Manure

[goes2fast]

Your pics are nice!

 

We took a ride in the mountains today with a group of German car enthusiasts as well, had a great time other than I forgot to bring my camera. The Aspens aren't changing yet so all I missed was cool car pics. There was an older woman in the group with an Audi RS5, that car is fast and she could drive too!

Edited September 13, 2020 by goes2fast

[datsunfreak]

On 9/12/2020 at 3:38 PM, KELMO said:

 I am thinking gas cap vent....maybe.

 

Could well be, especially on a very hot day. 

 

Easy to check, if it does it again. Just pop the cap off when you hear it. 

[KELMO]

Verified.

Yeah, that happened.

Remote diagnosis, you get 10,000 interwebs points.

 

The points don't matter but you still get 'em.

[datsunfreak]

On 9/14/2020 at 9:19 PM, KELMO said:

Verified.

Yeah, that happened.

 

Did you remove the vent tank thingy at some point? This should only happen if the tank is not properly vented...

 

Well, and if it's hot as hell outside...  😁

Edited September 17, 2020 by datsunfreak

[KELMO]

Hot as hell outside is the case.

[KELMO]

On 9/17/2020 at 4:55 PM, datsunfreak said:

 

Did you remove the vent tank thingy at some point? This should only happen if the tank is not properly vented...

 

Well, and if it's hot as hell outside...  😁

Very technical bro.😀

 

So, the vent tank thingy....there is one in the engine compartment that vents vapor back to the tank. Pretty sure I replaced that (could have been the grey car tho). The big cannister in the right rear corner is still the original and is hooked up. (on both coupes)

I also seem to remember stopping for gas and getting that whoosh sound upon removing the gas cap. Now the question is was it this car or the grey car...or both? I honestly couldn't tell you.

[datzenmike]

The flow guide valve??? A hose to the air filter, the crank case vent tube behind the exhaust manifold and one to the gas tank.

 

Engine off. On hot days, fuel evaporated in the tank build a very small pressure and push past the flow guide valve and are directed into the crank case for storage.

 

Engine on. Intake vacuum draws stored gas fumes from the crank case through the PCV valve and are burned. As the fuel is emptied from the tank a slight vacuum condition is caused opening a port in the flow guide valve that allows filtered air from the air filter back into the tank to replace the used gas.

 

For this to work properly it has to be a closed system and a sealed gas cap is used. Zero evaporated hydrocarbons escape into the atmosphere..

[KELMO]

So a year and half later.

Finally took the tank out.

Also fiddling with the evapo routing since I had one hose routed wrong. I had to remove the 1/4 trim which I hate to do because if you fart in the wrong direction you'll break something.

I have a spare tank that my buddy welded up for me and hope to have her back together by the weekend.

[KELMO]

Well, it's back together and running. Took it to C&C yesterday and it did fine. It ran a little hotter than I care for but all in all, for an about 80 mile round trip, not too bad.

 

[Draker]

So beautiful 😍 

[KELMO]

So the running hot thing has continued. When I built this motor, I put in a 160 degree t/stat as that is what I have in the grey coupe. So, what better way to spend an hour or so on your Saturday? 

It was stuck in there pretty good. Every Datsun t/stat I've replaced has pretty much just fallen out. Not this one.

Look Ma, no jiggle valve in this t/stat.

Well, what do you know? No jiggle valve on the new one either. It seems the 160's don't have it but the 180's do.

First, I put in a 180 and had the same basic results. The car ran up to about 3/4 on the guage. Now, some will say that is normal but watch, hold on, This car has consistently run right in the mid range of the gauge since becoming a driver in 2016. It also has the exact same set up at the grey car and I beat that car like a redheaded stepchild and also runs right in the mid range.  On Sunday I put a 160 back in it with pretty much the same results as the 180. I have a pretty well slanted area to park it on and burp out any air. I will check fluid level today. I am thinking there may be some build up somewhere in the system and may be time for a flush. This car does get driven but maybe not enough. I've only put about 3K miles on it since September of 2016.

[Duncan]

Kelly, did you check the radiator for clogs? 

 

Warm the car up, shut her off, then feel around the radiator to see of there are cool spots.  If you're fancy schmancy, you can also use one of those laser thermometers and measure the temps in various spots, too..

 

I've had two 1200's over the years, and had clogs in both of them.  That stock radiator is tiny (as you know) and they are somewhat prone to getting blockages.

 

 

 

 

Edited September 4, 2023 by Duncan

[datzenmike]

Probably doesn't need a jiggle valve as the thermostat is right in the head, unlike the L series that has a separate thermostat housing mounted on the side which traps stagnant water until it opens. 160F is what they ran in the '50 engines. 180F sounds way better. When ever I have anything radiator heat related I put a new thermostat in. They don't last forever anyway and it's cheap, easy to do. I never test them, that only shows they open not how they really work under driving conditions.

 

Yes the way gauges are if they start to read differently than what they normally do signals something has changed.

 

Has the heater core been by-passed and the hoses joined? This is a bad idea unless you block the flow of coolant first.

 

Two causes of running too warm, lack of air flow or lack of coolant flow.

 

AIR

1/ excessive clutch fan slippage. Spin fan by hand and it should offer firm resistance and stop as soon as you let go. It should NOT spin by itself.

2/ dirt, bugs or roar debris blocking air flow through the radiator

3/ lack of fan shroud that increases fan efficiency

4/ some hoods have a rubber 'dam' the helps seal air from getting past the top of the radiator and over the rad support. Also look for openings at sides or under radiator where air can get past. Some, like my 710, have a 'belly pan' or splash shield that  seals the area forward of the cross member to the rad support and under the alternator and fan forming a low pressure area behind the radiator. They are removed to get at stuff and then left off.    

 

COOLANT

1/ soft lower rad hose that collapses from water pump suction. Might also indicate that the radiator is somewhat plugged with scale.

2/ scale build up in radiator from years of using tap instead of distilled water for top ups. Reduces flow and is bad for heat transfer. Just remove cap and look in the top of the vertical tubes. CLR is good for removing lime scale.

3/ as mentioned, joining the heater hoses without blocking flow is bad.

 

 

[KELMO]

Duncan; I'm not fancy shmancy (you know this, we've met .....my apologies), but I do have one of them laser thermo thingys....I think free from HF tools. Had not thought about checking spots on the rad. Both of the 1200's have a 210 radiator in them. Not much, but a little larger than original.

 

Mike; Drove it a bit today with the 160 t/stat and it did not get quite as hot but, it was 10 degrees cooler out today than yesterday. Probably irrelevant.

Heater core is connected and functional and I have had the valve open (set to heat) while driving.

Fan does not slip and there is no fan clutch.

No dirt and debris clogging the radiator.

Fan shroud installed on both cars.

The rubber dam and or belly pan are non existent on either car. I may have a belly pan around here somewhere but if not, it may be easier to find a set of chicken lips.

 

Lower hose does not collapse.

No scale build up at the top of the radiator. This radiator was cleaned and boiled prior to installation. As I said 3K miles ago. (give or take)

The water where I live is so hard that it tends to ruin stuff in short order. Have only used distilled water on all of my Datsuns.

 

The lower hose had a temperature of about 140-150 degrees. The t/stat housing was 165-175 degrees and the head just past the housing was in the 200 range.

For grins I hit it between the spark plugs on the head and that came in at the 150-160 range.

 

Since this seems to have started as an intermittent issue, I am leaning towards the gauge. I mean, it's over 50 years old and I remember once I passed 50 I didn't work as well as I used to either.

[datsunfreak]

On 9/4/2023 at 3:18 PM, KELMO said:

Since this seems to have started as an intermittent issue, I am leaning towards the gauge. I mean, it's over 50 years old and I remember once I passed 50 I didn't work as well as I used to either.

 

A new sender is pretty cheap and easy to swap in also. 👍

 

Usually if I am insistent on using the stock gauges (rarely do any more), I will rig up a temporary aftermarket gauge to verify function of the stock one. 

[goes2fast]

I was going to say try temporarily installing a mechanical gauge to check the operating temp. then go from there. If the original gauge is the problem then there are companies that can restore/repair it. I hope it is only the sending unit though as that is the easiest fix.

[datsunfreak]

3 hours ago, goes2fast said:

If the original gauge is the problem then there are companies that can restore/repair it

 

On that front, a 620 gauge is a direct swap. In fact, the whole gauge cluster will swap over. Those are much easier to find in good condition than 1200 bits. 

[goes2fast]

3 hours ago, datsunfreak said:

 

On that front, a 620 gauge is a direct swap. In fact, the whole gauge cluster will swap over. Those are much easier to find in good condition than 1200 bits. 

I don't know if you remember but I put a 280Z speedo in mine so I would have a trip odometer plus the 160 mph speedo looked impressive. 🤣

[KELMO]

4 hours ago, goes2fast said:

160 mph speedo looked impressive. 🤣

No one, in their right mind, would drive a 1200 160 MPH. Mine barely do 60 MPH.

[KELMO]

14 hours ago, datsunfreak said:

A new sender is pretty cheap and easy to swap in also. 👍

I am pretty sure this one was new but again, that was 7 years ago and minimal miles. I have been giving some thought to an AM set up for verification.

Gonna try a sending unit first.

[goes2fast]

1 hour ago, KELMO said:

No one, in their right mind, would drive a 1200 160 MPH. Mine barely do 60 MPH.

I did get mine up to 97 in Nevada when I drove it home from purchasing in the Bay Area. It did have a 1400 and 5 speed though.

[Dguy210]

2 hours ago, KELMO said:

No one, in their right mind, would drive a 1200 160 MPH. Mine barely do 60 MPH.

 

54 minutes ago, goes2fast said:

I did get mine up to 97 in Nevada when I drove it home from purchasing in the Bay Area. It did have a 1400 and 5 speed though.

 

 

[datsunfreak]

9 hours ago, KELMO said:

No one, in their right mind, would drive a 1200 160 MPH. 

 

I think the "right mind" part is the key...  😄

 

As I recall, I saw this one do 154mph at an IDRA event...

 

 

[goes2fast]

10 hours ago, Dguy210 said:

 

 

 

It turns out that my memory isn't as good as I thought. I managed to find the photo that I took of the speedometer that night. I knew that someday I would need proof.

 

[goes2fast]

3 hours ago, datsunfreak said:

 

I think the "right mind" part is the key...  😄

 

As I recall, I saw this one do 154mph at an IDRA event...

 

 

154 is slow for a 1200 drag car. How about 6.937 and 198.20!