18 replies to this topic

[dstevens]

According to SCCA GCR 9.1.8.l I can take the fuel filler trap door and restricter out of the system. Doing that now. Yep, it's 3 am. That's how I roll when I work until midnight. I try not to let the compressor or grinders run too long. Now this red plastic check valve ball is supposed to close and protect a spill even if it's a 110 mph plus multi cart wheel? Good luck with that. Mine won't seal at 90 psi air pressure. I'd bet a 3 or 4 G multi flip would would be more that 90 psi against the valve. Besides, that lateral torsion on the chick car fuel tank is going to rip it open like an Xmas turkey it the shunt is bad enough. The red check ball is at best going to delay the fire.

A better option would be a fuel cell. You know, like they have in race cars. Even my 83 Delta 88 has a Fuel Safe cell and they don't let hobby stocks, where our race speed isn't more than 70 mph on the track unless we have at least a marine or poly prop cell with a rollover valve installed. Extra cost you say. Well, yeah. I've hit my $1750 limit on insurance out of pocket this year. My last angiogram was billed at almost 20 grand. And I've got great insurance. What do you reckon 3rd degree burns from a race car wreck will cost. That is, if you live. At that point a $300 fuel cell is a pretty good bargain.

[FTodaro]

I am going to do this project this winter. Is it as simple as disconnecting the filler neck from the car and using a dremel or saw on that outer restrictor lip?

I assume that does not interfere with that check valve you were describing?

[LarryKing]

You know which race cars I've observed catch fire at club races? The classes with fuel cells. No data but my suspicion is that it's because of the piss-poor plumbing job done by some builders. I've seen some real shadetree crap.

I feel relative safe with the OEM, DOT-approved Miata fuel tank.

Yep Frank, it's that simple.

Hidden benefit of check-ball - prevents foreign objects from failing into fuel tank. (don't ask)

[Qik Nip]

As an official member of the Nelson Ledges Turtle Club, I was pretty thankful that my check ball seemed to be working perfectly (as I hung upside down in my straps like a bat awaiting the safety crew's arrival) and looking in my driver's side mirror at the tank filler outlet. Nary a drop of gas came out!
Rick

[Jim Drago]

You know which race cars I've observed catch fire at club races? The classes with fuel cells. No data but my suspicion is that it's because of the piss-poor plumbing job done by some builders. I've seen some real shadetree crap.

I feel relative safe with the OEM, DOT-approved Miata fuel tank.

Yep Frank, it's that simple.

Hidden benefit of check-ball - prevents foreign objects from failing into fuel tank. (don't ask)

I tend to agree... I have yet to see a Miata in SM catch fire other than electrical smoldering under the hood, has anyone else? Not to say a properly installed fuel cell isn't a "better" option, problem is many aren't installed properly. I think as far as fuel fire safety, the Miata has proven to be very safe, lord knows we have all done a good job crash testing them.

With regards to that ball, removing it presents does more harm than good IMO. I see lots of issues arise when people remove them, including filling up the entire emissions system up with fuel and causing the car to stumble and misfire. That and I often see fuel trailing cars in corners when the check valve is removed. I think that in itself is a potential fire hazard.

[LarryKing]

PS: Mr. Stevens, do not underestimate the value of adequate sleep for your general health and well-being.

[Jim Boemler]

When we talk about removing the check ball, just curious what the rules have to say...

Exactly what does anybody think the benefit of removing it would be?

[LarryKing]

First they came for the check balls....

[Randy Thieme]

As someone who also wears the corner-worker hat I've seen my share of cars spilling fuel at the start of a session. And more than once we've had to meatball those cars. One session had a car spilling fuel and another which would spitfire out the exhaust during shifts. Fortunately they did not get together before we got the fuel problem fixed.

[davew]

Removing the check ball could make refueling faster in an enduro. Otherwise, I see no solid reason the remove it.

On 99+ cars, they don't have check balls. They use a little flapper door. These have a tendancy to stick shut. This makes refuelling a street car a royal pain in the ...

Mazda has an updated flapper door assembly if yours is sticking for about $10

Dave

[Keith Novak]

I tend to agree... I have yet to see a Miata in SM catch fire other than electrical smoldering under the hood, has anyone else? Not to say a properly installed fuel cell isn't a "better" option, problem is many aren't installed properly. I think as far as fuel fire safety, the Miata has proven to be very safe, lord knows we have all done a good job crash testing them.

With regards to that ball, removing it presents does more harm than good IMO. I see lots of issues arise when people remove them, including filling up the entire emissions system up with fuel and causing the car to stumble and misfire. That and I often see fuel trailing cars in corners when the check valve is removed. I think that in itself is a potential fire hazard.

I've seen a leaky brake caliper catch fire on a Miata. Not a big fire but there were flames. I've also driven behind cars leaking fuel on turns. It's horrible to drive behind that. Filled my cockpit with vapors that made my eyes sting like mad.

[dstevens]

PS: Mr. Stevens, do not underestimate the value of adequate sleep for your general health and well-being.

You don't realize I work some nights until 1 am. Big time show biz is like that...

[dstevens]

When we talk about removing the check ball, just curious what the rules have to say...

Exactly what does anybody think the benefit of removing it would be?

I'm back.

Where did I say I wanted to remove it? Read what I write, dude, not to the post which you think you want to respond. If you are wanting a debate, don't bring a knife to a gun fight. Here is what I actually wrote....

Now this red plastic check valve ball is supposed to close and protect a spill even if it's a 110 mph plus multi cart wheel? Good luck with that. Mine won't seal at 90 psi air pressure. I'd bet a 3 or 4 G multi flip would would be more that 90 psi against the valve. Besides, that lateral torsion on the chick car fuel tank is going to rip it open like an Xmas turkey it the shunt is bad enough. The red check ball is at best going to delay the fire.

I hope you or others aren't implying that that little orange ball is more effective than the Fuel Safe I had in the stock car or any other SFI or FIA rollover flapper. Most race vehicle fires happen in the engine compartment. Hot metal, fuel, bad mix. I suggest a fuel cell and now I'm some sort of ass hat? Whiskey-Tango-Foxtrot? A fuel cell in racing is safer than a street gas tank in any form of racing. How many responding have actually raced cars that had fuel cells installed? Not seen them but actually have owned, used or installed them?

The argument, or as I see it, excuse is that it might be installed wrong is specious at best. My cage or belt mounts could be installed wrong as well. Since that's the case, why not just use the stock items? Where do we draw the line? Fuel cell installation suitability can be monitored in the log book, just like the cage, belts and my nomex socks. If you're in a bad fire, a good cell will do more than some 20 dollar socks.

If I had the inclination, I might get back to that 96 I visited at Pic A Part the other day (if they haven't crushed it yet, I still want the trans as a training mule) and get the fill pipe and do a test to see the temps that the ball would melt and what my cell would withstand but a) I don't want to spend the time proving something I already know (like that meaningless saw blade test for weld strength) b ) more importantly, I'm parting out the stock car and have buyers for the cell.

Here is the finished part...


check ball 1 by Dave Stevens, on Flickr


filler restrictor gone 1 by Dave Stevens, on Flickr

[Jim Boemler]

Good grief, you're going off the deep end, Dave. When you get back from de-tox we can talk. There is no gun fight, and no one has called you an ass-hat. At least not before this last little diatribe of yours.

[James York]

I tend to agree... I have yet to see a Miata in SM catch fire other than electrical smoldering under the hood, has anyone else? Not to say a properly installed fuel cell isn't a "better" option, problem is many aren't installed properly. I think as far as fuel fire safety, the Miata has proven to be very safe, lord knows we have all done a good job crash testing them.

With regards to that ball, removing it presents does more harm than good IMO. I see lots of issues arise when people remove them, including filling up the entire emissions system up with fuel and causing the car to stumble and misfire. That and I often see fuel trailing cars in corners when the check valve is removed. I think that in itself is a potential fire hazard.

Like you, the only SM fire I have seen in nine years was due to a fuel leak from the rail under the hood due to poor installation after an injector service.

In my car, originally the flapper door was removed and on its shakedown test did exactly what you described. Filled up the evaporative emission system with liquid fuel and caused the car to stumble out of certain corners. Put the little flapper check back in and no issues.

[Bench Racer]

A little side note about fuel cells for production cars. Fuel cell NOT required if OEM fuel tank is located within the main chassis structure between the axle centerlines. SO, if one wanted to with a couple other slight changes one could enter a Spec Miata in F production group races. That would be more track time & maybe a triple dip.

[dstevens]

Good grief, you're going off the deep end, Dave. When you get back from de-tox we can talk. There is no gun fight, and no one has called you an ass-hat. At least not before this last little diatribe of yours.

Deep end? Irony Jim, irony....

Where did I say I wanted to take the ball out? You didn't answer the question Jim. I said I took the filler flap out, not the ball. Then folks, like you, for example, chime in about taking it out when it was never an issue in the first place. I'm leaving the check in because in the event this goes over, that's the only thing that could keep the fuel from flowing back out, like what happened to Rick. I suppose a more concise observation "what the hell, that's the only anti flow device in the fuel storage system?".

Gotta run, the detox van is circling the block looking for me.....

[dstevens]

A little side note about fuel cells for production cars. Fuel cell NOT required if OEM fuel tank is located within the main chassis structure between the axle centerlines. SO, if one wanted to with a couple other slight changes one could enter a Spec Miata in F production group races. That would be more track time & maybe a triple dip.

That's interesting. My question/concern about the cell install under current SM rules is if it would permissible to include the mounting and protection hoop structures. Doesn't look like those mods are kosher per current rules.

[Jim Boemler]

Deep end? Irony Jim, irony....

Where did I say I wanted to take the ball out? You didn't answer the question Jim. I said I took the filler flap out, not the ball. Then folks, like you, for example, chime in about taking it out when it was never an issue in the first place.

I was reponding to JD's mention of removing it. You're right, you never said you wanted to, but you're not the only person in the conversation.