Gas tank location

[LittleLiner]

Deciding where to position the fuel tank in my gas coupe build . . . did a search on ' fuel tank location' and nothing helpful came up.  Looking through rules and I see that in some classes there are places you can't mount the tank like the rule that says you can't put it in front of the grill on fuel/gas roadsters but you can on street roadsters.  Looking under the Modified category and the Gas Coupe rules I haven't seen anything that addresses this. (Did I miss something?)

I am running an engine of less than 750cc so I don't need a very big tank.  This gives me a lot of options, space-wise, like ahead of a front fender well, under the hood, etc. . .

Anyway, I guess my question is –

. . .Per the rules is there anywhere you CANNOT mount a fuel tank in a gas coupe?   As long as there is some sort of firewall between the tank and the driver is there any other restriction?  And even if legal by the rules, are there places that I should not place the tank?

[Glen]

Page #31, 2009 SCTA rule book PP 3.I fuel systems. Should answer your questions.

[LittleLiner]

Page #31, 2009 SCTA rule book PP 3.I fuel systems. Should answer your questions.

It answers most of my question.  Thanks Glen.  That was one of the first places I looked.  It tells me to mount it solidly and if I run lines through the drivers compartment to be sure the lines are safe.  If the lines are near the blower drive (don't have one in my application) or near the clutch area, to protect them.  etc., etc,.  It really doesn't say where I can or cannot mount the gas tank.  Therefore I guess I can pretty much mount it anywhere as long as I follow guidance in the rule book. 

Mounting the tank close to the engine (just like in the donor bike) saves a lot of aggravation and costs.  This allows me to use the original 'in-tank' CBR600RR fuel pump and keep all the fuel system components and EFI from the CBR600RR to include the original high pressure lines.   This photo shows a test fit of the engine and the stock (from the donor bike) gas tank. 
 

If time and budget permit I'll get a smaller tank and will mount it in the same location. 
Probably something like this one that Jason McVicar ran a few years ago on a Honda CBR600RR in the 650 class.

Now with tank location set I can now start to cut the steel for engine/differential and tank mounts, the chain guard plus start to fab a hood scoop. 

Although I'd rather be at Maxton this weekend. 

[manta22]

LL;

Make sure that in the event of a grenaded engine, the gas tank isn't turned into a firebomb. A steel shield might be a lifesafer.

Regards, Neil  Tucson, AZ

[LittleLiner]

Neil

Isn't that why I have a firesuit??   

Do you mean something like this??




Or were you thinking of a full steel 'can' around the tank like used in NASCAR?

[manta22]

LL;

The shield in your drawing should be good protection-- you don't want to get that firesuit covered with soot, after all.

Regards, Neil  Tucson, AZ

[Stainless1]

LL, be sure you shield it from the chain as well...

[jimmy six]

Back in the day there were a lot of gas coupes ran moon tanks mounted to the front of the cars. Usually a 2 or 3 gal moon tank mounted to the bumper. I'm sure this would still allowed.

However if were some other design was used and in apperared to be areodymamic in shape I would feel it would not be allowed. Look to the definition in the Street Roadster rules. Street roadsters and Gas Coupes do have some similar rules especially in the vintage class..............Good Luck

[LittleLiner]

LL, be sure you shield it from the chain as well...

Plans are for a heavy chain guard to keep the short 530 from whipping up on the engine, firewall, steering and anything else in harms way.   BTW - A prototype of this design is running on the west coast in 24 hours of lemons events and the chain (now chains) have not failed. (google for METRO GNOME LEMONS)

Here is what my chain drive looks like so far.  That's half a 45 tooth split sprocket that Sprocket Specialities made up for me to bolt to the Metro differential.  I have not installed the bearing hangers yet.


Here is what the bearing hangers look like (photo is of the west coast car setup)



And here it is installed in that car . .  (note it used an early CBR600 (F2 I think) ) It now has an early CBR900.


That setup lasted 24 hours without throwing a chain.  However the mounting frame holding the differential in place didn't hold up and was replaced before the next 24 hours with beefier mounts and a double chain. shown here.

[LittleLiner]

Back in the day there were a lot of gas coupes ran moon tanks mounted to the front of the cars. Usually a 2 or 3 gal moon tank mounted to the bumper. I'm sure this would still allowed.

Thanks for the idea but I'll pass.  Not sure it would be legal mounted out front.  Smacks of extending the nose and that would send me into Competition Coupe.  In any case if seems criminal to hang a traditional moon tank on a geo metro.   Especially one that will be this slow (minimum for J/GC at El Mirage is 90MPH)  Hopefully I go that fast at Maxton.