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Unread 10-18-2010, 09:21 PM   #31
cevans87
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and as far as the shifter, you can by anew shifter which will offset it and make it just like the stock one... just a thought

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Unread 10-18-2010, 11:42 PM   #32
lclark2074
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i have not sean this much info on a swap hope to see more pic thanks
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Unread 10-19-2010, 02:02 PM   #33
cevans87
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ok, home from work, going to eat real quick run to pick up some small parts then head down to try to get as much done... will update when i return
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Unread 10-19-2010, 02:05 PM   #34
monkeyhouse
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so what did you do with that weber?
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Unread 10-19-2010, 02:36 PM   #35
remmons
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Nice thread! I will rate yours right up there with a few others that I have had the pleasure of following along with. I'll be lurking around here to check out your progress. My progress has all but halted.
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Unread 10-19-2010, 02:44 PM   #36
cevans87
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still have the weber, and the borla header, sitting in the garage... any takers
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Unread 10-19-2010, 08:22 PM   #37
cevans87
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OK UPDATE ...

Wiring harness is in, motor is completly bolted down, belt is back on, the modification i made to the 4.2l power steering pump worked great

still have to tie in the wiring harness, but won't take but a few minutes, need to mount the ecm, put the pump in, run the fuel lines, weld up the exhaust pipe, and get the gooseneck back on and a new section of heater hose, get a new cap, rotor and wires... and then we are ready for the test fire... and hopefully there won't be a fire... just kidding

things are slow during the week i know but i can only do so much by myself during the week, plus i have to spend 45 minutes feeding horses, a pig and 2 cats...

Oh, and I had a friend go with me to pull the parts, and he disconnected the wire harness for the coil, so i need source one, or i'ma go to a MSD Coil since I'm going to but putting in MSD ignition...once I find a spot to mount it, I've realized that I'm running out of room for things, and it's irritating, but I do have a PIAA box, fan controller, msd, ecm, and PDC to mount...

Hopefully this thread is helping people answer a lot of question, and when it's all said and done, i know everything is not in great order but atleast all the information is in one thread, and should be easy enough to find...
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Unread 10-19-2010, 08:39 PM   #38
cevans87
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Some Quick Stroker Information

The 4.0L engine has a 3.411" stroke, 3.875" bore, 6 cylinders, and a displacement of 241.5ci (3956cc). You can increase the displacement of your 4.0L engine by installing a stroker kit. At the heart of the kit is the 3.895" stroke crankshaft that was used in the AMC/Jeep 258ci (4.2L) I6 engine.

On an engine with the stock 3.875" bore, the stroker crank increases displacement to 276ci (4517cc or 4.5L). Add 30 thousandths or 60 thousandths overbored pistons, and displacement is increased to 280ci (4587cc or 4.6L) and 284ci (4657cc or 4.7L) respectively.

If you're feeling really brave, you can overbore your engine to 4.00" and use custom forged pistons. The block must be sonic-tested to ensure that there's adequate cylinder wall thickness before overboring this far, though. Displacement with the 3.895" stroker crank is increased to 294ci (4812cc or 4.8L). The next step up the ladder includes an offset-ground 3.98" stroker crank that increases displacement to 300.1ci (4917cc or 4.9L). The ultimate stroker includes an offset-ground 4.06" stroker crank producing a displacement of 306.1ci (5016cc or 5.0L).

Stroker engines require oversize injectors to provide adequate fuel flow rates and prevent pinging due to lean air/fuel mixtures.

To calculate optimum injector size, use the following formula:

Injector flow rate (lb/hr) = [Expected HP x 0.5 (BSFC)] / [no. of cylinders x 0.8 (injector duty cycle)]

The actual injector flow rate from each injector depends on the fuel pressure (FP) in the injector rail. Most injectors have rated flows at 43.5psi fuel pressure. The actual flow rate from each injector is:

Actual injector flow rate = Rated injector flow rate at 43.5psi x square root of (FP/43.5)


Stroker engines need a longer duration camshaft (than stock) to maximise horsepower and torque.

The aim is to produce maximum torque over as wide an rpm range as possible. Stroker engines built with a compression ratio (CR) of about 9.5:1 will derive maximum benefit from these camshafts:

Crane #753905 204/216 degree cam
CompCams #68-231-4 206/214 degree cam

A stroker built to a CR of 8.8:1 that'll run with 87 octane fuel will benefit from a shorter duration dual-pattern cam for more low rev torque:

Crane #750501 192/204 degree cam
CompCams #68-115-4 192/200 degree cam

If the Jeep 4.2L 5.875" rods and stock Jeep 4.0L pistons are used, the pistons will be 0.008" further down the bore at TDC than those in the stock Jeep 4.0L engine. The deck clearance is thus increased to 0.030" and the quench height is increased to 0.081". The resultant CR is 9.7:1 with stock bore pistons and 9.9:1 with 0.060" overbore pistons. If the block is decked 0.010" to return the quench height to stock, the combustion volume is reduced by 2.0ml and the CR is increased to 9.9:1 and 10.1:1 respectively. Premium fuel will be required to prevent detonation.

If the stock Jeep 4.0L 6.125" rods are used, expensive custom forged pistons with a shorter pin height than stock (1.380") are required to achieve zero deck clearance. Using longer rods does enable you to choose pistons with a larger dish volume than stock. These reduce the CR and allow the use of low octane fuel without detonation. You can also use a shorter duration camshaft for increased low-rev torque, and select the head gasket thickness required to achieve the desired 0.040"-0.060" quench height.
If you use the shorter Jeep 4.2L rods with cheaper cast aluminium or hypereutectic pistons, the quench height can be reduced by milling the block deck and installing a thinner head gasket. The CR can be reduced by increasing the combustion chamber volume and the piston dish volume.
*For each 0.010" milled from the block deck (or taken from head gasket thickness) to reduce quench height, the combustion volume decreases by ~2.0ml and the CR increases by ~0.2*.

Here are some formulae, and how they apply to the stock Jeep 4.0L engine:

1. Deck height = Rod length + stroke/2 + piston pin height + deck clearance

9.453" = 6.125" + 1.705" + 1.601" + 0.022"

2. Combustion volume = Combustion chamber volume + head gasket volume + deck clearance volume + piston dish volume

84.6cc = 56.7cc + 10.5cc + 4.3cc + 13.1cc

3. Compression ratio (CR) = Cylinder volume/combustion volume + 1.0

CR = 660/84.6 + 1.0 = 7.80 + 1.0 = 8.80

4. Quench height = Deck clearance + compressed head gasket thickness

0.073" = 0.022" + 0.051"


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Unread 10-20-2010, 03:48 AM   #39
RookieJeeper01
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So what about the VSS. That is the last loose end I have to wrap up from my swap, but I have not been able to get one yet. I have an AX 15 with 231 transfer case, so I need the adapter at the end of the speedo cable. Have you found one online or did you get one from a doner jeep? If so what years.

I just recieved the wrong one yesterday. Oh yeah I already snagged what I think is the correct adapter from the cruise control line of an XJ. Still Looking
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Unread 10-20-2010, 06:30 AM   #40
cevans87
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if you revert back to my first post, you need to go to the parts store and get a vss for a 1991 jeep wrangler with a 4cyl, or you can purchase the vss and adapter from Hesco, or just the thread adapter from Hesco
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Unread 10-20-2010, 08:45 AM   #41
LoggingRoads
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I have an '88 YJ, 4.2, weber carb.. and can't register it (i'm in Ca.) ubtil I do a FI upgrade..

I've been looking at the Howell FI kit, but this thread has me wondering if perhaps there is a cheaper way..

So a couple questions,

Can the Howell TBI kit be used with this HO head on my 4.2 YJ? This seems like it would be less hassle than what you're going through, but much more costly..

Would I see significant gains in power and mileage, by swapping the head and using the TBI kit? Even if I keep the stock intake and exhaust manifolds?

With the new head, is a cam shaft replacement required?

Your engine has a serpentine belt, as opposed to the conventional V belts on mine.. Can I upgrade to the serpentine belt, or is that a big can of worms?

Anyone know if this will still be okay with the smog peeps in CA, if I also switch the head along with the Howell kit, or will they even know?

Would doing the same injector system and head replacement you are doing pass muster in CA? Anyone in Ca done this and can attest?

Thanks,
This is a great thread..
Mark
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Unread 10-20-2010, 11:55 AM   #42
cevans87
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tbi= throttle body injection
mpi= multi port injection

this swap has cost me less than $500, and will take you only about a week to do or a weekend if you don't get hun up on the top two bolts like i did, it's straight forward and very easy to do this swap, and you save yourself money in the long run going this route, plus if you swap in .030 over or .060 over pistons... you have a stroker...

i calculated it up, and i was getting 175miles a tank... thats filling up every 2 days at $2.55 a gallon with a 20 gallon tank...

so in 26 weeks (six months) filling up 3 times a week... at $51 a fill

$3978 every 6 months in gas with a carb

if i switch to mpi fuel injection you get another 100 miles a tank so my number changes from 3 fills a week to 1

26 weeks (3 months) filling up once a week at $2.55 a gallon at $51 a fill...

$1326 in gas every 6 months...

so just by spending a week, and $500 in parts... i'm saving $2652 in GAS... you would be dumb not to do the MPI like i'm doing...

The TPI gains you a little more than the carb, but not as much as the full swap... hope this helps
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Unread 10-20-2010, 04:05 PM   #43
LoggingRoads
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Quote:
Originally Posted by cevans87 View Post
so just by spending a week, and $500 in parts... i'm saving $2652 in GAS... you would be dumb not to do the MPI like i'm doing...

The TPI gains you a little more than the carb, but not as much as the full swap... hope this helps

I just gotta find out if it'll fly with the smog nazis at the DMV here in commiefornia....
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Unread 10-20-2010, 05:32 PM   #44
Douglas S.
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Unread 10-20-2010, 08:10 PM   #45
cevans87
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bump
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