NoPistons -Mazda Rx7 & Rx8 Rotary Forum - Jb Welb Holding Up In Motor?

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- - Jb Welb Holding Up In Motor? (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/jb-welb-holding-up-motor-33832/)

I think Vosko mentioned that he had to use Devcon in his motor, and it broke. JB weld held better.

Quote:

Originally Posted by Judge Ito' date='Feb 15 2004, 06:05 AM

I also have tips and tricks for this problem. I think I should write a "if you ported into the water jacket fix it mod"

Mm...that would be great for us newbies that **** **** up when we so our own porting , Judge Ito.

Its pretty hard to go too far if you are doing just a regular street port. The one I made is VERY aggressive.

Quote:

Originally Posted by Silver Ninety Three' date='Feb 14 2004, 08:12 PM

Well after spending like 5 hours on my 2ndary ports, SOMEONE decided that they needed to be cleaned up further and broke into the water jacket. The port is a monstrous street port and the pinhole is about 1/4" from where it closes towards the center of the rotor housing. I couldn't find any devcon at the autoparts store, just some other liquid steel stuff that wasn't recomended for coolant. I used some jb weld to fill in the pinhole. This was the front iron, so I was also able to put jb welb on the inside through the hole for the water pump gasket. I plan to let it cure for a coupkle days then sand it down smooth to the rest of the port. I considered welding it. I could probably get to the back through the hole from the water pump and put a spot weld in there. Think I should do that, or will the jb hold up? I don't have the time to report another housing.

I would clean the back side of the damaged area to bare metal. Use a corse sanding drum on a dremel.

Tape over the hole on the port side and lay in about 1/4 of epoxy material inside the water jacket. Make a big spot of it. Pile it on. If it was down to bare metal. If it was rough, and if it was clean. it will never leak. Just not a problem. It only ever gets hot after shut down when the engine normalizes (heat soaks). While running, the intake side is cold on a NA engine.

Here's a pic. Its not great. The jb is the grayish stuff where the port begins to close. I sanded it smooth to the rest of the port.

Shot ofthe backside. Coudln't really get in there with the camera but the jb weld can be seen right along the bottomline of the hole for the water pump.

just happened to me today trying to get my ports to match in my int. i was just thinking just a little more then i see that little black bitch of a hole and that was it i was so pissed https://www.nopistons.com/forums/pub...1047683358.gif anyways any one have any tips for port matching?

This is one of the reasons why I refuse to offer porting templates.

Porting is a 3D process which goes beyond the 2D porting template.

Experienced rotary engine porting experts know what the limits of the irons are, and do their best not to induce damage or dangerous porting techniques that can compromise the engine (i.e. water jacket).

-Ted