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Old 02-14-2004, 03:03 AM   #1
skid
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Pictures of two into one exhaust

I'm using Brzyzinski Racing's two into one exhaust collector and mandrel bent 2.5" pipe from ported (to a 1404 Fel-Pro gasket) Corvette Ram Horn manifolds.

Here is a picture of the passenger side exhaust from the collector to just in front of the transfer case cross member



Here is the same pipe turning in front of the transfer case and getting ready to join into the collector



Here is a picture of the 2 into 1 collector. I have a band clamp on the bottom pipe and will be putting one on the top as well. This will allow me to dis-assemble the system easily for any maintenance.



This is the 2-1 leading into the muffler (dynomax ultra-flow rv muffler)



Here is a picture from behind the transfer case



Here is the drivers side



This is from the transfer case crossmember forward



Here is a picture of the beast (sorry for the mess)



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Last edited by skid; 02-14-2004 at 09:45 PM.
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Old 02-14-2004, 03:23 AM   #2
skid
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More pic's



Drivers side



The muffler is a 3" in and out". Here is a pic of 3" mandrel bent (180 degree) and 2.5" (90 degree)



Corvette manifold. Looks the same as stock except for the paint color. I would have used a cast iron colored paint if I could find one which would handle the heat. The tin for the snorkel warmer tube that goes to the air cleaner fits around these manifolds



Another pic of just how tight I had to tuck it up against the cross member and the front drive shaft to minimize damage when off roading


Now I just have to get off my butt and build from the muffler back!
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Last edited by skid; 02-14-2004 at 03:27 AM.
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Old 02-14-2004, 09:11 AM   #3
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the dreaded X strikes again
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71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension.
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Old 02-14-2004, 02:11 PM   #4
skid
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Still not working? The pics come up for me.
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Old 02-14-2004, 06:32 PM   #5
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got the dreaded x too.....

maybe i need to change something in the OS?
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Old 02-14-2004, 10:10 PM   #6
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No pics for me either...
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Old 02-15-2004, 03:48 PM   #7
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Please fix. I am interested in seeing pics. I htink the 'vette manifolds are a fine alternative to headers. Got any pics of the ported manifolds? How about price?
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Old 02-15-2004, 08:16 PM   #8
skid
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Mike C

I ported the manifolds myself. I used a 1404 felpro for a template. I just sprayed the flange with machinists blue (even dark spray paint would work), and used the gasket to scribe the larger dimensions. I talked to Randy Brzyzinsky www.castheads.com and he said that's all he does as well. In years past he ported the inside of the manifold, but the dyno has proven that unnecessary. He did say that ported corvette manifolds will NOT restrict your exhaust valve. I bought my manifolds new from a local Chevy dealer, and ground off the generator mounts. They look completely stock! I put the ground portion facing towards the firewall.
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Old 02-17-2004, 10:44 PM   #9
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Thanks for the info. I have the 'vette manifolds on my Jimmy. I want to get another set and fully port them for the 355 I am installing in my 64 'vette. I will use 72 Chevy truck brackets for alternator and WP, so I will chop and grind generator mounts off. I whacked mine off with a band saw and then used a grinder to round off edges. I used two drivers side manifolds because they were a few dollars cheaper. But as a result, one of the sawed off mounts goes forward, but you can't see it behind AC and alternator anyhow. Exhaust looks good in the other pics. But why did you decide single? I am thinking about single 3" on my BB with a 36" Walker RV muffler and the FLowmaster 2 1.2" into 3" Y-pipe.
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Old 02-18-2004, 12:01 AM   #10
skid
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Mike C

As long as a single can flow enough cfm for your application, it will be superior to duals. The reasoning behind this is that the exhaust from one side of the engine will help scavenge (pull) from the other side. That is the reasoning behind the X pipe as well. A single is easier to package on a blazer because the transfer case blocks one side of the frame rails, plus it requires 1/2 as much welding and work and materials (muffler, tailpipe, hangers, etc.). Plus with all the flow going throught the single pipe, it keeps the pipe hotter, allowing more efficiency.

With the advent of mandrel bent exhaust pipe, unrestricted flow for a 500 hp engine can be had in a single 3" pipe. I do have a 400+ hp smallblock sitting in the garage that may eventually find its way into the blazer. Just have to change to a milder cam.
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Old 02-18-2004, 12:28 PM   #11
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skid,

what do you think about torque? I hear the 2 into 1 is great for torque..........What if you have a stock 350 (actually a mild RV cam and a 600cfm edlebrock carb).........I have heard that with a mild setup one can kill torque with big pipes........I think 2.25 is a good pipe size for a stock 350 w/ duals.......but would 2.5 be ok for a 2 into 1?
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Old 02-19-2004, 01:59 AM   #12
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72 C5

That's a good question, because smaller primaries in a header help torque but limit hp while larger primaries are better for high rpm hp. This is my opinion: The Corvette manifolds act as your "header", while the rest of the exhaust just serves to muffle and expel the gases and hopefully not cause any back pressure.

Under cursory examination, the Corvette manifold "primaries" appear to be the same size as the stock truck ram horns (the tin for the snorkel heater fits the same as stock). The only difference is the size of the output "collector". I don't think that you would lose any torque as compared to stock, but would gain hp in the upper ranges.

The best system for torque would be small diameter primary (say 1.5"), long tube headers with a 2.5" collector. The best system for hp would be larger primary (1.625 or 1.75") headers with a 3" collector. I think the Corvette manifolds will make more hp than stock with the same amount of torque, but will make less hp and torque than either header system. The 2-1 will help make more power, but would work equally well with headers. I went with the Corvette manifolds because they look stock, make more power, and the snorkel warmer tube would work with them. Plus headers can sometimes be a hassle to package, maintain, and work around.

I don't know if using 2.25" pipes from the manifold would make more torque than 2.5" pipes. Only the dyno would know for sure. That would be a good question to ask Randy Brzezinsky, as he sells that kit as well. Call him at 262 246-8577. He is actually quite pleasant and knowlegeable to talk to. When I start driving my truck again in a couple of weeks or so, I will let you know what the butt dyno tells me!
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