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Topic: 4.2 internals into an 87 3.8L (Read 2243 times) previous topic - next topic

4.2 internals into an 87 3.8L

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
87 cougar 3.8
99 jimmy

4.2 internals into an 87 3.8L

Reply #1
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...

4.2 internals into an 87 3.8L

Reply #2
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.
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

4.2 internals into an 87 3.8L

Reply #3
thanks for the help, i will do some reading on those sites.
87 cougar 3.8
99 jimmy

4.2 internals into an 87 3.8L

Reply #4
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)
--Steve
[thread=28690]1988 Cougar V6[/thread]
2012 F-150 3.7L
2011 Mustang 3.7L

4.2 internals into an 87 3.8L

Reply #5
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).
87 cougar 3.8
99 jimmy

4.2 internals into an 87 3.8L

Reply #6
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.
--Steve
[thread=28690]1988 Cougar V6[/thread]
2012 F-150 3.7L
2011 Mustang 3.7L

4.2 internals into an 87 3.8L

Reply #7
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
87 cougar 3.8
99 jimmy

4.2 internals into an 87 3.8L

Reply #8
Here's the easy fix: Windsor V8.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

4.2 internals into an 87 3.8L

Reply #9
Not everybody's dick gets hard over 8 cylinders
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

4.2 internals into an 87 3.8L

Reply #10
Quote from: ThunderbirdSport302;339220
Not everybody's dick gets hard over 8 cylinders


Thank you!:D:burnout:
1983 Tbird with '03 Split Port V6 motor swap done! Headers, dual exhaust, 500CFM Edelbrock, 3G upgrade, Electric fan. 3.73 Gears and an FRPP Limited Slip. Five lug complete! 5-Speed conversion complete! Standalone Fuel Injection in progress...

4.2 internals into an 87 3.8L

Reply #11
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...

4.2 internals into an 87 3.8L

Reply #12
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
My car is a gravity hybrid.  The gasoline engine gets me up the hills, and gravity gets me down.

4.2 internals into an 87 3.8L

Reply #13
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
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

4.2 internals into an 87 3.8L

Reply #14
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. :(
--Steve
[thread=28690]1988 Cougar V6[/thread]
2012 F-150 3.7L
2011 Mustang 3.7L