Lower thermostat housing sensors and de-smog question

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Raleigh, NC
Rebuilding a 2F motor in a late ‘85. In the lower thermostat housing there are 2 sensors. One is a switching valve and the other I thought was a coolant sensor, but doesn’t look like the replacement parts. Anyone know what this sensor is?

While removing this unknown sensor, the thread pulled out of the housing, so now I need a new housing. In the earlier model 60s, the therm housings do not have these sensor ports. If I am planning to de-smog, do I need either of these two ports?? I’m not exactly sure what function the switching valve has.

I can get the earlier model housing but the later ones (with the sensor ports) are not avail.

IMG_9105.jpeg


IMG_9104.jpeg
 
It looks like the broken one is the BVSV 1. In stock configuration this BVSV is used for the vacuum advance of the distributor as well as purging the Evaporative Emission Control (charcoal canister) into the intake manifold during engine operation.

The other one, BVSV 2, is used for the choke opener system. This opens the choke plate when the engine is warm to lean out the mixture.

You will have to wait for input from someone that knows desmog how the distributor vacuum advance is worked out. Technically you don't need the EVAP system but you don't have to eliminate it either. I suppose you don't need the choke breaker if you can remember to push choke knob in when the engine warms up and it starts running poorly.

You can find a copy of the emissions manual in the "Resources" tab in the top ribbon menu on IH8MUD.

1684416259934.png

1684416798189.png
 
It looks like the broken one is the BVSV 1. In stock configuration this BVSV is used for the vacuum advance of the distributor as well as purging the Evaporative Emission Control (charcoal canister) into the intake manifold during engine operation.

The other one, BVSV 2, is used for the choke opener system. This opens the choke plate when the engine is warm to lean out the mixture.

You will have to wait for input from someone that knows desmog how the distributor vacuum advance is worked out. Technically you don't need the EVAP system but you don't have to eliminate it either. I suppose you don't need the choke breaker if you can remember to push choke knob in when the engine warms up and it starts running poorly.

You can find a copy of the emissions manual in the "Resources" tab in the top ribbon menu on IH8MUD.

Oh wow, thank you for such a detailed reply. I guess we are one of the lucky ones who remembers to push the choke knob in, esp since I’m pretty sure that port has never had the sensor in the time we’ve owned it. ;-)

The next question is, do we need to get a replacement with the sensor ports if we are looking to de-smog….? Need to do some additional research on de-smogging, but right now we’re just focused on getting the engine back together. Hopefully someone can weigh-in on this one.
 
The standard desmog keeps BVSV 1 (top, broken in your picture) and runs one vacuum to the EVAP valve on the driver's side fender and one to the EGR port on the stock carb.
 
Rebuilding a 2F motor in a late ‘85. In the lower thermostat housing there are 2 sensors. One is a switching valve and the other I thought was a coolant sensor, but doesn’t look like the replacement parts. Anyone know what this sensor is?

While removing this unknown sensor, the thread pulled out of the housing, so now I need a new housing. In the earlier model 60s, the therm housings do not have these sensor ports. If I am planning to de-smog, do I need either of these two ports?? I’m not exactly sure what function the switching valve has.

I can get the earlier model housing but the later ones (with the sensor ports) are not avail.

View attachment 3325526

View attachment 3325527



.
who told you the 2F lower Thermostat housing with the Double BVSV ports is not available ?


there in-stock in my Vintage Teq Parts Dept. .... :cool: 💥


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CF638610-666F-40E9-BA8E-CC8609307EAC.jpeg
 
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who told you the 2F lower Thermostat housing with the Double BVSV ports is not available ?


there in-stock in my Vintage Teq Parts Dept. .... :cool: 💥


.
View attachment 3349656

Sorry for the late reply. I had actually been on your website before after finding an older post here from you on this part. But I cannot find it on your website. Where do I need to look? I’m not finding it when searching for thermostat.
 
Sorry for the late reply. I had actually been on your website before after finding an older post here from you on this part. But I cannot find it on your website. Where do I need to look? I’m not finding it when searching for thermostat.


- i do not have these listed on the store , because there a professionally restored unicorn special request needs parts topic , on a case by case basses as well

- ANY pre-owned part or parts in offer , is NEVER a stock photo in any way also ......


THIS IS THE WAY ...... :) :wrench: :wrench: :wrench:
 

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