Need an engine!!!!!!
- Thread starter JTR0569
- Start date
What would be the advantage of going to a 4.0L? I am realatively new to the Jeep ownership club and have heard that '89 4.2L has somewhat of a bad reputation. What I am looking to do is build a dependable daily driver that has no problem hanging with the best in Moab.
Unless you really want to get into it... just find a junk yard motor, or the one you currently have, rebuild it and add a stand alone fuel injection kit(ex howell), should cost a little under $1300 if you do all the assembally your self. $800 for the fuel injection $500 for the machining and new rings. this set up will out last just about everything else on your jeep.
If you do want to go 4.0, I can not give an acurate cost, I have seen it done for less than $400 and I have seen it cost over $1500, all depends on your machanical ability, parts you have laying around, and what condition you source used parts in, but for the amount of work for the minimal gain, go small block chevy, way more aftermarket support for the swap and a TBI setup is dumb easy to swap into a vehicle with out Fuel injection.
If you do want to go 4.0, I can not give an acurate cost, I have seen it done for less than $400 and I have seen it cost over $1500, all depends on your machanical ability, parts you have laying around, and what condition you source used parts in, but for the amount of work for the minimal gain, go small block chevy, way more aftermarket support for the swap and a TBI setup is dumb easy to swap into a vehicle with out Fuel injection.
100 hp is a bit generous. I have seen a number of differnt power ratings for the 87+ 258, most are between 113-118 horse depending on what you source. the HO 4.0 put out a consistant 180 hp so a 62-67 hp gain are presumable. As for them being the same motor, that is an even farther reach. there is not one interchangable part from one to the other that I can think of other than a spark plug and wire.
60biscayne
New member
Ok here's my 2 cents worth!
I have an '89 Wrangler that was a 4.2 standard shift! I had all the usual carb problems etc...........
My son asked why wasn't I driving it?
I said because it needed tires real bad.
He said he would buy me a set of tires & I thought what a good boy!
In a couple of days a tractor / trailer shows up and unloads Five 33 x12 1/2 x 15" Thornbirds on these wild rims! I called him and said there's No Way those tires will go on that Little Jeep!
He said OH I ment to tell you the lift kit will be there in a day or two!
Good thing I'm retired - so after installing the lift kit and rebuilding the complete front end............ we still had this 4.2 that I had previously changed over to a Holly 2bbl but it still just about could turn these tires.
My oldest son heard about a motor out of a 2004 Wrangler that his buddy told him about. This neighbor of his (down in New York on Long Island) had this in his garage for over two years and never used it. We went over & to make a long story short - I bought a complete 4.0 which had less than 15,000 miles on it. It came with the automatic trans & transfer case! It also had the computer, wiring harness / fusebox & relays, complete A/C, Power Steering, drive shafts etc. for $1,500
I spent another $1,500 I'd say on a new radiator, some motor mounts, shift linkage, all new Sun mechanical gauges which I mounted on a redwood panel to replace the stock gauge set-up, a 20 gallon fuel tank from a '95 which has the electric pump etc. & a fuel rail out of a cherokee because the 2004 wants to run on more pressure than the stock 95 pump could put out.... I also found some beautiful leather seats from a Grand Cherokee which I installed...... OH yeah, one more thing - Lunch for my buddy Mike & his brother Pat anytime I see them for the rest of their lives (who's garage we did this swap at)!
I've bought a couple of different speedometers / tachometers but I can't seem to get any of them to work properly! I went out & bought a Tom Tom navigation system & this gives me the time & tells me accurately how fast I'm driving even with the big Thornbirds. With the old drivetrain the speedometer was all screwed up with those tires!
So let's see we have a few bucks tied up in this now - I bought this Cherry / One previous owner Wrangler for $3,500 - than approx. $3,000 for the suspension / tires + around $3,000 for the drivetrain stuff!
I'm happy that's what counts!
I have an '89 Wrangler that was a 4.2 standard shift! I had all the usual carb problems etc...........
My son asked why wasn't I driving it?
I said because it needed tires real bad.
He said he would buy me a set of tires & I thought what a good boy!
In a couple of days a tractor / trailer shows up and unloads Five 33 x12 1/2 x 15" Thornbirds on these wild rims! I called him and said there's No Way those tires will go on that Little Jeep!
He said OH I ment to tell you the lift kit will be there in a day or two!
Good thing I'm retired - so after installing the lift kit and rebuilding the complete front end............ we still had this 4.2 that I had previously changed over to a Holly 2bbl but it still just about could turn these tires.
My oldest son heard about a motor out of a 2004 Wrangler that his buddy told him about. This neighbor of his (down in New York on Long Island) had this in his garage for over two years and never used it. We went over & to make a long story short - I bought a complete 4.0 which had less than 15,000 miles on it. It came with the automatic trans & transfer case! It also had the computer, wiring harness / fusebox & relays, complete A/C, Power Steering, drive shafts etc. for $1,500
I spent another $1,500 I'd say on a new radiator, some motor mounts, shift linkage, all new Sun mechanical gauges which I mounted on a redwood panel to replace the stock gauge set-up, a 20 gallon fuel tank from a '95 which has the electric pump etc. & a fuel rail out of a cherokee because the 2004 wants to run on more pressure than the stock 95 pump could put out.... I also found some beautiful leather seats from a Grand Cherokee which I installed...... OH yeah, one more thing - Lunch for my buddy Mike & his brother Pat anytime I see them for the rest of their lives (who's garage we did this swap at)!
I've bought a couple of different speedometers / tachometers but I can't seem to get any of them to work properly! I went out & bought a Tom Tom navigation system & this gives me the time & tells me accurately how fast I'm driving even with the big Thornbirds. With the old drivetrain the speedometer was all screwed up with those tires!
So let's see we have a few bucks tied up in this now - I bought this Cherry / One previous owner Wrangler for $3,500 - than approx. $3,000 for the suspension / tires + around $3,000 for the drivetrain stuff!
I'm happy that's what counts!
carnuck
New member
From Wikipedia: The 4.0L HO's were rated at 190 HP and 225 ft lbs of torque. (AMC Straight-6 engine - Wikipedia, the free encyclopedia )
The later 258s were 118 which is 78 HP difference. The early 258s (71 to '79) were 96 HP. (almost 100 HP difference)
My stroker I'm assembling is @300 HP and 350 ft lbs of torque (but I'm running almost 11:1 compression on LPG fuel injection. They have complete systems on EBay for less than $1500)
You can swap the 4.2L crank into the 4.0L block with 4.0L pistons and 4.2L rods (which nets about 278 Cu inches w/o boring) The 4.0L head can be easily grafted onto the 4.2L engine (some years require the water ports on the passenger's side to be sealed up. No biggie) Renix and later model 4.2L use the same head casting, BUT the ports were altered for the fuel injection by adding notches and raising the ports slightly.
You can bolt all the accessories on the outside of most 4.0Ls (up till '99) onto a 4.2L except the valve cover (they are matched to heads with certain casting numbers, so if you do teh ehad swap, you're golden!)
I currently have a '93 Grand Cherokee 4.0L in place of the 4.2L in my '83 J10 (I had to change to Hydroboost brakes due to the proximity of the HO intake manifold to the brake master)
Well, Wikipedi said it's 190... must be right.....
Yes you can swap parts, but are not interchangable, what you are describing is esentially a stroked motor. If you swap a crank, there is way more parts that need to be addressde inorder to have a running engine. My point was that if he bought a 4.0 block, he can't just drop it in and swap all his 4.2 junk onto it.
And the horse power rating, I had to look into a bit. the 87-90 4.0 in the xj and 91-97 in the wranglers made 177-180 depending on reg or HO motors 91-02 xj and 97-02 TJ made 190hp. TJ's were a mid year change to the XJ ZJ motor from the previous yj version. you were correct, but still not a 100 horse increase.
Dead horse is beat.
Yes you can swap parts, but are not interchangable, what you are describing is esentially a stroked motor. If you swap a crank, there is way more parts that need to be addressde inorder to have a running engine. My point was that if he bought a 4.0 block, he can't just drop it in and swap all his 4.2 junk onto it.
And the horse power rating, I had to look into a bit. the 87-90 4.0 in the xj and 91-97 in the wranglers made 177-180 depending on reg or HO motors 91-02 xj and 97-02 TJ made 190hp. TJ's were a mid year change to the XJ ZJ motor from the previous yj version. you were correct, but still not a 100 horse increase.
Dead horse is beat.
carnuck
New member
You are saying you can't just pull a 4.2L and replace it with a (pre '99) 4.0L and bolt on all the accessories. I'm saying you can AND I have done it myself in 1 afternoon. Someone gave that horse CPR.
PS: I have 30 years as an ASE Certified tech to back that up.
rusteehawk71
New member
I have a working complete 4.2 block sitting in my garage I will see for $300, also have a 4.0 head and intake too. hit me back at rustee hawk 71 at yahoo (remove spaces etc). I live north of Syracuse NY. Might be worth the trip for you. Let me know.
54cj3b
New member
:thisthreadisworthle:welder:
Collin the Hen
New member
It's true.
Check here. Less then 1,500 for a 89 4.2 and a 4.0
JEEP ENGINES & MOTORS | Rebuilt Engines
JEEP ENGINES & MOTORS | Rebuilt Engines
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