SBF water t/stat opening temp

[Keith Stafford]

I am in the process of installing an electric water pump in the front compartment along with a bypass thermostat, I notice some SBF stats seem to be quoted to open at 91C/196F (seems high). I was looking at some BMW bypass ones were switching at 71C/160F and 80C/176F. I am not sure how critical it is for the SBF? Is there a recommended band where it OK for the stat to open? CBS do a couple which open at 78C and 80C, I may go for the 80C? Any advice welcome. K

 

[mark b.]

Not a GT40, but on a cobra replica i have tried 160, 180 and 195. And have settled on the 180 as best for my purposes. Oil temps usually follow the engine coolant temp unless running hard btw.

 

[Robert May Eng.]

I am in the process of installing an electric water pump in the front compartment along with a bypass thermostat, I notice some SBF stats seem to be quoted to open at 91C/196F (seems high). I was looking at some BMW bypass ones were switching at 71C/160F and 80C/176F. I am not sure how critical it is for the SBF? Is there a recommended band where it OK for the stat to open? CBS do a couple which open at 78C and 80C, I may go for the 80C? Any advice welcome. K

I remember reading an article some years ago relating to engine temperature vs engine longevity. The outcome of the study was that a typical sb ford needs to run at between 82c/90c . Below 80c bore wear became an issue and continued use in the high 90`s head gaskets became an issue. The test engine was also run continuously stone cold for 40 hours and exhibited in excess of 10 thou bore wear in that 40 hours test. There is an optimum running temperature so best to stick with the makers stat. I know some cars run outside of these temperatures but its not ideal.

Bob

 

[Keith Stafford]

Thanks guys,... G'day Bob. Of course the running temp and stat open temp are different, I understand that opening early will subject the engine to unnecessary wear. The problem I am having is that a lot of bypass stats seem to have sealed housings, therefore you can't change the stat mechanism to suit the temp you want.

Can anyone point me in the direction of a bypass housing (with 38mm nozzles) that allows the stat to be changed?

BTW, tested the stat that I took from the engine, marked as 54mm USA, 9292 A160 on the end of the spindle (does the A160 mean it's a 160F/71C stat?) Tried searching, found nothing. Stuck it in a pan with a probe, it starts to open at about 75C and is fully open at 88C.

 

[Jack Houpe]

I had the same problem that the off the shelf bypass thermostats housing is pointed in the wrong direction so I milled my own housing, I run a 185 F bypass with a Meziere 55 GPM block mounted electric pump, I think that it a 35 GPM plump would have worked perfect and the 55 was overkill. You will be very happy with the results.

 

[mark b.]

I had a 35 gpm electric csr pump on a 406, worked fine on the street, from my experience you wouldn't want one on a road course. Stewart water pump site has a lot of good information.