What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

GM 4.2 straight 6

HankScorpio

HankScorpio

Customize everything
 Premium
GMOTM Winner
Joined
Dec 9, 2016
Posts
3,319
Reaction score
6,553
Location
Laramie WY
GM 4.2 straight 6, trailblazer, envoy, ?,

Anyone know much about these engines?

I have a 1960's Thiokol Spryte snowcat. They came with a ford 230? or 300 straight 6. This one is a 230 I think with a manual that has some issues. I am thinking a repower but there is no room for a V8. I don't really speak Ford. This brings me to looking for other options. 2wd trans to a rear axle with brake bands from the snowcat.

My buddy has a smaller IMP with a 300 and an auto that he swapped. It hauls ass. Sketchy wiring harness from early 90's F150 but its fuel injected.

Ford 300 6. Fits for sure. All pretty old at this point.

GM 4.2 straight 6. 270 hp, 275 lb/ft. Usually a 4L60 in the RWD.

Jeep 4.0 straight 6. Had a few of these, all great engines. Not sure about the auto trans yet. Mostly about shift controls. The one in my 4wd Cherokee was rock solid well past 200K.

Cummins straight 6. Way, way, way too heavy. Diesel sucks in the cold.

If the GM 4.2 engine is good and bolts up to standard GM bellhousings it would open up some possibilities for me. I know there are older carbed motors from everyone but I feel if a swap is happening then fuel injection for high altitude running would be preferred.

Any thoughts? Just no experience with the GM straight 6.

If a V8 would just fit I would be raising hell in no time.
 
I know folks that ran them in the original application, no issues. Seems like a good idea
 
I have heard of a few people that liked them. No actual experience past my parents have one with 90K on it with no problem except needing a thermostat last year.
 
HankScorpio said:
If the GM 4.2 engine is good and bolts up to standard GM bellhousings it would open up some possibilities for me.
Click to expand...

Therein lies the only real problem with this idea. The Atlas family of engines has its own unique bellhousing pattern. If you bring along the 4L60 with the engine, you'll have a good combination. But you won't bolt a standard 4L60 to the back of a 4200 (or its sibling models) without an adapter.

Bell housing adapter - EMTECH MOTORSPORTS

emtechmotorsports.com emtechmotorsports.com


If you do choose the 4200, inliners.org is a good source for information. It's a well-explored swap, you won't be breaking new ground.

4200 swaps into older vehicles - basic information

With 100's of different potential homes for the 4200 this will be a general guide.The 4200 only came with the a 4l60E transmission from GM. So using that combination is the path of least resistance. The best way to do a 4200 swap is to buy a running vehicle - one that came to an unplanned ...
www.inliners.org www.inliners.org

4200 to GM 194/292/SBC/BBC trans adapers

For the few of you that want to do the 4200 swap, using your existing automatic (note the bellhousing adapter will work for a std transmission bell as well) all the parts are available to do so-Bell housing adapter - this adapts the 4200 bolt pattern to the 194/292/SBC/BBC bell housing pat...
www.inliners.org www.inliners.org
 
We had a similar snow cat in Idaho with the power company. It had a 300 I believe. They had a parts unit behind the shop for any needed repairs to the working unit. I think the comm techs only used it to go on one mountain to get to some towers. I like the 300 Ford motor. We have one here at the plant in an airline tug we use to pull a Big 40 welder mounted to a trailer. It purrs like a kitten.
 
They aren't bad engines. Just not an average swap. I've bought a '04 TB new and put a lot of miles on it. It did end up chucking a rod, but I don't blame the design, but more a certain somebody, driving the piss out of it and never ever letting me know what was going on with it. Stuffed another engine in it and she kept beating it to death.

I've seen a sno-cat type ride depowered with a 4.3 V6 that would probably work pretty well. But if there was room for a 4.3 width-wise, I would guess a small block would be able to drop in and you wouldn't be asking about inline 6's.
 
campfire said:
Therein lies the only real problem with this idea. The Atlas family of engines has its own unique bellhousing pattern. If you bring along the 4L60 with the engine, you'll have a good combination. But you won't bolt a standard 4L60 to the back of a 4200 (or its sibling models) without an adapter.

Bell housing adapter - EMTECH MOTORSPORTS

emtechmotorsports.com emtechmotorsports.com


If you do choose the 4200, inliners.org is a good source for information. It's a well-explored swap, you won't be breaking new ground.

4200 swaps into older vehicles - basic information

With 100's of different potential homes for the 4200 this will be a general guide.The 4200 only came with the a 4l60E transmission from GM. So using that combination is the path of least resistance. The best way to do a 4200 swap is to buy a running vehicle - one that came to an unplanned ...
www.inliners.org www.inliners.org

4200 to GM 194/292/SBC/BBC trans adapers

For the few of you that want to do the 4200 swap, using your existing automatic (note the bellhousing adapter will work for a std transmission bell as well) all the parts are available to do so-Bell housing adapter - this adapts the 4200 bolt pattern to the 194/292/SBC/BBC bell housing pat...
www.inliners.org www.inliners.org
Click to expand...
That answers my question on the bellhousing. Thanks.
 
az_762_nato said:
Im jealous! I've been looking for a Spryte for a while now, they're all either absolutely mint and $$$$, or completely roached
Click to expand...
Had to go up to northern WY to find the one I have. Be patient, decent deals are out there but you have to be ready to jump on them and be willing to travel for a good deal. The Snowcat market is kind of crazy but if you need one (or just want one) there are not a ton of choices out there.
 
Truckman4life said:
We had a similar snow cat in Idaho with the power company. It had a 300 I believe. They had a parts unit behind the shop for any needed repairs to the working unit. I think the comm techs only used it to go on one mountain to get to some towers. I like the 300 Ford motor. We have one here at the plant in an airline tug we use to pull a Big 40 welder mounted to a trailer. It purrs like a kitten.
Click to expand...
Of all the ford motors out there the 300 6 is one that I could support having in a machine. It really was a great motor for industrial applications.
 
ZooMad75 said:
They aren't bad engines. Just not an average swap. I've bought a '04 TB new and put a lot of miles on it. It did end up chucking a rod, but I don't blame the design, but more a certain somebody, driving the piss out of it and never ever letting me know what was going on with it. Stuffed another engine in it and she kept beating it to death.

I've seen a sno-cat type ride depowered with a 4.3 V6 that would probably work pretty well. But if there was room for a 4.3 width-wise, I would guess a small block would be able to drop in and you wouldn't be asking about inline 6's.
Click to expand...
You can see in the above spryte photo there is not a lot of room between the tracks. The engine and trans have to fit in that narrow slot in the center of the machine. The doghouse continues straight up above the tracks, going wider would put the valve covers out into the seating position which is already pretty narrow. The current setup has a manual behind the smaller 6. Shifting on the fly in a tracked vehicle is difficult, especially while climbing. This is where an automatic would be excellent. I talked to a guy down in Castle Rock that has a few snowcats and he did not recommend an auto with the smaller 6, just not enough power.

My Tucker is a manual, it will go anywhere on the mountain. Using the plow to build road you can get crazy places but it is also geared for that plow and tops out at 12mph. Some days you just want to go fast.
dec 2019.jpg

Thanks for the knowledge on the GM 4.2. Still in the running for a possible swap.
 
We had a Trailblazer 4.2 I actually really liked the engine it did have lots of power and it had over 400 thousand kilometres on it. No failures from the engine that I know of and we got it from the original owner.
That would be a fun engine in that snow machine!

The Ford 300 is a really good choice too!
 
I'm not a big Ford guy but what about the 2.3L four cylinder? I would bet they make more power than an old straight 6.
 
The GM 4.2 has no distributor provisions, to my knowledge anyhow, you might be stuck with fuel injection. The Ford 300 is a supurb engine and still has aftermarket support, plus a dizzy and carb intakes.
 
bigblock454 said:
The GM 4.2 has no distributor provisions, to my knowledge anyhow, you might be stuck with fuel injection. The Ford 300 is a supurb engine and still has aftermarket support, plus a dizzy and carb intakes.
Click to expand...
I think fuel injection would be ideal for a vehicle like that. Starting a carb'd engine in the cold sucks.

Find a 2wd Trailblazer/Envoy and pull the engine and trans as a unit.
 
how about Toyota? may not be an economical solution, but the mid 2000s Landcruiser's and lexus' have inline 6 engines, and they are to known run forever. should be the 1fz-fe 4.5 liter. make around 210HP i think. there are a few turbo kits out there - a friend of mine just put a turbo on his 1997lx450... . I think its the most refined version, and just about the pinnacle for the old gm inline 6 design that toyota built.
the older toyota F, 2F, 3F, 3FE versions all had some good qualities, but not much to speak of for performance.
 
You must log in or register to reply here.

Latest Posts

Top Bottom