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-   -   Is it possible/feasible to braze collapsed side iron coolant retaining walls? NA S5 (https://www.rx7club.com/general-rotary-tech-support-11/possible-feasible-braze-collapsed-side-iron-coolant-retaining-walls-na-s5-1071802/)

300D50 09-21-14 04:21 PM

Is it possible/feasible to braze collapsed side iron coolant retaining walls? NA S5
 
As the post title says, I'm looking at the feasibility of brazing the collapsed jacket walls on the side irons.

I would think that as long as I can machine the seal groove to match, and dust down the brazed portion to the same height as the rest of the iron via the glass + laping compound method, it should work.

I've got a center iron that has one failed jacket wall, and is otherwise good as far as a cursory inspection goes.

The front iron has 2 spots of breakout, pitting in the iron face at the breakout zones, and some corner seal step wear that my fingernail catches on over by the plugs.
http://zarnochwf1.com/gallery2/d/783...1278343458.jpg


http://zarnochwf1.com/gallery2/d/783...1278556813.jpg

This was a junkyard special engine that I got as a measurement aid for a project, and prev owners ran it with straight water and leak seal powder for who knows how long.

Luckily the rotors and their housings are within specifications, as are the bearings and gears.

I remember seeing a inner seal "repair" thread on one of the forums, where someone used a loop of thin stainless spring stock laid in the groove, and thinner combustion seals, to limp engines along.
Also have heard of the shadetree "throw an apex seal spring in and give it some RTV" method.

I'm inclined to believe that proper brazing and re-machining should hold up better than those options.
We all know cast iron is a pain in the nether regions to weld, hence the thought of brazing.

The hunt is on for new (to me) center and front irons anyways, in case this is infeasible.

Any insights and comments are appreciated.

diabolical1 09-21-14 06:07 PM

i remember a member on here did repair an eroded/broken water seal groove a while back and from what i remember it looked fine. however, i don't remember if he ran the engine, and if so, i certainly don't know how long it lasted.

honestly though, you're better off getting some new housings. even if you repaired the water seal area, that gouge is pretty bad.

rmx5 09-22-14 12:05 AM

I've thought about doing this on some spare irons that I have laying around.

misterstyx69 09-22-14 12:49 AM

No offense but I'd call the Navy and see if they need a spare anchor.

Personally,I wouldn't use that iron,and for what its worth I wouldn't even put an effort into it,considering that you can get irons rather cheaply used now a days.

Don't get me wrong.There is always a way to 'make a better mousetrap'.But seeing the time and effort being consumed to fix this piece,I'd rather see you use your time in a better manner actually driving the car with a good engine in it,than having to tear the whole damn engine apart again because the fix didn't work.
Best of luck to ya regardless.

300D50 09-23-14 01:04 AM

Yeah, I'll probably end up sending these to Davy Jones' locker.
Step wear on the front housing is well outside the lap limits, and the intermediate looks like there's another wall on it's way out.

After consulting some associates in the welding trade, I was informed that theyd have to have them TIG welded, all along the sides, in order for it to hold.

So it'd be weld, blanchard grind flat, remachine the seal grooves to proper depth/width, diamond lap, then TiNi sputter.

Might be worth it for a 20B fat iron, but not for an S5 NA one.

Anyways, thanks for the input gentlemen, it's been a good thought experiment.


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