decision in spite of what you said. There have been a number of times that my Wife has told me to be careful in dealing with someone and after words says "I told you so". She earned the right to say it as well as you have earned the right to say I TOLD YOU SO. I made a decision that went against my better judgment and as usual it turned out poorly." .... Tom Brewer
Ignorant:
"I do not purchase programs unless I know before hand that they are what I want and/ or need."... Tom Brewer who can't follow his own advice. See above.
Ignorant:
Tom Brewer thinking he and his pals like Joe788 can play their Usenet staking games, lie on a repeated basis and suffer no consequences for doing so.
Ignorant:
"I have shot myself in the foot, not an easy thing to do when it is in your mouth and your head is in your ass."... Tom Brewer admitting what he's often like.
Ignorant:
Someone who has a proven track record of not being able to deal with or accept the kind of change that occurs in the cadcam market... now that's ignorant or should we say that's Tom Brewer.
Ignorant:
Someone who doesn't live in San Diego yet insists there is no shortage of CNC machinists here... now that's ignorant or should we say that's Tom Brewer.
Ignorant:
Someone who criticizes someone on SolidWorks but has never helped anyone with specific SolidWorks answers. Someone who is not able to answer any questions that "Vinny" had on master modeling or skeletal modeling. Someone who has never posted any models they have done... now that's ignorant or should we say that's Tom Brewer.
Ignorant:
Tom Brewer's failure to understand who Matt Lombard really is.
Ignorant:
Tom Brewer's unable to comprehend what's on the cover of the SolidWorks Bible:
"Whether you're a new, intermediate, ...."
Ignorant:
Someone who can't understand more than a simple "I love it!" or "I hate it!" type of comment ... now that's ignorant or should we say that's Tom Brewer.
Ignorant:
Tom Brewer implies that because you acknowledge that the $25 SolidWorks course covers subjects / topics that the $650 SolidWorks course didn't that you're now somehow an idiot and got screwed when you decided to purchase the $650 SolidWorks course.
Tom Brewer Writing About SmartCAM:
"I ended up paying a consultant $40.00 per hour for two weeks."
"FYI, when I said "Solid modeling" in reference to SmartCam it was tongue in cheek. What you could not see is that when I was typing that I was laughing to myself. Anyone that uses SmartCam and Solid Modeling in the same sentence cannot be taken seriously."
Recently Tom Brewer said SmartCAM had no user interface problems and yet the record shows Tom Brewer thinks SmartCAM does indeed have user interface problems:
"The only real problem that I run into is that the screen can get cluttered and it becomes difficult to pick and choose elements in Free Form. I just use the utility masking feature to hide what is in the way, that cures the problem but it does add work (I tried the snap filtering and snap options but for me it was not the best way), I have seen other packages that handle picking and choosing in better."
Conclusion:
Tom Brewer thinks he's a SolidWorks expert. A SolidWorks expert is someone who knows more and more about less and less until he knows absolutely everything about nothing.
I spend a lot of time on line trying to make Tom Brewer look bad. So far I have been a complete failure. Maybe it is because most people would rather believe a real business person instead of a high school dropout although I surely don't understand why.
"I spend a lot of time on line trying to make Jon Banquer look bad. Unfortunately for me I have been a complete failure. Maybe it is because most people don't have any respect for me because I've had my ass handed to me so many times by Jon Banquer than the only thing I can now come up with is imitating Jon Banquer. I realize that imitation is the sincerest form of flattery."
Using this old valve grinder might be the most expensive mistake you could make. Valve and seat concentricity is absolutely critical. In FACT it might be the most critical thing in a head. If I were to grind valves it would only be on a centerless valve grinder which will hold .
0004. The collet type of valve grinder will be double that.
.0008 runout? I'm sure in Jonnie's Precision Word that this would be totally unacceptable! Fortunately, we didn't know about these type of errors and were able to get by with a "collet type" valve refacer (they aren't grinders") and worse yet, a Hall Toledo flex shaft driven seat refacer (with a stone as a Souix type would use) was used to do the seats. This unit was located by a pilot placed in the valve guide. It's a little hard to use a Serdi on seats that are in a cylinder head that also has the block attached. (Yes, this was an automotive engine.)
The FACT was that we won many races (including the "500" several times) using this type of totally inaccurate equipment.
Are you kidding? Your real world experience is MEANINGLESS compared to Jonnie Bonkers' "got hired at an engine machine shop 3 weeks ago so I've been wiki and googling everything in sight" experience.
He reads advertisements, and watches advertorial Youtube videos. How are you going to compete with that? If a manufacturer of a product says it's the BEST and the ONLY way to go, they are definitely telling the truth......
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.