Tweet
Always admired simple GM push rod motors and prefer 6 cylinders. In the past I did 2 swaps into this chasis including a 305 TBI and a Vortec 4200 using AX-15 and AR5 5 speeds. So at it again this winter I sourced 38,000 km's 3900 for under 600 Canadian. Upon inspection I believe this to be true as it's absolutely spotless inside with no serious oil staining or debris in the bottom oil pan. I'm bound to have a few questions about cross compatibility between 3400 Firebird/Camaro V6's and this 2011 3900 LGD. I'll get to these as I stumble upon them while planning and ordering compatible parts from Rockauto.
The list so far aside from buying this motor is a 1998 Firebird 4l60e core to salvage the removable bell housing to get a correct drivers side starter pocket compatible with a FWD starter. At the moment this is where I have a question. The 3900 has a verified 142 tooth at 11 15/16 diameter (11.94") . Rockauto is telling me a neutrally balanced 3400 flywheel is 148 teeth at 12 7/16 (12.430) diameter. Seems odd considering the automatic flexplate is 142 teeth while starters are the same for both. Are the blocks drilled different, and are the 3500/3900 blocks drilled the same for starters vs. early blocks? I'd like to use a 3400 manual flywheel if I could....otherwise I see making a new flywheel and sourcing a 142 tooth flywheel to press on and run a stock 3900 starter.
After I get past that, I'll focus on flipping the intake while retaining the stock coolant crossover and lower water pump/timing chain housing. They are less than ideal at first look. My first thought is to raise the manifold with a pair of matched plenum spacers (1 1/4" to 2" and might look a bit strange) and grind out the stock power steering mount from the crossover. Keeping the crossover will save me the stock alternator mount and water pump location. Power steering will be a Vortec 4200 pump mounted on the upper passenger side driven from a custom double pulley from the crank via a 3400 harmonic.
Cyber monday I found a new 2008/2009 Equinox camshaft for 138 US as I plan to delete the VVT despite having a MS3Pro ECU. I lso have a Holley Terminator X that I might use if it's capable of being directly wired to the 3900 wasted fire coil setup. I have to say that coil is looking amazing to re use on the MS3 as it's fully supported. It's a huge value not having to buy anything else custom.
Exhaust manifolds if I'm not mistaken just don't exist and I'll need to start with flanges that I'll make. Seeing this under the hood will dictate what they will look like.
Immediately the next goal is to measure the 4l60e bell housing face and measure the AR5 face for bolt patterns and come up with and adapter similar to a Fabbot LS AR5 adapter. BTW...bell's are different heights and LS applications are @7 inches tall while 3800 4l60e's are 6.5". Shorter is better in this situation and just add's thickness to the adapter. I'll know this dimension when I get the flywheel height worked out.
I should add, I don't Facebook and here on this Forum is the only place this thread will exist. Hopefully folks still use forums.
Later,
Nailgun
Edit....appears Chevy S10/Sonoma 2.2 engines have a bolt on flywheel clutch that has the 142 tooth flywheel to work with a stock 3900 starter. I could be wrong.
The list so far aside from buying this motor is a 1998 Firebird 4l60e core to salvage the removable bell housing to get a correct drivers side starter pocket compatible with a FWD starter. At the moment this is where I have a question. The 3900 has a verified 142 tooth at 11 15/16 diameter (11.94") . Rockauto is telling me a neutrally balanced 3400 flywheel is 148 teeth at 12 7/16 (12.430) diameter. Seems odd considering the automatic flexplate is 142 teeth while starters are the same for both. Are the blocks drilled different, and are the 3500/3900 blocks drilled the same for starters vs. early blocks? I'd like to use a 3400 manual flywheel if I could....otherwise I see making a new flywheel and sourcing a 142 tooth flywheel to press on and run a stock 3900 starter.
After I get past that, I'll focus on flipping the intake while retaining the stock coolant crossover and lower water pump/timing chain housing. They are less than ideal at first look. My first thought is to raise the manifold with a pair of matched plenum spacers (1 1/4" to 2" and might look a bit strange) and grind out the stock power steering mount from the crossover. Keeping the crossover will save me the stock alternator mount and water pump location. Power steering will be a Vortec 4200 pump mounted on the upper passenger side driven from a custom double pulley from the crank via a 3400 harmonic.
Cyber monday I found a new 2008/2009 Equinox camshaft for 138 US as I plan to delete the VVT despite having a MS3Pro ECU. I lso have a Holley Terminator X that I might use if it's capable of being directly wired to the 3900 wasted fire coil setup. I have to say that coil is looking amazing to re use on the MS3 as it's fully supported. It's a huge value not having to buy anything else custom.
Exhaust manifolds if I'm not mistaken just don't exist and I'll need to start with flanges that I'll make. Seeing this under the hood will dictate what they will look like.
Immediately the next goal is to measure the 4l60e bell housing face and measure the AR5 face for bolt patterns and come up with and adapter similar to a Fabbot LS AR5 adapter. BTW...bell's are different heights and LS applications are @7 inches tall while 3800 4l60e's are 6.5". Shorter is better in this situation and just add's thickness to the adapter. I'll know this dimension when I get the flywheel height worked out.
I should add, I don't Facebook and here on this Forum is the only place this thread will exist. Hopefully folks still use forums.
Later,
Nailgun
Edit....appears Chevy S10/Sonoma 2.2 engines have a bolt on flywheel clutch that has the 142 tooth flywheel to work with a stock 3900 starter. I could be wrong.
The F23 setup works, but I don't really know what, if any, differences there are between that and what the older manuals had. I didn't do the install but nothing was brought up about it.
Comment