The V8 Owners Forum -

Hi, can anyone advise if it is possible to use the standard thermostat housing from a 3.5 SD1 manifold on an Offenhauser 360 with a four barrel Holley? I am currently in the middle of fitting the Holley and manifold on my SD1 engined Landrover.

it will fit but it wont have the bypass connection built into it. You would be better off buying the proper housing.

Cheers for the reply. What difference does the by-pass conection make?

The bypass allows limited circulation before the thermostat opens, with a small diameter hose going from the thermostat elbow to the rear of the water pump.

If my understanding is correct this is to prevent localised hot spots in the water jacket in the heads before the entire body of water is hot enough to open the thermostat. If anyone can explain it better I'm all ears (or eyes )

I have an Edlebrock manifold with std housing. This setup has the same problem but I have drilled a couple of holes in the thermostat allowing some bypass flow. Works nice. (This is an old trick with A-series engines where the notorious bypass hose used to cause problems... simple remedy is to ditch the hose, plug the hose inlet/outlet and drill the thermostat.)

Stat manifold with bypass suitable for the Edelbrock is sold by Real Steel, about £17. Can't recall if it's a Rover one or Offy or what. 302 Ford is cheaper though and fits Performer (no idea about Offy) with minimal filing.