Rusted Exhaust Pipe

[fund razor]

I think that recreating a version of the stock exhaust would not be difficult or crazy expensive. My concern would be if it has been dramatically (Overlapping) re-cammed. The concern is for reversion of water back into the cylinders, and hydrolock, which breaks stuff in the rotating assy.

Do you have any idea of how it is cammed? I ask knowing that you probably do not, because whatever was done was done before you bought it.

(Note: I am not a mechanic or engine expert. But after years of being around boats and having several repowers and a few custom engines, I have picked up a couple of things.)
This is a cool animation of regular vs. performance cam and when the valves are open.

http://auto.howstuffworks.com/camshaft.htm

My intent is not to freak you out or spend your money. It is possible that the exhaust was done and the cams were never touched. It just seems reasonable to raise the issue.

 

[Ratickle]

You Guys are Awesome! I actually thought that ya'll had abandoned me and my problem, but today I saw the page button on the bottom right of the screen.(Duuuuu) No need to answer the PM Ratickle. (I'm sure you thought I had lost my mind.) Sounds like you guys are getting close. Appreciate it much!

I don't know how close we are getting, but we are sure asking lots of questions. I was going to answer the PM that we were trying. You said you knew someone who could build new exhaust out of stainless? Does that mean you have a stainless fabricator friend or business contact? Because if you do, it may be the easiest and best way to get what you need. I also believe John will be checking with some of his contacts out west to see if they can build what you need.

 

[Ratickle]

I think that recreating a version of the stock exhaust would not be difficult or crazy expensive. My concern would be if it has been dramatically (Overlapping) re-cammed. The concern is for reversion of water back into the cylinders, and hydrolock, which breaks stuff in the rotating assy.

Do you have any idea of how it is cammed? I ask knowing that you probably do not, because whatever was done was done before you bought it.

(Note: I am not a mechanic or engine expert. But after years of being around boats and having several repowers and a few custom engines, I have picked up a couple of things.)
This is a cool animation of regular vs. performance cam and when the valves are open.

http://auto.howstuffworks.com/camshaft.htm

My intent is not to freak you out or spend your money. It is possible that the exhaust was done and the cams were never touched. It just seems reasonable to raise the issue.

Very reasonable and probably a mandatory concern. As John Teague said in his post, we need four jacked elbows made that will dump the water after 6 inches past the elbow.

 

[fund razor]

Is the "6 inches behind the elbow" the prescription for any reasonable possible exhaust valve duration?
If so, my point, and concern, is moot.

I remember that when Bob M. ground my cams, he had me measure that distance very carefully.

 

[Ratickle]

I don't know. Was Bob's advice for past the collector 6 inches or below the collector 6 inches before injecting water into the exhaust? I would think the below amount would also be of concern.

 

[fund razor]

I wonder if he could modify Gils by attaching to them with behind the point that they mix with a tube that would route to his euro through hulls?

 

[fund razor]

I don't know. Was Bob's advice for past the collector 6 inches or below the collector 6 inches before injecting water into the exhaust? I would think the below amount would also be of concern.

He had me measure the point that my Gils mixed at, and then he designed based on that. I want to say that they mixed like 11 inches back in the Gil stainless tube from the riser.

 

[fund razor]

Gils:

 

[Poolman]

I have a friend of a friend who I understand is a very good welder/fabricator who has the equipment to weld stainless. I would have to give him specific direction on how to weld the exhaust. After reading all of your posts, I am convinced that this exhaust is not right and that it needs to be changed. I have spoke to my engine builder (Tom) and have invited him to the discussion.... to the best of Toms recollection the cams were .525 lift ,.260 duration....
in regards to the last post, where do I get the jacketed elbows and how do I have the exhaust assembled so that it is functional and more importantly safe??

 

[Ratickle]

I'm still digging, but you may have to make your own elbows so you can fit them to the available space in your bilge. You would have to use something like this ebay tubing provider:

http://www.ebay.com/itm/5-409-Stain...d=100005&prg=8934&rk=2&rkt=5&sd=201005413598&

and this one, (both may have 4' and 5"):

http://www.ebay.com/itm/Flowmaster-...Parts_Accessories&hash=item5d4463ba6b&vxp=mtr

So, to manufacturer your own elbow. You'd put a 4" that was longer inside a 5" and weld the ends closed to make the jacketed elbow. It would have to be the correct inside diameter on the one end to slip over the current header, and weld the studs on for the strap attachments. Plus a water inlet so the water could come out the header like now but go immediately into the elboe inlet. There would be holes inside the 4" inner tube on the outlet end to let all of the water go into the exhaust so it would be wet the rest of the way. You could probably shorten your existing tees to use, and everything would be held together with 4" ID exhaust hose and stainless hose clamps. That way your elbow would be cooled by the water in the jacket, which would continue inside your exhaust the rest of the way.

I'll think about it more, but it may be the only way. As the others think about it and put in their input, plus others review and comment, we should be able to sketch up a workable plan that can be quoted.

 

[rschap1]

For what it is worth...
and just because it has not been mentioned yet,
may be easier to check the cams' overlap and replace with stock or something acceptable if too great
and
replace the headers with stock manifolds, risers, and just tie into the euro exits with rubber hose.
just throwing it out there...

 

[Ratickle]

I was thinking of that also, but with all f the changes that have been made, and the good headers, I'm not sure I would go that route because of the issue with the tees etc.

 

[Poolman]

So this may sound a bit silly to ya'll,but could someone draw me a picture of what this new exhaust should look like? I understand the concept of the pipe inside the pipe for water and cooling, but not too sure of the distances that have been discussed...

I do appreciate the knowledge and advice you guys have provided....

 

[Ratickle]

Nope, not silly at all. Will do in the next few days.

 

[Poolman]

Had the fabricator here today, he is concerned the there will not be enough space between the distributor and the bulkhead. We did some measuring and it will be a very tight fit (1/4 of an inch tight) using a 5" pipe. Maybe this is why "they" built the exhaust the way they did?? Looking at it, I am also concerned that the movement of the motor might make the pipe rub or create heat on other components being so tight at the rear of the motor. We discussed turning the headers 180 degrees. is that possible? We thought that if we could do that, it would allow for allot more space and fabrication would be considerably easier.

 

[Ratickle]

You would be back down to 4" where the exhaust passes the distributor. Smaller than your current 4" wrapped.

I'll have a sketch and some pics up tomorrow.

 

[Ratickle]

This is not an exact picture, but will give you an idea. You will have an elbow inside an elbow. The beginning, because of the way your headers are, will have the ID size the same as th OD of your header exit. That way it will slip over exactly like your current elbow and you will use high temp silicone just as you do now.

That elbow will make the entire curve and actually be longer on both ends than the outer, 5", elbow that will jacket the interior 4" elbow.

You will need four of these elbows. The actual 4" elbow should be exactly the same radius as your current elbows I believe, but you will know more as you mock up the first piece.

 

[Ratickle]

Your second piece may end up as a tee instead of an elbow, it is hard to tell from your pictures how much room you have.

 

[Ratickle]

You can get an idea of what I'm talking about from this photo. Your final will be very similar. The water will come out of your header and go directly into the elbow. The end of the elbow, approximately 10" after the 90 degree bend, will have passage holes to dump the water into your exhaust and mix with the exhaust gas to hold the exjhaust temperature down so exhaust hose and non-jacketed stainless tees or elbows will work. Only the first elbow, or possibly a tee on the outside exhausts, will be jacketed.

Because of your clearance restrictions, you will not be able to go to 5" and leave it that way, you will go back to the 4", (I assume that's what it is), you currently have.

 

[Ratickle]

If you can picture this elbow without the flange, you can kind of get the idea. It will start at 4", slip over your exhaust headers and the water line from your header will go to the water line in the elbow. Then it will neck back down, tapered looks good but not a necessity for function, the hose will slip over (the inside of the inner tube has holes to allow the water to dump into the exhaust), and it goes from there.