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A couple su related questions


Just Joel

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Alrighty then... :D ...who is running 46 mm SUs on a L4?

Should of bookmarked/subscribed to the thread...but

Need a linkage pic...

sublimedatsun610.

You have to use a longer bent linkage or heim joints to "overextend" so the motion of the original motion of the bell crank on the fire wall.

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sublimedatsun610.

You have to use a longer bent linkage or heim joints to "overextend" so the motion of the original motion of the bell crank on the fire wall.

 

 

Thanks...I PMd sublime

 

Or go cable?

 

Later

Joel

 

Yup...but 720 cable pulling from the bottom with a Hitachi trunnion welded to the 'bar' between SUs.

I believe sublime just shortened the L6 bar/shaft between SUs

Not much left on length being that the L6 was about 4 3/4 inch...and needs to be cut down to about 1 3/4 inch.

I have a Lynx manifold with 46s and linkage and figured I could just somewhat 'swap' that to the K14 manifold....negative.

 

P1010032-1.jpg

 

PC200020.jpg

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Figured this lever (lower in pic) somehow synced the front SU... and was necessary.....which somewhat (temporarily) confused me :blink: .... :D

Actually...it has nothing to do with it, it's for emissions.

Carbs are synced by a set screw on the rear carb.

 

So....removed that lever, shortened the shaft and slipped the trunnion on it...just need to get it welded up.

 

PC210021.jpg

 

Another question.....what is this spring loaded 'bolt' used for?

Looks like it might be to meter the vacuum for the threaded hole/port below it....?

No clue....

 

PC210023.jpg

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this lever (lower in pic) ... it's for emissions.

...

th_PC210021.jpg

 

The other pics of the linkage look like A12 twin hitachi linkage -- they are setup for a throttle cable, which 510 SSS did not use.

 

If that is the A12 linkage, the lever is for the throttle cable stop, not for emissions. There is also another lever for synchronizing.

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what is this spring loaded 'bolt' used for?

...

th_PC210023.jpg

 

That's the IMS (idle air/fuel mixture screw) for the 2nd-gen twin hitachis (flat-top setup). Most guys just plug it, because they don't know what it is for and so throw away the idle mixture hoses. It is superior, but a bit more complex than the round-top setup.

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The other pics of the linkage look like A12 twin hitachi linkage -- they are setup for a throttle cable, which 510 SSS did not use.

 

 

Not sure about the A12....but

 

L to R....in different formation... :P

 

PC210024.jpg

 

Modified.... Assorted parts to run 46s on Lynz manifold...cable operated

Little harder to sync....no set screw

 

NOS 510 linkage...unless I shorten the shaft and abort my throttle cable apps etc....negative. Sell it.

 

240Z linkage....shortened to fit 46mm SUs on K14...etc IM

Cable pulling down

... :D

 

That's the IMS (idle air/fuel mixture screw) for the 2nd-gen twin hitachis (flat-top setup). Most guys just plug it, because they don't know what it is for and so throw away the idle mixture hoses. It is superior, but a bit more complex than the round-top setup.

 

Good to know... :cool:

 

Thread jack complete.... :D

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Back on topic for a sec ;) how critical do you think it is to maintain 1/4" hose running to the bottom of the thermostat housing off the 3/8 line running to the IM? Could i up size it to 3/8" or will that allow to much flow?

 

Thanks

Joel

Go with an inline adaptor. NAPA sells them for under 3 bucks.

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Go with an inline adaptor. NAPA sells them for under 3 bucks.

 

I can make it 1/4" if i need to, but I've already made it out of 3/8" and now I'm concerned that there may be too much flow and thought that perhaps the original line was a restricting point in the system. Do you think this is true or do you think they made it 1/4" out of convenience (what I thought originally) due to space constraints ?

 

Or am i just over thinking this whole thing (as usual) :P

 

Thanks

Joel

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You can't have too much flow, only too little.

 

The last time Nissan revised the L20B thermostat housing they increased the outlet to a larger diameter, and used larger hoses. This was to (yet again) prevent overheating issues. It seems to have worked.

 

I don't know why the L20B had this problem when the L16 didn't have any outlet there at all. Maybe the coolant flow is different in the L20B or maybe it simply generates more heat.

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Well good then... I screwed it up and did it right :P One more semi related question, my local auto parts store only has 3/16 soft fuel hose in stock. I know that the hard line and fittings are 1/4" but do you think that 3/16" will work or should I order 1/4"? To recap, I'm feeding su carbs...

 

Thanks

Joel

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