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'95 4.3 vortec motor swap issue


GNXdreamin
03-20-2011, 12:04 PM
hello, i have a '95 blazer, 4x4, 4.3 vortec, vin W, CPI that i am swapping out. the donor motor is a 4.3 vortec, vin W, CPI out of a '93 blazer. At first glance, everything appeared in order, the only difference i noticed between the two was in the distributor. My motor has side mounted plugs, where as the donor had top mounted. Naturally, i assumed the difference between the two was simply for clearance, as the top mounted will not fit in my engine compartment. Upon arriving home with the donor motor, i find something else. The donor motor has no crank position sensor. Can i just swap out my timing chain covers, and install the crank sensor? or is it a deeper problem than that? Where does the sensor pick up it's signal from? And do i need to switch out the cam and crank sprockets, as well as the chain? Those i believe are different between model years. But as far as the crank goes, I thought they were the same? What do i need to do here? Thanks in advance, ---T.J.

MT-2500
03-20-2011, 03:35 PM
hello, i have a '95 blazer, 4x4, 4.3 vortec, vin W, CPI that i am swapping out. the donor motor is a 4.3 vortec, vin W, CPI out of a '93 blazer. At first glance, everything appeared in order, the only difference i noticed between the two was in the distributor. My motor has side mounted plugs, where as the donor had top mounted. Naturally, i assumed the difference between the two was simply for clearance, as the top mounted will not fit in my engine compartment. Upon arriving home with the donor motor, i find something else. The donor motor has no crank position sensor. Can i just swap out my timing chain covers, and install the crank sensor? or is it a deeper problem than that? Where does the sensor pick up it's signal from? And do i need to switch out the cam and crank sprockets, as well as the chain? Those i believe are different between model years. But as far as the crank goes, I thought they were the same? What do i need to do here? Thanks in advance, ---T.J.

You may be up the creek witout a paddle.
To get the front engine crank sensor to work you will have to have a trigger wheel inside the cover .
Probably mounted or may be made on end of crank.
Might check and see if 95 and 95 crank shaft is same.
Pull covers off of both engines and see if the chain and gear and CRANK SENSOR TRIGGER WHEEL from 95 will swap over to 93 engine.
If so then.
Also dist and intake and all sensors stuff will need swapped over.
Let us know how it goes.

GNXdreamin
03-20-2011, 04:23 PM
well the upper intake (plenum) is the same, as well as the fuel feed lines that run from the rear of the lower intake to the injector. The injector is the same, as well. Also, it appears as though the Idle air control valve, throttle position sensor, MAP sensor, and EGR valve are the same between years. There is a slight difference (minor) between EGR valves, that being the couplers are the same, but the female end (on EGR itself) is slightly different. on one year, the coupler mates to the EGR from the right hand side of the EGR valve, via a 90 degree elbow off the front of the valve. The other year, it mounts directly into the front. I can swap them out, but as long as there is no interference, i may not. The lower intakes are different in the fact that the '95 model has a nub that sticks up off the side of the circular hole at the rear of the motor where the distributor drops in. The '93 model does not. I will be swithing those out, just so i don't have to worry about the distributor spinning out of place accidentally. I have yet to compare casting numbers on the cranks, as well as timing chains, sprockets, and other components. I will repost my findings. ---T.J.

MT-2500
03-20-2011, 06:00 PM
well the upper intake (plenum) is the same, as well as the fuel feed lines that run from the rear of the lower intake to the injector. The injector is the same, as well. Also, it appears as though the Idle air control valve, throttle position sensor, MAP sensor, and EGR valve are the same between years. There is a slight difference (minor) between EGR valves, that being the couplers are the same, but the female end (on EGR itself) is slightly different. on one year, the coupler mates to the EGR from the right hand side of the EGR valve, via a 90 degree elbow off the front of the valve. The other year, it mounts directly into the front. I can swap them out, but as long as there is no interference, i may not. The lower intakes are different in the fact that the '95 model has a nub that sticks up off the side of the circular hole at the rear of the motor where the distributor drops in. The '93 model does not. I will be swithing those out, just so i don't have to worry about the distributor spinning out of place accidentally. I have yet to compare casting numbers on the cranks, as well as timing chains, sprockets, and other components. I will repost my findings. ---T.J.



Last time I tryed a swap I ran into problems with the balance shaft.
Check everything good.
Good luck

GNXdreamin
03-20-2011, 07:52 PM
alright, here's what i've figured out so far.....MT-2500, you were right. i guess in the disassembly process of the bad '95 motor, i missed the trigger wheel for the crank sensor that was slid onto the end of the crank, last thing before the cover. So, i pulled the oil pan and timing cover off of the '93 donor motor, and sure enough, they are the same crank. Also, the timing chain, and timing chain sprockets (cam and crank) are the same. So at this point, i thought things would work out great.....until i picked up the timing chain cover off of the '95 and tried to mate it to the donor '93 block.....it does not line up. The '95 cover is plastic, and has 6 mounting bolts. the '93 cover is metal, and has 10 mounting bolts. So, here are my options, as i see them: put good '93 motor back together, and sell it for the money to buy the one i need. Or, swap out all internal components from donor '93 block into '95 block (which i really DON'T want to do), Or, i can scour the internet for an aftermarket timing chain cover that matches the '93 block with 10 mounting bolt holes, and a crank sensor hole........Ideas, anyone??? Thanks, --T.J.

MT-2500
03-21-2011, 06:33 AM
alright, here's what i've figured out so far.....MT-2500, you were right. i guess in the disassembly process of the bad '95 motor, i missed the trigger wheel for the crank sensor that was slid onto the end of the crank, last thing before the cover. So, i pulled the oil pan and timing cover off of the '93 donor motor, and sure enough, they are the same crank. Also, the timing chain, and timing chain sprockets (cam and crank) are the same. So at this point, i thought things would work out great.....until i picked up the timing chain cover off of the '95 and tried to mate it to the donor '93 block.....it does not line up. The '95 cover is plastic, and has 6 mounting bolts. the '93 cover is metal, and has 10 mounting bolts. So, here are my options, as i see them: put good '93 motor back together, and sell it for the money to buy the one i need. Or, swap out all internal components from donor '93 block into '95 block (which i really DON'T want to do), Or, i can scour the internet for an aftermarket timing chain cover that matches the '93 block with 10 mounting bolt holes, and a crank sensor hole........Ideas, anyone??? Thanks, --T.J.


Concerding what you have found so far with carefull and good checking out the things I would try to find
one that is the same as you old engine.
Good Luck and let us know how it goes.

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