Thanks Dai!

Your description is "in line" with my basic thinking, that the lower pipe is the inlet to the Webasto and the upper pipe is the outlet.  You're right that there are some minor differences in my approach, making the webasto feed the engine first, rather than the cabin.

I don't have a valve that's switched by the Webasto.  I need to remember to leave the heater valve open if the Webasto's going to run.  I see that as a possible source of trouble if the valve is accidentally left closed and the webasto's water pump is sucking against the closed valve.

Hmm.....I do have a Webasto system from a G that a guy from the list gave me way back.  It's a petrol one, but it's an original G one (the one I'm fitting now is a generic Thermotop T) so there may be a water valve in that pile of stuff....I'll have to look.

Maybe I can find some install instructions and components list for a Thermo Top T somewhere....

-Dave G.

Well, the G made the trip ALL THE WAY to work this morning, making it's first meaningful trip since the engine swap.  All seems well so far.  I parked on a nice clean piece of pavement to see if any leaks crop up.

The most remarkable thing was I was able to drive all the way in top gear.  I have at least 3 hills on the way in that used to require 3rd gear with the M110 and the 617A can go up those doing the speed limit (55mph)  in top gear.  Very nice.  I'm glad I have an overdrive trans (iron box 5 speed) coming in addition to the granny-low box.  I don't have a working tach yet, but I know what the revs are for different wheel speeds and I'd like to not flog it over 3000 on the freeway if I can help it.  We'll see.

I need to swing by the muffler shop and have the downpipe from the turbo to the flange near the transfer case done, but that shouldn't be too big a deal.  Then I plan to let Mark have a drive in it to get his opinion on how it's running.  Having zero experience with these things, I'll feel better if an expert gives me an opinion on how it's running.

As far as the block heaters go, wow, that little Webasto is a marvel!  I fired it off yesterday just to see if it was working and within 15 minutes, the temp gauge on the dash was at the top of the white!  It'll be nice to have that around when it starts to get really cold.  I don't know how to make the preset timer light it up though, so I didn't have the Webasto run this morning.  I just set a timer to turn the block heater on for about 3 hours before I was ready to drive.  It didn't show anything appreciable on the temp gauge, but it did crank over pretty easy for as cold as it was.

Gotta figure out that timer on the Webasto.  I could get used to that!

-Dave G.

Thanks for confirming that water routing, Warren.  I have mine set up the other way right now (thru heater first), but the way you say would cut down on the number of hoses running around the engine compartment, so I may switch to that way some time.

The setup I have came with a double-throw relay for the fan actuation, so I don't need to leave the fan on.  I have the normally closed contacts of this relay in the circuit from the low-speed contact on the fan switch with a wire running to the relay and then from the relay back to the wire to the fan.  In essence, cut the low speed wire from the switch to the fan and run it through the normally closed relay contacts.  This way, the normally closed relay contacts complete the circuit to the low speed side for normal operation of the fan while driving, but when the Webasto fires, the relay is energized and the normally open contacts close, delivering power to the low speed side of the fan from the relay (instead of from the fan switch).  This way it doesn't matter whether you leave the fan switch in off, low, or high, the Webasto will always run the fan at low speed.

If anyone's interested I can draw and scan a schematic.

-Dave G.