201 hop up project

[Cpt.Fred]

Thanks, bloodyknuckles! hearing that from you is good.

when it all won't work in the end we'll have to take the intake out again and

install a balance tube.

that would mean the original idea of an independant runner setup will be washed up,

so i'll try a little harder first before i admit that:rolleyes:

i don't really think i need a pressure regulator, because i'm running an electric pump only delivering fuel at 0,3 bar operating pressure all the time.

that was ok for the single setup, so i assume it will be alright for the 3 carb setup as well.

i can run the pump against the float needle valves with open float bowl

with engine shut off and can watch the needle valves close.

thank you once more, greg, i will lower the float level even more now.

i might have to intstall vac ports on the intake, too, but i wait and see what comes out before i have to go through the pain and take eveything off the engine again.

more finger crossing...

[greg g]

Fred, The way your manifold is built, I do not think much of the direct runner effect, as far as the general intake charge is concerned is going to be lost, by adding small ballance runners. I know you are dedicated to the idea and I hope you can get it worked out. For a racing engine where it would be running WOT all the time, I can see where it might be more effective than the common log type manifold. but for a street engine where WOT is limited to short bursts, and or hill climbing, it seems you want to design for effective fuel delivery from idle to mid throttle where the engine will most likely spend most of it time.

The other day I was looking at my motor cycle. An older Kawasaki 650 4 cylinder.

It has a carb for each cylinder but it also has balance tubes running between the spacers between the carb and the engine. So here is a 40 cubic inch engine making 65 HP which runs at 4500 RPM at 70MPH. Se even this is a bit more tweeked ad has inter carb commuication.

Keeping my fingerrs crossed also.

[Cpt.Fred]

that's interesting...

a friend of mine who's into motorcycles a lot and

built katana drag bikes talked me into the independant runner thing

in the first place...

also the design was chosen to smoothen the gas flow from carb to port

and to lenghten the gas column inside the intake in order to improve torque at low rpms.

at least that's what the numbers said

the balance tube was left out to avoid unnecessary gas turbulence.

this may sound silly on a flathead engine, but it made sense to me when

we talked about it.

if it really doesn't work:

how big would the balance tube need to be to have the desired effect?

do i need equal diameter tubing or just a small passage, like i understand

your honda is built like?

lots and lots of interesting questions.

[greg g]

I would think you could do it with hose barbs and heater hose. two pieces close to the carbs.

Put it behind the bracing, and even you won't notice it.

Edited April 4, 2011 by greg g

[Cpt.Fred]

ok, thanks... i'll do some more testing and measuring, especially for that

compression issue, and then take the intake off again and have a closer look

at these matters...

Edited April 8, 2011 by Cpt.Fred

[Don Coatney]

I would think you could do it with hose barbs and heater hose. two pieces close to the carbs.

Put it behind the bracing, and even you won't notice it.

Heater hose might collapse from the vacuum?

[Alshere59]

Some copper pipe wouldn't look bad. May be able to keep it low visibility and have it large enough to balance the carbs if needed.

[greg g]

The sections would only need to be about 1.5 inches long so I don't think collapse would be an issue.

[Cpt.Fred]

you're right, don.

one should use vacuum hose which is reinforced to prevent collapsing.

but i think it should stay all metal.

i think steel would be the easiest way.

i'll let my welding friend decide if it comes to this.

[Cpt.Fred]

the mysteries keep coming here...

since i was pretty sure i'd have a bad valve on either cyl #5 or#6

i did a compression test yesterday evening.

Well, i have one.

But on #3.

Here's what i found:

#6 ---> 6,0 bar

#5 ---> 6,4 bar

#4 ---> 6,5 bar

#3 ---> 2,5 bar

#2 ---> 6,0 bar

#1 ---> 6,5 bar

i put some SAE30 into #3 and checked again, still only 3,5 bar

and a big puff of oil mist coming out of the center carb.

so i guess the culprit is the intake valve on #3...

that leaves me with 2 questions:

1. what do i do about this darn valve?

2. why is the 3rd carb acting weird on the step up jet when it's actually

the 2nd one having problems? guess i'll have to take it apart once more.

[moose]

Hey Fred, can you explain your numbers? Is this a leak down check? 6 bar is about 90psi. That would be fairly low for a cranking check.

[Cpt.Fred]

just a normal compression check, pressure gauge, no plugs, throttles wide open,

and crank it.

i know 6 bar is low, but at least it's consistent... except the #3, of course.

this doesn't fit at all to what the engine looks like on the inside and how it handled... enough power, great starting, cold or hot...

looks i have some patient here with more than one desease.

i should have done this test long ago,

but my pressure gauge was broken

and i always thought "oh, well, the engine runs great,

that's the last thing you have to worry about"...

[moose]

OK I got it now. I thought you were giving the numbers as a set. Two different numbers for each cylinder. Normally we Americans are used to seeing 6.0 bar, not 6,0 bar.

Gotcha

[Cpt.Fred]

aah, ok. right, i heard about that in school... way back:D

but anyway, i'm sad.

my beauuuuutiful flattie is rrrruined... *dexter voice*

[greg g]

Fred it may just be stuck from sitting around. I guess you will need to pull your manifild and get the side cover off to see of the valve is closing all the way. You might get lucky and be able to address it throught he side cover.

Did you try swaping the carbs position on the intake to see if it was the carb at fault?

[Cpt.Fred]

i messed around some more and got it to run quite nice,

so i could let it sit and idle for a while to build up some temperature.

afterwards i got hold of a guy who's building VW beetles for the drags.

he came over and looked everything up and down and did some tests

with the carbs and had a look at the plugs.

we found that only cyl #5 and #6 (the ones i suspected to be bad) work

correctly, #3 and #4 are more or less just flooded, and the ones in front are something in between.

so i decided to pull the head and grind the seats and give the valves a little attention to make sure they really close tight.

i guess this not a hard thing to do and afterwards i'll know more.

can anyone tell me where to buy head gaskets and prper ignition parts?

the last parts i got didn't fit at all. i need breaker points, dizzy cap and finger, and a set of new wires and plugs. also i want a manifold hardware kit

and all gaskets i need for the head job.

thanks!

fred

[james curl]

On the ignition parts you need to match them to the model number of the Distributor. Mother MoPar used three or four different models of distributors and the points on some are mirror imagines of the others. The rotor and cap is taller on some and the overall diameter of the distributor body and cap is larger on one model. Any good parts house that handle industrial engine parts should have them. Most any of the MoPar parts suppliers here in the U.S. should have them but you need to supply the distributor part number to get the correct parts. Jim Terrell at Terrell Machine in De Leon, Texas can supply the parts and the gaskets, his information is located on the home site of this forum under suppliers. Hope this helps.

Edited April 11, 2011 by james curl
spelling

[Cpt.Fred]

thanks, james!

of course i did give them the correct number, but still i got lousy repops that

wouldn't even go in there... i hope this time i get the right stuff, i'll contact

Jim Terell later on.

[Cpt.Fred]

ok, very nice gentleman, this Jim Terell, he had all my stuff in stock

and sent it right away.

so i went down to the old garage to tear apart what i built the weeks before.

here's what i found. it seems the last 2 cyls were really the only ones working

like they should, the others appear too wet and cyl #3, and even #4, seem pretty clean

from all the raw gas...

next week i take the valves out and check seats and guides for damage.

[Cpt.Fred]

you're probably right, Frankie,

and we're actually already thinking about constructing a

balancer segment that consists of another 3 flanges,

a little thicker than the others, that are connected through a metal tube.

this can be inserted between the carbs and the actual intake.

i just want to make sure i choose the right diameter tube for this job,

and so far i haven't found any real calculations or info about this.

also i thought the balancer would just make sure all tubes have the same atmospheric pressure?

but i hardly doubt that the things i found in the head and cylinders

come from the few test runs i did with the new intake.

i think this has been going on for quite some time, actually.

my guess is, as i know the engine has been sitting for about 10 years,

the seat of the intake valve on #3 has suffered corrosion

from standing in open position all this time, or something in that direction.

in the end i also might have to build new jets giving me a leaner mixture.

[greg g]

Fred, fom watching your test run again, and thinking about it, I realized what was goig on. The third carb step up piston was reacting properly. It was infact reacting to the vacuum signals generated by the intake strokes of the two pistons it served, Down on the intake, and up (with no vacuum in the intake runner until the other in the pair tarted its intake stroke. So the vacuum signal was correct only as there was no common vacuum to keep it closed generated by the other 4 cylinders it was being opened by the spring when the vacuum was missing.

So your other cylinders and carburettors should have been open due to low vacuum causing the over rich mixture. So you need to adress why those cylinders were not providing vacuum, pobably due to poorly sealing valves.

However I believe under the running conditions of 5 &6, that that poor little spring would not last long in those metal fatiguing conditions, and that regadless a shared vacuum sigal is likely best for your system.

You may not need to worry about rejetting as when those step ups are working properly ie closed at high vacuum and open under acc and load, you wet plug problem will not be such an issue. This because the mainjet fuel volume will be proportional to the air flow through the carb, which will be reduced by 1/3 and so should the fuel flow through each carb. and because the step up are also holding closed until needed they will also flow the proper proportion of fuel as established by the air flow.

[Cpt.Fred]

Good thinking, greg!

that might very well be the reason for the jumping valve on carb 3,

i never thought of it this way.

but... the front carbs' step up valves were closing correctly, so i guess they had enough vacuum?

we'll see. first of all i get my valves done and then i take car of the balancer issue.

now i'm off to copenhagen, i have to work there till saturday (though i'd rather stay and grind some seats:rolleyes:)

good night, everyone!

fred

[greg g]

As long as the head is of you might want to think about getting shaves some to up you Compression ratio.

I took .040 off mine. Don;t know about where you are but the machine shop only charged me 45 USD to do the work.

[Cpt.Fred]

good idea.... i go ask some people here,

if they remember the name of a decent machine shop.

how thick has the head to be originally? i might check first if someone

else had a try on that before me. how much did you gain with the .040 off?

also i hope i don't damage the old mains by putting more bearing load on them?

[greg g]

You might gain a 1 or 1.5 cr increase from 6.5 to 7.5 so nothing much to worry about.

Don't know the thickness of the original head by your seems to look pretty much stock.

Also check where your pistons are at TDC. on eht enon 230's they are usually about .030 or more from the top off the cylinder.

I also took .010 of the Block for a total of .050. The machinist estimated my CR withthe .030 overboe and bigger pistons to about 8.5 or so.