A 521 in Massachusetts

[mainer311]

3 minutes ago, BrothersGarage said:

I gotta say, that's about the worst way I've heard to wake up from a nap!

 

My brother fell asleep coming home from work one morning in his V6 Altima. He plowed through an ice cream stand, took out one of those exterior ice chest things, and blew a hole through the front of a country store. Luckily no one was injured. He didn't wake up until it was all over. Not a scratch on him.

[BrothersGarage]

20 hours ago, mainer311 said:

 

My brother fell asleep coming home from work one morning in his V6 Altima. He plowed through an ice cream stand, took out one of those exterior ice chest things, and blew a hole through the front of a country store. Luckily no one was injured. He didn't wake up until it was all over. Not a scratch on him.

Holy shit, that's some "JESUS TAKE THE WHEEL" shenanigans if I've ever heard it!

[Crashtd420]

1Got some work done....

 

Carburetor is off....

 

And the intake....

 

I forgot how much of a pain in the ass that is..... 

 

Next is drilling and tapping....

 

Those 2 bolt locations are pretty much the only place I can drill and tap to keep it all balanced between the cylinders.....

 

[Crashtd420]

Unfortunately I think I might need to buy some new fittings....

I think I bought 1/4npt.... and by looking at the picture I should have gotten 1/8 npt....

[Charlie69]

Sent you a pm.

[Crashtd420]

33 minutes ago, Crashtd420 said:

Unfortunately I think I might need to buy some new fittings....

I think I bought 1/4npt.... and by looking at the picture I should have gotten 1/8 npt....

Ok so I think I figured out why I bought what I did.... one of the holes is already on the big size for an 1/8 npt tap...  and I cant find an 1/8 npt to 3/8 hose tee....

After holding a 1/4 npt plug over the hole I think I'm going to roll the dice and drill and tap it as I originally intended...

I should still have enough wall thickness when done....

 

[Crashtd420]

Was a little nerve racking at first but I got the intake drilled and tapped without screwing up.... 

 

 

 

 

 

 

The last piece of hose will obviously be trimmed when I figure out how long I need it.... now I just need a 5/8 to 7/8 Id hose to adapt the pcv to the block vent....

[datzenmike]

You might find that the 3&4 ports or cylinders dirty up more than the 1&2.  I would put a T between two elbows and the PCV valve as close to it as I could. Run the hose down between the manifold runners out of sight. Insulate the pipe to the block vent from exhaust heat. I got a car once with L20B and someone had fit a smaller hose into the larger block vent hose. I guess it worked. There is only a very small flow of fumes out of the block and sucked into the intake.

[Crashtd420]

Why do you have to make sense.....

 

I see what your saying..... 

A tee in the middle seems better and would probably look a little cleaner.....

 

[datzenmike]

Yeah, and run down between and under the intake.

[Crashtd420]

As much as I love your idea I dont think it's going to be possible..... 

I just went out to my garage to see....

 

Because of the intake where the hose would need to go it's going to be way to close to the exhaust going down between the intake.... 

Not to mention my block vent comes around to the back of the block like the l20bs do... so connecting things would get really interesting.....

 

Right now that hose is actually lower than or atleast level with the top of the carburetor... and it will give me a good transition over to the block vent tube....

 

I'm gonna continue with my current plan and get everything reassembled and see what I actually have for clearance....

 

I have a couple ideas that may work to tie the two sides together from the center, but I'll need to do a little searching.....

[Stoffregen Motorsports]

You may also want to adjust the restrictor orifice size. A PCV system needs very little vacuum to work and the larger the orifice, the more vacuum you lose to the open loop, which can change your carb tune.

 

Here's a basic explanation of PCV as it pertains to performance (non-original) engine tuning. - https://www.jalopyjournal.com/forum/threads/positive-crankcase-ventilation-101-tech.31741/

 

 

[wayno]

Have you really looked at that manifold Mike, it appears to me that cylinders 2 and 3 are connected together, and 1 and 4 are connected together, how do you figure 3 and 4 are going to get dirtier?

1 hour ago, datzenmike said:

You might find that the 3&4 ports or cylinders dirty up more than the 1&2.  I would put a T between two elbows and the PCV valve as close to it as I could. Run the hose down between the manifold runners out of sight. Insulate the pipe to the block vent from exhaust heat. I got a car once with L20B and someone had fit a smaller hose into the larger block vent hose. I guess it worked. There is only a very small flow of fumes out of the block and sucked into the intake.

I would have went with smaller fittings/hoses which you can still do if you want, just buy fittings with smaller barbed ends on them, I am not sure on the size of the hose determining how much vacuum it takes to open the PCV but I would put it as close to the manifold as I could get, in between them sounds like the best place to me, just use a metal tube routed down past the exhaust manifold from a "T" in the middle where the PCV would be mounted, this is easy to talk about but it may take some thinking to put it all together, a "T" in the middle will also create a more balanced situation for the PCV rather than what you have came up with.

[Crashtd420]

19 minutes ago, wayno said:

Have you really looked at that manifold Mike, it appears to me that cylinders 2 and 3 are connected together, and 1 and 4 are connected together, how do you figure 3 and 4 are going to get dirtier?

 

Yes you are right on the way they are paired... Well atleast the hard part is done..... 

[Crashtd420]

1 hour ago, Stoffregen Motorsports said:

You may also want to adjust the restrictor orifice size. A PCV system needs very little vacuum to work and the larger the orifice, the more vacuum you lose to the open loop, which can change your carb tune.

 

Here's a basic explanation of PCV as it pertains to performance (non-original) engine tuning. - https://www.jalopyjournal.com/forum/threads/positive-crankcase-ventilation-101-tech.31741/

 

 

I'll give that a read in a bit.....

 

I figured the pcv was the regulator of the amount of air it could suck through but I could be wrong....

 

I know very little about this subject... 

I just figured the stock manifold has a big opening that the pcv screws into....

 

Right now as I stated the hard part is done.... 

I can stick a couple plugs in it for now if I needed to.... 

 

Once I fit the manifold and carburetor back on I'll have a better idea of what I can and or need to do.. .

[Charlie69]

All 3 motors work on all 3 speeds.  All 3 motors are different. 

 

Heater Box 1

 

 

Heater box 2

 

 

 

Heater Box 3

 

 

 

Bottoms Heater box 1 (Left to right) does not have the bottom flapper door.  Heater box 2 is the flat motor.  Heater box 3 is the the one that Wayno and I think came out of my 66 520.

 

Edited February 2, 2020 by Charlie69

[wayno]

I wondered how they got them wires past the seal on the big motor, they put them end not on the side like the big motor I have, I have no idea where the large motor I have came from.

 

[Crashtd420]

Well after thinking and reading everyone's advice I ordered a few other fittings today.... I also have some 3/8 metal fuel line which I'm thinking i can connect to the bottom of a centered tee and bent in an S shape to get out from under the intake...

 

I have a couple ideas for restrictors if I need to .... but I really thought that's the pcv's job....

 

[mainer311]

21 minutes ago, Crashtd420 said:

I have a couple ideas for restrictors if I need to .... but I really thought that's the pcv's job....

 

It is, at least that’s what it said in the article posted above. It definitely changes your carb settings when you hook it up, as it’s basically a small vacuum leak, and needs to be adjusted for.

Edited January 27, 2020 by mainer311

[Stoffregen Motorsports]

15 hours ago, mainer311 said:

It is, at least that’s what it said in the article posted above. It definitely changes your carb settings when you hook it up, as it’s basically a small vacuum leak, and needs to be adjusted for.

Right, the PCV valve does have it's own restrictor, but they vary in size. If it has too big an orifice, you can either take the PCV valve apart and install a washer with a smaller hole, or you can cut a piece of anything round (the OD = the size of the hose ID) and drill a hole in it, then stuff it inside the hose.

[Crashtd420]

4 minutes ago, Stoffregen Motorsports said:

Right, the PCV valve does have it's own restrictor, but they vary in size. If it has too big an orifice, you can either take the PCV valve apart and install a washer with a smaller hole, or you can cut a piece of anything round (the OD = the size of the hose ID) and drill a hole in it, then stuff it inside the hose.

I am using a proper datsun pcv for the 521 .... 

How would I know or what what determine if I need to add a restrictor?

[mainer311]

10 minutes ago, Crashtd420 said:

I am using a proper datsun pcv for the 521 .... 

How would I know or what what determine if I need to add a restrictor?

 

Small enough that you can maintain the correct carb tube, but large enough so that it actually functions. If you run out of adjustment on the carb, in terms of idle, etc., then it's too big and sucking too much.

[Crashtd420]

1 minute ago, mainer311 said:

 

Small enough that you can maintain the correct carb tube, but large enough so that it actually functions. If you run out of adjustment on the carb, in terms of idle, etc., then it's too big and sucking too much.

Sounds easy enough.... I always assumed I would have to adjust the tune some....

Hopefully with it being correct  for the motor that I should atleast be close....

We will see I guess.  .

[Stoffregen Motorsports]

The original PCV system was designed to help with emissions. Not that I don't care about emissions...

 

I want the PCV to pull a vacuum. That's all. So the minimum orifice size you can get and still have some draw, that's the perfect setup.

 

This topic is in the mainstream these days, with engine builders and tuners wanting clean running engines tuned to the max. I know there are adjustable PCV valves on the market, and I have read articles on the subject. The Jalopy Journal link is a brief description, but if you wanted more in depth reading, I'm sure you could find it.

[yenpit]

FYI that LYNX manifold (out of Australia?) was the only single carb manifold with the ports 1 & 4 vs 2 & 3 connected.................all others ie Cannon, Pierce, TWM etc etc were 1 & 2 vs 3 & 4.  I read that the LYNX had a better fuel distribution because of it........