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Posted in January 3, 2005 ¬ 3:10 amh.adminComments Off

Use Parts

Can I use a 3100 long block and put the 3400sfi external parts on it?

I have a 2002 grand am with a 3400sfi engine. The engine is no good. I also have a 3100 engine that is good. I was wondering if I could use the 3100 long block and put the 3400sfi external parts on it. That way all my fuel and wiring connections will be the same.

Yes, this is very possible. The block is basically the same with one exception. Make sure you use the 3100 from a front wheel drive vehicle. The motor mount locations on the block is in a different location on the rear wheel drive version of this block.

Swapping a 3400 for a 3100 is a very popular swap. You are simply doing the reverse, which would be easier.

Use your heads, manifolds, which will make the swap easier.

The first link will have the family tree of this vehicle showing the progression of the changes in this engine. This may be useful in selecting a donor block

Use a 3100 from a 1996 or newer vehicle. It will use the same roller camshaft so you won't be messing around with custom push rods. Remember, the push rods are different lengths on this engine and can not be mixed up.

The camshaft synch ring changed in 2000. This could be an issue. However you could swap the 3400 camshaft into your 3100 donor engine. Better yet install a new camshaft for a 2002 - 3400 engine. You will also want to use the camshaft position sensor from your old 3400.

Also, torque on the upper and lower intake manifolds are critical. Too loose and they leak. Too tight and they crack and must be replaced. The 60 Degree V6 website will have all of the fastener torque settings.

They make a valve grind gasket kit for this engine. It will have all of the gaskets that you will need for this swap. Use the kit for the 3400 as you will be using these heads and manifolds. You will find this gasket kit at any major automotive parts store.

The gasket kit comes with a set of fuel injector "O" rings. Use them. Use a small amount of assembly lube in the "O" rings and ports and they go in much easier.

The cylinder head bolts are not reusable. They are torqued by a calibrated stretch value. Once removed they must be thrown away.

I have never removed a 3100 engine, but I have removed the heads from a couple of them. I have some additional suggestions from my experience.

Most people have access to a digital camera. Take several pictures from different angles before you start. Also, each time you remove a major component, take a new set of pictures. This can help jog your memory if you have problems putting something back together.

Get some 1 quart and 1 gallon zip lock bags, generic will do. Get some 2 inch masking tape. Get some sharpies.

Each time you remove a part place all of the fasteners, brackets, etc in a bag. If the part is small enough, bag it also. Label it with a sharpie. Keep the parts bag along with the componet they came from. Also mark each electrical connection or tubing connection with masking tape and a sharpie.

If you stay organized you won't lose parts or have extra parts left over.

I also bagged each set of lifter, push rod, and rocker arm, and rocker arm nut as a set and labeled them by cylinder and intake or exhaust. This way I got all of these parts back in the correct positions.

Early in the dis-assembly you will need to disconnect and remove the passenger side motor mount. The engine must be supported when this mount is disconnected. I used a floor jack and a block of wood under the oil pan. You will also be able to jack the engine up about 4 inches which makes it easier to get to some of the fasteners.

The Auto Zone website has an excellent Do It Yourself section. You must register but I have never received any SPAM by registering. Here you will have access to an online service manual. You can not download the manual, but you can print any pages that you will need. They will have specific instructions on how to remove and install some of the individual engine assemblies.

See the links below. Lots of good information on the GM 60 degree V6.

Good luck on your project.