I hope I am not redoing an old topic here. Does anyone have any advice or preference when it comes to a set of Fentons or splitting the original exhaust. Fentons are expensive and difficult to locate. I can readily pick up an original split exhaust of Ebay for less than $100. I am looking fo better fuel economy but of course more or less looking for the buzzing of half a dozen. Do Fentons sound better? Most of the original split exhuasts I see have the heat riser welded open and the new welded port is usually smaller than the stock opening... two different sizes of pipes? I want to get the stock split exhaust but I am hesitating. Let me know
Fuel Economy ? What's that on a older straight 6 ? None of those engines get anything close to decent mileage normally. The Fenton manifolds were a performance upgrade option not really meant to improve gas mileage. What Year truck do you have anyway Ryan ?
Lots of factors effective gas mileage. Mainly to start proper valve adjustment,tuning such as proper timing,engine idle speed.etc... Not sure what your expections are ? Switching the exhaust will not gain much if anything. Probably best to make sure your basic settings are all proper then make sure the carb is set proper. Gauge your mileage after that. These trucks brand new were never the Gas Mileage Kings much less after a bunch of years added on. Also other items such as proper tire pressures come into effect. I think Nate & the boys had a recent post related to proper tire pressures.
I think, and you guys correct me if i'm wrong, rear end ratio has a lot to do with fuel efficiency. It stands to reason that the higher the ratio, the more pulling power you have, but less fuel efficiency. Has anyone out there ever ran a 4:11 then changed to a 3:55 checking fuel economy before? If not I may be the guinea pig on that (Assuming i ever get mine to that point!)
Yeah Ken, the rear end is a big factor for fuel economy. Ok, I guess basically that it was a kanundrum to bring in gas efficiency into this matter. I really want to know from one of you guys who have done the split original manifold and your opinion of it. How did it sound? Did it sound like a set of Fentons or does it sound like a stock exhaust? Either way, you are reducing the amount of exhaust back pressure on the valves adding moderate performance and extending engine life, right? TIA~Ryan
I had a split on a 53 Chevy sedan more years ago than I care to remember,but it sounded great! Depending on what mufflers you use,it could sound good or it could sound awful. LOL And yes,it destroys the function of your heat riser.
A Conundrum ? O.K. , BTDT many times over ; It all depends on what you want ~ fuel milage isn't the reason to split the exhaust manifold , it's either ear splitting noise you want (true split) or increased power (joined split) . In either case the outlet _MUST_ be the same diameter else it'll run funny . You should NOT allow anyone to remove the heat risor flapper & spring ! it is very important and still helps warmup on a split exhaust . A true split (breathes 3 cylinders into each exhaust pipe) will increase noise and decrease actual power below 3,000 or so RPM . Either don't install the internal restrictor or add a crossover pipe as close to the exhasut manifold's outlet as possible , this will increase the mid-range power right where you need it in daily driving . I prefer a split stock manifold but it is getting harder to find guys who know how to do this anymore . Lots written on this in the archives . If you simply delete the muffler & run one long straight pipe , it'll breathe _much_ better and have a nice tone too , you have to try it to belive it . Long ' Smitty ' typ glasspacks will sharpen up the tone , make it rap a little . Cheap , short glass pack mufflers make nasty sounding noise everyone will hate you for . Splitting the exhaust completely with no crossover whatsoever , will make it rap loudly and sharply reduce power except at WFO where you engine will grenade in short order . low riders love this noise but hate the Police attention (duh) . I dunno if exhaust ' poppers ' are still available ? makes LOADS of rapping noise but restricts power -so- sharply as the engine speed increases you'll be lucky to go over 40 MPH . Good luck however you choose to go .
Thanks Nate, I knew I should of searched for some of that in the archives and now I will. I want to get this guys split exhuast off Ebay but he has the flapper welded open. It appears as the modified second outlet is smaller than the stock exhuast outlet. I made an attachment of the pic of it and hope it appears. Tell me what you think. ~TIA , Ryan
Well ; I dunno how to make that tiny thumbnail pic expand . you may find the inner diameter of the actual hole is the same as the stock outlet is pretty thick . If it's cheap and has NO CRACKS it'll prolly work O.K. This is the typ of split manifold I prefer , there may or may not be a restrictor plate up inside if it , have the guy either take a clear pic up the stock outlet or ask , that's the thing that'll make it rap or not .
