LocostUSA.com

I agree with Greg! Give it a go. Just hold on to something solid.

Looking good Rod.

Cheers,

_________________
Larry in Seattle

CX3

Inquiring minds would like to know from what type of bike did you get the carbs from? Did you do any modifications to them prior to putting them on the engine? Any and all details you could provide is appreciated.

It sounded good and strong to me.

Thanks Red

I just noticed how small your battery is. What is the CCA and have you actually turned the engine over several times in a row, without it going flat? Dave W

Red,
The carbs are off a mid 90's Honda CBR900. I've drilled the main jet out to 1.6 mm and re-spaced them so that the intake manifold runners are all the same length. Other than that, they're stock CBR carbs. I'm planning on putting an O2 sensor just downstream of the collector and running an AFR gauge once I get back to tuning the thing.

Dave W,
The battery is a 16LB that's used in powersports applications. I haven't filled it yet, so I haven't been able to test it out. But, there was a discussion on a Lotus Europa forum about batteries and that size/type has been used before. It's rated at 275 CCA, which isn't that great, but a Europa owner did say that it worked well in his car. I will report back when I fill it, and use it.

Rod

I used lawn tractor batteries in my Locost for a few years, but I only got about 2 years out of them before they died. I've been running a Miata battery now for a while, and having much better life out of them.

_________________
The Lethal Locost
The Lethal Locost 2 - Even More Lethalerer

I'm using lawn tractor batteries in my locost too, and so far they're working good. I think the current one is about 4 or 5 years old. I only have a 35A alternator though.
Kristian

_________________
V6 in a book frame build. Now registered.
viewtopic.php?f=35&t=7587
viewtopic.php?f=33&t=18172

I've used a ODYSSEY DRY CELL PC-680 in the rally car for a number of years (it's about the same size as the one in the picture). They seem to be capable of multiple starts just fine but have two issues; hates trickle drains when in storage and can live a short life if drained in the cold. Otherwise the small batteries are great and have an awesome shelf life if disconnected.

For what it's worth a 26 or a 121R are fairly compact for the CCA. Not sure how much they weigh however. Thought it was in the high 30 lb range last I checked.

I had originally thought about going with a 26 series battery, but finding space for it was difficult. I wanted to have the battery mounted to the chassis rather than the body, and as low as I could get it. The battery I've chosen is very light (and even lighter when it's not full of acid), and very compact. If it lasts two driving seasons I'll be pleased, the last automotive battery I bought (for the Eleven) lasted just over two years. If I can remember, I'll put the current battery on a scale and post the weight.

In regular service people expect their cars to start at least as low as -10F, in comfortable temperatures over 40F or so you will be just fine.

I have one what they call now "AGM" batteries. I think that stands for absorbed? glass matt? The one in my formula ford has lasted decades, got some of those from an expired computer backup supply in the 80's and it worked fine last time I used it maybe 5-6 years ago. Because there is so little electrolyte in the battery they work better. The electrolyte causes problems like reactions that deposit sulfur on the plates when they are discharged.

Do not over charge them or deplete them all the way and they may last as long a very long time. DIsconnect, with a master switch makes that easy, when not being used for a long time. I also use the terminals on the master switch to connect a trickle charger when required, my formula car doesn't have an alternator so that is basically all the time at an event. Use a voltmeter to monitor the charge there should be info with the battery to help with that.

Also keep the battery clean. The stuff that coats the battery can be enough to discharge it, but I think that's just a big issue with the old vented batteries you added water to. The coating becomes acidic and acid is conductive.

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Still a very real problem with top post batteries. If you suspect an issue a voltmeter can help. You can measure the voltage drop from B+ to a point on the battery case between terminals if its dirty enough to cause a problem.

I have my students do a "Battery Servicing Lab," part of which includes measuring voltage drop through the dirt on the battery. Record so far: 11.9V

_________________
The Lethal Locost
The Lethal Locost 2 - Even More Lethalerer

Well, I didn't strap myself to the chassis and drive it up and down the driveway, but I did run it again with the wheels off to test out the clutch, brakes and gearbox. All seemed to work ok, though I think I'll be swapping the 5/8" clutch master for a 3/4" and I need to replace the lh rear caliper (RH rear from a Miata). Once the testing was done, closing panels and insulating foam were applied:





This past weekend, the chassis was reunited with the body and wet sanding was more or less completed:



I had to pull the body back off, as the foam on the tunnel had folded back on itself near the top which wouldn't allow the body to sit on the chassis properly. Hopefully next weekend the car will be sent off to a paint shop and I can get started on building the seats. I've given up on painting the car myself, the last paint job was a bit thin so it needs to be resprayed, so I'll be going well beyond my budget to get it painted. But, it should be nearly perfect when I get it back.

Rod

Nice progress. Makes me want to take mine out to play, but sadly salty roads and it is in hiding till the roads are clean again.

_________________
Parts left out cost nothing and cause no problems!!

Rod

Nice build!

I think you said the front cross member is rebuilt using stock parts (trunnions) which I believe result in parallel A arm travel. A problem I'm familiar with. So, may I ask, what caster angle are you using? I would also like a few details on the front cross member. Please.