Cast iron exhaust manifold repair

Quote
Dazed_Driver
I'm getting the martelius header, but I need something until then. TRD Group A used the stock exhaust manifolds, at roughly the same power my engine should be making. Plus, as far as stock cast manifolds go, the 4ag's isnt HORRIBLE. It's just heavy and cracked lol.

I was going to get a cheap OBX trd knock off or something, but that was before... now they're apparently 2.5-3x the price they used to be. I refuse to spend that much just to replace it again.


Al, I can't tell if that was a joke, an insult, or actual shock lol

Nope.

It hadn't crossed my mind that of course they are available. But come on, add 10 hp. drop 40 lbs. and a sweet welding project, I though you would be all over it. Heck, if you came up with a good one you could even sell some.

I actually have flanges cut already, lol. I have 3 or 4 of them

I did consider making a header. But if I was going to make the header, I would get a collector built (burns perhaps?) and want to try to work a deal with Bob at drift office (who is interested in development) and actually make a few prototypes etc to actually create a WORKING viable decent header.

Something I really just don't care to do. I wouldn't want to cobble one together "just because I can" :/

I think if anything I'm going to keep searching for a used ebay header lol. The finnish header is like 750 shipped here, so I'd rather put anything over about 150 towards it, vs buy a "good" header for 400, only to turn around and buy that one for 750 and then sell the "good" one for 300 or less :/

That's my dilemma. So, I guess that's basically driving my wanting to repair this one/find a used cheap header.


Note on Group A - Yeah, I realize that, too. They had to use the stock intake as well. And as you said, I'm sure they were modified stock or even shenanigan stock.

---

Welcome to the cult of JVL drink the koolaid or be banned.

Timm, got a call from Larry said he tried the number you left and no one there heard of you? Call him back.

Well, if you figure out the formula let us know, I have a pile of turbo manifolds with cracks I've been planning to fix.

Mild threadjack: what would a good header design be for a 4 banger rally car? All the tube headers I've seen available for the volvo are 4 into 2 into 1 with loooong tubes, except for this one blurry photo I saw from the fabled volvo "R-sport" catalogue, labeled "rally exhaust". It was 4 into one and had super short, like 5 inch primaries. ?

Back in the day....
I always used the shorter 4 into 1 Datsun truck header. Rumor said it made more torque. Primaries were maybe 12-14 inches (been a while). The long headers and triY headers were said to have more top end. The bigger problem was fitment and ground clearance. Having a 2 1/2 inch pipe drop down is better than a bunch of header tubes.

Quote
heymagic
Back in the day....
I always used the shorter 4 into 1 Datsun truck header. Rumor said it made more torque. Primaries were maybe 12-14 inches (been a while). The long headers and triY headers were said to have more top end. The bigger problem was fitment and ground clearance. Having a 2 1/2 inch pipe drop down is better than a bunch of header tubes.

Yeah what people say is sometimes in conflict with simple concepts we can reflect upon and see.

Long pipes: takes longer for a pulse going 1725 ft/s to get to the end and reflect back.


Short pipe: takes less time.
For a given pipe diameter of course.

Think of organs Short fat pipes make LOW pitch sounds, long skinny ones high notes

You want the thing to work at HIGH frequency of LOW frequency?

A little 1600 motor should have one throttle setting WIDE OPEN...
High revs fed thru a big reduction gear to convert little tint torques into lotsa bigger torques.

(Of course that demands a gear set that doesn't let the rev drop into the basement on every shift)

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Quote
alkun
Well, if you figure out the formula let us know, I have a pile of turbo manifolds with cracks I've been planning to fix.
?

Has anyone used brazing rod on a turbo manifold? I didn't becuase I was unsure of the temps. I ended up using a TIG welder and MG200 rod ($$$$). It worked out okay, but not great.
I have welded/brazed exhaust manifolds on Detroit diesels with a turbo, and they are still holding up after 5+ years.

Quote
phlat65
Timm, got a call from Larry said he tried the number you left and no one there heard of you? Call him back.

hmm, that's odd. I'll give him a call tomorrow. Thanks for the heads up!

---

Welcome to the cult of JVL drink the koolaid or be banned.

Here's a quick and dirty calculator. Lots of articles on the 'net regarding tube length.
http://www.bgsoflex.com/bestheader.html

smartypants.

As far as repairing your cast manifold goes, I have had great success TIG welding them up with Cascade 17T, NI-99, or 99% nickel all the same stuff. As mentioned before, nice big V ground out and pre heat, but don't sweat the post heat with the nickel. Missle rod, or SMW as it is commonly referred to is nothing more than over priced 312 stainless. It will work for cast iron repairs, but is more finicky. It's stronger, but really more trouble and more prone to crack in the future.

---

Boost early and Boost often

I think I got my cheap BBP/ebay header for 170 shipped.

I think I paid my friend another 75-100 or so for the work he did to make it fit (and to make some cam pins that weren't too small for the slots in my adjustable cam gears).

Pics are here if you wanna look how he did it: http://sharkpork.com/gallery/v/vehick/ae86/VPT/

Basically he sliced the collector off where it was (crappily) welded to the primaries, then sliced the two outer primaries off right at the flange, then rotated them a hair to give me a half-inch clearance from the steering rack, probably about a one-inch movement overall, then re-welded the primaries together before attaching the collector again. And he re-cut/welded the back part so it didn't run right into the floorpan anymore.

Bob was pretty spot-on when he told me how well it was going to work, I was not disappointed!

--sarge

---

---** To be in compliance with the Anarchy **---
Jorden R. Kleier
Baraboo, Wisconsin, USA
1990 Mazdog Protege 4WD
1973