So, as I've found out, holsets use a one-off size for the vband flange. Rather than spend $90 on a weld-on flange and a clamp to match the outlet flange on my turbine housing, I spent $170 on a dodge cummins downpipe, which has been rumored to be a close fit.

http://www.puredieselpower.com/catal...ipe-p-219.html

Turns out it fits great, just took about four inches out of the middle out of it and welded it back up. The problem is on the Vband side. With the v-band torqued tight, the V band won't move, but the downpipe is still loose.

A little work with a caliper says the OD of both pipes are the same. Distance across the very outside peak of the Vband flange is .1-ish on the downpipe and .15 on the turbo. The flange is about .300" across at this area, so the downpipe is the problem.

What do I do now? My first thought was to find a thinner v-band flange, but with this strange size, it's hard enough finding holset specific flanges, nevermind a custom sized flange.

My idea is to get some 16 gauge sheet steel and CNC out a spacer that is the same size as the Vband flange. That should give me the extra .05" to make the clamp fit snugly. It would be the same as the spacers found here, fifth from the bottom...except I have no idea what size these are.

http://rjcracing.com/RJC_Buick_Produ...s/gaskets.html

What do you think? Any ideas?

 

Actually, reading this thread:

https://www.rx7club.com/single-turbo-rx-7s-23/v-band-flange-gasket-467421/

and doing a little bit of google work, I think i'm going to try this "compressed graphite" stuff.

http://www.phelpsweb.com/phel3_12.htm

 

Haha you did the same thing i didnt a few years back, and i actually ardered mine from the exsact same place!

 

I saw that...so did your Vband fit okay, or did you make a spacer or gasket, or what?

 

yeah it fits fines no gasket or anything.

 

This is good info to know. I'm getting ready to do a H1C swap here in a couple of weeks, what sort of flanges or modifications do I need to do in order for the v-band to work on the H1C?

 

I can try to get you Cummins part number for their marmon joint. I have it at work--I am on a 2010 Emmissions project and work with Cummins. You can also try to get a part from a truck (semi) dealership or repair shop.

At work we found out that Cummins changed the shape of their marmon joints slightly. Evedently this shape is not controlled very well. This is causing us to look at using a thicker gasket to reduce any leaks.

Hope this helps.

 

Oh wow yeah that would be cool. I was under the impression that most holset single turbo swaps on our cars just used a normal v-band flange for the exhaust... Does the same hold true for the compressor side? Im glad I have a couple of weeks to research this stuff :-)

 

Although some holsets came with a v-band flange off the compressor, i think most just machine it down into a lip and use a standard coupler.

I shot them an e-mail, hopefully I can get a few scraps off a sheet or something.

Thanks for the offer on the P/N...If you remember, it would be good reference. Otherwise, I'm sure it's just

Flange:3910995
clamp: 3905216

and I'm not sure how that helps me, other than cutting off the flange on the downpipe, or maybe if we can find out how big that clamp is...

 

These part numbers for the flange and clamp, what shop or company are they for? And are they for the H1E or do they fit a variety of holsets? I have to ask since I'm dealing with an H1C

 

Cummins Emmission Solutions - 4" Marmon V-band gasket = Q312526
Peterbilt V-band 4"clamp = 90-0012

I don't know if this helps or not. You should be able to get these parts at any Peterbilt dealership. God only knows what we charge the public for parts though.

 

Thanks for the heads up....I'm going to try this gasket material stuff.

 

hope it turns out well.

You could also try a dodge dealership for a late model gasket and clamp. Could be much cheaper than at a class 8 dealership.

 

I called the company and they sent me a free sample/scrap of some of the gasket stuff. However, they didn't have any scraps of just the plain compressed graphite, they sent me stuff that's got a really thin layer of stainless foil in the middle, which, as the representative explained to me, makes it just about impossible to cut with everything you can think of.

Believe me, I tried.

As a last resort, I sent an e-mail to my buddy who works at a laser place asking how much it would be to get a spacer cut out of steel. 1 hour later, I had an e-mail saying they were done and asking where I wanted them shipped! I think this will do it!

Also, for future reference, the H1E custom vband is 3.950" outside diameter, and the inside diameter is 3.385".