95 replies to this topic

[Bench Racer]

Thanks for the upload Danny.

The reason for the weight/deflection experiment was an effort to search for contributors why the RELIEF gauge end results were not as expected. I did not have the luxury of playing touchy/feel with the head and gauge at the ARRC. Jim and all thanks for taking the gauge to the next level.

Picture A.

The distance from the head surface to the center top outside diameter of valve is 7/16 inch with the far end of the valve stem flush with the other end of the valve guide. The distance from top of valve to the top of the valve guide is 2 1/16 inch. (Dan, the distance from the top end of valve guide to the valve seat is 1 1/4 inch & 1 3/8 inch to the head surface. The measuring with the drill rod weighted 4 inchs from the top of the valve guide was thinking, a person applying load on the gauge top side stem extension.)

Picture B.

10 pound weight loaded to center top of valve, dial indicator in place. Crude weight holder , but workable. Dial indicator gauge set to 0*.

Picture C.

VERY CAREFULY removed the weight so to not disturb the setup. Dial indicator gauge reads .012 inches. Re-did this A. through C. process three times with the endresult being the same .012 inch deflection each time. With little firger gentle push, one can deflect the valve .012 inche.

Contex comments from this thread:

Tool not gravity drop from own weight. Gentle push. May require thin oil. Gentle gauge side load push failed an OEM un-machined relief cut head. Tool produces different results in different peoples hands.

With this tool learning experience a different tool concept might be the following.

Visualize a valve with the stem end being same diameter as normal while being extended longer and with threads on the the far end. The valve head (ground like a normal valve for seating/centering purposes)end would have a round extension of some length ground to a 32 finish for a flag (round with cut outs so the top of the relief cut may be viewed with tool in place) with it's hole also being ground to to a 32 finish. The flag will through gravity slide down on this round extension (this could be tested using a G&P shaft with a round flag with a hole ground to a 32 finish). The tool will seat in the valve seat just like the current valve. If required on the threaded stem end a valve spring will be put in place and a flat washer and nut would confirm the tool is secured to the valve seat. Gravity drop the flag and the existing contributors will (may) be eliminated.

A bit more complex tool, now is the time to pick the nits and or come forward with other tool concepts. We have had issues for two straight years, we don't need three.

[Danny Steyn]

Dave

I personally think you are making this way too complex. If you go back to Dan's post about using a FLAG as opposed to a CIRCULAR tool, his logic is absolutely right - You have to use a flag for the very reason I mentioned and for the reason he stated. If you use a circular tool, as simple dimple can cause the tool to pass the head when in fact the relief cut could be in excess of the spec. The same goes for oval machining of the relief cut. A circular tool would pass an oval relief cut where the minor axis is under the spec, but the major axis is over the spec. A flag that falls in ANYWHERE into the relief cut will FAIL both those examples.

So IMHO you have to stay with the FLAG. We just have to make sure that the flag stem is the same diameter as the valve guide and that it is long enough so that it is not easy to create any deflection. Then make the tool 2-3 thou over size relative to our published relief cut spec, and if the tool passes into the relief cut on EVEN A SINGLE VALVE then fail that engine and DQ the driver.

Drago, Collins, Wheeler - what are your thoughts on this?

[Kyle Freiheit]

Maybe this has been mentioned but how about make 3-4 different Flag type tools with different diameter stems so that you can account for worn valve guides. Tech just starts with the largest flag and works down until the finding the stem that fits the guide.... More costly but seems more reliable.

Kyle

[Bench Racer]

It sems that both flag tools tested to date do not meet the expected results. Some folks believe either of the two existing flag tools should not require a personal touch/load/force to have the flag tool fall in the valve guide hole. The first tool by the SCCA may fall into the valve guide hole. The second flag tool does not fall into the valve guide hole. Both flag tools have deflection the moment a person starts applying a side load. Looking at photo A. several posts back which has a normal valve, this valve will not fall from it's own weight and it deflects with very little little finger side load.

Listed below are several potential contributing issues that caused the improved flag tool to not meet expectations.

1. Tool not gravity drop from own weight.

2. Gentle push.

3. May require thin oil.

4. Gentle gauge side load push failed an OEM un-machined relief cut head.

5. Tool produces different results in different peoples hands.

Will the proposed tool concept in post #41 eliminate contributing issues items 1. through 5., yes.

Within this thread we have proposed methods to check relief cuts.

A. Two tool concepts have been proposed in post # 41 and post #43,

B. Change the flag length dimension as proposed in post #33.

Danny, I may be making this deal way to complicated by looking for the potential root cause issues for the tool failure. Then I'm sure concepting a tool that eliminates the potential root cause issues of the tool failure through a new tool concept is another deal that's way to complicated. Earlier in the thread it was suggested that some root cause analysis be done and some blue skying tool concepts be proposed. Normally during this stage of the game, it's good business to encourage positive thought. I'm quite sure my motor head will never be relief checked so I really could care less if a new tool is concepted or if the throat specs are changed by playing games with the flag length. The dimple and oval stuff as as had been suggested in earlier posts can be elminated by adding/improving a few words in the original written spec.

My only goal was to help improve the throat checking tool.

Thanks for uploading the photos.

[Bench Racer]

Oops, please see next post with three pictures.

Attached Files

•  Relief Cut Tool.JPG   58.92KB   18 downloads

[Bench Racer]

Pictures attached of a relief cut rotate no go (legal) - go (illegal) tool concept.

The bottom side of the tool head will be machined to the same angle as the valve seat surface angle. When the tool is inserted the tool will be centered equal as it was during the Runoffs tech shed caliper measurement from the outside diameter of the valve head to the radius of the relief cut for the cars that finished 1st and 2nd. No caliper measurement required with this relief cut tool. The tool measuring flag will be a radius per check gauge standards with respect to the maximum allowed relief cut radius. The current (un-tested) logic for the extended tool threaded stem length along with the valve spring, upper valve spring seat and nut is to apply minimal axial load to remove end play and keep the tool seated in the valve seat. If the tool flag does not rotate into the relief cut the relief cut is legal. If the tool flag rotates into the relief cut the relief cut is illegal.

Please consider this a proto type tool. The added threaded stem length, valve spring and nut may not be required. A real tool will need to be fabed and test.

Please openly pick the nits.

Attached Files

•  Relief Cut Tool Parts.JPG   19.15KB   47 downloads
•  Relief Cut Tool Inserted.JPG   14.99KB   50 downloads
•  Relief Cut Tool Measure.JPG   11.6KB   50 downloads

[AW33COM]

After reading this long threat I can say this: It would be much cheaper to just buy a sealed engine from Mazda. Then we would know who is actually fast.

I just purchased F1000 (Formula B in SCCA) machine, and in that series we basically have the same engine even though we have nothing to do with "SPEC".

[LarryKing]

After reading this long threat I can say this: It would be much cheaper to just buy a sealed engine from Mazda. Then we would know who is actually fast.

Don't you know this is an impossibility?

The genie is out of the bottle the big money guys will buy 200 sealed motors to get a good one people will still find a way to cheat it will just be more expensive Mazda can't supply enough motors who will seal them blah blah blah...

[AW33COM]

Hmm. You guys open up a motor to go what? 5mph faster? Both stock and "pro" engine is slow motion racing no matter how much you grind/polish/etc in there.

It's going to sound wrong these days, but I'm going to say it anyway. I can afford to build the fastest Spec Miata in the country, but I choose not to. Why? Because I'm a very competitive person. How would I feel passing people with the fastest car? Remember this is spec racing. This is not sports car racing where you race what the factory created. Something to think about if you're trying to be a champion.

Now, if you really want to make it competitive you can simply tech the engine the first time it shows up at SCCA. Seal it there. Only stock motors allowed. You pay $300 for the tech inspection. Whoever gets caught later on is banned for life plus $10,000 penalty. This would bring the costs down like you would not believe.

[LarryKing]

Note: I was pegging the "Sarcasmeter" and listing some of the reasons given through the years why a sealed motor class would "never work."

If I had unlimited funds I'd build the fastest f'ing SM in the land and smile like an idiot every time I blew by someone else. (actually, I'd probably race something else)

[Ron Alan]

Hmm. You guys open up a motor to go what? 5mph faster? Both stock and "pro" engine is slow motion racing no matter how much you grind/polish/etc in there.

It's going to sound wrong these days, but I'm going to say it anyway. I can afford to build the fastest Spec Miata in the country, but I choose not to. Why? Because I'm a very competitive person. How would I feel passing people with the fastest car? Remember this is spec racing. This is not sports car racing where you race what the factory created. Something to think about if you're trying to be a champion.

[Rob Burgoon]

Hmm. You guys open up a motor to go what? 5mph faster? Both stock and "pro" engine is slow motion racing no matter how much you grind/polish/etc in there.

It's going to sound wrong these days, but I'm going to say it anyway. I can afford to build the fastest Spec Miata in the country, but I choose not to. Why? Because I'm a very competitive person. How would I feel passing people with the fastest car? Remember this is spec racing. This is not sports car racing where you race what the factory created. Something to think about if you're trying to be a champion.

Now, if you really want to make it competitive you can simply tech the engine the first time it shows up at SCCA. Seal it there. Only stock motors allowed. You pay $300 for the tech inspection. Whoever gets caught later on is banned for life plus $10,000 penalty. This would bring the costs down like you would not believe.

LOL yeah that makes sense. If you ban them for life, how do you expect to collect the 10K? Seize their car?

[Jim Drago]

It's going to sound wrong these days, but I'm going to say it anyway. I can afford to build the fastest Spec Miata in the country, but I choose not to. Why? Because I'm a very competitive person. How would I feel passing people with the fastest car? Remember this is spec racing. This is not sports car racing where you race what the factory created. Something to think about if you're trying to be a champion.

There are plenty in SM that can afford to race just about anything they want to. Most who buy or develop top sm's do it because they are competitive people. Everyone wants the best car they can race within the rules. When speaking to friends and customers and even competitors, the most common answer I get to car prep is " I just want what everyone else has" Very few if any have ever asked for a car better than the rest. To get what "everyone" else has at the front of a competitive class, it means you have to develop a car to the rules. You don''t have to cheat, break or even bend the rules. The engine is certainly a big part of the equation, but 95% put too much emphasis on the engine and not enough on the entire package. My opinion has remained unchanged, long before I ever built my first SM has always been the same. Build or buy the best legal car you can. If you start there, then you can work on driving and set up and take the car out of the equation. NONE of us is so good to start with a mid to back pack car and expect to win, NO ONE! Our class is great in that a very inexpensive car can be built from a used 100k miata, no one said you could win in that car, but you can race it and have fun.
Jim

[MPR22]

Off topic, sort of,

Weird how its always someone elses car is faster or they must have cheated because they are too fast. Top prepped cars driven by top level drivers are scary similar in lap times. I had the 2nd fastest car in a field of 48 drivers at TWS in April, best I could manage was 3rd. So it wasn't and isn't the car in many situations. Usually it boils down to driving without making a significant mistake, ie > .5 seconds in a lap, at the Runoffs it might be even less. Nobody talks about Jim's Runoff drive because it looked too easy. Yes he has one most developed cars in the country and he still would have lost if he made a significant mistake.

Pro engines are hear to stay. Maybe SM5 takes off someday because of the cost to compete gets too high in SM. The SMAC suggested several changes to the rules a few years back to allow the shade tree mechanic with the help of a machine shop get a nearly pro engine without having to go to a pro builder. That will get you within a few HP of the top cars. The trade secrets are still the pro builders domain but the average Joe can get close at a significant discount. Those last few get expensive. As Jim suggested there are more gains to be had than just pure HP, most of which are free or low cost.

These are mass produced engines that had a huge variance in tolerances from the factory. Most of what the pro builders do is try to make these engines more similar. If we all had to use a junk yard engine the cost would go sky high because the top guys would buy dozens of engines to find the best ones. Don't belive me go see what the top karters spend on engines in a year. A 10k kart can cost 150k for a season of racing. That is not were we want to go.

I applaude the work of the SMAC and those who are trying hard to make this Similar Miata. If the bright folks on this board can come up with a better mouse trap on go/no go compliance tools then I applaude them as well. A rule or regulation is only of value if it can be easily enforced.

[LarryKing]

Most of what the pro builders do is try to make these engines more similar.

With all due respect - baloney.

Sealed motors work for other spec series, they would work for ours too.

[Caveman-kwebb99]

"work" the same word is used many places and nearly always means something different to everyone involved...

what works for one doesnt always work for another...

[LarryKing]

So why didn't the Playboy MX5 series allow "pro motors" if all the builders do is make them "more similar"?

[MPR22]

With all due respect - baloney.

Sealed motors work for other spec series, they would work for ours too.

Go measure the cam journal tolerances in 3 serperate heads and then tell me how similar these engines are from the factory. The tolerance is ridiculous, one engine is not nearly the same as the next. We would spend a small fortune buying engines to get 3 that are as alike as you would suggest. Baloney is a cheap sandwhich meat made from the leftover parts of swine or other animals mixed with fine cubes of lard. It has nothing to do with Spec Racing.

[MPR22]

So why didn't the Playboy MX5 series allow "pro motors" if all the builders do is make them "more similar"?

Now you are mixing apples and oranges. The NC engines are much more similar from the factory.

You can get a head out of the junk pile on an NA or NB that flows as good or better than many manipulated heads. Don't believe me ask somone who has flowed a few hundred heads. The core shift in these things are all over the board.

Moose or Squirel never quite sure who I am talking too, please spend more time developing your race craft and less time trying to make the world more EQUAL. The world will never be equal, Entropy will always win. We can try to make everything fit in nice little box and eventually it all returns to its most basic chaotic form.

[Caveman-kwebb99]

EQUAL.

Now this is a word that means the same to most all of us, when I am beating you I feel the rules are equal, when you are beating me I feel the rules are unequal.

Who gives a shiit about what class has sealed motors or what class doesnt? Our class doesnt! It never has far as I know... why pick this class if you want sealed motor class?

the pass fail gauge on sealed motors is simple if it has sealed motors run that class Pass, if it dont have sealed motor Fail dont run that class,

Problem solved! Good night