I've got the 225 3.7 liter engine. Anyone know the size of the sending unit threads? When I eye ball it it looks like a 1/8th. Everyone I ask around here says it 1/4 NPT. It looks like fine thread. Anyone know for sure. I was told to switch it to mechanical gauge. In the gauge kit it only goes down to 1/4 NPT.
water sending unit
- Thread starter Road/Rage
- Start date
-
I think everyone is right and question why you need to here it once again. Is a trip to the auto parts store far?
Here is what Vixen has. It is a 1/8" port.
Next is the original 170 I pulled out of Vixen. It is also 1/8" NPT.
Finally is my 1977 model closed chamber prototype head. It has two 3/8 NPT ports. So you could say the people you talked to were WRONG.
Because auto parts stores are ran by 20 year old kids that have to google everything and come back to you with 20 different answers! Or just say, Whuuuuuuuuut!
UGH! I get ya. My bad, sorry.
Just saying “Water temp sender” has there head in a knot.
Just saying “Water temp sender” has there head in a knot.
Watch when you use a adapter on them it can stick up to high and not read the actual temperature.
Closed chamber head for a 225 ?
Last edited:
Charrlie_S
Well-Known Member
Most slant six heads have a 1/8 NPT hole for the factory temp sender. Some later heads also have one or two 3/8 NPT holes for other things. The after market mechanical temp gauge requires a 3/8 NPT hole. When I add a mechanical gauge to an early head, I drill and retap the 1/8 hole to 3/8 NPT.
diymirage
HP@idle > hondaHP@redline
Or they'll say "Plymouth? Who makes that?"
I weep for the future!
Johnny71dusty
Well-Known Member
I keep getting new 1/8 npt Tempe sender for my 198 . But my new head is much bigger . Bigger than the 3/8 people been talking about . It's as big as my finger . Anyone know of a another size they used ?
Charrlie_S
Well-Known Member
Can you post a picture of the top, front section of your head? I looked at over 10 different heads, from 1964 to 1984, and they all take a temp sensor of 1/8 NPT. Some heads only have one 1/8 npt hole, other heads have the 1/8 NPT, plus one or two 3/8 NPT holes.
that hole around the corner is 1/8 NPT on the 77 head, if it were me I would put the stock sending unit back in that hole and hook up the auxiliary gauge via one of the 3/8 npt holes
Yes sir. One of like five prototype heads.
How does a man get his hands on one of those heads?
Believe it or don't I found this one on ebay.
-
