Exh Manifold to turbo bolts... options?

[Kenny_Kline]

Ok here is the deal. I no longer can run the standard length turbo bolts anymore. The hotside I have has the threads drilled out for some reason. If I wanted to use the standard size length bolts but get thicker bolts, I would have to drill out my manifold bolt holes and then tap the hotside for the larger bolts.

As some of you may know, this is a critical sealing point for the turbo. I cannot have a leak and need to make sure I can torque this flange down good and not have to worry about it leaking.

One option is I was thinking of getting 1/2"-3/4" longer bolts and putting a nut on the other side of the flange. Do it to all 4 and weld the nut in place then take it back apart and there are my threads. Its really the only reasonable thing I can think of but then the question is, what material should the bolt be made out of and what thread pitch. I think a stainless steel bolt will be the best w/ a fine pitch?

Need some reasonable opinions and possibly maybe a better way to seal this gasket . Need a bolt material that can take this kind of stress and heat and wont have issues. Whatever the stock bolts are made out of, thats what I want but needs to be 1/2" longer.

I dont know. Here are a few pics of the flange. I have room for the nut to get under there and if I didnt, I could easily clean up to make one fit.

Also, I am thinking about using ultra grey RTV for the O2 housing to hot side seal. They dont make a gasket big enough for the hotside I have.

 

[iLLeffeKt vr-4]

I can't help you with the bolts but I can tell you that any RTV used in that area will burn off right away. Try porting out the gasket as much as possible.

 

[Kenny_Kline]

I will try to port out the gasket. Good idea.

 

[slugsgomoo]

buy a SS gasket designed for the 7cm hotside, RTV is just going to make a mess, and will seal worse than no gasket. /ubbthreads/images/graemlins/dunno.gif

as for the bolt holes, I don't know. I gave up on trying to get that ship to sail and threw the housing away and got a new one- and that's after putting like 6 hours of port work into it. d'oh. /ubbthreads/images/graemlins/banghead.gif

 

[Kenny_Kline]

A 7cm gasket is WAY to small. I already have one but am going to try and port it out.

I really want to run this hotside. The most restricted part of our exhausts is the hotside. This hotside is a beast and will outflow any 14b/16g/20g hotside. I must stick with this hotside. I have to make it work.

Did you have issues with your holes being stripped out? Did you try and use the nut and weld method at all?

 

[bigblock4g63]

pita but get longer studs and weld the them to the bottom of the flange were it bolts to the manifold. i have seen this done more then once

 

[bigblock4g63]

that looks like a evo16g so the 7cm gasket does work but i have seen so peoples 7cm gasket be a little smaller then a oem 7cm gasket
Quoting Kenny_Kline:
A 7cm gasket is WAY to small. I already have one but am going to try and port it out.

I really want to run this hotside. The most restricted part of our exhausts is the hotside. This hotside is a beast and will outflow any 14b/16g/20g hotside. I must stick with this hotside. I have to make it work.

Did you have issues with your holes being stripped out? Did you try and use the nut and weld method at all?

 

[mikus]

i used 2 bolts/nuts before, along with two proper turbo bolts - you can do that on two of them without grinding/welding... I used some hard metal from local hardware store, it worked fine.

Do as you will, but I agree with above - this will be at best difficult, and at worst a tedious effort with no payoff. Even drilling out the exh mani and using those thread fix thingies (sorry, brain doesn't work) would be easier IMO.

I keep an extra hotside on teh shelf for next time mine eats turbo bolts beyond reasonable repair.

 

[Kenny_Kline]

Again, no a 7cm gasket is WAY to small. Will not work... unless I port out the gasket which I will try.

If anyone can find the right gasket for me, that would be awesome but I doubt it. I have looked.

 

[Kenny_Kline]

I have 3 hotside. 2 of them are 7cm and one of them is a 6cm. All mint no cracks. But I want to run this hotside.

What about a heli coil? I can use the stock bolts for that if they can handle the stress. Anyone ever done it?

 

[bigblock4g63]

 

[Kenny_Kline]

I can clean it up a bit to fit the nut in... I dont know. I will try a couple differing things. First will be a heli coil

 

[bigblock4g63]

from what i remember. the part number is md185805, some people are saleing the 2gen gasket as the evo3 and some shops are 7cm gasket are not really 7cm more like 6 and half cm gasket. can you post a pic of the 7cm gasket over the 02. there is a guy here in new jersey who make a 8cm gasket
Quoting Kenny_Kline:
I have 3 hotside. 2 of them are 7cm and one of them is a 6cm. All mint no cracks. But I want to run this hotside.

What about a heli coil? I can use the stock bolts for that if they can handle the stress. Anyone ever done it?

 

[Kenny_Kline]

8cm gasket is to small too. Here is a pic of the 7cm gasket on a 7cm hotside:

to confirm its a 7cm hotside:

Here is a pic of the new hotside:

I dont have any pics of the gasket over it... trust me when I say its to small.



I might just start looking for the material they use to make these gaskets so I can just make my own so it will fit this hotside



I found this for the thread issue I am having. I think this is my best bet. click

 

[Kenny_Kline]

All figured out. Thanks for the help anyways guys.

-K

 

[turbowop]

I highly doubt you'd even notice a difference between a normal 7cm housing and that thing, be it spool up or power.

Sand in Kenny's vagina in 3...2...1...

 

[Kenny_Kline]

Why wouldn't you notice a power difference? The exhaust side is .33" bigger than a ported 7cm hotside. You want to maintain a back pressure level as close to the boost pressure your running. Some of these hotsides are around 40-50psi back pressure. Thats bad! The turbine side has a fatter scroll and more room for exhaust to go. You might lose about 600-900rpm spool up with this hotside, but will make up for it up top where the power is needed.

 

[turbowop]

It has a .33" bigger inlet, or is the entire volute bigger thoughout? It looks like one of those Chinese housings? /ubbthreads/images/graemlins/dunno.gif

I find it a bit strange that a guy who thought he could use ultragrey RTV to seal the O2 housing is such an expert on turbine housings. /ubbthreads/images/graemlins/hsugh.gif

 

[Kenny_Kline]

its .33 bigger on the exhaust outlet into the O2 housings. The actual turbine housing has better machine work inside to help flow. That and its alot bigger as it goes through the turbine.

FYI, I have seen ultra grey used all the time on turbo flanges but these cars maybe see about 5 miles tops a year. I was just questioning the durability of it over time. Wasnt sure. Sue me for not knowing.

And I know more about turbine housings than you think. Do you have some personal thing against me? That why your questioning me/riding me hard? Find something else better to do with your time please. kthxbye

 

[turbowop]

Well .33" bigger in the outlet has nothing to do with any backpressure before the turbine wheel, which is what you say you're trying to lower. /ubbthreads/images/graemlins/confused.gif

It's certainly not going to make a measureable horsepower difference in that 2" before the O2 housing.

I don't really like you or your posts because of your past arrogance, but that has nothing to do with my questioning your need to go to such lengths to use a turbine housing that's probably not worth it.