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Thermostat with 4 1/8 in holes drilled in it?

scubabatdan

Jedi Trainee
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Well I have always wondered why it took forever for my temp to get up to normal operating temp. Today I replaced the thermostat with a 180 degree thermostat from MM. Upon removal I noticed the PO had drilled 4 1/8" holes in the thermostat. And it would take forever for the water temp to get to normal operating tempratures.

Unfortunantly I have a temprature gauge that is L...N...H so when I run it up I am hoping in 5 min that the temp gets to the N and stays put.

While running about I noticed that when it gets to N it will continue past N and if I coast down a long hill it will drop back below N.

Question: where does everyones needle hover around when it get to normal operating temp? And does anyone have this problem?

I have had the radiator cleaned and rodded and the water pump is definatly working, and the heater valve is open and I get hot air from the heater. any Ideas?

Thanks
Dan
 
Hi Dan, the needle following engine load is normal.However what the swing range normally is I do not know. A 180 degree Stat in that part of the country seems a bit much. I would have thought a 160 was quite adequate. Those 1/8" holes insure that in the event of a Stat failure your car does not boil over.--Fwiw--Keoke
 
I have often (usually) drilled ONE 1/8" hole in the thermostat for my Britmobiles but that is only to make it easier to fill the water system. Some t-stats have a hole in them with a little plastic barbell in the hole for the same purpose.
I doubt that 4 holes would prevent overheating in the event of a t-stat failure but it would help.
Bill
 
My needle stabilizes just to the left of the N, right above the M in "Made in U.K." (I made sure to test it with a cup of boiling water and a meat thermometer. On my gauge, that's bang on 160.) IMO, it's always a good idea to find out just where your temps really fall on a C-N-H gauge.
 
Billm said:
I have often (usually) drilled ONE 1/8" hole in the thermostat for my Britmobiles but that is only to make it easier to fill the water system. Some t-stats have a hole in them with a little plastic barbell in the hole for the same purpose.
I doubt that 4 holes would prevent overheating in the event of a t-stat failure but it would help.
Bill

Mine had the little dumbell weight, ok I might try a 160 as suggested above.

bthompson said:
My needle stabilizes just to the left of the N, right above the M in "Made in U.K." (I made sure to test it with a cup of boiling water and a meat thermometer. On my gauge, that's bang on 160.) IMO, it's always a good idea to find out just where your temps really fall on a C-N-H gauge.

I guess I should boil some water and see where 160 and 180 falls on the temp gauge, then I know where the needle should be and when the stat opens fully and I am and heading into a overheating situation.

Thanks!
Dan
 
Billm said:
I have often (usually) drilled ONE 1/8" hole in the thermostat for my Britmobiles but that is only to make it easier to fill the water system. Some t-stats have a hole in them with a little plastic barbell in the hole for the same purpose.
I doubt that 4 holes would prevent overheating in the event of a t-stat failure but it would help.

Well consider this Rolls Royce Uses this very technique in all of their cars. The Difference being they are normally closed with a very low temperature solder which melts in the case of the stat's failure to prevent the engine from boiling over.--Keoke
Bill
 
Hi Dan excuse me if I misinterpreted your last statement. When the Stat opens it only allows the coolant inside of the engine block to begin circulating through the radiator, it is not a signal that you are over heating. If you leave the radiator cap off and watch the water flow in the header tank the minuet the Stat opens the coolant's flow will become a bit turbulent.--Keoke
 
scubabatdan said:
While running about I noticed that when it gets to N it will continue past N and if I coast down a long hill it will drop back below N.

Have you checked your timing and plugs / fuel mixture lately? This could be a sign that things are amiss.
 
Dan,

With my 1098 engine the temp conditions you describe are normal. Now I've got a BE Bonnet on my '68 and an oil cooler positioned up front but normally running around town temps will stay just below N level. 80-85+ days it will be right at N. Going out and buzzing on the expressway I'll see temps go up to the right of N perhaps 3/4 of the way towards H. Never over to H but to the right of N. Coming off of the Expressway ramp I see temps drop quickly and oil pressure rise from 50-60 psi as the engine cools down a little bit. Adding a 13 row oil cooler to replace a 40 y.o 9 row oil cooler seems to have helped stabilize oil temps and pressures as well.
 
ChrisS said:
Have you checked your timing and plugs / fuel mixture lately? This could be a sign that things are amiss.

Plugs are good, nice and brown. The timing is in, but will double check it.
Thanks
Dan
 
Jim_Gruber said:
Dan,

With my 1098 engine the temp conditions you describe are normal. Now I've got a BE Bonnet on my '68 and an oil cooler positioned up front but normally running around town temps will stay just below N level. 80-85+ days it will be right at N. Going out and buzzing on the expressway I'll see temps go up to the right of N perhaps 3/4 of the way towards H. Never over to H but to the right of N. Coming off of the Expressway ramp I see temps drop quickly and oil pressure rise from 50-60 psi as the engine cools down a little bit. Adding a 13 row oil cooler to replace a 40 y.o 9 row oil cooler seems to have helped stabilize oil temps and pressures as well.

Was thinking of an oil cooler/radiator, is there a kit for Midgets? Or do I have to piece one together?
Thanks
Dan
 
Right in the MOSS Catalog although I bought mine on line from someone on one of the Spridget lists for $50. I think Moss is double that. On a Spridget it fits right at the bottom of the radiator shroud. When I added the BE Bonnet I had to raise about 6" to get needed clearance for BE Bonnet to clear and tyhen I stiil needed to do a couple of notches in the BE Bonnet to get it to fit. Not sure if it interferes with airflow or not. I just feel better with an oil cooler on there especially on long high speed pulls on summer days. I saw temps rise not nearly as much after I added the new oil cooler. Used to be that water temps would start to creep up gradually and oil pressure would drop very slowly as I spent longer and longer at 70-75. Temps would drop back immediately on hte exit ramp withing 2-3 minutes of cooling down. Instead of oil pressure dropping backto say 40-45 psi during a long hight speed run it stays up at 45-50 and goes back to 60 psi after it cools down after again 2-3 minutes. I don't think this is out of bounds for normal Spridget operating temps.
 
i recently read a thread (can't remember if it was here or not) about oil coolers, some debate on whether you really need one, or want one. Something about oil being at the correct running temp, you don't want it on the cold side anymore than you do the hot side. For proper viscosity and to reach operating temp quicker? I remember something about temp controllers on some of them, like a thermostat on the rad, same principal.
I have one on my 1098 but it was PO installed, I don't know why. I'm keeping it on there. So far oil pressure and coolant temps are good so I'm letting that sleeping dog lie. Mine is in front of the rad, behind the grill. Wonder if that's detrimental to coolant cooling efficiency but, like I said, everything works fine. My temp seems to stay right around 185 and oil pressure is at 60 hot and 3000rpms, 30 hot at idle.
 
Cool, thanks for the info, I have a 1275. I will be picking up a laser gun for reading temprature today (Always wanted one anyway perfect excuse) and I will see what the readings tell me.

Thanks again!
Dan
 
scubabatdan said:
Cool, thanks for the info, I have a 1275. I will be picking up a laser gun for reading temprature today (Always wanted one anyway perfect excuse) and I will see what the readings tell me.

Thanks again!
Dan


I love those things! I bought one for the kitchen and
have found all kind of uses for it. Now it's in the garage.
Shhhh...don't tell my wife. :wink:
 
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