Heater hose configuration

[Marine240z]

Hi all,  I noticed recently that there are several variations on the heater hose configuration where they exit the firewall.  My 72 ( 06/72 build) is set up differently than others I have seen.  See pic.  As you can see the upper hose exits and runs the full length of the motor. The short lower hose runs to the engine block/head.

Most of the others attach to a 3 way connector at the lower hose entry point.  Both the upper and lower feed into it at that point.

As you can see, there is no exit fitting on the lower hose on my engine.  Can anyone chime in and let me know if this was a factory variation on some engines or a modification made by the PO.  My water temp has always been normal even sitting in traffic with the a/c running.

I did not realize this until recently when I went to replace the hoses with original braided ones and they did not match up.

Should I leave it alone or renconfigure.

 

Thanks

M240Z 

 

 

[siteunseen]

That exit runs through the intake manifold then to the thermostat housing on my 240.  Coolant circulates through there to help on cold starting, that's with SUs.  A lot of folks remove that stuff, less chance of leaks?

FWIW

[Marine240z]

Thanks Site, I have done a little research on this topic and it appears that there are many comments and opinions addressing this issue. A lot have to do with variations of the temperatures at different points on the head.  Hotter in the back vs cooler in the front.  Lots of opinions.  I just recently completed a full engine- transmission out rebuild at 130K miles.  

I increased the bore 83.75, installed Silvolite pistons and circle high performance rings, put in a slightly aggressive cam, port-polished the E 88 head, also balanced - ground the crank, had Z therapy redo my SU's and completely redone ( upgraded)  the entire a/c system. I also replaced the entire exhaust system with a NOS Abarth free-flow model I found from a supplier who attended Z con in Memphis.  

Just completed the break-in period so have not run the engine hard, just the normal rpm variations. 

I am going to dyno the engine to see how much hp was gained ( if any) and will check head temps at various points.  This should answer some questions.

 

Lon

 

Also, this shot was pre- rebuild.  I have post build shots in my gallery.

Edited October 25, 2015 by Marine240z

[siteunseen]

That sounds awesome.  Maybe we met at ZCON?  I had the Memphis Shakes. 

 

I read all that too and decided to stay with what Nissan did originally, probably the only thing on my car that's that way. 

[jfa.series1]

If you did not already have an idea on the original set-up, here's a pic of the stock plumbing when coolant is routed to the intake manifolds.

[Patcon]

Lon,

Were you in Memphis? I would hate to think I failed to meet anyone else besides Cliff...

[Marine240z]

Jim, Charles, I* did not make it to Z Conn ( at least not in person), but as I said, I purchased my complete ABARTH muffler system from a vender who was there.  I only mentioned it in case someone else had seen the mufflers while attending the event.  I saw all the picks that everyone took, it looked like a real Z love fest! 

Thanks for the pic Jim. I will use it as a guide should it become necessary to revert.

I am going to do the dyno first and run a laser temp sensor on each cylinder to check out the temp. range.   I will let everyone know the results.

 

Thanks for the input I hope to meet up with everyone in the near future.

 

Lon Davis

Kingwood

[Patcon]

I understand. I saw the vendor at the peoples choice show. He had a few units still in the paper. I look forward to meeting another Texan...

[Marine240z]

Charles, love Spartanburg, great city.  I grew up in Beaufort, our football team used to make the trip to both Charleston and Spartanburg to get our "low country" asses kicked.  We were always in awe of the football stadium there and in Summerville.   I was up that way last year when we took the long way home from an annual Porsche 928 get together in Elk Mountain, N.C. 

Need to take that kind of road trip in the Z...

[Patcon]

My wife is from Fredericksburg, Texas so we make it back that way once a year or so.

[siteunseen]

Porsche 928 

There's a car that is disappearing!

[Marine240z]

Yes, it's a good stable mate for the Z. Both give a different type of driving pleasure. Refined German engineering vs raw Japanese 70's roadster driving that demands more attention when taking things to the edge of the envelope.