My 1971 521

[Charlie69]

I know I have owned over 30 521s over theyaers that is why when I redid the fire wall I changed out the throttle pedal and cable for the 1980 720.

[d.p]

Looking for something like this guy has on his.  Brass bracket holding the throttle cable.

 

from here:http://www.the510realm.com/viewtopic.php?t=12004 

 

[d.p]

14 minutes ago, Charlie69 said:

I know I have owned over 30 521s over theyaers that is why when I redid the fire wall I changed out the throttle pedal and cable for the 1980 720.

 

 

Ok well not trying to do all that just to solve my throttle cable problem.   Plus that area of the firewall is caved in on my truck from the PO so really not trying to change any of that if I dont have to.  

[d.p]

Anyone know if this would work?  https://www.ebay.com/itm/Mikuni-40PHH-44PHH-Perf-Carburetor-Bracket-Throttle-Stop-N107-073-240Z-Solex-/143333278678

 

[Stoffregen Motorsports]

I really hate those linkage rod style linkage setups. Bar none, the best ever dual Mikuni linkage is the centerpull style. Nissan motorsports (Datsun Competition as it was called back then) used the centerpull linkage on the 67.5 2000 Roadster, and subsequently sold the kit in their catalog. Mikuni also sold a kit, but this hasn't been available for along time. You can scab pieces from Webers together to make your own kit, or you can buy a kit from Troy Ermish, or you can probably get a NOS Mikuni linkage kit from Mike Malone.

 

Those linage rods are a pain to keep synch'd and are a pain to adjust. The centerpull is so simple, a Datsun owner could do it.

[Stoffregen Motorsports]

1 hour ago, d.p said:

Anyone know if this would work?  https://www.ebay.com/itm/Mikuni-40PHH-44PHH-Perf-Carburetor-Bracket-Throttle-Stop-N107-073-240Z-Solex-/143333278678

 

That piece there is just a throttle stop/idle adjuster. One of the many pieces in the Mikuni centerpull kit.

[d.p]

Yeah looking at my carbs I see that piece. And right now my options are limited and I looked for Mikuni setups but they are long gone as far as I can tell.  If they are out there I don’t know about them otherwise I would buy it. 
 

I also read the center links with Mikuni manifolds hits the bar and Troy not making them anymore so no go there either. 
 

just have to try and make work with what I got. And I truck is just toy more or less. Use to it haul shit and putz around so hoping they won’t require constant maintenance.  
 

Which begs my next question do I need a choke with these? And what am I looking at for HP? Cam’d 1 over and dual mikunis? 

Edited January 28, 2021 by d.p

[banzai510(hainz)]

Troy Ermish used to have Toyota cable kits I think but I don't think he has them anymore.

Really this is EZ to figure out. Make it work

[d.p]

12 hours ago, d.p said:

..... Troy not making them anymore so no go there either. 

 

56 minutes ago, banzai510(hainz) said:

Troy Ermish used to have Toyota cable kits I think but I don't think he has them anymore.

 

 

Damn echo in here.  

[Stoffregen Motorsports]

Try Mike Malone. He definitely has centerpull stuff.

 

If the carbs are tuned and jetted properly, pumping the throttle twice squirts enough gas to start it up.

 

What motor is it? L20B? Depending on the cam, exhaust and distributor, it could be 150hp.

[d.p]

Just now, Stoffregen Motorsports said:

Try Mike Malone. He definitely has centerpull stuff.

 

If the carbs are tuned and jetted properly, pumping the throttle twice squirts enough gas to start it up.

 

What motor is it? L20B? Depending on the cam, exhaust and distributor, it could be 150hp.

 

Yeah Mike is looking for something in his stash.  Its an l20b, racer brown cam, bored 1 over and el-dizzy .  

 

[Stoffregen Motorsports]

Compression ratio too. If it's at or near 10:1, that helps.

 

You could modify a Weber DCOE linkage kit, and mix and match Mikuni pieces to get it to work.

 

https://www.carburetion.com/Products/ProductDetails.aspx?Part=99006.110

[d.p]

no idea what the compression ratio is.  How do I figure that out? 

[Crashtd420]

19 minutes ago, d.p said:

no idea what the compression ratio is.  How do I figure that out? 

You ask datsunmike....

There are online calculators....

Mostly you need to know 

Bore size, piston dish, and head cc....

Those would be your variables....

Couple other things like deck height, stroke and stuff are also a factor but Mike know those those numbers....

[datzenmike]

Open or closed head will do but if milled or valves un-shrouded should be cc'd to be sure.

 

Piston dish if custom or other than stock Nissan

 

Bore & Stroke if different if different than stock

 

Crushed gasket thickness unless different than 1.2mm that I use.

 

Rod length center line to center line unless it is stock

 

Piston height center line pin hole to piston top if different than stock.

 

Deck height if block decked if different than stock

 

In most cases just saying stock L20B tells me everything I need to know.

 

 

[banzai510(hainz)]

it  don't matter whats the comp ratio if it aint running yet. your not going to change it now anyways

[d.p]

18 minutes ago, banzai510(hainz) said:

it  don't matter whats the comp ratio if it aint running yet. your not going to change it now anyways

 

lol I must have struck a nerve with the old L motor God.

 

 

[Crashtd420]

On 1/26/2021 at 5:18 PM, d.p said:

Can your shoot me a pic ?  

@banzai510(hainz)  I figure I would have to somehow use a 521 cable I just don’t know how to lock it in place at the carb.  Figure I need some kind of bracket (bought) or made for me. 

Might not be worth me sending to you.... 

Moves freely and It's intact but the ball end is a little questionable....

[d.p]

My dude I will take it because that ball end is the pedal side so it’s fine. Plus it would allow me to use the nut on another (lokar) cable and thread into the FW.  
 

I’ll text you. 

[d.p]

Ok so learned something new.

The mount I have on the 510 cable is the period correct mount and Mike Malone has 1 but is reluctant to sell to me because I already have one albeit I would rather have 2.  I showed my cards and it bit me in the ass.  But its nice to know if I can remove the mount I have off the 510 cable and get it on a 521 cable I should be in business.  

 

 

 

 

[NC85ST]

If you need a second one, why not try making one. It seams to be a fairly simple design.

[Rat-a-tat-Dat]

Here I used the cantilever linkage off a Hitachi (original) 720 L20B carburetor.

Attached to Redline's dual throttle linkage, centre pull set up.

The support bracket is simple enough, just drill the holes to accommodate the U-bolt that will hold the cable.

 

 

[d.p]

Hey man is that on a 521? If so what is on the Other end of the cable where it goes through the firewall?  
 

I am making progress on my setup just waiting for that 521 cable from crash which I am going bastardize along with my 510 cable.    I really just need the nut that holds the cable to the FW which I will swap on the 510 cable and grind down the insert (521 7mm 510 8mm) that goes through the FW.  
 

 

 

 

[d.p]

How much bend do I want or don’t want with a throttle cable?  Is this ok? 

[Rat-a-tat-Dat]

1 hour ago, d.p said:

Hey man is that on a 521? If so what is on the Other end of the cable where it goes through the firewall?  

Apologies d.p., my set up is actually on a 720 KC but my cable isn't much longer then yours. It's bolted to the f/w btw.

On the centre pull cantilever, there's a pivot ball end, this can be modified or replaced with something that came be drilled out and pass the cable through which can then be anchored off. 

Liking the Kameari heat shield.