Would NG engine mate to 4KQ tranny/chassis?

[Tony Hoffman]

Huw pretty much covered it. I currently have four 4000Q's to compare. All
JT's, all different states of tune. One, an 84, the lowest milage, Starts
and runs the best, is completely stock and pulls by far the nicest right off
idle. However, it gets flat above 4000 or so, and really flat above 5000. My
daily driver (86) has the MC1 cam and 2.25 exhaust. It is a good bit softer
off the line, but pulls linearly to 6000. Just drops off a bit after that. A
completely stock (86) pulls slightly harder off the line, but goes flat
above 4500. Petunia (85) is the track car. She pulls almost as hard as the
84, but pulls higher revs a bit better, going flat at about 5000. She has a
2.25 exhaust as well, but stock drivetrain otherwise. However, none of them
are night and day difference, other than off the line comparing the dd and
the 84. In a drag race, they will probably all run within tenths of each
other.

Most of the NG/NF's I've driven are a good bit stronger than the JT's.
However, Casey (a friend) had an 86 with an NG, and he couldn't keep up with
a stock 4000Q. Not sure what the state of tuning was, and it was running all
of the 4000 management. He is now swapping in an MC1.

The stock 90Q ran 0-60 in 8.3, while the 4000Q ran 9.6. The 90 wieghed about
100 lbs more.

You can build a hybrid, but you are better off using the NG/NF head and
whatnot than the clock adn JT head. The tiny amount of displacement increase
isn't worth it, unless your JT is worn out. But, the breathing is much
better in the NG/NF head. However, if you are looking to do some work to it,
I'll agree with the others. At some point, 15 hp isn't worth it. The turbo
5000Q went 0-60 in 7.8, and had 400 lbs over the 90q. And, as Huw mentioned,
that's stock. VERY easy to get more hp out of one. especially with
aftermarket EFI. Then again, a V8 is fun as well ;-)

Tony


On Fri, Feb 4, 2011 at 2:34 PM, Huw Powell <audi at humanspeakers.com> wrote:
Yes, the head would bolt to the block, but you have no idea what the
compression ratio or displacement will be.  Some i5s have more
combustion chamber in the head, others in the block.

You are far better off getting an NF out of a 5 speed '87 or so 5k.
That will drop in, CIS-E will run it fine or you can add the
knock-sensing ignition controller.

The NG out of an automatic just creates far too many questions and
problems for the "value" of the upgrade.

Now, FWIW, I have driven a handful of n/a i5 cars, usually with quite
old engines - >150k is the norm (my coupe was young when I bought it at
146k), and at this age they vary a *lot* in performance.

I have seen a JT 4kq that was easily as strong as my black 90Q, though
most aren't.  My grey 90Q is *noticeably* faster than the black one,
mostly on the top end - the first time I had to mat it pulling onto the
local 55 mph highway I barely had time to shift, it seemed - it got to
redline before I expected it to.

Factor that in.  What if you have a "good example" JT, still pulling 115
hp, or maybe even better (?), and the NG is a more "worn" example.  You
do all this work and get nothing, perhaps.

If you really want to do a useful engine swap in the 4kq, put in a turbo
engine with aftermarket management.  The BTDT out there on such a job is
very deep, making it not only much easier, but also making a serious
upgrade in power - a stock MC1 makes 160hp, IIRC, and who runs a
turbocharged engine "stock" anyway?

On another tack, swapping in the cam is *much* easier, so even if there
isn't much difference, you won't mind, especially if you combine the job
with, say, a water pump/TB swap.  You'll need a cam front seal, and a
new rubber cam cover gasket would be nice.  $30 in parts, IIRC.  Remove
front cover, remove cam cover, remove cam pulley (don't lose woodruff
key), gradually undo the cap bolts in the correct order, set caps aside,
swap cam, install new seal, torque caps in correct order and position,
put covers back on.  I probably forgot a step or a part, but you get the
picture.