Cooling system tweak

[Bill Bayard]

Like everyone else here, I have had my share of heat issues.
To add to my problems, my TWM manifold has only one water port, so I was forced to seek sensor(ECU water temp & gauge sender) ports elsewhere. I decided that the thermostat housing was the best, most accesible spot where I could add sensors, without tearing apart my throttle bodies and manifold, for access with a drill. I also added a bleeder tap(still in need of a barb and hose), as this is about the highest point in the system.
The (7/8" thick)spacer block cost $130 to have machined, the tap was free. I was concerned about clearance issues, but was pleasantly surprised to see that I had tons of room. I have 1/2"+ between the upper water pump hose/thermo housing and the bulkhead panel, and loads of room around and above the sensors/tap.
I will be bleeding the system later today, and will post the results.

Bill

 

[Bill Bayard]

Another photo

 

[Bill Bayard]

In place.

 

[Lynn Larsen]

Bill,

Very nice solution!

Lynn

 

[Bill Bayard]

Lynn,

So far, so good! 184-188F BEFORE bleeding(idling for 30 minutes after warmup in 90F air temp)! I'll be bleeding it tonight(it's raining again!) and road testing tomorrow. I hope that the temp stays right where it is!

Bill

 

[Trevor Booth]

Bill,
I am curious as to why you need a bleeder in the thermo housing. If the hose from the thermo hsg to the expansion tank is uphill all the way no air should be trapped at this point.( thats the theory) Did you have a particular problem or was it just a precautionary measure.
Trevor

 

[Bill Bayard]

Trevor,

I only had one water port on my manifold. I had a heater

hose, ECU sensor, and gauge sender to plumb. These were the

primary reasons for the spacer. I added the bleeder because

there was extra room in the spacer, and because I hoped

that it would release any air from the front of the

manifold that had not been purged to the expansion tank. I

bled it today, and sure enough, there were a few bubbles in

there. After bleeding it, I ran the car pretty hard, and

had a temp spike that went away pretty quickly, so I am

assuming that there's more air to be bled. With the

bleeder, this takes all of 10 seconds and it's done.


Bill

 

[Trevor Booth]

Thanks Bill, sounds like good insurance. I am not to that stage yet but will pinch your idea and run a 1/8 line to exp tank. I have had similar problems with other engines sitting level and trapping air in the head but I do not have a lot of exp with V8. I had intended to run a 1/8 bleed line from back of manifold to exp tank but had not considered the front.
Trevor

 

[Peter Delaney]

For what its worth - there are a few guys running the DC&O 8-stack who have adopted the "belts & braces" approach, and report nice cool running & no bleeding problems :

- the stock DC&O manifold has no water ports at the back, but most owners drill & tap one into each side - right where the water ports are in the heads. These are often tee'd together, then run up to either a spigot on the thermo housing, or into the expansion tank.

- another line is taken from the front water port to one of the above spots.

- a small-bore hose is run from the top of the radiator to the expansion tank.

I think that I will run with Bill's idea of a tap at the top/front of the manifold (the highest spot on a DC&O) & also add taps at the top of the radiator & the highest point in the heater piping. I seem to remember from a previous thread that nearly everyone had bleeding problems, but once it was done prpoerly, there were no more hassles until it came time to change the coolant. Bill's little taps would make bleeding a no-brainer - so much better than 10 shots at bleeding, with coolant all over the place !

Kind Regards,

Peter D.

 

[Bill Bayard]

Trevor,

I forgot to mention that the manufacturer of my manifold
(TWM), suggested drilling the manifold directly behind the thermo housing. As I'm not a masochist (didn't want to dismantle everything to accomplish this), my spacer was a whole lot easier and simpler way to get the same result, without all the pain!
If someone was so inclined, they could re-route their heater bypass hose into the spacer(plug the T-stat housing hole for the bypass hose), to allow a better angle where the large hose exits the housing.

Bill

 

[Trevor Booth]

Bill,
What you have done is very nifty, much better than drilling and tapping the manifold. It sure is a tight squeeze under that crossmember. why dont you cut 6" out of it..))
Trevor

 

[Bill Bayard]

Trevor,

NOT AN OPTION!!!!

The deck height on my 351W makes things a little bit snug.
I feel for you guys in Oz, being forced to go with the 4.6L engine.
Talk about a square peg in a round hole!
That's gotta be a really tight squeeze!

Bill

 

[Trevor Booth]

Bill,
I suppose your warranty would be cancelled if you did that!!
The 4.6 is going to present problems but for those who do the research and put in the effort it is not mandatory. I have told a few interested parties how to do it but......
Cheers
Trevor

 

[Bill Bayard]

Trevor,

You wouldn't happen to be an RTA inspector, would you? /ubbthreads/images/graemlins/wink.gif


Bill

 

[Trevor Booth]

Bill,
No I am not. I am one of the (un)fortunate few who sign pieces of paper to say they are Ok before the RTA inspector sees them. I therefore study the regs in fine detail so that I am well armed to do "battle" on behalf of my clients.
Ask The owner of DRB #27 some time.
cheers,
Trevor

 

[Bill Bayard]

Trevor,

The owner of #27 has told me all about you.
Let's hope that his car passes RTA soon.
He's lost enough sleep already!

Bill

 

[Trevor Booth]

Oh No! dont tell me has let the cat out of the bag!! And by the way, his insomnia is probably due to him having his cooling system tweaked!!~

 

[Peter Delaney]

Cooling system tweaked - and the rest !!

The main recipient of tweaking has been my wallet ! Over the last 3 years, it has been like a mobile ATM - I just keep taking it around to the next "needy" supplier / expert engine builder (real or imaginary), etc !

To add insult to injury : now that I am getting close to being able to drive the car (I hope), what happens to the price of bloody petrol ? It's been up at about $1.09/L around here for the last few days !

Kind Regards,

Peter D.

 

[JimmyMac]

Fill your boots Peter, your lucky.
Fuel is around £0.92 per litre and on the up here in the UK.
We are also charged OPEC prices for a mineral water.