Opening up BBK longtube collector

Grn92LX

Fidanza Man!
Founding Member
Jan 14, 2001
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New York
What are you guys doing to open them up? They are incredibly tiny and restrictive. Whats the most you've opened it up to? I wanna run a 3" mid pipe but I wanna see how much the colllector can open up to first.
 
I would junk 'em and get the appropriate header. I really like the MAC 1 3/4" shorties. They are of a much higher quality than most other MAC headers. I'm not sure why. They are rather pricey at $300 but they are coated beautifully and really thick.
 
I already have the ceramic 1 3/4" bbk LT's in the car now. I just never opened them up like I should have. JUst looking to open them up to as close to 3" as possible and run a 3" mid pipe like my combo needs. Gain a few ponys in the process, then its 4.30's and possibly some rear end work and maybe rear suspension work. Just trying to fix my power robbing bottleneck, then its time finish up the rear.
 
I opened mine up a little bit. I think the best thing to do would be run them stock hooked up to your mid pipe for a while. Pop off the mid pipe and check out the black marks from xhaust gasses around the collector, then work from there. Last thing you want is an xhaust leak up that far.
 
Rick 91GT said:
Mike I've done 3", used my die grinder....it doesn't leave you much room though, the rest of the exahust has got to fit really nice and straight.

Rick do you happen to have a pic of what you did? I don't have a die grinder. How much does one cost? The plan is to open my exhaust with a 3" vrs x pipe and open the collector as much as I safely can and then I want to swap in 4.30's (or may just go 4.10) I emailed Ed and he said 4.30's would be a good move.
 
Mike I don't have pics, I took some parts cleaner and cleaned the collector and h-pipe while on the car then I sprayed blue Dykem (machinest blue) on the joint, let it dry then took it apart to see how far I could grind.

I have a air powered die grinder that I use carbide bits on (port heads, manifolds, etc), you could use an electric model as well.
 
A guy on corral said I could use grease, then bolt the pipe up and see how much I could grind. I'll check home depot or lowes and see how much a die grinder is. I'd be nice if I can get close to 3" safely or at least over 2.5".
 
Mike. Heres what my buddy did to open his up on his 331. He welded on 3 bolt flanges on his 1 3/4" BBK's and re-coated them.
581377_136_full.jpg
 
That looks good and is certainly the right way to go about it. I just don't want to have to buy a new collector and have it cut/welded and made to fit. I'd rather just buy a die grinder and open up my collector best I can and use a 3" vrs x pipe.
 
just spray a light coat of paint on the collector then bolt up the pipe then remove it to see how much you can grind away. you can open it up to almost the full 3" and the ball collectors are a lot better than dealing with the 3 bolt collectors and you don't have to fool with gaskets. it's a worth while modification. here are some pics of mine, they look nasty but the car has been sitting for over 3 years. hope that helps.

http://img384.imageshack.us/img384/8950/dsc005661du.jpg

http://img384.imageshack.us/img384/6457/dsc005672ze.jpg

http://img384.imageshack.us/img384/4153/dsc005693ao.jpg
 
Grn92LX said:
I already have the ceramic 1 3/4" bbk LT's in the car now. I just never opened them up like I should have. JUst looking to open them up to as close to 3" as possible and run a 3" mid pipe like my combo needs. Gain a few ponys in the process, then its 4.30's and possibly some rear end work and maybe rear suspension work. Just trying to fix my power robbing bottleneck, then its time finish up the rear.


....I would have thought that those headers would have a big collector already. What junk! I had 1 3/4" mac's and those did have a 3" collector but they were junk anyway!!
 
....I would have thought that those headers would have a big collector already. What junk! I had 1 3/4" mac's and those did have a 3" collector but they were junk anyway!!

They're of the ball and socket variety and BBK really reduces them to make a good fit. You can open them up a little and you're good to go with a leak free connection. I've owned many brands of headers over the years and these are the best I've ever used, fit and finish wise.
 
Thank you Dirtysohc, thats exactly what I was hoping to see! I just want to get as close as I could get to 3" and still be safe.

Qdr, the bbk longtubes are far from junk. I'm on my second set and they are a great fitting header. The only thing thats junk is how their collector necks down so much.

Now, heres another tough question :D Anyone have dyno results by opening up the collector on the bbk's? I remember seeing someone post something about that a while ago but I can't recall who.
 
I've used BBK shorties and for the money I thought they were worth it. But I will say this- once you have bought anything from Bassani everything else is junk. Since I know you do not skimp when it comes to your car, that's what I would recommend. Personally, the Bassani stuff is so expensive that I generally don't buy it.

By the way- I finally got a new clutch and an aluminum flywheel. I did not get the Fidenza though. I got a 9lb flywheel from 10,000 RPM and another Centerforce clutch....I hope it works.
 
Wow 9lbs is light!

Anyhow, I had a set of bassani longtubes I bought for my 347 and I agree they will probably outpower the bbk's but the install of them would have been a nightmare. The slip fits were tighter than a virgin and a HUGE pain in the balls to put together. I sold them and it was a very good decision. I don't have any patience to be banging on a collector with a hammer and then when the time comes to remove them having to deal with a nightmare. I had the 1 5/8-1 3/4" stepped ones. Fwiw the end of the slip on collector necked down to under 3" (around 2.75") Sold them for $250, but I bought them used. You could not pay me enough to deal with that crap!
 
Grn92LX said:
Now, heres another tough question :D Anyone have dyno results by opening up the collector on the bbk's? I remember seeing someone post something about that a while ago but I can't recall who.
When my friend did this his car was N/A. It made 378.5 RWHP before switching the collectors and 402.6 RWHP after switching. Now that he has a blower, I'm sure the gains would have been more. He also switched valve springs but that just extended his RPM more.
 
I had a feeling it was you who posted the results, Sleeper. Thank you. I'd like to see near 400rwhp on a dynojet if possible. Regardless, these collectors are restrictions on my combo and most other combo's.
 
No Problem.

When my buddy made 410 it was with a Cam Motions hydraulic cam that ended up being a little much for the street with his springs. The springs would have been OK for a 1/4 mile at a time but he was driving it all over to break in the new motor. It ended up weakening the springs and dropped a valve at the track and that was the end of that motor. Then he decided to build a blower motor instead of pushing every last HP out of his N/A motor.

Detuned with only 20* of total timing he makes 591 RWHP now.