It's running [img]i/expressions/face-icon-small-smile.gif[/img] Here's my uppdate:
1) Used the dremel to grind down alittle on the seat lip where the float tang hits to give it alittle more drop; worked real good now if I open my bowl drain I get a real good flow instead of the trickling I was getting before. IMO sucessful mod.
2) Got it running best with 167.5/172.5 mains, needle 3rd clip, AF 2 / 2.5 turns.
3) If I went bigger on the mains it would hessitate in the midrange so I will have to do a WOT plug chop and check, if running lean will try to go with the stock needle and bigger mains.

Talked to VP and they explained that these fuels are made to run faster through smaller opening and act differently than pump fuels, If you want pour alittle pump gas in a glass and some racing fuel in another and look at the way the racing fuel is always moving, but anyways I think Im O.K. since I did not port my head thus not increasing as much air flow as your ported heads, which will be my next mod.but as soon as I can go out and do a plug chop I will report back.

FYI I was originally running AF 3 / 3.5 , 22.5 pilots, 3rd clip and 160/165 mains before the piston and cam upgrade.

 

I hate to be the barer of bad news but the spec. is like 3mm below the mating surface. But if it's running good, what the heck do they know.
7 thou. instead of 8 was giving your engine fits? I don't know what to think of that, not that didn't cure your problem but....well I just don't know what to think of it. Finicky?

 

This is going to take me two hours to type everything I have been thinking, and I'm sure I'll forget some of it.[img]i/expressions/face-icon-small-confused.gif[/img] This might be long and out of order, but I am just adding comments as I scroll down.

I'm not sure but I bet this shouldn't matter. The differance in the SG of the two shouldn't be enough to make the floats level any different. Does anybody know the SG of regular gas?



Mine were about the same. Odd. I wonder why? I really don't think it is the SG(specific garvity). We are both running the same fuel though. C-12

This I disagree with. I have heard some one, Gary I think, talk about using a vaccume gauge for screw adjustments. Just adjust one untill the needle on the gauge is the least erratic, then do the other, so on and so on untill it is as smooth as possible. It makes alot of sense although I have never tried it. But someone said sync the carbs, I didn't really think you meant a carb syncraniser, right???


If that is true, and its because of fuel, and you want to run the red try jetting the red more lean than the C-12. They have pretty much the same properties excpet the 12 has less SG. This means that you have more fuel going through the same jets with the C-12. If you un the red, and it doesn't knock, jetted right (which would be larger jets than you have in it now) it might make more power.

 

On Vavle adjustment I'm running .006 int and .008 Exh seems to be perfect on the stage 1 and stage 2 good power less clatter.


Pat

 

Quote

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the carbs share common ports and of course a common cyl. so a sepperate vacuum may not do any good not like a 2 cyl. with a carb for each cyl.
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This I disagree with. I have heard some one, Gary I think, talk about using a vaccume gauge for screw adjustments. Just adjust one untill the needle on the gauge is the least erratic, then do the other, so on and so on untill it is as smooth as possible. It makes alot of sense although I have never tried it. But someone said sync the carbs, I didn't really think you meant a carb syncraniser, right???

In the post you brought up and in his response to my post, he only used the one port on the left boot unless I missed something.

 

Your right. Maybe I am confused or just type confused.?.?.?.

What I meant was do one carb and the do the other, not switch the gauge to another. What Gary said is what I meant, weather I make any sense or not. LOL

Carb sync. really check to make sure the are openning and closing at the same time, right?

 

Now that you say it and I reread the post it makes more sense.
I was thinking of what Hiram did to drop the floats for better flow. Another way that it could be done and if your having problems getting the float level lowered, is to heat the arms on the floats and bend the plastic and then fine tune it with the tab. That would let the needle to drop to it's maximum and that little tab would not have to be bent nearly in half to adjust the level. It would be best if the tab stays flatter on the needle too.
It might also be a good idea to check the flow after float adjustments. I'm thinking a 60 HP engine would need 4 GPH that would be about a quart in 4 mins. a pint in 2 and a cup in 1. maybe a little more gas than that but it should be close.

 

Sixsixt - Yes, those little float tabs were bent at more than 45 degrees to keep the level at the carb/bowl mating line. I didn't like it either, as much horizontal tension as vertical. I wanted to get back to square 1 before I left for Boston and went with the factory float measurement. I'll pull it back apart and play with the level if it acts up in the rough stuff.


Ward - Mechanical sync and vacuum sync, different adjustments. If the AF screw is adjusted for max vacuum at idle, the carb will respond fastest to the throttle opening. If multiple carbs don't react to the throttle opening the same, you won't get max grunt. It might be even more important to a CV carb since everything operates off that initial vacuum baseline. I've got to get/make a tool to adjust the AF screws while the engine is running. As soon as I get that tool, I am going to put a small bung in the right boot and see what's up with a vacuum gauge.

Hiram - How much plastic did you remove from the stop tab?

 

UBETRUN, check out motionpro's web site. They have the tool you/I need. I would link it but I can't remember the addy off hand.
Thanks for clearing that up. I didn't realise there were two different ways to sync. the carbs.

You know after reading how much you guys bent your tabs I wonder if I could have made mine work.?.? I had it all the way to the stop but never went any further. I go get my new needle and seat tommorrow, I over slept today, and we will see what happens.

 

Awesome ! Sounds like you guys are getting things running. I do know from tnuing carbs with race fuel for drag racers that the fuel type will affect the float operation - so factory specs for pump gas are out the window... nice job you guys!