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-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   since i am on a budget now.... JB weld is my friend! (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/since-i-am-budget-now-jb-weld-my-friend-366162/)

RotaryEvolution 11-07-04 05:22 PM

since i am on a budget now.... JB weld is my friend!
 
well after the first overhaul failed and i was forced to pull it out and troubleshoot the failure...

i found that i overlooked some electrolysis, it ate away at the front rotor housing water jacket, the water pump housing was also pitted all to hell, i was able to find a replacement for the water pump housing. the iron housings i ordered from a seller on the forums was damaged in shipping so i added some JB weld to the chip at the coolant jacket....

well i have seen it do some pretty miraculous things so i am going to risk it all an go for it. this project taken 8 months to complete i am fed up with the problems so i am not going to waste more time and money so i am going with the $6 fix!

i am shooting for 300 RWHP with this engine, which will be an even tougher task for this gamble.

wish me luck, i will post some pics of my repairs a little later.

1RevvinFC3S 11-07-04 05:52 PM

LOL!!! I used JB Weld on my air pump bracket (cracked completely through) and its holding up just fine. That stuff is like, religion, or something. ALL HAIL JB WELD :bowdown: :bowdown: JB Weld :bowdown: :bowdown:

gsracer 11-07-04 07:26 PM

Sure will be a pain in the ass when the JB weld cracks.

boogerboy 11-07-04 07:33 PM

thats what i was thinking, itll be like a big chunk of carbon, but jbweld

tecknomage 11-07-04 08:50 PM

JBweld is like duck tape if you cant duck it fuck it :)

RotaryEvolution 11-07-04 09:20 PM

lol well we will see, and how long it lasts... it isn't anywhere inside the engine or near moving parts, it is just in the water jackets where the coolant will keep it cool.

RotaryEvolution 11-07-04 09:29 PM

http://img108.exs.cx/img108/8305/Picture034.jpg

http://img108.exs.cx/img108/5480/Picture035.jpg




the holes in the rotor housing were minimal but since it is the hottest part i wrapped a decent amount around the whole exhaust port so it won't be able to work itself loose.

the iron housing, the chip is only about 6mm long. the seal would probably have stayed in on it's own(the break was rather jagged and not below the seal surface) but i would rather not leave it as it was.

one or the other will probably fail in time, just how long is the question.

RotaryEvolution 11-07-04 10:24 PM

i realize i must look like an idiot for even admitting to doing this with my engine, but hey, when you got nothing to lose you sure can push your engine to it's limits without worry because you expect it to fail. if it doesn't and you exceed your expectations then you should be grateful. :)

RotaryEvolution 11-12-04 08:26 PM

http://img35.exs.cx/img35/1743/Picture1358.jpg

http://img35.exs.cx/img35/6964/Picture1359.jpg

http://img35.exs.cx/img35/8496/Picture1360.jpg

RotaryEvolution 11-12-04 08:31 PM

it should be in and running tomorrow evening, i have to fix a customer's car before i finish this project. i will let you all know if/how it holds up. :)

RotaryEvolution 11-14-04 11:52 AM

coolant leaking into rear housing now, the electrolysis was in the front rotor housing. though i checked for leaks at both rotor housings.... i was sure i found the problem, this is becoming too aggravating.

Kingofl337 11-14-04 11:56 AM

Sounds like you have a cracked housing. You just installed the front housing in the rear. So the problem moved.

RotaryEvolution 11-14-04 01:16 PM

the housings never changed position, i checked for cracks and even sealed the side of the housings and filled them with water and checked them for leaks. this problem is eluding me and irritating to say the least.


it is drawing coolant in during the intake cycle because the coolant is spraying out the combustion chamber when i have the leading plug removed, the cooling system is also being pressurized, it has classic symptoms of a blown compression o-ring but i lapped the housings and checked the clearances, i couldn't fit my smallest feeler guage between the rotor housing and the iron housings. i guess i will pull it back out and start over.

i would scrap the project aside from the fact that i have at the very least $1k in parts invested in the engine alone and about a full days work porting and cleaning the housings not to mention the time i have spent measuring the tolerances and clearancing everything. i put brand new mazda side seals and springs in, brand new Atkins solid corner seals, new Atkins apex seals and all new factory gaskets and seals, and i just installed a new clutch set as well.

gildardo 11-14-04 01:40 PM

That sucks man, hope you fix it.


Gil

Turblown 11-14-04 01:59 PM

People usually just build up thin walls, not broken ones. Should report back to this thread every 5k miles or so; I'm curious how long that will last.

RotaryEvolution 11-14-04 02:05 PM

read further down, i'm sure it isn't the my repairs that are causing this on going issue though.. i have had the engine out 2 times, this will be the third. unless anyone has any ideas of something to check or have had similar problems?

RotaryEvolution 11-24-04 09:20 PM

here is your update....


the boost is creeping to 6PSI now after the port mods and the JB weld rebuild has close to 300 miles on it and got it's first oil change today, though i had to add in some thicker oil because i think the front cover o-ring is bypassing but i plan on omitting the gasket and updating the fitment on that soon and likely install a high pressure oil pump because this one is pushing 160k miles on it...

it did have a couple instances of getting warm but i believe that is/was a thermostat problem so i am going to replace it soon as well.

i did rev it kind of high on a few occasions accidentally(7500+ RPMs) but nothing of note happened afterwards and it drove fine still. the 3800 RPM hesitation is more pronounced now though, when i first got the car i don't remember feeling it at all but i only drove the car 60 or so miles..

the car pulls harder than ever and seems to be doing just fine and more mods are in the works soon, starting with my SAFC2 and looking to get a full 3" turboback system. ;)

RotaryEvolution 11-24-04 09:23 PM

oh, and the last and final problem was electrolysis at the rear rotor housing leading plug, it was shooting right on the tip of the spark plug... nothing a little more JB weld couldn't fix.

scary huh?! :D

Wankel7 05-13-05 10:22 PM

Yeah, gonna need an update on this one :)

James

RotaryEvolution 05-13-05 10:30 PM

the JB weld on the rotor housings actually seemed to hold up well, the iron didn't last long but i'm sure you all knew that... =P


it lasted 4k miles before it failed. got what i needed out of it and pulled and tore down the engine, replaced the bad iron with one of my spare good ones and retroffited some n/a rotor housings to work in turbo applications. the car, i would estimate is putting out ~230-240RWHP at 10psi and i will be adding a T04B hybrid and microtech standalone in a few weeks.


long story short, don't try to short cut and listen to your elders.... :)

all in all, it was a good learning experience for me and i don't listen to what the old crotchety guy down the street who used to rebuild 10 and 12a's and owns his own shop sais anymore. :p: i should have went with my gut and found some good parts in the first place.

you only can learn from mistakes though, i feel 100% comfortable rebuilding my own and other people's engines now after my own trial and errors.

i've rebuilt one other forum members engine since and i'm working on another members T2 right now and i'll be doing a few mods to it to free up things a bit.

i've learned a lifetime's worth in these past 5 months about what works, what doesn't and what works well in these engines.

RETed 05-14-05 03:10 AM

Uh, be prepared for another rebuild.
Stuff like this isn't supposed to hold.
It's not the bond of the JB Weld to the steel that's the problem.
It's the difference in expansion and contraction rates that will cause the JB Weld to fail.


-Ted

rcjunkie 05-14-05 08:00 AM

I've been fairly impressed with JB weld in many uses from fixing a radiator endcap to plugging an oil leak on a 4,500 HP turbine's engine case that was cracked.

Wankel7 05-14-05 08:55 AM


Originally Posted by rcjunkie
I've been fairly impressed with JB weld in many uses from fixing a radiator endcap to plugging an oil leak on a 4,500 HP turbine's engine case that was cracked.


Please say that turbine engine wasn't in a plane

NSBerkland 05-14-05 09:42 AM


Originally Posted by Wankel7
Please say that turbine engine wasn't in a plane

:crackup: ohman that would suck.

sleejay 05-14-05 10:41 AM

terrorist. :rlaugh:


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