Known as "The Barnacle" ... it is a 1984 CJ-7. I picked it up in 1989 as a vehicle to go back and forth to school in Rhode Island with. It was bone stock and had 34,000 on the odometer-- a creampuff.

It is still my daily driver- also doubles as my plow, trail and tow rig (for the pop-up camper).



From it's simple beginnings, it now boasts: - 4.2 bored 0.030 (now 4.3), balanced, w/ 4.0 head and MPI, Centerforce Clutch, T-18, D300 w/Lo-Max 4:1 & clocked flat, CV shafts F&R, front axle: D30 w/ ARB, Yukon shafts and joints, rear axle: M20(thanks Mike!), - shaved & trussed w/ ARB, Summers Brothers shafts, disc brakes & U-bolt flip kit, 4" BDS springs w/ RS9000's in the rear, 34 x 9.50 TSL's w/Staun internal beadlocks on 15 x 7.5 OEM chrome wagons, York OBA w/ tank, electric cooling fan, grafted in 1/4" steel rockers, 6 point cage w/ padding : ), Hundai Tiberon seats, Warn M8000 w/ in-cab-control & masterpull synthetic, HD shackles, HD steering box brace, CB radio, Prodigy brake control, 4 point belts, hydro snow plow pump/valving for plowing snow, roughly 300,000 miles, home made muffler & exhaust, brushed/rolled on paint, patched body.
here are a few things that I have done to it:
CLICK HERE 4.0 Head/EFI conversion -- this was the second conversion I did-- the first was to mine.

CLICK HERE for the D300 rebuild with the Lomax 4:1 install

Well, I finally accrued all the necessary parts and reasons to tuck into the respiratory upgrades for my H.O. I-6.
My goal is a late model intake, stainless performance header with a full 2.25" stainless exhaust, larger injectors, and bored throttle body.
I started with removing the manifolds from the drivers side of the engine.

I had been running the OEM header since I did the 4.0 head swap 3 years ago. The tubing was small (1.75" I.D.) and bombed out due to numerous exhaust retrofits, battles with rocks, and general 4 wheeling carnage.

The muffler I had made about 10 years ago out of a old water filled SS fire extinguisher. It has held up very well, and will be spruced up (again) and installed on the Willys.

The new stainless steel header I bought off Ebay for about $210 (including shipping). As far as I can tell it is exactly what Banks sells as their Torque Tube. This is the SS409 model. Pictured below, before I cut the flange off it, laying on top of the old header.

Here are the "new" and "old" intake manifolds. The 'new ' one is (as far as I know) from '99-'06 4.0's. The 'old' manifold is from '91 - '98 4.0's. I have heard a ton of hype on the late model manifolds that claimed a ton of power increase by installing it. You can clearly see the octopus like design of the late model.

the earlier model has the runners branching off each other

the late model has all the runners meeting in the plenum, which is much larger than the earlier models'. The equal length runners to each cylinder gives them all the same advantage as far as air delivery. I wish I had this manifold on my 258 years ago!

I had a bunch of figuring to do with the exhaust routing, as I was planning on enlarging the exhaust pipe to 2.5" O.D. I first has to cut off the OEM style exhaust flange.

It all took a bunch if times of installing, tacking and rechecking the fit and placement of the parts-- at least 10 times... here is the final result- the header pipe travels strait down, underneath the clutch linkage. Note the O2 sensor bung.

I have installed a hanger on the pipe to allow the header to be bolted to the engine/transmission assembly. I have found this GREATLY reduces the stresses on the header and allows it to remain crack free for a MUCH longer time.


To establish a serviceable joint between the header and the rest of the exhaust, I have grown fond of using stainless steel plumbing unions. Using copious amounts of anti-seize when installing and then copious amounts of WD-40 upon removal allows for a maintenance free joint. They hold up very well, provide a great seal, and don't require any sort of gasket.
Here is the one that was removed

I have found that the facets on the nut can make it difficult to get the wrench in just-the-right spot, so I turned the new one smooth on the lathe. It will allow for quick work with a chain wrench. :D


For anyone wondering what a chain wrench is.

The only trouble spot with the late model intake manifold swap is that the power steering pump brackets don't line up -- at all. For starters, I didn't like how close the one bolt hole/mount was to the power steering pump, so I cut it off and cleaned it up.


I then fabbed up a few little parts, tacked them together in-place, took it off and welded it up solid. I was a little fearful from what I has heard about this part of the install, but it went quickly and easily.



It was then time to install the throttle body, but not before 'boring it out' which entails removing the 'choke' from it's bore. The choke is located below the throttle plate. Again-- having a lathe comes in handy. For those that know the notorious whistle that comes with the 4.0 throttle body, this boring seems to have quieted it down quite a bit.

I installed the freshly painted fuel rail, along with the slightly over-sized HESCO 23.2 lb/hr (black -pn 53030778) injectors. This is to make up for the larger throttle body and the increase in displacement from 4.0l to 4.3l (it's a bored 258 bottom end). Note the fuel pressure gauge and adjustable HESCO fuel pressure regulator. I adjusted it to just under the stock 39 lbs., with the vacuum line disconnected.

Running-- I have clear coated the intake to keep it nice and shiny for a while-- we'll see how the lacquer holds up to the underhood temps. Especially with parts of it being right next to the exhaust. 8-[

- the cat ( I reused the one pictured above) and muffler (Dynomax all stainless glasspack -- ebay $20 brand new!) are together.

straight through... that is the cat honeycomb down there


tailpipe



As for the performance of it all-- well, it certainly has a bit more throttle snap! It accelerates much smoother and has a bit more all through the power range. It was worth the $$, time and materials. I am planning to get it on a dyno some time this winter.
It sure sounds cool.Throaty but not booming.
Huge thanks to Absolute Auto and Sean Ivey for all the stainless tube, Ebay for the great prices, and Marc Salvatore for the injectors and intake manifold! Biggest thanks to Joanna for allowing me to play with and build my toys!
`

It is still my daily driver- also doubles as my plow, trail and tow rig (for the pop-up camper).



From it's simple beginnings, it now boasts: - 4.2 bored 0.030 (now 4.3), balanced, w/ 4.0 head and MPI, Centerforce Clutch, T-18, D300 w/Lo-Max 4:1 & clocked flat, CV shafts F&R, front axle: D30 w/ ARB, Yukon shafts and joints, rear axle: M20(thanks Mike!), - shaved & trussed w/ ARB, Summers Brothers shafts, disc brakes & U-bolt flip kit, 4" BDS springs w/ RS9000's in the rear, 34 x 9.50 TSL's w/Staun internal beadlocks on 15 x 7.5 OEM chrome wagons, York OBA w/ tank, electric cooling fan, grafted in 1/4" steel rockers, 6 point cage w/ padding : ), Hundai Tiberon seats, Warn M8000 w/ in-cab-control & masterpull synthetic, HD shackles, HD steering box brace, CB radio, Prodigy brake control, 4 point belts, hydro snow plow pump/valving for plowing snow, roughly 300,000 miles, home made muffler & exhaust, brushed/rolled on paint, patched body.
here are a few things that I have done to it:
CLICK HERE 4.0 Head/EFI conversion -- this was the second conversion I did-- the first was to mine.

CLICK HERE for the D300 rebuild with the Lomax 4:1 install

Well, I finally accrued all the necessary parts and reasons to tuck into the respiratory upgrades for my H.O. I-6.
My goal is a late model intake, stainless performance header with a full 2.25" stainless exhaust, larger injectors, and bored throttle body.
I started with removing the manifolds from the drivers side of the engine.

I had been running the OEM header since I did the 4.0 head swap 3 years ago. The tubing was small (1.75" I.D.) and bombed out due to numerous exhaust retrofits, battles with rocks, and general 4 wheeling carnage.

The muffler I had made about 10 years ago out of a old water filled SS fire extinguisher. It has held up very well, and will be spruced up (again) and installed on the Willys.

The new stainless steel header I bought off Ebay for about $210 (including shipping). As far as I can tell it is exactly what Banks sells as their Torque Tube. This is the SS409 model. Pictured below, before I cut the flange off it, laying on top of the old header.

Here are the "new" and "old" intake manifolds. The 'new ' one is (as far as I know) from '99-'06 4.0's. The 'old' manifold is from '91 - '98 4.0's. I have heard a ton of hype on the late model manifolds that claimed a ton of power increase by installing it. You can clearly see the octopus like design of the late model.

the earlier model has the runners branching off each other

the late model has all the runners meeting in the plenum, which is much larger than the earlier models'. The equal length runners to each cylinder gives them all the same advantage as far as air delivery. I wish I had this manifold on my 258 years ago!

I had a bunch of figuring to do with the exhaust routing, as I was planning on enlarging the exhaust pipe to 2.5" O.D. I first has to cut off the OEM style exhaust flange.

It all took a bunch if times of installing, tacking and rechecking the fit and placement of the parts-- at least 10 times... here is the final result- the header pipe travels strait down, underneath the clutch linkage. Note the O2 sensor bung.

I have installed a hanger on the pipe to allow the header to be bolted to the engine/transmission assembly. I have found this GREATLY reduces the stresses on the header and allows it to remain crack free for a MUCH longer time.


To establish a serviceable joint between the header and the rest of the exhaust, I have grown fond of using stainless steel plumbing unions. Using copious amounts of anti-seize when installing and then copious amounts of WD-40 upon removal allows for a maintenance free joint. They hold up very well, provide a great seal, and don't require any sort of gasket.
Here is the one that was removed

I have found that the facets on the nut can make it difficult to get the wrench in just-the-right spot, so I turned the new one smooth on the lathe. It will allow for quick work with a chain wrench. :D


For anyone wondering what a chain wrench is.

The only trouble spot with the late model intake manifold swap is that the power steering pump brackets don't line up -- at all. For starters, I didn't like how close the one bolt hole/mount was to the power steering pump, so I cut it off and cleaned it up.


I then fabbed up a few little parts, tacked them together in-place, took it off and welded it up solid. I was a little fearful from what I has heard about this part of the install, but it went quickly and easily.



It was then time to install the throttle body, but not before 'boring it out' which entails removing the 'choke' from it's bore. The choke is located below the throttle plate. Again-- having a lathe comes in handy. For those that know the notorious whistle that comes with the 4.0 throttle body, this boring seems to have quieted it down quite a bit.

I installed the freshly painted fuel rail, along with the slightly over-sized HESCO 23.2 lb/hr (black -pn 53030778) injectors. This is to make up for the larger throttle body and the increase in displacement from 4.0l to 4.3l (it's a bored 258 bottom end). Note the fuel pressure gauge and adjustable HESCO fuel pressure regulator. I adjusted it to just under the stock 39 lbs., with the vacuum line disconnected.

Running-- I have clear coated the intake to keep it nice and shiny for a while-- we'll see how the lacquer holds up to the underhood temps. Especially with parts of it being right next to the exhaust. 8-[

- the cat ( I reused the one pictured above) and muffler (Dynomax all stainless glasspack -- ebay $20 brand new!) are together.

straight through... that is the cat honeycomb down there


tailpipe



As for the performance of it all-- well, it certainly has a bit more throttle snap! It accelerates much smoother and has a bit more all through the power range. It was worth the $$, time and materials. I am planning to get it on a dyno some time this winter.
It sure sounds cool.Throaty but not booming.
Huge thanks to Absolute Auto and Sean Ivey for all the stainless tube, Ebay for the great prices, and Marc Salvatore for the injectors and intake manifold! Biggest thanks to Joanna for allowing me to play with and build my toys!
`
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