The Tom Thatch Modification

[hanleyclifford]

Shawn - You make a good point here. The RWC group can get a big benefit from this modification. It's like back flushing and driving the chips and crud out the exhaust pipe.

[sastanley]

Hanley, I took my cooling lines apart (I may start a new thread over in the off topic area for fun) to do some 'spring cleaning' and painting of the engine compartment today, so I got to thinking...even if I don't actually get my FWC system installed this spring, I am still considering sending the outflow from the late model head t-stat housing into the back of the manifold and then the forward manifold port would now be the exit to the exhaust system injection point.

Regardless, I will be shifting to cast pieces wherever possible based on Tom's flow analysis of the improvement that said pieces provide. When I pulled my aft manifold fitting today I immediately said to myself, "why did I ever allow that restriction in the system??" - it is funny the continuing education one receives from this great site. - The threads in the aft manifold fitting are 1/2" NPT if I recall, but the silly fitting squished down so far on the hose barbs that it was probably 3/8" or less ID of water actually flowing thru the hose.. - I put it in a ziploc, labeled it and noted, "replace with better flowing fitting ASAP!"

[hanleyclifford]

The funny thing about those boxy brass fittings is that they do work if kept clean but in the real world that just does not happen.

[Baltimore Sailor]

Consider how the cooling lines now cross over the engine, perhaps we could call the mod "The Thatch Weave"?

/ducksandruns

[sastanley]

bay sludge

Hanley, in this case it was a straight thru barb, but the barb's ID was quite skinny (& clogged), despite the manifold hole being 1/2" NPT...the stuff in the manifold came out with a shop vac, but I am sure it was inhibiting water flow that far away from the pump..not much pressure there I figure.

Here is a pic of the fitting (clamps hanging on the fitting, before I put the hose on) - I am going to replace it with a cast 90 elbow I picked up at my local hardware store for about $5. I got parts for both ends of the manifold for less than $20..I still need to re-read thru Tom's thread to design the side plate improvements. My brain doesn't stay on one task very long, so I make lots of little trips to the hardware store and have lots of small orders from McMaster Carr.

I also noticed some sizeable chunks come off the manifold in the area between the cooling water fitting and the exhaust flange...I hope I can get the FWC assembled to stop the decay before it is too late..it is already an MMI replacement..I assume from lack of care the original failed long ago as well.

P.S.> Hanley, I've been meaning to ask you, what is the turnbuckle attached to in your picture and where does the other end go?!?!?

[hanleyclifford]

Consider how the cooling lines now cross over the engine, perhaps we could call the mod "The Thatch Weave"?

/ducksandruns

If we can adapt this for maneuvers at sea we might get hired by the brass at the Pentagon. Who says people with A4 gas engines are backward?

[hanleyclifford]

Shawn - The turnbuckle is to adjust the hot section "headstay".

[sastanley]

Wow...great idea! I worry a little bit about the 10+ lbs of iron hanging off those two little bolts.

[Dave Neptune]

Hanley, I too wondered from the angle what the heck. The new angle certainly eleminate alot of head scratching.
Thanx for another bald spot.

Dave Neptune

[thatch]

"Oops'

All,
After my posts on saturday I disconnected my computer to do some home painting. I did not expect so many questions to crop up but will try to address the ones that have not been delt with.
Balti,
The concept of having the water enter at the lowest point of any accessory and exiting at the highest point should hold true for components of raw water or fresh water cooling systems. This concept just tries to eliminate as many air pockets as possible.
Dave N.
Recently there has been some photographic evidence showing bearing damage on the lower main bearing shell, toward the center of the A4's in question. I personally had misdiagnosed this condition as "acid erosion" but have come to believe that the problem was caused by crankshaft flexing caused by "lugging". Because of this, I have come to the conclusion that trying to add any more horsepower to the basic design would be unwise.... On the subject of the hot spot on our manifolds, since there is an un-waterjackted section on the manifold at the #1 exhaust valve, no change in the cooling systen should "cure" this condition.
Shawn and Lat64,
IMHO, real men don't need facebook.
Sincerely, Tom Thatcher (Thatch)

[sastanley]

Tom, sorry I keep screwing up your name in my posts..I made assumptions based on thatch that your last name was hatch, and not thatch. I went back and modified my earlier post where I coined the "Thatch modification" in case it becomes reality some day.

(if it is any consolation, I get lots of people calling me stan or stanley..I even have a guy at work that messed it up so many times he just calls me "Stan Shawnley" now for fun...so, I just roll with it..but as a 'victim' of botched names myself, I wanted to acknowledge and correct it.)

[thatch]

Shawn,
Before retireing, Thatch or Thatcher would be among the the more flattering "lables" I have been given. Although I sincerely appreciate your appologies, I must admit that It's not really your fault. Since some of the discussions tend to become somewhat "heated" at times, It's probably best that finding any of us in the phone book might present somewhat of a challenge.
Your Bud, Tom...Whatever.

[roadnsky]

...It's probably best that finding any of us in the phone book might present somewhat of a challenge.

What the hell is a Phone Book?

[thatch]

"Ouch"

Jerry,
Now I really feel old.
Tom

[ndutton]

Jerry,
Now I really feel old.
Tom

Yeah, I was going to say it's that thing we used to sit you kids up on instead of a booster seat.

Or it's that thing we'd prop up our dial phone up on before that abomination called a Princess phone was developed.

Or it's that book where we'd look up that cute girl's phone number before numbers could be hidden.

Where's my Geritol?