Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: cugrhntr on October 10, 2010, 06:37:26 PM

Title: 4.2 internals into an 87 3.8L
Post by: cugrhntr on October 10, 2010, 06:37:26 PM
Well i just read the other thread about putting the 4.2L into a fox body.  There was some discussion on putting the 4.2 internals into the 3.8L and this sounds quite interesting. I was wondering if there was any more information on this, would you have to swap ALL internals (valve springs valves etc) or just the crank, rods, pistons, cam?  Was there a definate answer on how balancing it would work?  I have rebuilt an engine once about 7 or 8 years ago.  It was an 87s 302 so i have a basic idea of how it works and would rather do the work myself and learn something than to pay someone else to do it.

Thanks for any help

Eric
Title: 4.2 internals into an 87 3.8L
Post by: TurboCoupe50 on October 11, 2010, 12:31:48 PM
Well since there are no answers(I really don't know Jack Schitt about a 3.8, never owned one)...

Yes I believe it can be done but requires a block the has a balance shaft('88 -up), reason being is the front main bearing is slightly relocated to accommodate the drive components for the shaft...
Title: 4.2 internals into an 87 3.8L
Post by: Beau on October 11, 2010, 03:13:09 PM
Only the '88 Thunderbird/Cougar had the balance shaft 3.8...not sure if later V6 Mustangs used it or not.

to the OP, you may check some other sites that are more oriented to the Esshag 6....SCCOA might be one...HTH.
Title: 4.2 internals into an 87 3.8L
Post by: cugrhntr on October 11, 2010, 09:50:59 PM
thanks for the help, i will do some reading on those sites.
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 11, 2010, 10:40:05 PM
Quote from: TurboCoupe50;339034
Yes I believe it can be done but requires a block the has a balance shaft('88 -up), reason being is the front main bearing is slightly relocated to accommodate the drive components for the shaft...

yes, 88's had them, but after 88 they deleted the balance shaft. However they did use the same block (kinda, but for this application, it remained the same).  In 99, when the split-port switch was made, they put it back in. However, coming from and owner of both the 88 and the 96, if you want to incorporate the shaft, trust me, there is less vibration with it in. However, I don't know how the stroke would affect that... you would probably want to go ahead and leave it out.

If your going to do this, the easiest way would be to go with a swap from a 4.2 F-150. Most of the motor is setup for our cars already. They also have the split port intakes and heads, so they are more powerful. The most important thing is that they use a return style fuel setup, which is the same as ours. I am not sure if the other 4.2 engines do or not. I do know they are the only split-port motors that do, which is why they are best for split-port 3.8 upgrades.

If you wanted to, you could go ahead and keep the MAF and DIS systems from the f-150, but you would have to also swap the ECU and all related wiring.

However, you might not have to. You can take the distrubutor from ours and attach it, (I THINK.... I don't know if the timing gears on the 4.2 is able to have a distrubutor geared into it... but I think thats how DIS works anyway... Idk that stuffs too advanced for me...)

But you may also be able to run the speed density setup, and rewire the injectors for batch-firing, which is how the 88's run. Even though they are port injected, they still work the same way as the 84-87's. Just make sure you use 88-98 injectors, the 99-04 split port motors used bigger injectors and they will not work correctly with the tuning setup for our cars.

You may also want to look here:
http://moranav6racing.com/category.html?CategoryID=16
and here:
http://www.enginebuildermag.com/Article/2393/rebuilding_the_ford_38l_engine.aspx
(the 4.2 is directly derived from the 3.8 engine, and there is some information on it in here)
Title: 4.2 internals into an 87 3.8L
Post by: cugrhntr on October 12, 2010, 08:46:06 PM
will the 87 heads, intake and transmission fit on a 4.2 block from a 97 newer f-150?  Im thinking it might be easier (setup wise) to just use the 4.2 block and swap the heads intake and such unless the 88 and 87 3.8L engines are direct swaps (same harness, same gas line setup and everything).
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 12, 2010, 10:11:22 PM
The cams and lifters are different. There is a roller cam and lifters in anything 89>. But, if you swap out the cams and the lifters it might work. I say might because I'm pretty sure the 4.2 has its own cam grind and to put your outdated 3.8 cam in there would probably run terrible, or not at all.

On that note though, there is always the choice of pulling your engine and the donor, and then swapping out the cams, cranks, rods, pistons, and so forth and throwing it into yours.

I don't think they used different valves or springs, but I could be wrong. I know the 4.2's are very heavily derived from the 3.8's, since they do use the same block and heads, but I don't know for sure if everything other than the stroke itself is the same or not. I think they're the same though. The easiest way to find out of course, would be to see if you can find the individual castings on each one and check for yourself.

It sucks that you have the 87 and not the 88 b/c pretty much from 88 and up the whole engines were all very similar up until the split port's in 99.
Title: 4.2 internals into an 87 3.8L
Post by: cugrhntr on October 12, 2010, 10:24:30 PM
Yeah it seems that 87 owners kind of have it tough, the 88's on are easier to swap the 302 into and the 4.2 lol.  Thats alright, ill figure out a way to make it work and the longer it takes me to figure it out the less I will see the money turn into parts :D
Title: 4.2 internals into an 87 3.8L
Post by: thunderjet302 on October 13, 2010, 12:14:54 AM
Here's the easy fix: Windsor V8.
Title: 4.2 internals into an 87 3.8L
Post by: Beau on October 13, 2010, 02:07:04 AM
Not everybody's dick gets hard over 8 cylinders
Title: 4.2 internals into an 87 3.8L
Post by: jrad235 on October 13, 2010, 08:19:33 AM
Quote from: ThunderbirdSport302;339220
Not everybody's dick gets hard over 8 cylinders


Thank you!:D:burnout:
Title: 4.2 internals into an 87 3.8L
Post by: TurboCoupe50 on October 13, 2010, 10:41:39 AM
Quote from: ThunderbirdSport302;339220
Not everybody's dick gets hard over 8 cylinders


Quote from: jrad235;339223
Thank you!:D:burnout:


Wait till you're over 60, you won't care... You'll be happy if your woodie is over a Yugo...
Title: 4.2 internals into an 87 3.8L
Post by: 88CougarGT on October 13, 2010, 11:01:17 AM
The poor Esshag V6 has undergone alot of surgery over the years.  I wouldn't expect a 4.2 crank to fit without machine work.  Wouldn't it be easier and cheaper to get a complete 4.0 or 3.7 out of a late model mustang?

I do remember some guys on the SCCOA forum doing this kinda swap (short block into an SC).
http://www.sccoa.com/forums/showthread.php?t=116911&highlight=4.2
Title: 4.2 internals into an 87 3.8L
Post by: Beau on October 13, 2010, 11:53:27 AM
Quote from: 88CougarGT;339241
I wouldn't expect a 4.2 crank to fit without machine work.


Quote from: enginebuildermag.com
Cranks
There have been four different variations of the crank used in the  3.8L over the last 17 years. There’s also a new casting in 2001 that we  haven’t seen yet, so there may be a fifth one. Each one is unique, but  some of the early ones can be converted into the later ones with a  little machining.

Bada bing :D
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 13, 2010, 03:45:04 PM
Yeah but when they talk about that engine, they mean the 3.8 and only the 3.8 version. They did not include the stroked engines in that write up.

However, it should be the same. What I'm curious about now that I started thinking about it though is whether the 4.2 does use different heads. Part of the stroke is of course further down the cylinder, but the other half is back up. I don't know what it would do to compression on a stock 3.8 and depending on how much tolerance there is the pistons might hit the top of cylinder or valves. :(
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 13, 2010, 03:46:51 PM
Quote from: ThunderbirdSport302;339220
Not everybody's dick gets hard over 8 cylinders


x3.

But a supercharged v6...:fordbang:
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 13, 2010, 03:54:12 PM
4.2 is in:
Quote
Applications:

    * 1997–2008 Ford F-150
    * 1997–2005 Ford E-150
    * 1997–2005 Ford E-250
    * 2004–2007 Ford Freestar
    * 2004–2007 Mercury Monterey
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 13, 2010, 03:56:50 PM
Quote from: thunderjet302;339207
Here's the easy fix: Windsor V8.


its really not in an 87... Hes gotta change so much it honestly would probably be easier to rebuild his 3.8
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 13, 2010, 04:03:58 PM
Quote from: 88CougarGT;339241
Wouldn't it be easier and cheaper to get a complete 4.0 or 3.7 out of a late model mustang?



That would also require a new transmission and most likely drive shaft work.

Depends on your definition of easier and cheaper.
Title: 4.2 internals into an 87 3.8L
Post by: Ductape91 on October 13, 2010, 05:26:38 PM
someone either here or over at FEP did this swap(swapping internals) i vaguely remember something with the flexplate(AOD) and harmonic balancer being an issue.
i know someone here was going to swap a 4.2 into thier car.
adding your 87 parts to the 4.2 will not work.
alot of info reguarding this subject is around if you search for it.

Quote from: ThunderbirdSport302;339220
Not everybody's dick gets hard over 8 cylinders


this was almost quote(sig) worthy :P
Title: 4.2 internals into an 87 3.8L
Post by: Scott D on October 13, 2010, 08:35:15 PM
Maybe this article may help?
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 13, 2010, 09:00:50 PM
Quote from: Scott D;339372
Maybe this article may help?


which one is that?
Title: 4.2 internals into an 87 3.8L
Post by: jrad235 on October 14, 2010, 12:12:19 AM
Ok, so the externals of the 4.2L ARE THE SAME(Minus the intake) as the late model 3.8l, which I have in my car. the late model setup looks suspiciously similar to the 87 and up block, but only in pictures I've seen. Anything after 99(97 for the Windstar van) is going to have a split port intake. If you aren't swapping computers/wiring/everything, you have to either do the carb conversion like I did, or ditch the heads/intake off the late model 3.8L/4.2L engine. At that point you'll need port work to regain all the flow you've lost by using old style heads.

My '83 accessories would not bolt up, they had to be spaced out on the new style heads/block, but that was an '83 to an '03, things change a bit. I made them work, but swapped over to the later model front accessories(Alt, PS Pump). Eventually I'll convert the AC to work as well.

Hopefully that helps.
Title: 4.2 internals into an 87 3.8L
Post by: Scott D on October 14, 2010, 02:52:24 AM
Quote from: sarjxxx;339377
which one is that?


this one that I forgot to paste in my reply :rollin:

http://forums.tccoa.com/showthread.php?t=6680
Title: 4.2 internals into an 87 3.8L
Post by: Scott D on October 14, 2010, 02:54:02 AM
Quote from: jrad235;339429
Eventually I'll convert the AC to work as well.


cooch, that's what windows are for :punchballs:

[SIZE="1"]Just shaging with you, dude, you know I love ya[/SIZE]
Title: 4.2 internals into an 87 3.8L
Post by: 88CougarGT on October 14, 2010, 10:05:56 AM
I got a spare set of SC heads sitting in my garage.  Bolt em up and run a turbo....instant super sleeper.
Title: 4.2 internals into an 87 3.8L
Post by: Charlie_chaos on October 14, 2010, 11:44:57 AM
Quote from: ThunderbirdSport302;339220
Not everybody's dick gets hard over 8 cylinders


LOL,  Almost sig'd that .

Quote from: Scott D;339442
cooch, that's what windows are for :punchballs:

Valid point. 


I built a "Monster 3.8L"  in high school back before they had the 4.2L.

people laugh now but is was a pretty Strong runner. 

Carb'd  4BBL, ported heads, open element air cleaner,  Good plugs and wires,  I had dual exhaust and ran an AOD and 8.8 posi out of a wrecked '86 Mustang and it would smoke the tires pretty good but didn't really kill me on gas.

To each there own.  Honestly though... if I went 6 again make mine SC!!!  :burnout:
Title: 4.2 internals into an 87 3.8L
Post by: sarjxxx on October 14, 2010, 08:33:43 PM
Quote from: 88CougarGT;339451
I got a spare set of SC heads sitting in my garage. 


Why am I not surprised...:rollin: