Thermostat Housings; learn me the differences

[Peter Florance]

A version or non A

It appears that A are used on newer M30's and I believe the thermostats are different.

What are the differences?

Thanks!

[Blaise]

Peter:

I took some photos of both styles here:

The thermostat on the right is the later M30B34

https://picasaweb.google.com/1030509870 ... -6eEsv2STA

The main difference is the angle of the lower radiator hose exit to go around the later distributor.

The motor in the photos is the one I am building for my car.

[Robert Bondi]

A version or non A

It appears that A are used on newer M30's and I believe the thermostats are different.

What are the differences?

Thanks!

I also think the t-stat housings are a little different internally for the later engines. I previously attempted to use a new housing with my old t-stat. It all fit together fine, but when running the car, the t-stat would never open. Upon inspection of the new and old housing side-by-side, the new version has a much higher, raised, boss-like annular seat inside that the t-stat sits against.

I was able to carefully grind down that inner seat and make it work normally, but just getting a newer t-stat would be simpler looking back.