Oil System Question For The J13 Gurus

[difrangia]

I've got a question about the J-Series engines in comparison to the earlier and similar E1 engine that it replaced. Question is: does the J13 have a pressure relief valve built into the engine block like the E-series does? The E1 block has a relief valve built into the bottom of the block just above the oil pan and on the left side with about a 3/4" thread that takes the valve plunger , a spring, and the large hex plug that screws into the thread. In this photo it is the hole just below the exhaust manifold outlet:

 

 

I'm thinking that the J-Series doesn't have this, but has the relief valve built into the oil pump. Here is a photo of the same E1 upside down with the hex plug in the port at the left side of the photo:

 

 

If someone has a J13, either in or out of a vehicle, and would take a look, I'd be much grateful.

 

 

steve

[Stoffregen Motorsports]

I see a flywheel. Are you actually building the motor now? How did the rope seal turn out?

[difrangia]

Bottom end is nearly together. Gotta finish up a little on the oil pump which is what prompted this post about the relief valves. I'm using a 520 pump which required a little modification to clear the pan. The pan liked 3/8" - 1/2" mating the block bottom surface as the pump pickup/screen were lower than the original. The 520 has a deeper pan, I'd suspect. The 520 pump has a relief valve built in so I'm just curious as to whether the J13 block is not machined for a valve like the E1, which is what I suspect. This thread is just to add to my knowledge on the transition from E1 to J13 engines. I'll post some photos of the oil pump mod on my build thread in a day or two. I utilized a knee mill and turntable and it could also be accomplished with a lathe & faceplate.

 

Rope seal turned out OK. It's been probably 30 years since I put one in (56 Chevy V8) and it took longer than it should have. It was tight as hell at first, but I've oiled the seal and I've been rotating the crank and it's loosened up about right.

[Stoffregen Motorsports]

There's almost nothing more gratifying than the feel of a crank as it spins inside a rope seal. If you've ever done one, you know what I'm talking about!

 

The oil pump situation could have three possible scenarios. 1 - both the pump and the block have a relief valve. Result, nothing catastrophic. 2 - neither the pump or block have a relief valve. Again, nothing catastrophic would hapeen, you would just need to be sure to get the proper oil filter. 3 - one or the other has the valve. Best scenario.

 

So you only have the E1 motor and don't have access to a J13 motor? Is that right?

[Stoffregen Motorsports]

Here is some text from a 320 website (http://datsun320.com/). It may shed some light on the situation, although, not an answer to your question.

 

Mark 1 E-1 engines from 000001 to 152699 have offset connecting rods with bearings are 1 inch wide. Uses a bypass type lubrication system.

Mark 2 E-1 engines from 152700 to 280169 use a bypass type lubrication system, oil filter housing is cast into the engine block. Camshaft oil pump/distributor drive cog has 10 teeth.

Mark 3 E-1 engines from 280170 to 547143 use a full-flow type lubrication system with a detachable alloy oil filter housing. Camshaft oil pump/distributor drive cog has 13 teeth.

Mark 4 E-1 engines from 547144 onwards have the oil pressure relief valve located on the oil filter housing.

[difrangia]

Yes, that's the case, Stoffregen, I do not have access to a J13.

 

Actually, I have a pressure relief valve on the filter housing also and I have the 13 teeth cam/dizy/pump gearing. My pickup is titled 64, but has 63 characteristics. Someone probably changed the oil filter housing to the one with pressure relief. I've seen the engine outline before that you posted.  Looks like I will end up with three pressure relief valves, one in block, one in filter housing, and one in oil pump which shouldn't be a problem ??

 

Pressure will damn well be relieved, I guess.

 

Steve

[Stoffregen Motorsports]

I wonder if you could bypass two of them. I, personally, would like to have access to it without removing the pan. Maybe use the one in the block and remove the two others. That should work...right?

[difrangia]

I'm thinking that to negate one of the relief valves you'd remove the spring and replace it with a solid rod calcu alted for the right length.to keep the plunger from working as it should. I can't really envision how having a couple of the valves would be detrimental. The weakest one would be the one that would relieve the pressure. and the others would be redundant. Having more than one would provide backup in case one froze up for some reason.

 

  At any rate, I'm leaving the three in place.The motore had the block and oil filter housing valves for who knows how long. If I could have sourced an NOS E1 pump, I'd have gone with it. Strictly E1 stuff is like the proverbial 'Hen's Teeth'.

[Stoffregen Motorsports]

I suppose. It's not a bypass valve so there would be no harm at all. Even if one of them got stuck open or closed, the other two should manage the psi.

[difrangia]

If you had more than one, you could afford for one to be stuck closed. You sure wouldn't want one to be stuck open. There goes your oil pressure.

[Stoffregen Motorsports]

What about the other question I raised about using the lower portion of the E1 pump on the J13 pump?

[datsunrides]

Here is a pic of that area on a J13.

 

[Stoffregen Motorsports]

Wow! A header on a J13? Is that a BMC item?