Too many interruptions to get much done.....but....got the heat exchangers off and took off the necessary tins off the bottom of the engine to accommodate the new exhaust.
Next time I'll do this with the engine out. Getting at those nuts on the exhaust outlets at the front of the engine isn't a lot of fun. Also the tins that had to be removed had to be cut out because there is no access from the top and virtually none from the bottom to get to the retaining screws.
The tins I'm talking about are the ones that go under the push rod tubes and then go up between the block and trans. The upper tins don't have to be messed with and will go back in place with a new foam "H" shaped liner to seal off the outer rim of the engine compartment. That was what was in the car before I started this little adventure and that kept things cool.
I also need to order heating duct covers for the shroud. Looks like 48mm from Aircooled.net - $3.95.
Are there plugs for the heater hose openings on the tin that goes across the back and under the crankshaft pulley? If not I will just buy a new one without the cut outs.
They're called sled tins, Bob, and make sure a set go back in. I've seen a lot of engines without run fine around town, but have temp problems on the highway when it gets hot. The sled tins direct the spent cooling air out back, where it can join in the airstream under the car. At highway speeds the air pressure under the car is as much as 2 psi more than around or over the car, and without the bottom tins the air comes straight down through the cylinders and hits that horizontal air pressure flow.. It can't join the under car airstream easily, so it becomes turbulent, most of it goes nowhere and creates air pressure downstream of the fan, seriously reducing flow (and cooling). The faster the vehicle speed (and more solid the layer of air under the car), the higher temps will go. The sled tins allow the air to turn the corner efficiently and enter the airstream behind the car.
Since the new exhaust has J tubes replacing the heater boxes you'll need some industrial tins to complete the package. Normally, the heater boxes keep the air channelled, so when you remove them they have to be replaced. The industrial tins are from industrial engines without heater boxes, and again, serve a very specific purpose. Al
PS- to cap off the shroud, look for the appropriate size frost plugs (available at any auto store), or if you know someone with a baby, Gerber baby food lids fit as well.
PPSS The tins can be bent up yourself; I'll find the drawings later if you (or anyone else) are interested.
- Soup can lids (or anything similar) screwed down to the rear tin will do the job, as a low budget (and quick) fix.
