2.8 to 3.4 Engine Swap
- Thread starter VerdeXJ
- Start date
the 3.4L swap is a very easy swap for the 2.8L...everything is almost bolt for bolt externally...I have a great write-up (or I used to) I will have to see if I can find it and if so you are welcome to it...I dont know of any shops that will jump at the opp to swap motors like this...most dont get into this kind of stuff...I would try JR at MS Conception Motorsports...he is my best guess???
If you do have the write-up, please let me know.
I have been doing some research, the past day, and am toying with the idea of throwing in a 700R4 tranny.
Most of what I have read, the swap doesn't seem too difficult.
The issue with me a shop to do it.
I think it would be cool if there was a garage where you could rent a bay. They would have all the air tools, presses and lifts. Then you could go in there and do your oil changes replace bushings, engine swaps, etc. I am realizing the downside to condo living.
Thanks
I have been doing some research, the past day, and am toying with the idea of throwing in a 700R4 tranny.
Most of what I have read, the swap doesn't seem too difficult.
The issue with me a shop to do it.
I think it would be cool if there was a garage where you could rent a bay. They would have all the air tools, presses and lifts. Then you could go in there and do your oil changes replace bushings, engine swaps, etc. I am realizing the downside to condo living.
Thanks
Floppy Hat
mbryson's hairdresser
- Location
- Lehi, Ut.
I happen to have a copy of the write-up Caleb is referring to. He sent it to me a couple of years ago when my father-in-law was considering this same swap. He ended up backing out and now his XJ has been sitting for about 6 months. Anyway, here is the write-up (I don't know who wrote it):
2.8 to 3.4 engine swap
The chevy 2.8L is notorious for its lack of power and low torque. I have a 1984 Cherokee that suffered from this weak powerplant. After reading about the recently announced upgrade for this engine on the Internet, I began some investigations.
The chevy 3.4 60 degree V6 originally comes from the 1993 Camaro. In this vehicle it is combined with multi port fuel injection. What's convenient about this engine is that it it's externally bolt for bolt the same as the 2.8L. That makes the engine swapping a simple matter.
I decided to do the engine swap because my 2.8L was beginning to show signs of needing rebuilding. The main crank was producing sounds of bad rod bearings, etc. The idea of putting out all the money just to get another lousy engine didn't excite me. The $1700 cost for a new engine seemed to be worth the projected power increase.
The 3.4L is a internally balanced engine and comes with a standard 3-hole flexplate. The problem for me arose when I realized my 904 transmission required a 4-hole flexplate, but the 3.4l required a balanced flexplate.
Some Points
* The 2.8L is an internally balanced engine, requiring the flex plate to be heavy weighted to one side.
* The spacing between the engine and the bellhousing will be increased up to 1/2" if the flexplate is used.
* They don't make a flexplate for the 904 transmission that is
neutrally balanced.
Because of all of this, I was forced to use my original flexplate from the 2.8l and have it balanced. A local machine shop that also balances warehouse ventilation fans was able to do the job for about $85. They claimed to balance the flexplate within .5 gram. Most specs call for engines to be balanced within 10 grams. I felt confident that this would work.
A side note: A representative from Autocraft in Miami, Florida, a
company that makes flexplates, explained that weights should not be welded to the flexplate to balance it. It is better to remove the current weights by drilling out the welds. Fine-tuning and balancing can be done by drilling additional holes in the plate, preferably, near the external rim rather than near the center. The main stress on a flexplate is between the center
crank area and the torque mounting holes, so put the holes outside the area that has the most stress.
I was able to easily remove the engine by removing the accessories; steering pump, alternator, a/c, air pump, etc. Next, I removed the distributor. This gives room to the bell housing bolts. Next, remove the exhaust y-pipe. (Leave the exhaust manifolds on to have something to hook the chain to if you don't have lift attachments bolted on elsewhere.) Remove the starter
and support the transmission. Remove the bell housing bolts. Make sure all the wiring, vacuum, and fuel lines are attached and labeled. Loosen the engine mounting nuts. The bolts can be pulled as the engine is being lifted out.
Hook up the engine chain and pull the engine. This part of the job could be done in about 1.5 hours.
After the engine is out, you'll need to transfer the intake manifold
and exhaust manifolds as well as the other engine sensors. If your 2.8L has a manual fuel pump you will need to get an oil pressure switch and an electric fuel pump. The 3.4L does not have the setup for a manual. (The oil pressure switch will turn off the fuel pump if the engine dies. It's a safety thing.)
If you have a 4-hole torque converter, prepare ahead of time a properly balanced flexplate. This will save you time and frustration. If you torque converter is a 3-hole you'll probably be able to use the new one that comes with the new engine. Also remember to remove the brass pilot bearing if you have an automatic transmission.
After transferring all the pieces, you're ready to install. Generally,
this process takes a bit longer. I did this part of the job in about 2.5 hours.
Point to consider: if you have a carburetor induction system and want to change it to a fuel injector system, this is a good time to do it. I haven't done this yet, but am doing the research to eventually change it over. I've been told the parts needed are: Edelbrock intake base #3785, 4V Top #3789, and the Holley Pro-Jection TBI Kit #501-2. The Holley kit comes with everything; computer, fuel pump, wiring harness, etc. It is considered
a stand-alone system - not needing anything from the vehicle's wiring harness. I'm concerned that that the intake manifold top (#3789) doesn't have a place for the EGR valve. This could cause a problem if the Holley kit requires access to an EGR valve. I haven't checked this out yet but will be calling for a full description next week from Holley.
My concern is: many states don't have a very serious emissions test, but they are getting tougher. Without a port for an EGR valve, many induction systems can't provide the proper emissions to meet the states' standards. I'll admit not know too much about fuel injection. Maybe FI doesn't require an EGR, or maybe some systems don't and other do. That could explain why I
was told to use the non-EGR intake with the fuel injection TBI!?
As a note: The Holley intake manifold is a two piece setup. One piece fits onto the heads the other piece fits on top and holds the carb/injection unit. This allows for changing the port setup (2 or 4 barrel) without having to pull the entire intake off.
Check with your GM dealer when you buy the engine, they can get a fax sent that describes specifically what you'll need to do and what parts to buy ahead of time. The fax is labeled: "3.4L engine conversion."
Another way to go with fuel injection is via:
Fuel Injection Specialties
4317 Centergate
San Antonio, TX 78217
210-654-0774
FAX: 210-654-0775
http://www.fuelinjection .com
These guys are good. They can make any type of setup you want. They will even replicate the Camaro MPI system in a stand-alone setup. I was given an estimate of about $2500 for this, ready to install. Edelbrock/ Holley setup is a TBI twin-injector setup for about $110. For a decent carb setup you could spend about $400-(00. There are choices, but in any case this is the time to do it!
Reinstall the engine according to normal practices. Take your time...
and
remember...
...you get 2 points for each EXTRA bolt and 1 point for each EXTRA nut. The one with the most points wins!
Seriously, I also took the opportunity to replace the bell housing
bolts and other accessory nuts/bolts that I could easily get at the local parts store.
Some things to check BEFORE starting the engine up:
* Transmission fluid level. (I had to remove my torque converter and needed to replace almost 9 quarts of tranny fluid.)
* Engine Oil
* Radiator Fluid
* Throttle Linkage
* Vacuum hoses properly hooked up.
* Wiring Harness reinstalled to all the sensors.
* Distributor set to TDC number one cylinder.
* Starter shims in place(if needed)
I was able to start my engine on the first try, although everyone left the garage when I did it!
The first 2K-4K miles on a vehicle are very important. My advice is to run the engine VERY conservatively; long warm-ups, slow accelerations, easy revs (if necessary), etc. I changed the oil at 300 miles and will change it again when it reaches 1000 miles, then again at 2500 miles and according to regular intervals after that. Fir the first week I checked all the fluids twice a day and closely inspected the engine for leaks. I now have about
550 miles on it and the engine has already proven the money well spent.
I've had many people E-mail me about the swap. Many were not sure whether it would be worth it. Considering the amount of money involved, I don't blame the hesitation. I was pushed into it a little bit because my 2.8L was getting ready to quit and I had to put the money out anyway. If your not sure about pulling an engine, have an experienced friend help. This is not a difficult job, but it does need an experienced hand to do it without
incident. I wouldn't hesitate to do it again if I had the choice.
The cost for the project is about $1900. This is less than I spent. I felt since I was at it I would replace other things, exhaust, engine mounts, etc. The total cost really depends on the individual needs...then again you and I both know the MANY things that are discovered to need replacing DURING the
project! The engine is the major cost and is generally available for a negotiated price of about $1700, an additional few accessories items (oil press sw., elec. fuel pump, wire, fuel line, etc.) will add about another $200 or so.
Good luck
2.8 to 3.4 engine swap
The chevy 2.8L is notorious for its lack of power and low torque. I have a 1984 Cherokee that suffered from this weak powerplant. After reading about the recently announced upgrade for this engine on the Internet, I began some investigations.
The chevy 3.4 60 degree V6 originally comes from the 1993 Camaro. In this vehicle it is combined with multi port fuel injection. What's convenient about this engine is that it it's externally bolt for bolt the same as the 2.8L. That makes the engine swapping a simple matter.
I decided to do the engine swap because my 2.8L was beginning to show signs of needing rebuilding. The main crank was producing sounds of bad rod bearings, etc. The idea of putting out all the money just to get another lousy engine didn't excite me. The $1700 cost for a new engine seemed to be worth the projected power increase.
The 3.4L is a internally balanced engine and comes with a standard 3-hole flexplate. The problem for me arose when I realized my 904 transmission required a 4-hole flexplate, but the 3.4l required a balanced flexplate.
Some Points
* The 2.8L is an internally balanced engine, requiring the flex plate to be heavy weighted to one side.
* The spacing between the engine and the bellhousing will be increased up to 1/2" if the flexplate is used.
* They don't make a flexplate for the 904 transmission that is
neutrally balanced.
Because of all of this, I was forced to use my original flexplate from the 2.8l and have it balanced. A local machine shop that also balances warehouse ventilation fans was able to do the job for about $85. They claimed to balance the flexplate within .5 gram. Most specs call for engines to be balanced within 10 grams. I felt confident that this would work.
A side note: A representative from Autocraft in Miami, Florida, a
company that makes flexplates, explained that weights should not be welded to the flexplate to balance it. It is better to remove the current weights by drilling out the welds. Fine-tuning and balancing can be done by drilling additional holes in the plate, preferably, near the external rim rather than near the center. The main stress on a flexplate is between the center
crank area and the torque mounting holes, so put the holes outside the area that has the most stress.
I was able to easily remove the engine by removing the accessories; steering pump, alternator, a/c, air pump, etc. Next, I removed the distributor. This gives room to the bell housing bolts. Next, remove the exhaust y-pipe. (Leave the exhaust manifolds on to have something to hook the chain to if you don't have lift attachments bolted on elsewhere.) Remove the starter
and support the transmission. Remove the bell housing bolts. Make sure all the wiring, vacuum, and fuel lines are attached and labeled. Loosen the engine mounting nuts. The bolts can be pulled as the engine is being lifted out.
Hook up the engine chain and pull the engine. This part of the job could be done in about 1.5 hours.
After the engine is out, you'll need to transfer the intake manifold
and exhaust manifolds as well as the other engine sensors. If your 2.8L has a manual fuel pump you will need to get an oil pressure switch and an electric fuel pump. The 3.4L does not have the setup for a manual. (The oil pressure switch will turn off the fuel pump if the engine dies. It's a safety thing.)
If you have a 4-hole torque converter, prepare ahead of time a properly balanced flexplate. This will save you time and frustration. If you torque converter is a 3-hole you'll probably be able to use the new one that comes with the new engine. Also remember to remove the brass pilot bearing if you have an automatic transmission.
After transferring all the pieces, you're ready to install. Generally,
this process takes a bit longer. I did this part of the job in about 2.5 hours.
Point to consider: if you have a carburetor induction system and want to change it to a fuel injector system, this is a good time to do it. I haven't done this yet, but am doing the research to eventually change it over. I've been told the parts needed are: Edelbrock intake base #3785, 4V Top #3789, and the Holley Pro-Jection TBI Kit #501-2. The Holley kit comes with everything; computer, fuel pump, wiring harness, etc. It is considered
a stand-alone system - not needing anything from the vehicle's wiring harness. I'm concerned that that the intake manifold top (#3789) doesn't have a place for the EGR valve. This could cause a problem if the Holley kit requires access to an EGR valve. I haven't checked this out yet but will be calling for a full description next week from Holley.
My concern is: many states don't have a very serious emissions test, but they are getting tougher. Without a port for an EGR valve, many induction systems can't provide the proper emissions to meet the states' standards. I'll admit not know too much about fuel injection. Maybe FI doesn't require an EGR, or maybe some systems don't and other do. That could explain why I
was told to use the non-EGR intake with the fuel injection TBI!?
As a note: The Holley intake manifold is a two piece setup. One piece fits onto the heads the other piece fits on top and holds the carb/injection unit. This allows for changing the port setup (2 or 4 barrel) without having to pull the entire intake off.
Check with your GM dealer when you buy the engine, they can get a fax sent that describes specifically what you'll need to do and what parts to buy ahead of time. The fax is labeled: "3.4L engine conversion."
Another way to go with fuel injection is via:
Fuel Injection Specialties
4317 Centergate
San Antonio, TX 78217
210-654-0774
FAX: 210-654-0775
http://www.fuelinjection .com
These guys are good. They can make any type of setup you want. They will even replicate the Camaro MPI system in a stand-alone setup. I was given an estimate of about $2500 for this, ready to install. Edelbrock/ Holley setup is a TBI twin-injector setup for about $110. For a decent carb setup you could spend about $400-(00. There are choices, but in any case this is the time to do it!
Reinstall the engine according to normal practices. Take your time...
and
remember...
...you get 2 points for each EXTRA bolt and 1 point for each EXTRA nut. The one with the most points wins!
Seriously, I also took the opportunity to replace the bell housing
bolts and other accessory nuts/bolts that I could easily get at the local parts store.
Some things to check BEFORE starting the engine up:
* Transmission fluid level. (I had to remove my torque converter and needed to replace almost 9 quarts of tranny fluid.)
* Engine Oil
* Radiator Fluid
* Throttle Linkage
* Vacuum hoses properly hooked up.
* Wiring Harness reinstalled to all the sensors.
* Distributor set to TDC number one cylinder.
* Starter shims in place(if needed)
I was able to start my engine on the first try, although everyone left the garage when I did it!
The first 2K-4K miles on a vehicle are very important. My advice is to run the engine VERY conservatively; long warm-ups, slow accelerations, easy revs (if necessary), etc. I changed the oil at 300 miles and will change it again when it reaches 1000 miles, then again at 2500 miles and according to regular intervals after that. Fir the first week I checked all the fluids twice a day and closely inspected the engine for leaks. I now have about
550 miles on it and the engine has already proven the money well spent.
I've had many people E-mail me about the swap. Many were not sure whether it would be worth it. Considering the amount of money involved, I don't blame the hesitation. I was pushed into it a little bit because my 2.8L was getting ready to quit and I had to put the money out anyway. If your not sure about pulling an engine, have an experienced friend help. This is not a difficult job, but it does need an experienced hand to do it without
incident. I wouldn't hesitate to do it again if I had the choice.
The cost for the project is about $1900. This is less than I spent. I felt since I was at it I would replace other things, exhaust, engine mounts, etc. The total cost really depends on the individual needs...then again you and I both know the MANY things that are discovered to need replacing DURING the
project! The engine is the major cost and is generally available for a negotiated price of about $1700, an additional few accessories items (oil press sw., elec. fuel pump, wire, fuel line, etc.) will add about another $200 or so.
Good luck