2f Tri-Mil Header Fitment Issues

[SliderJack]

I picked up a used Tri-Mil header from a fellow mudder. I was test fitting it today before I clean it up and I can't see how it's going to make a good seal in its current form, and I'm wondering what other peoples' experiences are.

It seems that the regular bolt and washer don't make contact with the header flange, the slip right by it.

I've searched and heard some mention of washers or shims. Is that what peolpe are doing? Do they come with the header? Are they oval in shape so that they don't exend onto the intake and only the header?

I'm tempted to try and weld some material into the bolt area so the bolt would actually have something to clamp to. I don't understand why they are so sloppy fitting.

In their current state there is little clamping pressure and I can rock the header back and forth with just the center bolts tightened with the intake installed.

 

[Weber Sarge]

That flange is worn , the bolt surface should be basically like the intake side . Got a good clear pic of the whole flange ?
Sarge

 

[SliderJack]

That flange is worn , the bolt surface should be basically like the intake side . Got a good clear pic of the whole flange ?
Sarge

I've seen pics of other peoples' headers and they look similar. There isn't a recessed portion where the bolt and washer clamps too--like on the intake side.

So I'm wonder what people with these headers do and whether this is why there are so many complaints about headers and not sealing.

 

[SliderJack]

For comparison here are some pictures posted by another mudder awhile ago and the flange looks similar.

 

[Weber Sarge]

The cutouts for the bolts on mine didn't look that big , that's my point .
I did have to mill out the intake side bolt surfaces to match the header flange height after milling the intake head surface dead flat . Still sounds like I have a very slight leak , haven't had time to figure out where .
Sarge

 

[Shark56]

Many have used a washer cut in half to make up the difference in thickness on the intake side. Then use a larger washer to clamp both the headed and the intake to the block. A Rem-Flex gasket helps with sealing.

 

[Pighead]

All headers require grinding/clearancing to mate up to the intake manifold...perhaps your header's PO went a little far? Or used bigger bolts?

 

[SliderJack]

Thanks for the replies. I'll try and figure something out with this in the next week or so. No time this week or this weekend.

I'll probably look at some type of split washer but I might end up adding some material to the flange.

 

[Weber Sarge]

Just a note - I used a trim router to mill off the bolt surfaces on my intake to the same height as the header flange - it's a bit tricky to find the right bit to match the radius but a roundover is what I used . Odd part is the router has to sit on the machined head side of the intake and you use the very top cutting face of the router bit to do the work . Just kept dialing down the fine adjustment until the height was correct . Someone posted up the idea here , not sure who it was but a great tip anyway .
Sarge

 

[SliderJack]

Took awhile, but got the header cleaned up. We cut and welded round blanks to fill the gaps. We drilled the holes and milled a recess into the header flange to match the thickness of the intake. Hopefully I get a good seal now. I don't understand while these headers aren't built better--is there that much variance of intake thickness and bolt placement? We wrestled with just cutting out a new flange and rewelding--that might have been easier.

Anyone know the collector size? Is it 2.5"? Next I'm going to order some universal exhaust pieces to complete the exhaust.

 

[DougAustinTx]

I have had two of the tri-mils on two different 2F's. The header flanges weren't flat on either set and I had to mill the sealing surfaces flat. Once that was done, I cut some 3/16" steel strips about an inch wide and 1 1/2" long and drilled the center. The metal strips acted like horizontal clamps when the nuts were tightened and pressed both the intake and the exhaust flanges down hard. Tri-Mils are kind of cheap basic headers that need "massaging" to work correctly.

 

[SliderJack]

I have had two of the tri-mils on two different 2F's. The header flanges weren't flat on either set and I had to mill the sealing surfaces flat. Once that was done, I cut some 3/16" steel strips about an inch wide and 1 1/2" long and drilled the center. The metal strips acted like horizontal clamps when the nuts were tightened and pressed both the intake and the exhaust flanges down hard. Tri-Mils are kind of cheap basic headers that need "massaging" to work correctly.

Nice job! I think people should know that about the headers before hand. Maybe this thread will help with that.

 

[Weber Sarge]

I had made a thread about this very issue , my header was well made and very flat but the whole issue is the thickness of the intake flange . I just chose to use a router bit from the head side on the intake to mill the thickness of the bolt seat area to match the header's flange - worked out great and doesn't leak .
Sarge