GM 4200 (4.2 straight six) swap into FJ62?
- Thread starter dpr64
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
"Why do so many equate more power or more potential with "better"? Sometimes enough is exactly that. We're not talking '69 Chevelles here, we're talking about old rugged 4wd's."
Agreed. The 'Sweet Spot' is that for a reason. But everyone has a different sweet spot I suppose.. I just rebuilt my 3fe, .20 over, gasket matched the intake and she's much more responsive than pre-rebuild. Could it have more power? Of course, but at low speeds it twists up the truck if I gas it. With the H55, it gets into freeway traffic no problem, and sounds mean doing it. Not to say I wouldn't like 300hp, but is it needed, not sure.
Agreed. The 'Sweet Spot' is that for a reason. But everyone has a different sweet spot I suppose.. I just rebuilt my 3fe, .20 over, gasket matched the intake and she's much more responsive than pre-rebuild. Could it have more power? Of course, but at low speeds it twists up the truck if I gas it. With the H55, it gets into freeway traffic no problem, and sounds mean doing it. Not to say I wouldn't like 300hp, but is it needed, not sure.
It's your vehicle.. I would and did go with an LS, but if you are wanting a straight 6, it sounds like this would be a great one... Good luck with the build..
I would much rather have an inline 6 than a lumpy v8. I like the engine layout personally of a straight 6. Look at all the big rigs and heavy equipment out there (granted they are diesel), pretty much everyone is going to have a straight 6. they are easier to work on and have half the head gaskets, valve cover gaskets and intake gaskets to fail. 
pretty much every industrial application piece of machinery is going to have some sort of inline cylinder engine. see a pattern perhaps?
pretty much every industrial application piece of machinery is going to have some sort of inline cylinder engine. see a pattern perhaps?
I think you're misjudging the cost of the 4.2. My junkyard is very competitive on its prices for our area, and for the 295hp model (2006+) that you said is dirt cheap, we would be anywhere from $1000 for an engine with 200k miles to $1500 for something with <100k miles, in addition to a possible core charge. The oldest and cheapest 4.2, an '02, will run you about $500 for one with high miles to $650 with good miles.
Also, this is not the most reliable engine. I've been running this yard for 3 1/2 years now and have sold maybe two LS engines that were actually for replacement and not people doing engine swaps. I've sold every single 4.2 that we've gotten in, which I think is about ten of them. I couldn't speak for the '06 or newer, but the '02-'05 throttlebodies are also apt to give trouble and cost $75 or more used.
I want to like the 4.2L and hate to be a naysayer, but it's just not as reliable and inexpensive an engine as I believe many people in this thread have the impression of. The only time I would say to go for it when doing this engine swap is in the OP's case when he already has the vehicle, knows it's a good drivetrain, and will incur little to no cost in the swap.
Good luck to you.
That sound like actual hands on knowledge, vs my virtual learning. I will admit that people on internet forums definitely fall into the trap of "wanting to like" something fairly often. That may well be the case with the Atlas engines.
if you are going to spend the time and effort doing the swap... a gm v8 is hard to beat for many reasons that have been stated multiple times...a couple might be worth saying again (1) well proven solution set regarding parts/configurations (2) endless supply of salvage yard donors engine/transmission combinations (3) very developed aftermarket support for all things GM v8 and transmission (4) proven combinations that work in the LC (5) direct support for some kits for install and setup (6) generally easy to setup for the most part (7) power and fuel economy both....are better than stock setup (8) affordable $$.
Fuel Injected GM V8's have proven very reliable and certainly perform for many years.
Pick what ever engine you want...but if you are pushing around that much weight...it seems a V8 is in order.
Fuel Injected GM V8's have proven very reliable and certainly perform for many years.
Pick what ever engine you want...but if you are pushing around that much weight...it seems a V8 is in order.
Not knocking your experience, but I've owned a few vehicles with these engines and have had great success with them. Currently have a '02 envoy with 215k and an '05 Colorado with 308k. I've replaced water pumps on both(twice on the Colorado, about 150k between) and a radiator on the Colorado as well, otherwise nothing but oil changes and air filters.
- Joined
- Jul 22, 2012
- Threads
- 637
- Messages
- 17,325
- Location
- Winter Park, Florida
- Website
- www.cruisermatts.com
Here's the reality, most likely no one is going to complete this swap. There are hundreds of modern engines with well suited power bands and weights to the 60 series and you could discuss ALL of them but look - how many Vortech engines and before that Chevy 350's have been swapped into Cruisers? A whole damn lot.
To the PO, the answer to the thread title is yes. Like mentioned just above me here, there are a great many motors out there that can be swapped into the 60 and bring better power and equal or better reliability. Chrysler has a brand new supercharged Hemi that I am sure would be unholy in a 60, but I am fairly sure this is not market support for adapters and such.
Anyway........ If you are interested in this swap for short term economic reasons I would think long and hard, cheap now usually equated to expensive down the line any time I have done it. What you cut corners on now will come back and bite you on the ass later. I read a swap thread where the guy took the OEM high pressure power steering line from the motor and had the Yota end put on it. Cheap for sure, but its those little things that get your ass on the freeway 40 miles from home at 2 AM on a Tuesday.
Hands down, the LSX series of motors are the most commonly swapped motors in all kinds of vehicles. The reason for this is simple, best bang for the buck out there. The Vortec variant has an iron block and aluminum heads and are considered "fleet" motors. They regularly run 300-500K miles with basic maintenance and wear item replacement. A 5.3L swap can be done with top shelf parts designed for another 20 years on the truck for right around $10K in parts. It can be done cheaper..............................................................
One man's OPINION
Anyway........ If you are interested in this swap for short term economic reasons I would think long and hard, cheap now usually equated to expensive down the line any time I have done it. What you cut corners on now will come back and bite you on the ass later. I read a swap thread where the guy took the OEM high pressure power steering line from the motor and had the Yota end put on it. Cheap for sure, but its those little things that get your ass on the freeway 40 miles from home at 2 AM on a Tuesday.
Hands down, the LSX series of motors are the most commonly swapped motors in all kinds of vehicles. The reason for this is simple, best bang for the buck out there. The Vortec variant has an iron block and aluminum heads and are considered "fleet" motors. They regularly run 300-500K miles with basic maintenance and wear item replacement. A 5.3L swap can be done with top shelf parts designed for another 20 years on the truck for right around $10K in parts. It can be done cheaper..............................................................
One man's OPINION
It amazes me that many of you haven't traded your 60's for Tahoes....
No one has ever denied that a SBC isn't the most common or the best bang for your buck---but that's not the only option.
I guess I just don't understand the arguments so vehemently against anything else when the vehicle we're talking about is old, uncommon, inefficient, has obsolete parts and others can be hard to find, to start with. I would venture to guess that there were more Trailblazers/Envoys built than 60/62's and parts are everywhere.
Rant over!
No one has ever denied that a SBC isn't the most common or the best bang for your buck---but that's not the only option.
I guess I just don't understand the arguments so vehemently against anything else when the vehicle we're talking about is old, uncommon, inefficient, has obsolete parts and others can be hard to find, to start with. I would venture to guess that there were more Trailblazers/Envoys built than 60/62's and parts are everywhere.
Rant over!
I do not see anyone arguing, the OP asked for opinions and that is what is being expressed. Heck, if you are determined enough pretty much any motor made can be made to work in one fashion or another. It all comes down to the individual, which is what makes all of this fun in the first place.
That want really directed at you, or anyone else in particular, just a rant on a personal pet peeve. For whatever reason it just bugs me that every single thread concerning engine swaps ends up basically with "go with a sbc or you're an idiot". Not everyone is after ultimate power(or the potential for it) or incredible parts availability.
Like I said, just a personal pet peeve, rant over!
- Joined
- Jul 22, 2012
- Threads
- 637
- Messages
- 17,325
- Location
- Winter Park, Florida
- Website
- www.cruisermatts.com
5 year bump. Since then in the last few years my friend Calvin has made great strides and is now a pioneer of using this engine for performance applications.
He’s shown repeatedly that these 4200’s can make over 400whp on boost only, on completely stock long blocks. And he’s solved the unique transmission pattern by making adapters to common GM bellhousing pattern.
In the last few years around here turbo’d junkyard LSx swaps into racecars has become so popular that go much faster at the pick-n-pull yard. However there’s always dozens of complete 4200’s that sit untouched for months. Maybe it is time for someone to swap one in a 60.. turbo’d of course.
(side note, this car was built for $2k, so that pretty much eliminates the cost problem if you are willing to spend some time to make stuff)
He’s shown repeatedly that these 4200’s can make over 400whp on boost only, on completely stock long blocks. And he’s solved the unique transmission pattern by making adapters to common GM bellhousing pattern.
In the last few years around here turbo’d junkyard LSx swaps into racecars has become so popular that go much faster at the pick-n-pull yard. However there’s always dozens of complete 4200’s that sit untouched for months. Maybe it is time for someone to swap one in a 60.. turbo’d of course.
(side note, this car was built for $2k, so that pretty much eliminates the cost problem if you are willing to spend some time to make stuff)
5 year bump. Since then in the last few years my friend Calvin has made great strides and is now a pioneer of using this engine for performance applications.
He’s shown repeatedly that these 4200’s can make over 400whp on boost only, on completely stock long blocks. And he’s solved the unique transmission pattern by making adapters to common GM bellhousing pattern.
In the last few years around here turbo’d junkyard LSx swaps into racecars has become so popular that go much faster at the pick-n-pull yard. However there’s always dozens of complete 4200’s that sit untouched for months. Maybe it is time for someone to swap one in a 60.. turbo’d of course.
(side note, this car was built for $2k, so that pretty much eliminates the cost problem if you are willing to spend some time to make stuff)
Never even new this engine existed. Your Friend Calvin make the adapter for the NV4500 then?
- Joined
- Jul 22, 2012
- Threads
- 637
- Messages
- 17,325
- Location
- Winter Park, Florida
- Website
- www.cruisermatts.com
It’s just a simple plate to make the back of the 4200 look like a typical GM 90 degree V8.
The problem with a manual transmission is that there was never a flywheel made to fit the 4200, so auto only until someone figures out a custom flywheel or adapts one.