Single Carb Conversion: Adapt the stock plenum

[dan filipi]

Mine looks to be the same as Tom's. Came with the same gasket it looks like.
Does your's have a bowl vent?

I have it apart right now looking it over.

It's all very clean.
Going to print the manual and specs and adjust everything.

 

[joedrum]

so this carb and first carb from tom are different westgl ?

 

[westgl]

Joe,

No, 1st carb., and this most recent Carb, From Tom, are the same.

Between both purchases, what Tom sent is very consistent.

On my previous GL1100 single carb Manifold build, I had the Air Filter, that i bought in the past.

This Most recent Carb from Tom

Here is what I bought from Tom,
1. Rectangular Air filter 2.5" high, like a K&N, $23.00
2. Lower Plate kit, Fit top of the 32DFT carb. this transitions from Carb to bottom Airfilter base, includes Alum. plate, Large O-ring as a seal from Carb to Airfilter base, and threaded rod and Nut (loctited to threaded rod), and Wing nut
3. 32DFT Carb.

from Him, this included a few parts like the Crank case vent termination fitting to air filter lower plate



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joedrum » Mon Sep 23, 2013 5:22 pm[/url]":3r9alhc6]
so this carb and first carb from tom are different westgl ?

 

[joedrum]

okay it really starting to look like dans and toms carb are just dang near the same except for jets that are different ....

today im out to get a 1100 airbox cleaned and ready for a sclex carb ...post a side picture of your runner hook up west id like to see that ... dang my camera batteries are dead and I havnt been able to put pics up the last couple days ....

 

[ianstaley]

I know this is going to sound weird but, the volume of air inside the plenum has been calculated for each carburettor in the standard rack. Therefore logic would suggest that as each carb feeds only one cylinder that the amount of air required per cylinder will remain constant. It is reasonable to assume that each carb would suck the required amount of air as needed from the plenum. The only change here is the fuel feed comes from one carb rather than four. The old Rover V8 based on a small 3.5 litre Buick engine used two SU carbs placed on either side of the plenum. Is it not then reasonable to assume that plenum will be filled with enough air/fuel mix anyway, I say this because only one cylinder at a time time will be taking IT'S turn at sucking in the mixture. Or am just being stupid? :doh:

 

[joedrum]

well im certain going with basic hook up .... and see what happens .. its more the speed of the air through carb to atomize gas ...but like you say it may do just fine .... will see

 

[westgl]

I was playing around last night, to see if i could build a inverted V,

Or, a Tent shaped Volume reducer that would reduce the internal size of the plenum, by raising the floor of the Plenum.

The Top, or peak, of the Tent, is just 1" from the top of the plenum where the carb adapter plate will mount, it then spreads down to each runner outlet.

I would say the inside of the plenum Volume, has been reduced down by over 50%.

Thank you ansimp, great idea.

I thought about, filling in any gaps around the plate, by soldering it inside the plenum, after the two halves have been bonded and screwed together.

I dont want to add a lot of heat to that adhesive/bonding, and ruin the seal only have to repair it later.

If i can get it bent right it will hold it self in place tightly.

If there are larger gaps than I want, I will have to figure out something that will hold up to this lousy fuel and a additive of ATF in the gas, Thanks Joe.

The Tent has made the 5/8" raised section in the Plenum floor, go away as it pretty much covers it.

 

[westgl]

We may be over thinking the whole plenum Volume thing.

But I cannot help but think.

Trying to drink water through a straw vs trying to drink water through a equal length garden hose.

The garden hose will take much more effort, and time to get the liquid through it.

joedrum » Tue Sep 24, 2013 5:25 am[/url]":1w649eul]
well im certain going with basic hook up .... and see what happens .. its more the speed of the air through carb to atomize gas ...but like you say it may do just fine .... will see

 

[joedrum]

that's good west :smilie_happy: :smilie_happy: :mrgreen:

I totally agree west completely but it good to have both ways going to see whats up ... im prettcertain I will half to do more than basic hook up

 

[westgl]

I see there is a Vaccum port, that runs from one side of the Plenum to the other side.

That Vacuum port goes across the plenum width centered, that raised section in the plenum floor.

Drill & Tap that Vacuum port hole on each side of the plenum, and there is your Heated Plenum.

Drill & Tap the water line at the Fitting for the water tubes on top of the engine to provide heated water to the plenum.

Plenum Coolant Heat using a Ball valve shut off

• westgl
• Sep 24, 2013

Plenum Coolant Heat using a Ball valve shut off

Plenum Heat using Coolant from Water Tube adding Fittings

• westgl
• Sep 24, 2013

Plenum Heat using Coolant from Water Tube adding Fittings

P1020108

• westgl
• Sep 24, 2013

Heated Plenum, using coolant to heat floor of plenum.
Vacuum port, see Left runner outlet, small...

 

[westgl]

I agree with you Joe,

I would love to see it simplified, if it runs good, I may not need that extra Plate at all, and it may just be added effort for, Zero benefit.


I can always make a plate after, if i feel it needs it.

joedrum » Tue Sep 24, 2013 5:36 am[/url]":3sqs7j06]
that's good west :smilie_happy: :smilie_happy: :mrgreen:

I totally agree west completely but it good to have both ways going to see whats up ... im prettcertain I will half to do more than basic hook up

 

[westgl]

How hot is the Air coming out of the Crankcase vent, when the engine is up to temp?

If enough heat is there then that may be a very good alternative to using water anywhere near our intake plenum.

As iam not very happy using water near a split plenum, to much chance of it getting in to the induction providing that sweet smell of coolant ala blown head gasket.

Route the Crankcase vented air up to the Vacuum port on the plenum, with a small brass fitting and hose blow through the Vacuum port in the plenum base for heat, out the other side and up to the bottom of the air filter base where it would be terminated there, for induction into the carb.

Nice thing about that is, It already flows out of the engine, we need to do something with it, it is Not a Vacuum, it is blown air, i believe it is from the reciprocation of the pistons, that builds pressure in crank case.

 

[joedrum]

yes .. but that vac line is actually the gas feed from one side to the other in the stock carb set up

 

[westgl]

yes,

But for our single conversion it will not be used.

So for heating it may work to our benefit

 

[westgl]

This should only be done on a extra Plenum that can be sacrificed

 

[westgl]

A piece of Brass tubing could be soldered into the hole, with high Temp Silver solder as it is Much stronger and will hold up, Much better than Regular Solder as Regular solder is Too soft and may not hold up for a long period of time.

Durability is #1, an long with performance, and many other goals.

 

[dan filipi]

I don't think there will be enough heated air if any coming out that vent. I've put my finger over it and there's almost nothing coming out.

I like the water idea.

 

[westgl]

Water may be the only real good way to heat that plenum.

It is the recommended way of plenum heating that Tom recommends.

I am just trying to remove bad scenarios from the mix.

That fuel port, (thanks Joe) is raised to the same height as the runner outlet on both sides, of the plenum.

What about removing some of the top flat fuel port area, then solder the hole shut, re-drill a new hole over to the right of that fuel port, hole that you soldered shut which is in the lower area of the fuel port, and further away from the runner outlet.

You may have to grind back some of the original port upper ridge to make room for the new fitting

dan filipi » Tue Sep 24, 2013 8:07 am[/url]":266pi9oj]
I don't think there will be enough heated air if any coming out that vent. I've put my finger over it and there's almost nothing coming out.

I like the water idea.

 

[westgl]

Looking inside plenum, the fuel port has a 1/4" thick alum. to the top of the outlet plenty of material there.

Probably closer to a 1/8" wall thickness on the lower area, outside of fuel port to the inside of the fuel port.

I would like to open that Fuel Port Hole up as large as i can, and still be durable with out getting in the way of the Tube Runner Outlet Seal Area.

 

[westgl]

I may drill the hole larger diameter.

Then solder a angled Brass tube, in to the existing hole that was drilled as large as possible on both sides.

It may not Take that much flow through there as that coolant will be HOT!

Should be hotter than i had on my Heater Bracket for Rev.#1