Topic: Homemade Manometer

[TwoTired]

Looks like the only thing missing is a common mount platform for the dials.

Gauges- Check
Hoses - Check
Damper valves - check
manifold adapters - check

[Dave-and-his-550]

Looks like the only thing missing is a common mount platform for the dials.

Gauges- Check
Hoses - Check
Damper valves - check
manifold adapters - check

Manifold adapters are the little do-hickeys that go into the screw on the intake right? What are the damper valves again? I'm basically gonna go buy (Or price quote) all the material used to make the one Oldschool posted:



And, also get some tubing and the manifold adapters like these:


Someone mentioned they found something like these at Lowes, so I'm hoping Menards will carry something similar with the 5mm thread.

All sounds like a lot more work then giving JCWhitney your credit card info, but I'm enjoying this do-it-yourself-even-if-you-dont-know-what-your-doing mentality

[martino1972]

Is $80 that much of a hardship?

no,not too bad,BUT.......!!!!! ,as costum to all of us that have a cb,why pay for something if you can make it yourself...

[mystic_1]

Looks like the only thing missing is a common mount platform for the dials.

No, this is a complete kit with everything you need.  If you read the product reviews it says "The guages are mounted on a nice metal backer that saves them from sliding around."

I have this set, works great.

mystic_1

[Dave-and-his-550]

I just talked to a guy at my local honda shop. He says if you're gonna make your own, you gotta have some kind of restrictor on em so the gauges don't pulsate up and down a lot...So, what kind of restricter is needed? Could I pick it up at Menards or a hardware store?

Bodi said you need restrictors in the vacuum tubes near the carb fittings to steady the needles enough to be useful.

[Joksa]

Once you put vacuum to one tube the level rises and the level in the other 3 will drop.

The idea in syncing is to have equal vacuum in each port = equal level in every tube.

It is a good idea to add some damping. MIG wire nozzle is a quite cost effective damper.

[Deltarider]

I own a set of 4 manometers, but I haven't used them in 20 years, since I suspect they are out of calibration. Three times in those years I have had my carbs out and benchsynched them, simply by sliding a small allankey in and out the small cutout in the frontside of the throttlevalves. I do this very accurately and I take my time. Then I have a drink and then a doublecheck. Afterwards I checked with the engine running, by connecting one manometer alternately and every time my carbs were within 2cm. If I can do it, you can too. Again, take your time and do it very precise. IMO there is no sense as sensitive as the human touch. When I find time, I will make the very cheap tube-balancer as described elsewhere. Just for the fun of it. I would appreciate advise on how to dampen the airmovement. Can it be done by closed beercans in the tubes?

[Dave-and-his-550]

Afterwards I checked with the engine running, by connecting one manometer alternately and every time my carbs were within 2cm. If I can do it, you can too.

I'm liking this idea. I might just buy one vacuum gauge and check each carb with it, take a reading, and adjust accordingly. Should save me some green.

[Deltarider]

I might just buy one vacuum gauge and check each carb with it, take a reading, and adjust accordingly.

I'm sorry, but it can't be done that way. Every time you adjust one carb, it effects the vacuum of the other 'suckers'.

[Dave-and-his-550]

/fail

[TwoTired]

Mechanical synch assumes each cylinder breathes identical to all the rest.  If the engine is in good condition, mechanical synch will get you close.  An old used engine, or ones that have not seen regular use, don't often have each cylinder behave exactly like the others. A Vacuum synch make such engines run smoother.  If your compression test shows identical numbers for each cylinder, then perhaps mechanical synch is "good enough".

Cheers,

[Deltarider]

Thats why after a benchsynch I check with a (only one) manometer. The way the meter moves also tells you a lot. I've never had to re-adjust. I've learned this method from a Swiss mechanic who worked for a racing-team. He never used clocks as he didn't trust them (for calibrationreasons). The first time I did his method, I was surprised that I could bring the idle down to as low as 850 RPM (as the man had predicted). Not that I recommend an idle that low as it may endanger the oilsupply to the camshaft.

[mystic_1]

I just talked to a guy at my local honda shop. He says if you're gonna make your own, you gotta have some kind of restrictor on em so the gauges don't pulsate up and down a lot...So, what kind of restricter is needed? Could I pick it up at Menards or a hardware store?

Bodi said you need restrictors in the vacuum tubes near the carb fittings to steady the needles enough to be useful.

You can use air valves from an aquarium.  That's what comes with a lot of these sync gauges.  It's just a little plastic (or brass in higher end sets) inline needle valve.


The $79 set that TT linked includes them, plus vacuum hose, plus the carb adapters.

mystic_1

[dustyc]

I've wondered about using valves as restrictors.  Would you need to have them set all the same?

[MoTo-BunnY]

I just talked to a guy at my local honda shop. He says if you're gonna make your own, you gotta have some kind of restrictor on em so the gauges don't pulsate up and down a lot...So, what kind of restricter is needed? Could I pick it up at Menards or a hardware store?

Bodi said you need restrictors in the vacuum tubes near the carb fittings to steady the needles enough to be useful.

That's why mine have those (big @$$ed) valves on them - look at the earlier post I did with pictures of the Hondaline setup, same thing - its just an on/off "ball valve". Its so if the needles are bouncing all around, you can close it some and settle them down.

Also, yeah I COULD have just bought a cheap set at $50 to $80 BUT it wouldn't have high-quality German made gauges, Italian chrome plated (and super-heavy duty. .lol) valves, USA made vacuum hoses and clamps, aluminum frame with all recycled Honda hardware and front fender bracket - all made by MOI!        All for only like $40, too!!!

I bought most of the parts off of feeBay. The gauges (see earlier post & link) for like $2-3 each, the valves were $2 each (though a bit bigger than I thought they would be.  ..lol). A roll of vacuum hose was $15 and the brass fittings were like $2-3 each at the local hardware store. (1/8" 1/4" hose barb with 1/8" NPT (pipe) thread - as are the gauges and valves). I will get some better pictures and closeups of the setup, later today, to try and help anyone else rolling their own.  

[Joksa]

A mig welder tip/nozzle with M5 thread and 0,6mm hole would make
a good restrictor/damper AND a sync port adapter.

[mystic_1]

A mig welder tip/nozzle with M5 thread and 0,6mm hole would make
a good restrictor/damper AND a sync port adapter.

There you have it.  Nice call, Joska, that should do the trick nicely.  I'll check the welding isle next time I'm at the store.

I should add that the JC Whitney kit linked above has restrictor orifice built into the carb adapters (two long ones and two short ones).

cheers
mystic_1

[Buber]

And having said all that, let me tell you - I tried both. That is, I borrowed a manometer-set one, and i made myself one with the tubes. The tube one is MUCH MORE sensitive and accurate. No problems with damping, and satisfaction of making it by myself - priceless....  It came to the stage where tightening of the locking nut would affect the setting. It's that sensitive.

[Deltarider]

A mig welder tip/nozzle with M5 thread and 0,6mm hole would make
a good restrictor/damper AND a sync port adapter.

Thanks Finlad! That's the kind of tip I was waiting for.

Buber, I'm interested to know two things. Are your oilfilled tubes simply interconnected or is there an extra tube to 'the outside world'. I would also like to know what lenght and diameter your tubes are in between let's say the oil level and the carbadapters. How is the damping of your set?

I agree that liquid filled tubes are the best way to measure. They simply can't lie. Manometers can as I know from experience and mine are made in Germany(!)

[Buber]

So, tubes are just interconnected, nothing fancy there. I used connectors from fish-tank assembly.
Damping woudl be only by the diameter of those connectors, which is like 1,5 mm (or so).
Tubes - inside diam is (i think) 7mm, but not bigger for sure. lenght - around 1,5 m. And I did a "transition" for carb adapter (done from copper brake pipe with threaded at the end, you can actually se them on the picture) from another piece of tube of smaller diameter.
All in all, i just went the easiest way possible to slap the thing in place. I'm considering a pipe-bridge between the outermost pipes, but... my laziness may kill this idea

Now some practicalities - After i connected it and fired the engine I could see one of them simply going too fast up. I switched off, did rough adjustment, fired up again. When I had them moving slower, i simply carried on tuning till all stayed in place. At the end, though, I wasn't able to lock the screws with nuts, as this was putting the setting totally out, so since the screws are with springs anyway, I just connected a bit of vinyl pipe (for precise application) to black spray can, and "sprayed" the screws in place. it works - at least till today it did
Ah, and filled it with old oil - black and harmless enough if swallowed by the engine.

As per german manometers... let's say I'm Polish....  , allright, joking, actually I do believe in german quality. it was proven too many times.

[Dave-and-his-550]

A mig welder tip/nozzle with M5 thread and 0,6mm hole would make
a good restrictor/damper AND a sync port adapter.

Cool! Thats the last piece I need to finish my homemade manometer. I got about $40 in material already. I hope they have these welder nozzles at Tractor Supply...

Where did YOU find em??

Cheers,

Dave

[bozo4onion]

Morgan Carbtune. Buy the best, you only cry once;D. I cried all day....till I got it and used it. Do you have restrictors? If not you will have wild fluctuations. Morgan uses smaller tubes inserted into the large tubes. Good luck.

[Deltarider]

Morgan can never offer you that satisfaction of building with your own hands something simple that works equally good. Personally I find the price of that Morgan set outrageous.

[UnCrash]

I want to roll my own as well.

It would be nice if we could work together to create a tutorial on an exact process with hyperlinks to purchase the parts.

[Joel]

Are the individual tubes connected to each other at the bottom or do they each have their own small fluid reservoir?  Are the dampers mentioned to allow a small amount of air in above the fluid reservoirs to smooth the reading?