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4bbl carb on a gl1000
Posted: Fri Sep 30, 2022 8:46 pm
by 5speed
has anyone ever attempted this?
I have a holley 4 bbl carb that came off my camaro hanging on a wall in the garage and a 78 wing project bike..
what got me thinking about it was an episode of engine masters where they were dyno testing a single plane,tunnel ram and cross ram manifold for horse power and torque comparisons and Steve Brule mentioned with a tunnel ram you can tune one venturi or barrel for a specific cylinder in regards to jet size and air bleed..
4 bbl carb..4 cylinder engine..

Re: 4bbl carb on a gl1000
Posted: Fri Sep 30, 2022 10:26 pm
by gltriker
Engine Masters is a fantastic program . Huge displacement engines on a dynamometer.
How many cubic inches does this particular 4bbl carburetor feed in your Camaro's engine?
Re: 4bbl carb on a gl1000
Posted: Sat Oct 01, 2022 6:31 am
by ericheath
Re: 4bbl carb on a gl1000
Posted: Sat Oct 01, 2022 7:46 am
by 5speed
gltriker wrote: ↑Fri Sep 30, 2022 10:26 pm
Engine Masters is a fantastic program . Huge displacement engines on a dynamometer.
How many cubic inches does this particular 4bbl carburetor feed in your Camaro's engine?
it's a 350 that's been punched out .040. I replaced the carb with a quick fuel one because the holley wouldn't play nice with it.
Thanks for the link Eric..I'll read up and see how his worked..although I wasn't planning on a tunnel ram like he made. I was hoping to keep the carb under the shelter.
Re: 4bbl carb on a gl1000
Posted: Sat Oct 01, 2022 8:13 am
by gregforesi
Some random thoughts...
With the dual Weber IDF's you get to tune each cylinder. I've never had to. Part of that may be that the intake runners and the exhaust are pretty even-steven for each cylinder. The stock carbs offer the same functionality in that they could be jetted differently, but nobody bothers.
Holley made a couple of smallish 4 barrels for V-8 boat motors (Mercruiser, OMC???) that were 350- or 400 cfm. One of those might be doable. A 600 or 750cfm made for a 350 chevy motor probably not. The bores are so big you'd likely never get enough velocity in the air coming through. Getting it to idle would be tough.
I saw a V-Max that had one of those "boat" 4 barrels on it. The carb was sitting on a blower. It idled perfect and was one of the nicest sounding motorcycles I've ever heard.
Re: 4bbl carb on a gl1000
Posted: Sat Oct 01, 2022 8:28 am
by 5speed
gregforesi wrote: ↑Sat Oct 01, 2022 8:13 am
Some random thoughts...
With the dual Weber IDF's you get to tune each cylinder. I've never had to. Part of that may be that the intake runners and the exhaust are pretty even-steven for each cylinder. The stock carbs offer the same functionality in that they could be jetted differently, but nobody bothers.
Holley made a couple of smallish 4 barrels for V-8 boat motors (Mercruiser, OMC???) that were 350- or 400 cfm. One of those might be doable. A 600 or 750cfm made for a 350 chevy motor probably not. The bores are so big you'd likely never get enough velocity in the air coming through. Getting it to idle would be tough.
I saw a V-Max that had one of those "boat" 4 barrels on it. The carb was sitting on a blower. It idled perfect and was one of the nicest sounding motorcycles I've ever heard.
awesome input..sitting here looking at my boat in the back yard with a v6 and rochester 4bbl on it.
as for the bore..the ones on my carb without measuring both are smaller than the carb on my wing.
this would be more for "I did it" then any type of performance or mileage gains.
Re: 4bbl carb on a gl1000
Posted: Sat Oct 01, 2022 7:43 pm
by gregforesi
With some proper thought this should be doable. Now if it was me, I'd stick it on a riser up through the glovebox area and out the top so everybody could see it. That's how that V-Max was. It definitely caught folks eyes (as if the blower whine and the exhaust note weren't enough).
If you ain't going for performance then go for the WOW factor. But it should run decent.
Ya know, a hi-rise might allow you to center the carb between the ports instead of having to push it rearward because of the cooling lines and thermostat housing. The carb is physically a lot larger but maybe not as big as the stock airbox?
If the particular carb is symmetrical with all the ports the same then you could have each feed a different port. A lot of 4bbl carbs are "primary and secondary" and so you would have to do a 180° or 360° manifold. A Carter 4bbl might have vacuum secondary's. I think I'd stay away from one like that.
40mm Weber IDF's are rated at about 212cfm. That's a ballpark figure because the internal throats can be changed. So I'm feeding my stock motor GL1000 with around 424cfm of carburetor. It runs very well thank you!
Nobody %$#@s with the old man on that white Goldwing. (Unless I take it to Muskegon again. There this other old guy up there...)
Re: 4bbl carb on a gl1000
Posted: Sun Oct 02, 2022 9:29 am
by 5speed
again great info Greg. my carb is vacuum secondary's so a rochester may be the way to go although they are spread bore.It's also more square than a holley and may fit better.
Re: 4bbl carb on a gl1000
Posted: Sun Oct 02, 2022 6:43 pm
by Whiskerfish
Re: 4bbl carb on a gl1000
Posted: Sun Oct 09, 2022 12:36 pm
by Not Done Yet
Years ago I had a Ford Pinto with the 2000cc engine.
(waits until the laughter dies down

)
The hot ticket on that engine back then was to put a big cam in it, then update to a different intake manifold with a Holley 390 cfm carb, and son of a gun if they don't still sell that set up:
https://racerwalsh.com/product/2-0-4bbl-intakecarb-kit/
Obviously the intake would be the hard part and the carb seems to be pretty doggone expensive, but I wanted to throw this out there.
Re: 4bbl carb on a gl1000
Posted: Mon Oct 10, 2022 8:23 am
by 5speed
Not Done Yet wrote: ↑Sun Oct 09, 2022 12:36 pm
Years ago I had a Ford Pinto with the 2000cc engine.
(waits until the laughter dies down

)
The hot ticket on that engine back then was to put a big cam in it, then update to a different intake manifold with a Holley 390 cfm carb, and son of a gun if they don't still sell that set up:
https://racerwalsh.com/product/2-0-4bbl-intakecarb-kit/
Obviously the intake would be the hard part and the carb seems to be pretty doggone expensive, but I wanted to throw this out there.
wow you weren't kidding on the price.
they sell refurbished ones. waiting to hear when they get them back in stock.