Running Mikuni 44s

Webers, Cam selection and Ignition upgrades.

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1.8te27
Posts: 45
Joined: Mon Jul 01, 2013 6:48 am

Running Mikuni 44s

Post by 1.8te27 »

Hey everyone I've recently picked up a pair of Mikuni 44s, a mikuni manifold, and T3 stacks. I've never messed around with side drafts and wanted to get some pointers before pulling off my 32/36 offenhauser setup.

My 3tc has some headwork, large valves, Norris 342 cam, the head was shaved so probably somewhere in the neighborhood of 10:1 compression. I also have dual valve springs, hardened push rods, a header and full exhaust.

I'm trying to figure out a baseline for jetting etc so I can hit the ground running when I get everything on.

I also need the linkage and a carb sync tool. I would like any references for online stores to buy jets and other parts from as well. Here are a few pics of my setup and some pics of what is under the jet covers.

Also, do I need to run a gasket between the carbs and stacks and what about between the manifold and the carbs?

Thanks for the help!

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Rodger
Posts: 9
Joined: Fri Jul 19, 2013 1:24 am
Location: Australia
Contact:

Re: Running Mikuni 44s

Post by Rodger »

Ok.

Nice buy. Have a look at some installs on my site.

Looks as if you have Mikuni factory jetting. Typically #34 Venturi, 200 Main air, 150 Main Fuel, 57.5 Pilot. Main jets maybe big for that combination of motor.

However this combination would allow you to start and run the car safely. Then it is down to either dyno time or learning how to tune by ear and feel. The Factory Mikuni Tuning Manual has good info of how to tune by ear and driving.

A current set-up I have on my motor (the green one): #34, 180, 125, 57.5

Check the idle mixture screws for damage or wear and set them to 1.5 turns from lightly seated.

PHH44s rarely self distruct like their smaller PHH40 S4 and S5s do over a long life on 2T-Gs however check all the things over before you bolt them on.

You should find and use Toyota carb spacer blocks or an after market version, with a gasket on each side.

Easiest to set up a cable. But I note you have not got Mikuni throttle arms and drop links for the manifold.

There is not enough space between the carbs to run a centre pull arrangement so you may need to source Mikuni levers. The throttle shafts are 10mm and not the same as Weber or Dellorto so any lever suiting them will not fit.

Plug off two manifold ports (1/8 BSP) and use the rear one for the brake booster connection.

You will need a long neck distributor to clear the manifold and carbs.

Lock your Vacuum advance plate as there is no effective vacuum with this set up. Set static timming to 12 degrees.

No need to have a gasket between ram tubes and carb. There should be enough space on your LHD car to run a deep dual filter element if you can find one that clears the ram tubes by 30mm. Any less will impeed air flow. You may have to run filter socks or filter screens now available on-line from several sources.
I have little space in my RHD Celica as the ram tubes come close to the brake booster and MC.

Fueling them. An electric fuel pump with high flow low pressure, look to 3-6psi. No need to run a return hose. They can run on the factory mechanical pump around town but this will restrict the maximum flow rate restricting your max time at full throttle.

Once on and tuned they go very well and sound awesome.

Enjoy
Regards
Rodger
Lover of the Solex/Mikuni sound
http://www.rmcarburetors.net
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