Hey all Im looking to fabricate a log style exhaust manifold for my car do to clearance issues. The engine is a 326 ci v12 from a jag. What diameter and thickness should i use ? I was thinking a 2" diameter 1/8" wall pipe? I'm hoping to have them exit almost right at end of the block then the exhaust will connect there. thanks in advance levi
Cheap exhaust tubing is 16 ga. Heavy duty tubing is 14 ga. Most header U bends are 16 ga. Just get the header U bends and make it look good. You don't want the extra weight anyway. The first bend is usually the smaller primary size to start the log and then the log is bumped up to the larger size. For a V12 with six ports per side, I think that I would use 2 1/4" for the log and the remaining exhaust. JMHO
Log intakes I've heard of; an early way to get a multi-carb manifold to act sort-of half-way like a plenum manifold. That is, make better use of the carbs' flow capacity. Log exhausts? Unless you mean those sort of large-diameter torpedo-looking things you saw on WWI aircraft and Edwardian racers? I wouldn't, unless you were doing something with a distinct Edwardian Monstrosity feel, as there's no pulse manipulation effect and probably a lot of restriction. Are you sure there's no way you can do tube headers, even made-up one-off ones? Surely there must be a way? I mean, twelve pipes can be bundled in lots of different combinations and led variously under, over, or around whatever needs to be cleared.
I got this from your other thread: It seems you've got those "shelves" to contend with. Where exactly is the frame inside/under them?
I wouldn't build a log unless I was going for the look that Tommy posted. just get yourself some U or J bends from the catalog race supplier of your choice, make some flamges to bolt to the head and build yourself a set of headers with a collector on the end. You could infact build them with 2 collectors per side linking 3 ports for each. That would guve you 4 exhaust pipe. or you could tie 2 exhaust pipes together per side to come up with a dual exhaust if you wanted. With a v-12 the possibilities are endless.
I really like these. The curves of the center ports make it very appealing to my eye. It's hard to take my eyes off of the 34 P/U but these headers stand out in a crowd. IMHO. I like log style headers because they look old. This style was used for engine transplants in the 60s and not necessarily to get the most HP. Someone took some time to get this set right. I tried to find the thread that I copied this from to credit it's source but I couldn't find it.
the shelves have been eliminated i cut those back past the frame rails the problem is the steering box the stock manifolds have a rams horn design and dump right on top of the box. also i have to lower the front of the engine down right now i have an 11 degree tail shaft angle. once i drop the front of the engine down the manifold on the driver's side will be resting on the steering box. if it was a lil warmer out i would go snap some pics but its -35 celcius outside so my time in my garage is limited lol.
My first thought is to build a set of headers of which the forward three pipes shoot out horizontally into the wheel-well area, around the steering box, and hence back to the collector. It might be necessary to make it in two parts, if it isn't possible to design it so that it can be wiggled into position with the engine installed. Otherwise you can pull the steering column and re-install once the header is in.
theses are taken from inside the fenderwell. I think i may have a solution what i need to do is build a plate that will allow me invert the stock manifolds so they exit up and not down.
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