LD 340 Manifold Water Mods

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blue missile

blue missile

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I know somewhere there was a thread about adding water through the manifold to the back of the heads.This was something I was always going to do, but in the light of wanting to push the compression envelope on pump gas, I thought it would be helpful.

The original poster correctly noticed that there were two ribs in the way of the modification. That was easy enough to remady. The manifold was marked from the back with a gasket and some layout dye, drilled and tapped npt3/8". That was the easy part the next challange was to find the right combo of fittings to bridge the gap and clear the distributer.
The first attempt used all AN fittings including a tee but it didnt have the room. I made several trips and had a very patient parts guy at the speed shop help with a couple more configurations after I brought the manifold to him.
The final result was a combo of AN and barbed fittings. As you can see the clearance behind the distributer is very tight.
Hope this helps

manifold#1.jpg


manifold#2.jpg


manifold#3.jpg


manifold#4.jpg
 
What is the tee for? I seen others do that , but not on that manifold and not with a tee in the line. Nice job.
 
I look foward to more pictures of this story and how you work it out.
What is that other fitting?
 
Has anyone ever done, or seen, a test to see actual water temps near the exhaust ports before and after this mod was done. Not the mixed coolant temp at the front crossover.
 
First the other fitting is an old oil return for a turbo, which I willuse for a bypass oil filtration return instead of punching a hole in the oil pan.

Second the Tee is to take in water from the heater return hose to join the coolant comming into the heads from the back of the block. Because of the length of the run it will be slightly cooler than the rest of the coolant.

Other than that it is worked out as you see it. The heater return hose is 1/2" and so is the Tee which I got from a home brew store, it is stainless.
Andrew
 
crackedback said:
Has anyone ever done, or seen, a test to see actual water temps near the exhaust ports before and after this mod was done. Not the mixed coolant temp at the front crossover.
Click to expand...
yes. its neglegable. but seems the outboard cylinders(1,7,2, &8) always run hotter the the middle ones (3,5,4 & 6).
I usually see that mod on alcohol race engines. not for heat, but they eliminate the upper rad hose becouse the engine runs VERY cool.
 
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