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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: wv-geo ()
Date: January 03, 2019 06:39AM

People have been installing motorcycle carbs in cars for years, especially in Europe.
Here's a company in the UK that makes intake flanges and kits to install bike carbs:
[www.danstengineering.co.uk]

Recently, people have progressed to motorcycle fuel injected individual throttle bodies (ITBs).

Don't be afraid to use a motorcycle ITB thinking it would be too small for your engine.
A four ITB setup for a 1000cc motorcycle engine that redlines at 12K should be capable of running on a 2000cc car engine that redlines at 6K.

Dan Stark
Hurricane, WV

1961 Lakewood 500, 80HP, PG
1964 Corvair 500 Coupe, 140HP, 4spd (Christine)
1965 Mustang Coupe, 6cyl, 3spd

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: MattNall ()
Date: January 03, 2019 07:25AM

Yup! Our Mark Wright did it 10 years ago...very potent!





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: Phil Dally ()
Date: January 03, 2019 07:47AM

This is Mark's (solo2r) set up...Y/N?

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: solo2r ()
Date: January 03, 2019 08:22AM

Nope Phil! That is Triple barrel TWM 46mm throttle Bodies! Here is my first try at FI using Suzuki GSXR Throttle bodies!

All bolt on per the SCCA ESP rules [ at the time]

The Engine in pics above are my Street Mod set up .



Edited 2 time(s). Last edit at 01/03/2019 08:26AM by solo2r.

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: Phil Dally ()
Date: January 03, 2019 09:21AM

Okay so I posted the good stuff!!!

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: viewmaster ()
Date: January 03, 2019 03:30PM

solo2r Wrote:
-------------------------------------------------------
> Nope Phil! That is Triple barrel TWM 46mm throttle
> Bodies! Here is my first try at FI using Suzuki
> GSXR Throttle bodies!
>
> All bolt on per the SCCA ESP rules [ at the time]
>
> The Engine in pics above are my Street Mod set up
> .


solo2r, how did that quad GSXR throttle body injection system work out? Did you have enough air flow with those???
-m



Mike
'65 '500' Sedan 110 PG
'65 Monza Sedan turbo'd 110 SU conversion
Fresno, CA

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: UGLYTRUK ()
Date: January 03, 2019 09:27PM

Interesting

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: solo2r ()
Date: January 03, 2019 10:13PM

"solo2r, how did that quad GSXR throttle body injection system work out? Did you have enough air flow with those???
-m"

Mike, Short answer is great and yes! Should look up my name for my posts in the past! Or PM me for specific questions!

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: kmart356 ()
Date: January 04, 2019 02:56PM

New Turbo Carb - almost there. . . the initial reading of fuel pump pressure was 5psig and the Mikuni HSR45 needs it between 2-3psi. I drove to the speed shop and picked up a QFT Fuel Pressure Regulator, 1-4psi, 30-804QFT. After adjusting it to 2.5psi the installation proceeded. It is tucked behind the methanol injection tank and should give the clearance needed for the K&N RC-4620 (due tomorrow).





With the limited running so far in the workshop, the engine starts more "briskly" than with the downdraft and does not require much coaxing with the pedal to fire up. Now the throttle response is more “snappy” than before. I reworked the throttle linkage for a little more air filter clearance by going to middle hole in the throttle shaft arm. The down link now is at a better angle than before and it feels good to the right foot without too much drag. The stock throttle return spring is used (connected to the factory air cleaner support bracket). Air filter install and then boost on!!!



Ken
'62 Spyder Coupe
Florida


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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: MattNall ()
Date: January 04, 2019 05:30PM

Slides are so much better than Butterflys!





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: nirvairna ()
Date: January 04, 2019 07:45PM

Very cool Ken! Do you know what mods are done to the carb to be usable on a car?

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: MattNall ()
Date: January 04, 2019 08:45PM

nirvairna Wrote:
-------------------------------------------------------
> Very cool Ken! Do you know what mods are done to
> the carb to be usable on a car?
===================================================

Read page 1





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: kmart356 ()
Date: January 05, 2019 06:04AM

nirvairna Wrote:
-------------------------------------------------------
> Very cool Ken! Do you know what mods are done to the carb to be usable on a car?
Thanks nirvairna. mods summarized below. Details on the Vintage Performance Developments web site

Basic modification: smaller needle and seat for higher fuel pressure, larger main jet, Mikuni mounting flange adapter and extended throttle shaft for lever type throttle linkage (custom shaft)

Turbo specific changes: modified float bowl, larger accelerator pump and additional jetting modifications. I also got jet tuning kit for optimization thumbs up

Ken
'62 Spyder Coupe
Florida


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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: gnvair ()
Date: January 05, 2019 07:22AM

What kind of cfm do they flow?

Lee J

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: 63turbo ()
Date: January 05, 2019 07:33AM

gnvair Wrote:
-------------------------------------------------------
> What kind of cfm do they flow?

The HSR45 flows 237 cfm at 12" of water, which is an amazing amount of flow considering how low of a test depression they use to rate their carbs. All other "butterfly" type of carbs either use 25" or 28" for their airflow ratings

Here's the airflow ratings for the other sizes (near the bottom of the page), from the Mikuni site:
[www.mikuni.com]

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car






Edited 1 time(s). Last edit at 01/05/2019 07:36AM by 63turbo.

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: kmart356 ()
Date: January 07, 2019 07:18AM

The K&N 4620 round tapered filter is flange mounted (65mm ID - 43MM length). Throttle arm clears the base of the filter and the offset flange allows for positioning with clearance all around.



Test drive resulting in no backfires, no spitting and no stumbling during take off thumbs up Throttle response was smooth and made boost easily. The AFR readings were a bit lean during acceleration. This was really just a shakedown run to make sure no fuel leaks and establish some baseline jetting. I made a few changes (smaller pilot jet, larger needle jet) and will re-adjust idle circuit before doing any serious "data gathering". The Mikuni is tuned based on throttle position/load and different jets/circuits are active as depicted in the diagram. That will be useful once I am able to make some steady throttle/load runs and record AFR...the fun begins!



Ken
'62 Spyder Coupe
Florida


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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: toms73novass ()
Date: January 07, 2019 07:42AM

Looks Nice! No up hill this time. grinning smiley

-Tom


63' Monza Spyder Convertable (in process) MY Build Thread
65' Monza MY Build Thread
73' NovaSS 454 Big block
86' BMW 325es
98' Dodge 2500 12v Cummins Diesel with 1200 lb torque!
98' VW Jetta TDI, for daughter
01' Audi Allroad Stage 3 twin turbo

NFCC
Grand Island, NY

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: tboltkc ()
Date: January 07, 2019 08:34AM

That looks great.

Where are you injecting your alcohol?

-Travis


'65 Corsa; '63 Convertible; '62 Wagon; '65 4 Door
Heart of America Corvair Owners Assocation (Kansas City, MO)

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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: kmart356 ()
Date: January 07, 2019 10:02AM

Use 2ea, one nozzle at the base of each manifold flange (just below crossover).



Ken
'62 Spyder Coupe
Florida


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Re: New Turbo Carb - Mikuni HSR45 smoothbore carburetor
Posted by: kmart356 ()
Date: January 13, 2019 02:10PM

Summary information for anyone considering the Mikuni HSR carburetor as a side-draft alternative to the Carter YH, Weber DCOE or SU.
Parts List:
* Otto Parts SU Carb Adapter for Turbo (bought from Clark's a few yrs back)
* Mikuni HSR45 45 mm carb with modified float bowl, modified for rod type linkage, short idle adjust screw, mounting flange, and Jet tuning kit. Supplied by Vintage Performance Developments.
* Quick Fuel 30-804QFT Fuel Pressure Regulator
* Two-hole throttle lever by Roger Parent
* K&N RC-4620 Clamp on Air Filter (65mm flange)
Notes:
- The SU adapter was 2" dia but now sleeved to match the 180 turbo intake - Adjusted the carb float to engage needle at 19mm (spec is 18mm +/-2mm) - Use a low pressure regulator and adjust to 2.4-2.5psi output to carb.

Baseline Jetting (as delivered): [Pilot Jet 22.5] [Needle Jet Y-8] [Jet Needle -97 on clip position 4] [Main Jet 200].

The next phase of tuning has started. The current condition of tune is shown on left side of diagram. The right side details jetting influence vs throttle position. The jet needle is affixed to the throttle slide and moves up when throttle is opened. I have larger main jets coming to address lean region as well as the lean -98 jet needle to address rich low end. I have one step lean/rich needle jets and can raise the jet needle one more notch if needed for mid range changes. Once the jetting is dialed in if there is further refinement needed, the profile of the jet needle tapered section can be customized (this was a technique used by Robert E. Mathew for an SU carb described in 1986 Corsa Tech Guide)

I will be striving the get the "air fuel ratio into happy land" thumbs up before doing any serious on-boost runs.




Ken
'62 Spyder Coupe
Florida


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