in this video we run up our 1900 ford x/flow engine and see what the difference is between a small bore 421 exhaust manifold and a bigger bore 4 into 1
the name of the game with this was produce a good torquey engine with reasonable power, which is what its doing, peak BHP number is never going to be massive because the torque is too low down in the rev range for that. but i can tell you ive already seen a bit more power than we saw in this video
The old original Janspeed 4-2-1 was the best street manifold for the X flow one could hope for, yes some others made more top end, and some more bottom end torque. But the Janspeed had the broadest range with good top end. You really could feel the difference from 3800rpm onward. It was easy to drive and sounded absolutely awesome.
back then Janspeed used to actually design and test manifolds, these days most are just made to fit an engine with little developement as to what actually works best
Thinking about it that makes sense. I guess the 4-1 has much longer pipes than either the primary or secondary pipes on the 4-2-1? And hence the 4-1 would be tuned for lower rpm than the 4-2-1.
Great vid always good to challenge the perceived wisdom! For what it is worth I have a LHD mk 2 Escort with an Xflow which has been modified and required an exhaust upgrade. To get a exhaust manifold to fit was very difficult. I ended up with a 4-2-1 manifold from Martelius in Finland as they have a design that fits perfectly around the steering column, etc etc. The big difference compared the the standard Ford 4-2-1 (apart from diameter) that was originally fitted to the car was the length of the 2 pipes before they merge into final 2" pipe.. In the original this is barely out of the engine bay in the new system the pipes continue merge way under the drivers footwell/seat area. i.e. much longer than original. This did seem to give more grunt in the mid range when compared to a home built 4-1 manifold i tried. A bit subjective I know but never the less it could be it is not just as simple as 4-1 vs 4-2-1 but the individual measurements of each part of the manifold will be important and as such you could end up with two different manifold designs with the same characteristics? I seem to remember some formulas somewhere to calculate header lengths etc.
Absolutely, there are a huge number of permutations of tube diameter primary and secondary lengths etc. and there are nearly as many theory's on pipe length and dia calculation. That said in the real world we mostly have to deal with what we can buy off the shelf which is what most of my testing is based on, what mr joe average can go and buy off the shelf
@@PenguinMotors Exactly. I was looking for a 4-1 manifold originally but could not get anything that would fit straight off off the shelf (custom built was far too expensive) so purchased what I could get and hoped for the best!
I have a Lotus Cortina (road car)with an Ashley exhaust and was going to upgrade it with a Tony Law manifold, thinking twice about that now. Looking forward to how the 45s perform in the next instalment.
i have never tested a tony law manifold on anything, but a couple of people i know and one i would defiantly trust and has 1000's of different engines worth of dyno test under his belt say they are too big for most applications
When you say small and big bore pipes what diameters are they? This is interesting to me as I am about to embark on replacing the exhaust on my 2.0 pinto for my sport 2000 race car. It is currently a worn out 4 into 1 system with 1.5" primary and 2.5" tail pipe.
if its a sports 2000, then i would imagine every conceivable and feasible option has already been tried. As they use basically bluprinted standard engines i cant see any major gains in the exhaust dept
Great video Penguin!!!!, like always!!!. What If reduces the chokes a little Bit with the 4-2-1?, I think iT will help to increase the intake speed so the torque will raise a Little Bit at very low engine speed. I have a doubt, How I can eliminate the gasoline spray spitted by the carbs at very high speed?, i have a 293 catcams cammed Renault Laguna with 2 44 IDF in the 2.0 8 valves, with 36 chokes. IT Do the same.
maybe, if the chokes are not too big and thus causing a lean mixture or requiring huge mains, then reducing them wont increase torque although it might increase engines flexibility. that said i have since run the engine on 45's and that didnt have a dramatic effect on the bottom end so i would expect small chokes in the 40's to do nothing for the torque.
Always a thumbs up before I even watch simply because I always learn something.
Great video again as usual and thank you for your time.
The meter never lies, proper comparison and proof testing. Not the ego of someone bumming up their shiny bits. Cheers mate.
I am loving this 1.9 xflow engine, it's making good road usable power and there is probably more to come.
the name of the game with this was produce a good torquey engine with reasonable power, which is what its doing, peak BHP number is never going to be massive because the torque is too low down in the rev range for that. but i can tell you ive already seen a bit more power than we saw in this video
The old original Janspeed 4-2-1 was the best street manifold for the X flow one could hope for, yes some others made more top end, and some more bottom end torque. But the Janspeed had the broadest range with good top end. You really could feel the difference from 3800rpm onward. It was easy to drive and sounded absolutely awesome.
back then Janspeed used to actually design and test manifolds, these days most are just made to fit an engine with little developement as to what actually works best
Interesting. Please test merge side and pipe length after the merge. Cheers.
Thinking about it that makes sense.
I guess the 4-1 has much longer pipes than either the primary or secondary pipes on the 4-2-1?
And hence the 4-1 would be tuned for lower rpm than the 4-2-1.
learning all the time...
Great vid always good to challenge the perceived wisdom!
For what it is worth I have a LHD mk 2 Escort with an Xflow which has been modified and required an exhaust upgrade. To get a exhaust manifold to fit was very difficult. I ended up with a 4-2-1 manifold from Martelius in Finland as they have a design that fits perfectly around the steering column, etc etc. The big difference compared the the standard Ford 4-2-1 (apart from diameter) that was originally fitted to the car was the length of the 2 pipes before they merge into final 2" pipe.. In the original this is barely out of the engine bay in the new system the pipes continue merge way under the drivers footwell/seat area. i.e. much longer than original. This did seem to give more grunt in the mid range when compared to a home built 4-1 manifold i tried. A bit subjective I know but never the less it could be it is not just as simple as 4-1 vs 4-2-1 but the individual measurements of each part of the manifold will be important and as such you could end up with two different manifold designs with the same characteristics? I seem to remember some formulas somewhere to calculate header lengths etc.
Absolutely, there are a huge number of permutations of tube diameter primary and secondary lengths etc. and there are nearly as many theory's on pipe length and dia calculation. That said in the real world we mostly have to deal with what we can buy off the shelf which is what most of my testing is based on, what mr joe average can go and buy off the shelf
@@PenguinMotors Exactly. I was looking for a 4-1 manifold originally but could not get anything that would fit straight off off the shelf (custom built was far too expensive) so purchased what I could get and hoped for the best!
I have a Lotus Cortina (road car)with an Ashley exhaust and was going to upgrade it with a Tony Law manifold, thinking twice about that now. Looking forward to how the 45s perform in the next instalment.
i have never tested a tony law manifold on anything, but a couple of people i know and one i would defiantly trust and has 1000's of different engines worth of dyno test under his belt say they are too big for most applications
That's what I thought. Thanks, information worth its weight in gold .
Hi Grayham, have you ever tried a CV manifold with the little stub stacks just inside the primaries. It worked very well for me..
Not yet! primarily i only try whats commonly used
would be fun to see a standard cast manifold and stock piping of the same lenght for comparasion to what effect a manifold trully got
ive done this on a stock pinto, the difference was 8bhp
@@PenguinMotors ohh i guess i have missed out then
Nice result , 4,2,1 looses at the bottom but then comes good all the way up. What about a bigger bore 4,2,1 to suit the extra 300cc ?
i dont think a bigger bore is needed, and as the 4,2,1 is same as client already has it makes sense just to run with that
When you say small and big bore pipes what diameters are they?
This is interesting to me as I am about to embark on replacing the exhaust on my 2.0 pinto for my sport 2000 race car. It is currently a worn out 4 into 1 system with 1.5" primary and 2.5" tail pipe.
if its a sports 2000, then i would imagine every conceivable and feasible option has already been tried. As they use basically bluprinted standard engines i cant see any major gains in the exhaust dept
Great video Penguin!!!!, like always!!!. What If reduces the chokes a little Bit with the 4-2-1?, I think iT will help to increase the intake speed so the torque will raise a Little Bit at very low engine speed.
I have a doubt, How I can eliminate the gasoline spray spitted by the carbs at very high speed?, i have a 293 catcams cammed Renault Laguna with 2 44 IDF in the 2.0 8 valves, with 36 chokes. IT Do the same.
maybe, if the chokes are not too big and thus causing a lean mixture or requiring huge mains, then reducing them wont increase torque although it might increase engines flexibility. that said i have since run the engine on 45's and that didnt have a dramatic effect on the bottom end so i would expect small chokes in the 40's to do nothing for the torque.
@@PenguinMotors its a pleasure to receive your knowledge!!! 😍💪💪.
Many thanks for Your answer!!, we Will keep waiting for Your next video👏👏👏👏👏👏
I´ll be darned. Its not every day you see a 4-2-1 header being beat in the lower rpms.