SLC 24 Howard Jones

When I asked I was told that the fastest laps of the day were being run by 200HP radicals, In the 2:09 - 12 range. Ya, that's fast.
Did you mean to say "200 mph"?
Seems unlikely a 200 HP car that is only capable of about 125 mph terminal could cut that lap (?)

I like that LIDAR fuel gauge, I'll have to keep that in mind for possible future needs.
 

Howard Jones

Supporter
Robert, they were Radicals. Some have 1350cc motors that make about 180-190HP and the 1500cc engines make 200-225HP, the older models were as light as right at 1000 pounds and the newer ones weigh a bit more in the 1300-1350 pound range but have a lot more aero-performance with far more downforce than their weight.

In a set of good hands they often are the fastest cars at a given track day event. There is a version that is the top of their line that uses an Eco-boost Ford turbo 4 banger that can make up to 400-500 +hp depending on tune.

450hp, 2000 pounds of downforce, and 1400 pounds. Ya, they are that fast.
 

Randy Folsom

Supporter
I do have a fuel level gauge in the main tank. It is one of the capacitive probe types. It does work but it is slow to react, If I start with the car sitting on flat ground and add 10 gallons to a dry tank then it tells me I have about 90% full. It will take me about 25 mins to burn off 6-7 gallons and at that point, I will have about 2-3 gallons left. BUT, it is sloshing back and forth in the tank and the gauge will read about 1/2 full until I park it and let it sit for a few mins. It will then read nearly empty The gauge is not effective in the car when on track,

If I were to use a gauge again it would need to be able to correct the reading at least 2 times a min. 10 would be better. Once a second would be ideal. The laser one is interesting. Maybe I'll call them and ask for the refresh rate.

This is why I like the idea of a pressure sender low warning switch/idiot light in the output line of the swirl tank hose coming from the swirl tank fill pump.
RCR is shipping the RCR40 with the Holley Lidar fuel level senders, PN 19-250.

I am going to have baffles welded in using the pictured design inspired by Paul Proe. The idea is to be able to cut slits in the tank, slide in the baffle and then weld the slits closed. Not shown is a small slit in the bottom that accepts the bottom locator tab. The positioning paddle on top is cut off after welding.

The current hole size and location is just a guess. If anyone has guidance or experience please share. I propose to locate one of the baffles near the fuel pickup and level sender. The other divides the remainder of the tank.

1716312217080.png
 

Ian Anderson

Lifetime Supporter
I would suggest a 1/4 barbed vent line from the rear of the tank T’d to the front one in case you end up filling with the car in a down slope attitude so the air can be relieved from either end

These things need filled often enough you really want it to be fully filled.

Ian
 

Howard Jones

Supporter
I finished the surge tank. The hoses were challenging to route in a way that they could be removed easily. I did one hard line because it was going to be very tight making all the turns. To be honest I don't like all these connections, every one of them is a potential point of failure. But I think I need a surge tank so.......

I still need to replace the circuit breaker with a higher-rated one now that I have two pumps running. Then I'll try it all out.
 

Attachments

  • HPIM2632.JPG
    HPIM2632.JPG
    830.4 KB · Views: 59
  • HPIM2633.JPG
    HPIM2633.JPG
    784.3 KB · Views: 56

Ken Roberts

Supporter
Howard is your fuel tank hard mounted? I wouldn't recommend that aluminum fuel line between the surge tank and fuel tank. It would be better to make one with a hose and a loop.
 

Howard Jones

Supporter
It's all hard-mounted. Nothing really moves around. The other thing is that hard-line is 1/2 diameter and very stout. But you got me thinking about impact/shunt failure, In that case, a flexible line would be better. Maybe I'll include another foot of hose and a couple of hose ends on the next Summit order.
 
Last edited:

Howard Jones

Supporter
The choices are hoses with reusable traditional AN fittings and hard lines using aluminum tubing or stainless tubing. All have issues and or failure risks. Let's start with AN/hose systems. The one thing that in my case that favors their use is the pressures in my system are very low because I am using a carburetor. The lift pump produces about 5-8 psi and the main pump makes 12 psi and then is regulated down to 6. The hose end fitting to hose connection type of failure is pretty low at these very low pressures. What is a problem is the hoses themselves are prone to deterioration as a result of the alcohol blend and the other additives. The older type rubber hose will typically begin to be at risk of leaking after about 5 years of continuous use, I have changed out my entire hose system in my GT40 twice so far. This was a result of a MASSIVE fuel leak after about 8-9 years that frankly scared the fuck out of me.

The hose type used can mitigate this issue BUT it requires a COMPLETE change in fitting type. This is a serious financial burden for a legacy owner of one of our cars. There are several dozen hose ends and most cost at least $20-30 each. A new build should use a PTFE-type hose and avoid this problem. I like hoses where they are easy to fit.

I would use hard lines when the location is tight, where the runs are short, larger in diameter or the line can be properly supported and thus there is less of a chance that the weight of the lines can cause metal fatigue. This would be less prone to happen when the line is supported and/or short in length or larger in diameter. The choice of line material is a one of diameter primarily and cost/availability of tooling. It can be very difficult to hand flair stainless tubing in excess of 3/8 inch in diameter and nearly impossible at 1/2 inch or larger. Aluminum tubing is pretty weak when 1/4 diameter or smaller tubing is used but gets pretty strong at 1/2 inch diameter or larger. Bespoke bending tools are also required.

The trains I worked on had a pressurized air system that was used for vehicle suspension as well as door control, and large electrical contractor actuation. Each vehicle had at least a couple of hundred feet of air lines and used 1/2-inch aluminum tubing exactly like the line you can see in the photo above. Air leaks due to the tube end and nut retention system were very rare unless subjected to mechanical damage. Tube splits were virtually nonexistent at working pressures in the 180 psi range. Tubing can be very reliable if installed correctly but will fail if allowed to flop around.
 
Last edited:

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
I can’t agree with you more. Actually, this post should be the top-post of a new thread in order to kick-start a level set on AN Hoses, tubing and fittings expectation. As a car builder and crew chief for many years, I was amazed at the naivety / ignorance of otherwise sharp individuals that believed their hoses and fittings were just fine for decades of use and reuse.. Very few people ever pressure tested their hoses and tubing …
 
If you use garbage Summit/Fragola/Earls/etc. hose then I wouldn't be surprised to see them fail after 5-10yrs ... gotta love on day 1 'I smell fuel permeating from the hose ... surely this will work long-term'.

My oldest car is my 65 cobra - I did the fuel and coolant system with Aeroquip Starlite back in ~2005. I re-did the cooling system last year and the hoses (inside) were perfect. I plan on re-doing the fuel system in 2030 (~25yrs of use) just for peace of mind, but I'm sure it'll still be fine. That said I only run pure gas (0% ethanol) so that helps them out tremendously since ethanol is the devil for carbs/aluminum gas tanks/rubber fuel line.

I've seen so much bullshit with the fuel systems people make it doesn't surprise me to see so many fails - i bought a Viper w/ a built engine and large supercharger 2yrs ago (i.e., big money build) .... to make the fuel lines the guy took some regular rubber hose you buy at NAPA and just jammed it into some Aeroquip fittings and said good enough :/
 

Howard Jones

Supporter
Alex. I only know what I know. I will only use Aeroquip or Earls hose and hose ends of fuel or oil. For other AN adapters "some" and I emphasize, that some other makes have proved to be suitable. Things like a straight AN to NPT adapter seem to work fine. However, it is tube-type hose ends where things can really go wrong if cheapo hose end fittings are used. As an example, I would NEVER use a Russel 90-degree hose end tube fitting for anything......ever.

Fuel.....pump gas has God knows what is in it. Most of it has alcohol in it as well as literally hundreds of different additives depending on locality, time of year, local state regulations, etc.....bla bla bla.

If I was doing a car from scratch today I would ONLY use PTFE lined hose and the bespoke fittings that are meant to be used with them with any petroleum product period.

The problem is that a lot of us have old cars that have a lot of AN fittings used on them that are several years old and were made with pre-dated PTFE hose. I can only recommend that the hose on these systems being used with especially pump gasoline, be replaced with new hose of THE SAME BRAND as the hose ends.

This is an important point. The high-quality hose ends I mentioned above, Areoquip and Earls, also make VERY high-quality hose especially made for their hose ends. If you try and use other brands it will be a crapshoot if it is reliable. Use Aeroquip hose ends with Aeroquipe hose and Earls nose ends with Earls hose. There may be others that are quality parts but I haven't tried them all. I do know that these two are very good. Treat this like it is a religion!

Look, this stuff all looks good and seems like it fits. In my experience and in more than one case it didn't!

AND!!!!! Old-style non-PTFE lines stainless braided rubber hose will leak like a sieve sooner or later if used with pump gas. If it's more than 5-6 years old I would recommend you replace the hose and reuse the hose ends or remake the complete assembly with PTFE hose and fittings.

That's my story and I'm sticking to it.
 
Agreed that you should never mix/match hoses and hose ends.

I'm not a fan of Earls hose - it was junk a decade ago (although maybe has improved since then, but I'm an Aeroquip fanboy through and through since it's never failed me)

I've got Aeroquip starlite and stainless braid hoses that range from 3yrs to 20yrs old and all are in fantastic shape and you couldn't tell the difference between the 3yr old hose or the 20yr old hose (both flexible, no fuel weep smell, etc.)

I'm not saying they'll last forever, but if you have to change hose every 5-6yrs either it's garbage hose (not Aeroquip) or there's some serious alcohol content in your gas (I test mine for ethanol and avoid it like the plague, which definitely helps)

Btw, Aeroquip hose is AQP which, to my understanding, means it is considered non-aging, the same as PTFE, with life expectancy exceeding 20yrs. So I ~think~ that Aeroquip hose, both stainless and starlite, would last the same length of time as PTFE.
 
Back
Top