Thanks and grateful.

[JohnnyTang]

Hi
Thanks for letting me join. I recently picked up an 87 STX 2.9l.
I have a million questions that I'm sure ill find more than one answer for them.
This is my first time in a forum so I really don't know what the rules are. But I am a quick study.
Please direct me towards getting info on an engine swap.
I would like to dump the 2.9 for a 4.0.

Thanks
Johnny.

 

[sheep herder]

Engine Swaps <---- click that

@PetroleumJunkie412 isn't gonna like you.

 

[JohnnyTang]

Do tell?

 

[PetroleumJunkie412]

4.0 is a boat anchor.

2.9 will handle 14psi on stock internals and produce over 500hp at the wheels.

If you swap, give me your 2.9.

 

[JohnnyTang]

4.0 is a boat anchor.

2.9 will handle 14psi on stock internals and produce over 500hp at the wheels.

If you swap, give me your 2.9.

Okay, enlighten me. I'm not needing 500 ponys but.

 

[Dirtman]

Don't mind him, he's clinicaly insane. He's only here as part of his court ordered social rehabilitation program.

 

[Curious Hound]

Don't mind him, he's clinicaly insane. He's only here as part of his court ordered social rehabilitation program.

The same court order was issued to Dirtman.


Petroleum junky will be happy to enlighten you on the merits of the 2.9.

We like to joke around here. But the knowledge base and technical advice are second to none as long as you can handle our humor.

Welcome to TRS.

 

[PetroleumJunkie412]

Okay, enlighten me. I'm not needing 500 ponys but.

The 2.9 was initially designed for World Rally Cup Group B and European Touring Car Championship.*

If you dont know what Group B was, it was Formula-worthy engines in hatchbacks and coupes doing 160+ mph in the woods.

Along the same lines, Geoff Kershaw and Brian Hart developed these engines into Lamborghini killers in the 1980s and 1990s. Google "Minker" and crack a 6 pack.

2.9 reference links, euro and american

Please guys, no replies unless to add link only. Sites I use to do homework on engine and euro stuff, and all cologne family. Welcome to the rabbit hole... http://forum.merkurclub.com/forum/index.php?sid=f02b0da0967e40619e73d24071700c26 https://www.rpmrons.com/index.html...

www.therangerstation.com

Reference info.




Adding boost is not necessarily easy, but you can do this. Remote mount turbos do not need intercooling. Any T04E will turn your engine into a friggin rocket, and they're $100 new on fleabay.

Your stock ecu won't handle it, though. Megasquirt is cheap, and i posted my tunes in the tech forum. A megasquirt will handle up to 48psi of gofasts, so no worries on running out of capabilities. Even naturally aspirated, MS is hand over fist above the factory tuning. With a megasquirt, stock cam, lifters, and injectors your 2.9 will eat a worn out 4.No alive. Odds are it'll kill a fresh 4.Slow as well.



I'd recommend aftermarket heads when you start building, and an awl poked around in your coolant passages. 2.9 and 4.0 typically have casting residues in them. Both are known for soft cams as well. Most colognes started dying terrible deaths with the reduction of ZDDP in motor oil in the 90s (iirc). A melling replacement cam is very cheap, $80 or less. The factory grind is quite good.

The lifespan of your heads is determined by the efficacy of your cooling system. Flush everything, that thing has been on the road for 32 years, there's crap built up in there.















*The 4.0 was designed to be a urinal. I use mine as intended.

Yes. I pee on it.

 

[19Walt93]

I recently worked on an 86 for a friend. The original plan was to replace the worn out 2.9 with a 4,0, but a 4.0 is EDIS and a 2.9 has a distributor so we would have needed an EDIS module, wiring harness, and PCM from a vehicle no newer than 95 to stay with EEC-IV. The odds of finding 25 year old electronic modules that would be functional changed the plan. The 2.9 is rebuilt and running fine with a mild cam from Camcraft.

 

[JohnnyTang]

The 2.9 was initially designed for World Rally Cup Group B and European Touring Car Championship.*

If you dont know what Group B was, it was Formula-worthy engines in hatchbacks and coupes doing 160+ mph in the woods.

Along the same lines, Geoff Kershaw and Brian Hart developed these engines into Lamborghini killers in the 1980s and 1990s. Google "Minker" and crack a 6 pack.

2.9 reference links, euro and american

Please guys, no replies unless to add link only. Sites I use to do homework on engine and euro stuff, and all cologne family. Welcome to the rabbit hole... http://forum.merkurclub.com/forum/index.php?sid=f02b0da0967e40619e73d24071700c26 https://www.rpmrons.com/index.html...

www.therangerstation.com

Reference info.




Adding boost is not necessarily easy, but you can do this. Remote mount turbos do not need intercooling. Any T04E will turn your engine into a friggin rocket, and they're $100 new on fleabay.

Your stock ecu won't handle it, though. Megasquirt is cheap, and i posted my tunes in the tech forum. A megasquirt will handle up to 48psi of gofasts, so no worries on running out of capabilities. Even naturally aspirated, MS is hand over fist above the factory tuning. With a megasquirt, stock cam, lifters, and injectors your 2.9 will eat a worn out 4.No alive. Odds are it'll kill a fresh 4.Slow as well.



I'd recommend aftermarket heads when you start building, and an awl poked around in your coolant passages. 2.9 and 4.0 typically have casting residues in them. Both are known for soft cams as well. Most colognes started dying terrible deaths with the reduction of ZDDP in motor oil in the 90s (iirc). A melling replacement cam is very cheap, $80 or less. The factory grind is quite good.

The lifespan of your heads is determined by the efficacy of your cooling system. Flush everything, that thing has been on the road for 32 years, there's crap built up in there.















*The 4.0 was designed to be a urinal. I use mine as intended.

Yes. I pee on it.

Well you certainly gave more than I already knew about smaller engines. You sold me on an idea. I'm gonna put you on speed dial.
If a fella was gonna look for an engine to build in the 2.9 family to fit my truck, what should I be looking for and what should I shun?
Casting numbers and such.

 

[JohnnyTang]

L

Don't mind him, he's clinicaly insane. He's only here as part of his court ordered social rehabilitation program.

Lol

 

[PetroleumJunkie412]

Even if rebuilt stock with 8DT box for 88+ 5spd is a big upgrade over the egr pcm you have now. Egr is awesome, but not on a cologne pushrod. Their pcms are tuned for specific octane rating, which means breathing oil is bad for them. Add egr to the mix over 32 years.... flush and drain your block, pull your intakes, clean em. Use a catch can, it'll thank you.

Ime, these critters like clean clean intake track, etc. My cam and carbon led me to the tear down and current build. Flip your phone sideways and click on my build thread, page 20+ covers a teardown and what youre in for. Devilishly simple to rebuild with a healthy supply of parts still. Few quirks here and there, just post, we're fast to respond.

Theyre tough as hell if kept up. Why ditch whats worked for 32 years?

I could have engine swapped.... but whats the fun in that when you have a race proven engine in your truck?


also, Walt knows his sh*t.

 

[JohnnyTang]

The same courtesy order was issued to Dirtman.


Petroleum junky will be happy to enlighten you on the merits of the 2.9.

We like to joke around here. But the knowledge base and technical advice are second to none as long as you can handle our humor.

Welcome to TRS.

Much appreciated. I hope the same for everyone here as well.

 

[JohnnyTang]

Even if rebuilt stock with 8DT box for 88+ 5spd is a big upgrade over the egr pcm you have now. Egr is awesome, but not on a cologne pushrod. Their pcms are tuned for specific octane rating, which means breathing oil is bad for them. Add egr to the mix over 32 years.... flush and drain your block, pull your intakes, clean em. Use a catch can, it'll thank you.

Ime, these critters like clean clean intake track, etc. My cam and carbon led me to the tear down and current build. Flip your phone sideways and click on my build thread, page 20+ covers a teardown and what youre in for. Devilishly simple to rebuild with a healthy supply of parts still. Few quirks here and there, just post, we're fast to respond.

Theyre tough as hell if kept up. Why ditch whats worked for 32 years?

I could have engine swapped.... but whats the fun in that when you have a race proven engine in your truck?


also, Walt knows his sh*t.

Fair enough. Thank you for the homework. I'll get started.

 

[PetroleumJunkie412]

L

Lol

Promax or 89tm heads, but if yours are good, run em till they dont vroom. Then promaxx or worlds if you can dig up a set. 24v dohc heads if you're feeling frisky and wealthy.

Blocks... vary. If rebuilding, hot tank, magnaflux, and check for straightness a must. Show them the photos of the casting sand i removed from mine - found 1/2 inch cast iron shrapnel, washers, etc in my coolant passages. Physically check when you get the block back around back two cyls.

If good, stick with what you got. Decide if you're going factory stock rebuild or with flat tops... @gaz has done it. Good budget build.

Have your deck height checked. Some 86 blocks are decked 0.020. Will be important to know if running 2.8l pistons.

cranks and rods are forged. Stock pistons are cast with 1.5something pin to top of really good cast. Frode at FroFix racing says 14psi all day on stock stuff. I shot for 5-8 psi before I figured out 5.8 trinity pistons fit. Then I hit a machining headache. Stick with what we know works for now.

Beware of rebuilt heads. They are sh*t. They reuse work out parts from cores.

ARP bolts are good idea for con rods. Other than that blocks are very strong. Power Engineering in the uk says 675 is their limit overall, so no worries ever.

Your 86tm heads are not great, but they are probably fine if still in existence. Odds are you already have worlds. If you do you should immediately remove them and send them to me. Theyre terrible awful give them to me now damnit.

Theres a thread here of a sectioned head. You'll see where the disaster areas are if they get clogged.