John(XJ)Jeep
NAXJA Forum User
- Location
- Guelph, Ontario, Canada
Well it took a little while but I'm throwing up my idea here. Now it has gone through a lot of changes and from
what I was able to test it with since I have no access to any flow bench that can get exact numbers or even
a good estimate at this point in time is with just by feeling and watching debris fly through it heh heh, but the
difference is measurable easily by eye. I have done a rudimentary flow test with the air hose with the original
intake and the modified intake that I am currently running and was satisfied with the gain in flow but the margin
was almost undetectable but was able to discern the difference by eye. Enlarging the bore of the inlet
of the manifold to 71mm did produce better flow rate. For most of you that was/or is pretty obvious.
I don't actually feel (meaning I'm not exactly sure) that there is so much a difference in fuel delivery between
runners that it should matter. I could be wrong or right since any information I have found about has fierce counter
arguments. Judging by the amount of debris and runoff around my injectors, valves, chambers, runners at the head
ect. when I rebuilt my engine there is possibly none but of course that can probably be answered by a reader I don't
have and for the moment don't even have access to one. So I just went on with my hunch and started building
anyway.
Now this is totally experimental and it should yield a good amount of R&D to me after a real life test but I think
it should succeed with great measure. The concept was to have an intake that acted like a velocity stack setup
mixed with a plenum configuration, lol I don't know what the best words would be but it's a little hard to describe.
It's not a brand new idea by any means but It should be somewhat new to the 4.0L engine which is the only reason
I'm really even bothering with this so bear with me if it flies in your face to some of you. For the longest time I've
always wondered why there really isn't much aftermarket support in terms of on-road performance upgrades for the
XJ's and MJ's. Of course, most Jeep guys think that our vehicles are the purest for the off road but I always thought
because if our unit-body design, one of the lightest and surprisingly most aerodynamic (try not to laugh, I'm serious)
of the the Jeep brand why not more people used it on the street scene? This makes it hard to make anything work
for us. So I like to experiment and I hope this actually helps us all. Along with experimenting with the suspension
which will come on another thread I want to make the baddest XJ there is on-road.
Alright, now that I got that out of the way. Here is some pictures of what I'm building. Like I said it looks a little
ugly now but it works and it works far better than I thought it would.
This is what I started with, stock intake and some I guess "upper" TB's from two 2K Lincolns from the scrapyard.
I get to chop off that ridiculous Chry-Co symbol and basically use 2 ford TB's, to some, not a very good start heheh!
Now I'm modifying the TB's to adapt. I needed the bottoms flat so what do you do? If your me you file them, good thing I'm
a great filer I managed to file them flat to match the machine ground block. Which was incredibly hard and time consuming
but was no problem to do. I also decided to lessen the angles of the TB's above the bore and smooth them out. All it I did
was really trumpet the bores a little more trying not to change the shape too much.
Now building up on aluminum cast is a hard thing to do especially if you hadn't done it before and decided to do it on a project
such as this, with a stick welder mind you. So it looks shitty but they are solid and strong and at this point that is all that really
matters sure as hell you can see I didn't care about looks. Anyway I digress, I had to build up the walls of the ports so that I had
material to weld the extra aluminum to make the mounting flanges.
what I was able to test it with since I have no access to any flow bench that can get exact numbers or even
a good estimate at this point in time is with just by feeling and watching debris fly through it heh heh, but the
difference is measurable easily by eye. I have done a rudimentary flow test with the air hose with the original
intake and the modified intake that I am currently running and was satisfied with the gain in flow but the margin
was almost undetectable but was able to discern the difference by eye. Enlarging the bore of the inlet
of the manifold to 71mm did produce better flow rate. For most of you that was/or is pretty obvious.
I don't actually feel (meaning I'm not exactly sure) that there is so much a difference in fuel delivery between
runners that it should matter. I could be wrong or right since any information I have found about has fierce counter
arguments. Judging by the amount of debris and runoff around my injectors, valves, chambers, runners at the head
ect. when I rebuilt my engine there is possibly none but of course that can probably be answered by a reader I don't
have and for the moment don't even have access to one. So I just went on with my hunch and started building
anyway.
Now this is totally experimental and it should yield a good amount of R&D to me after a real life test but I think
it should succeed with great measure. The concept was to have an intake that acted like a velocity stack setup
mixed with a plenum configuration, lol I don't know what the best words would be but it's a little hard to describe.
It's not a brand new idea by any means but It should be somewhat new to the 4.0L engine which is the only reason
I'm really even bothering with this so bear with me if it flies in your face to some of you. For the longest time I've
always wondered why there really isn't much aftermarket support in terms of on-road performance upgrades for the
XJ's and MJ's. Of course, most Jeep guys think that our vehicles are the purest for the off road but I always thought
because if our unit-body design, one of the lightest and surprisingly most aerodynamic (try not to laugh, I'm serious)
of the the Jeep brand why not more people used it on the street scene? This makes it hard to make anything work
for us. So I like to experiment and I hope this actually helps us all. Along with experimenting with the suspension
which will come on another thread I want to make the baddest XJ there is on-road.
Alright, now that I got that out of the way. Here is some pictures of what I'm building. Like I said it looks a little
ugly now but it works and it works far better than I thought it would.
This is what I started with, stock intake and some I guess "upper" TB's from two 2K Lincolns from the scrapyard.
I get to chop off that ridiculous Chry-Co symbol and basically use 2 ford TB's, to some, not a very good start heheh!
Now I'm modifying the TB's to adapt. I needed the bottoms flat so what do you do? If your me you file them, good thing I'm
a great filer I managed to file them flat to match the machine ground block. Which was incredibly hard and time consuming
but was no problem to do. I also decided to lessen the angles of the TB's above the bore and smooth them out. All it I did
was really trumpet the bores a little more trying not to change the shape too much.
Now building up on aluminum cast is a hard thing to do especially if you hadn't done it before and decided to do it on a project
such as this, with a stick welder mind you. So it looks shitty but they are solid and strong and at this point that is all that really
matters sure as hell you can see I didn't care about looks. Anyway I digress, I had to build up the walls of the ports so that I had
material to weld the extra aluminum to make the mounting flanges.