A 521 in Massachusetts

[Crashtd420]

I'll visit the rims again soon....

I definitely have a better idea of what it could look like....

I'll probably play with the look on the truck with that plastidip paint so I can really decide how I'll want them powder coated...... 

 

Car show was supposed to be today but got canceled due to weather...

 

Atleast I got all the new lug nuts installed  and was able to take it for a drive to breakfast with the wife.... and the speedometer is back to normal with the ratio adaptor.... 

 

 

[d.p]

Crash whatever you decide to do make sure you do not paint the lips black because it will make the wheel look smaller by making it disappear into the tire. 

 

Keep the lip polished and just paint the faces whatever color you want.  Black gunmetal or gold would be my votes.  Or if you want to do all a solid then that is ok to. 

 

 

[mrbigtanker]

14 minutes ago, d.p said:

Crash whatever you decide to do make sure you do not paint the lips black because it will make the wheel look smaller by making it disappear into the tire. 

 

Keep the lip polished and just paint the faces whatever color you want.  Black gunmetal or gold would be my votes.  Or if you want to do all a solid then that is ok to. 

 

 

Wow I can’t believe I so agree. There a light at the end of the tunnel, wait thats a train. 

[Crashtd420]

I'm coming around to leaving the lip alone.... right now that part of the rim looks pretty good it has that brushes aluminum look..... 

With the center being completely solid it does seem to be too much black....

Again why I wanna try it before I commit to powdercoaitng.....

[Stoffregen Motorsports]

How about this? - leave just the outermost part of the lip in bare/polished aluminum. So the flat horizontal portion of the lip gets coated, but the lip outside that flat remains bright.

[Crashtd420]

Well fuck..... the other day I got a damn misfire again..... only once but I still dont like it.... Last year after putting about 1500 miles on the motor this started to happen randomly....

 

I did new low resistance wires and a quality old stock bosche 1.8 ohm coil and non resistor plugs..

Per recommendation of distributorguy...

 

It have tried the standard b6es, b6es with a 36 gap and b6es-11 ..... 

 

Every time it would happen I changed the cap and it instantly goes away but not for to long.... so over the winter I picked up 2 new rotors from 123 Ignition and then I cross referenced the cap to an older BMW... and got a cap from the BMW dealer.... even after all that I got that miss fire....

 

So yesterday I polished the top of the rotor where the pin from the cap touches, but I'm not convinced that's the issue..... but it hasn't happened again...

 

I also yesterday I went up 1 on the idle jet, and at lunch i checked my plugs and they look perfect.. right color across all 4 and nothing funky looking.....

 

So I started thinking about timing....

I have an L16 with a single sidedraft setup and I'm running higher compression with dome pistons, I also have a w53 closed chamber head on the motor.... I have heard webers like a little more timing and have read similar things about dome pistons, but I'm not sure what I can get away with....

 

Since I have a 123 ignition distributor I was able to reduce the full advance rpm to 3000 from 3400, and brought the total timing up to 34, idle is 15.....

 

 

[Crashtd420]

Ok with all that said if anyone has any insight on which spark plug gap to go with that would be appreciated?

Currently I have the standard gap because I was reading somewhere about dome pistons liking a smaller gap but who knows if its true or not....

 

And the timing.... am I on the right track?

It's a nice visual curve from 15 to 34.... 

I've also been wondering if I should try to program some vacuum advance?

 

Usually the miss happens when I'm cruising on the highway,  barely on the throttle..... I do monitor manifold vacuum and I can program a vacuum advance into the distributor but I dont know what to actually input for that....

 

Atleast today it has been running good, seems to like the  extra timing I gave it.... 

 

[mainer311]

That's a good idle timing, and the same that I run. Then whatever mechanical advance I get from there (which I'm unsure about since it's a matchbox with the stock internals). I wouldn't go any more beyond 34 on the top end. You might be able to get to around 17 or so at idle. 

 

As far as spark plug gap, I run .040" with the matchbox and don't seem to have many problems. I do get some misfiring with the choke pulled, but it goes away once the engine is warm. 

[Crashtd420]

2 hours ago, mainer311 said:

That's a good idle timing, and the same that I run. Then whatever mechanical advance I get from there (which I'm unsure about since it's a matchbox with the stock internals). I wouldn't go any more beyond 34 on the top end. You might be able to get to around 17 or so at idle. 

 

As far as spark plug gap, I run .040" with the matchbox and don't seem to have many problems. I do get some misfiring with the choke pulled, but it goes away once the engine is warm. 

 

I agree on the timing not wanting to go past 34..... 

As far as the gap on the plug I'm after info more directly related to my piston choice..... I already ran the b6es-11 which are a 42 gap successfully, I only changed back to the standard ones because of things I was reading about the flame travel and other stuff I really dont know much about.....

 

[Crashtd420]

So as I was waiting to pick my son up a school I was looking at the app for my distributor timing,  well I guess the changes didnt save...

So i moved the rpms and advance around a little and saved it, apparently you actually have to write it back to the distributor for it to save correctly....

 

Any how this is what I came up with this..... sounded good no pinging, not like I know what it sounds like but I didnt hear anything wierd....

 

 

And for reference this is the vacuum advance I can edit..... totally clueless if i can use this to my benefit....

 

[Stoffregen Motorsports]

If it happens again, kill the motor right away and remove a spark plug and have a look. In engine tuning, it's similar to what we call a "plug cut", but that is usually performed at full throttle under hard acceleration. It may be worth trying here though. You might find some visual evidence of a too rich or too lean condition.

[d.p]

No gap?  I don't gap mine and just drive the fucker.   

 

Personally I got tired of worrying about every little sound or hiccup this truck makes.    Starting to take more and more of Hainz's advice of just driving it.  

 

 

[Crashtd420]

6 minutes ago, d.p said:

No gap?  I don't gap mine and just drive the fucker.   

 

Personally I got tired of worrying about every little sound or hiccup this truck makes.    Starting to take more and more of Hainz's advice of just driving it.  

 

 

If my motor was stock I would agree but it's far from stock....

[d.p]

Just now, Crashtd420 said:

If my motor was stock I would agree but it's far from stock....

 

I know, was mostly in jest.  Good luck with it though. 

[Crashtd420]

15 minutes ago, Stoffregen Motorsports said:

If it happens again, kill the motor right away and remove a spark plug and have a look. In engine tuning, it's similar to what we call a "plug cut", but that is usually performed at full throttle under hard acceleration. It may be worth trying here though. You might find some visual evidence of a too rich or too lean condition.

It's usually such a brief event I dont know if it would actually show something.... 

i am running an air/fuel gauge and wideband o2 sensor  and since I've been playing with the carburator I keep an eye on it.... 

[Crashtd420]

4 minutes ago, d.p said:

 

I know, was mostly in jest.  Good luck with it though. 

Atleast I'm driving it to figure things out.... I've been able to get back to daily driving it.... 3 days this week.... rain coming back but weekend and next week looks good....

[d.p]

30 minutes ago, Crashtd420 said:

Atleast I'm driving it to figure things out.... I've been able to get back to daily driving it.... 3 days this week.... rain coming back but weekend and next week looks good....

 

Wooooo!

[Crashtd420]

I really need to install those door seals..... 

[Crashtd420]

Got lucky rain not coming till later tonight so I got to drive the datsun....

And as I'm heading to work I noticed I no longer had a working speedometer....

 

Cable broke under the truck, that was just a matter of time anyhow, it was never in the best shape and was probably one of the oldest wear items on my truck...

Guess I'll get that on order today.....

[datzenmike]

Higher compression will shorten the burn time. All the molecules are crammed closer together so the flame will pass more quickly through it. A shorter burn time means you have to start the burn later in order to hit the maximum expansion of hot gasses at that sweet spot at about 15-20 degrees after TDC. Too soon and the piston and rod are aligned vertically and the effort just pounds down on an immovable object, too late and the piston is already racing and accelerating down the bore. At about 15-20 degrees the piston will capture most of the push. You might experiment with less timing off idle. 

 

 

 

[Crashtd420]

2 hours ago, datzenmike said:

Higher compression will shorten the burn time. All the molecules are crammed closer together so the flame will pass more quickly through it. A shorter burn time means you have to start the burn later in order to hit the maximum expansion of hot gasses at that sweet spot at about 15-20 degrees after TDC. Too soon and the piston and rod are aligned vertically and the effort just pounds down on an immovable object, too late and the piston is already racing and accelerating down the bore. At about 15-20 degrees the piston will capture most of the push. You might experiment with less timing off idle. 

 

 

 

Ok I half way understand what your saying .... this is definitely where I lack the knowledge....

Since your comment I found a couple articles supporting and explaining more about what you said.... 

It's starting to make some sense.....

 

Usually the miss happens when the distributor is at full advance and around 3000 rpm or more.... never really at idle... 

So should I lower both my idle and full advance....?

Currently 15 and 32....

Maybe drop to 12 and 28?

Also the curve is kind of a straight line to full advance , should I alter that at all?

I can move the rpm around and change how that line would look....

 

[Stoffregen Motorsports]

17 hours ago, Crashtd420 said:

It's usually such a brief event I dont know if it would actually show something.... 

i am running an air/fuel gauge and wideband o2 sensor  and since I've been playing with the carburator I keep an eye on it.... 

Right, but it may be the symptom you are noticingg, not the cause. A plug cut may reveal the cause.

[Crashtd420]

14 minutes ago, Stoffregen Motorsports said:

Right, but it may be the symptom you are noticingg, not the cause. A plug cut may reveal the cause.

I'll try.... but it never seems to happen when I have time to stop.... I'm usually on my way to work or to pick my kid up..... 

I did increase timing last year but I dont remember when in relation to when the first miss happened... so I'm gonna dial back the timing a little and see what happens..... 

If it does happen again hopefully i am in a position to kill the motor and check the plugs.....

[Crashtd420]

Well interesting ride home....

Lowered the timing about 3 degree up the whole curve ..... getting on the highway i stayed in the 3rd gear and ran the rpms up.. I varied the throttle a bit, a couple wot hits when I could, then just cruised and then around town a bit,  ran great, so far no miss, but I'm not saying I solved it, because that will just jinx me..... 

 

I found this graph which puts a visual to things.....

 

I did notice a slight increase in the running temp, not much,  usually the needle pointed slight left of center, now it's slightly right of center..... (half the needle is pointing towards the center gauge mark)..... again not a concerning increase.... 

 

I always thought lowering timing would decrease power and  increasing timing would make more power so with that logic I turned up the timing but I dont think that's the case.. maybe it's true on efi because you can change the fuel and the timing ... With the carburetor it seems to be more about finding the sweet spot of your engine configuration..... and it seems mine might want a little less timing...

 

Speedometer cable on the way....

[Crashtd420]

Well I got lucky, speedometer cable showed up today..  

Got that installed , all better....

 

Unfortunately while I was under there I noticed my slave cylinder was leaking.. I guess I tore the seal a couple weeks back when it over extended.... still drivable..... 

Regardless I have that fix on order..... 

 

I also took a minute to work on the carb... the accelerator pump also has a drain back ... so instead of all the fuel getting squirt into the engine some heads back to the bowl..... apparently its widely recommended to use a zero drain... so all the fuel gets sent to the engine when you hit the throttle quick..... 

 

Still need to go for a drive but even just putting it back in the garage I could tell a difference...