Re: American UpGrade DriveTrain

[farna@xxxxxxx]

On July 9, 2005 Brien Tourville wrote:
 
> IF that '87 4.0 was in *Nice* condition,
> I'd say get the later EFi system with
> manifold / harness / 4sp.
> Auto Trans & go for it.

Or use the Renix EFI, it's a bit more forgiving of cam and compression changes. You can run a little less overlap with the cam and not make any compression changes, but it will be turning the timing down to compensate. Best bet is to either lower compression or use a cam recommended on Din Savaa's page(www.jeep4.0performance.4mg.com) under "strokers". 

 
> 1/.  Tri-Power Carbed Manifold.
> 
> There is a builder on-line, and if I
> can find this again I'll let you know.
>
> I was ready for a Tri-Power EFi system
> to 'Blind' show goers with ........ however.
> 
> He built Two Carbed, Three Carbed
> manifolds for his Stroker.
> 
> Three carbed tanked - made less
> daily driver power than the stock
> BBD on a 258.
> 
> Two carbed
> looked nice as do the Twin H Power
> Hudsons but failed in making
> anything but Upper RPM power.
> 
> He runs a 4bbl.
> 
> This guy races too, so I don't dismiss
> his efforts nor the findings on Daily Drivers.

The only one I know who has SUCCESSFULY run three carbs is "NOSIGMA" (darn, can't recall real name. They are three small Webers though, shooting almost straight into the intake ports. Throttle response is said to be "wicked". I suspect that overcarburetion was a big problem with the two and three carb setups. A 258 doesn't work well with more than 500 cfm in either a 2V or 4V. Any more and velocity plummets. If you get some tiny Holley 1909 carbs three might be about right. I ran a pair of YFs on my 196 for a while. Looked nice, but were harder to tune and no better than the WCD 2V. I had a slightly bigger cam in mine too (0.10" more lift, 20* more duration). The YFs were a little bigger than the barrels on the WCD, but it didn't help a thing. I've seen six 750cc motorcycle carbs on the side of a Ford 200 six. It was supposed to have real snappy acceleration also. Six 1000cc bike carbs should be about right for a 258 or stroker. Might limit top end a bit, but would be great !
 for low end acceleration and mid range -- probably better for acceleration than EFI, but I'd stick with the EFI.

> 
> 2/.  The '96+ year 4.0 engines have
> more than stronger blocks & main
> girdles & better balanced cranks.
> 
> They also have vastly Improved Cylinder
> Heads and Intake Ports - that go with the
> EFi systems.

I don't recall any improvements in the head/ports, except for 91+, just the block improvements that were mainly to reduce engine noise. There are no block strength issues for any years -- don't get that idea!

> The EFi coupled with an Aisin 2wd
> 4 speed automatic ( run by a computer
> along with the EFi) STOCK > will
> put any 258 / 4.0 stroker carbed
> behind any TF 727 or 999 in the
> weeds in daily operation enjoyment
> and performance.

Having run both, I can only agree with that statement! The only thing better is running a five speed behind the stroker if you like to shift gears! I still wish I'd found a V-8 three speed with OD close by when I was changing transmissions. I have a Twin Stick shifter for it, but didn't want to pay for shipping the heavy thing from half way across the country. Never can find something like that when you want it, now I've run across three within easy driving distance since I've been back from Korea! Don't want to change now though. 


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