I can't wait for the fancy welded manifold so I'm making one from PVC

[Ansimp]

chuck c » Mon Sep 22, 2014 11:25 am[/url]":1oqtmfac]

slabghost » Sun Sep 21, 2014 8:53 pm[/url]":1oqtmfac]
May I suggest that you use the largest circumference of pipe you can as a support post. I strongly doubt the motor will ever get warm enough to deform CPVC if you use that and no buffer between it and the motor it might help keep the fuel charge warmer.

I don't understand. Why should I use a pipe with a large circumference?

As a vertical support post/ spacer , the larger diameter makes it more stable :yes:

 

[slabghost]

And holds heat to keep the manifold evenly warm.

 

[chuck c]

slabghost » Mon Sep 22, 2014 1:02 am[/url]":35e9a6qe]
And holds heat to keep the manifold evenly warm.

Gotcha. I think the runners are very stable and strong enough by themselves for normal riding, anything I add will be reinforcement for insurance against hard impact or vertical shock like speed bumps and potholes. As for warming the carb I don't think icing will be a problem with pvc. Thin aluminum is a great heat sink to chill the mix going through it but 1/8" to 1/4" pvc is just the opposite. If that should be a problem I found nifty little electric heaters that can attach right to the carb to warm it and the fuel. That's simpler and cleaner than trying to reroute engine coolant through the manifold risking leaks and overheating the carb (and plastic manifold) in hot weather. It only works when needed. I do plan to take temperature measurements of fuel, carb, manifold, and the mix going through it to see what's really going on.

 

[joedrum]

i would in no way have heat shield in place like the stock one or any kind of flow retarder..... but thats me

 

[chuck c]

I mean under the manifold to keep the worst of the heat from getting to it. It's rated for 122° and the mix going through will cool it a little (tho pvc is a terrible heat sink) and I think on really hot days sitting in traffic with it running could get there right over the engine. The heat from the radiator surely is but the oem heat shield takes care of that. I'm worried about what rises from the engine case when there's no airflow sitting still.

 

[joedrum]

just opinion here but open everywhere it seems to me will keep it the coolest ...

 

[Ansimp]

Even in PVC the atomisation of fuel has a cooling effect and I don't believe the support post will generate that much heat :yes:

 

[chuck c]

I need to get an indoor-outdoor thermometer and take some real measurements when I get this running to see how much the mix cools below outside air temp. While heat helps vaporization, cold makes the charge denser and gets more power. It's why turbocharged vehicles usually have an intercooler. The mix it so hot coming out of the turbo that a good portion of the advantage is lost by it expanding. The intercooler brings it back down to get maximum density in the charge. I may add a heater to the carb to warm the fuel so it vaporizes easily but I want the runners to stay cool for the densest charge.

 

[Ansimp]

Big difference between the heat generated by compressing air through a device that is powered by exhaust gases and radiant heat from the middle of a water cooled flat 4 ( they get hotter towards the deck area) :yes:

 

[chuck c]

Ansimp » Mon Sep 22, 2014 8:56 pm[/url]":2ddbffd2]
Big difference between the heat generated by compressing air through a device that is powered by exhaust gases and radiant heat from the middle of a water cooled flat 4 ( they get hotter towards the deck area) :yes:

True but the theory is the same. In this case it's probably not enough to be measurable. I think the mix coming out of a turbo is in the 300s and in this case none of the temps will be near 100. We're probably picking nits here. I'm making a 33 year old bike run dependably, not building a drag bike.

 

[joedrum]

chuck c » Mon Sep 22, 2014 8:10 pm[/url]":zfdyt8zf]
I need to get an indoor-outdoor thermometer and take some real measurements when I get this running to see how much the mix cools below outside air temp. While heat helps vaporization, cold makes the charge denser and gets more power. It's why turbocharged vehicles usually have an intercooler. The mix it so hot coming out of the turbo that a good portion of the advantage is lost by it expanding. The intercooler brings it back down to get maximum density in the charge. I may add a heater to the carb to warm the fuel so it vaporizes easily but I want the runners to stay cool for the densest charge.

on my set up it is for sure a good sign ...when the stainless steel runners are cool ... first this tells you that there is no leaks in the runner as gas is in the charge from carburator ...it wouldnt be cool if if there was a leak there before carb ...two when its cooler it dose run better than when it hotter ...this cold season will see where this might go the other way ...and icing might be issue ... but i believe if carb is modded and jetted right ...icing might not be much an issue.... :mrgreen:

 

[chuck c]

Last night I was mostly cleaning and painting. I had to scrub the crud and mouse droppings off the top of the engine and paint it while it was exposed. Painted several other parts, too. Tonight was getting the front of the engine back together: covers, water pump, and radiator. It's a real battle to get the hoses on especially with the "spring" covers. At last! Tomorrow the manifold and carb go on. With a bit of luck it will make noise tomorrow! There will be pics and maybe even video if it works.

 

[chuck c]

We're a bit behind schedule. The manifold went on and I learned a couple of things. Remember i went with the larger diameter fitting (2" I think) to add the section where the carb mounts, thinking the larger diameter would be stronger and more stable? It is, but it makes a bear to get to the nuts to tighten down the carb. Doable, but harder than it needed to be. A smaller one would have made getting to the nuts fairly simple. The 1/2" thick flange is also nice and strong but it's almost too thick, there is just barely enough stud left to get nuts on. 3/8" thickness would be much better to allow room for gasket and washers. Also, it doesn't need any extra support under the carb. It's very solid. Tomorrow I need to wire the electrics and figure out how to mount the throttle cable. The PO did a hack job on the rear lights. I have to completely rewire them before it's roadworthy.

 

[Steve83]

We're still with ya! opcorn:

 

[Ansimp]

Sounding good :good:

 

[joedrum]

:whip: no slacking off opcorn: :mrgreen:

 

[chuck c]

joedrum » Sat Sep 27, 2014 8:05 am[/url]":1c48b6jr]
:whip: no slacking off opcorn: :mrgreen:

SNORT

 

[chuck c]

IT'S ALIVE! Video after I get dinner. It won't run under 3000. Probably carb adjustment. Any Solex experts out there care to offer advice? But the important thing is IT WORKS! :rocks:

I did follow the standard instructions about turning the screws out 2.5 turns from bottom. Since those are for a 1600cc VW engine not an 1100 Honda, I assume that is not ideal.

 

[dan filipi]

Awesome.

Could be it's too lean, could be too rich.
Have you tried turning screws either way to lean or rich?

 

[dkl]

Vacuum lines Hooked up...? electric choke working? Check for manifold leaks? Don't be afraid to open up the little screw more than recommended.