Corivus' 1991 740SE v8 swap

Thought I would start a build thread on my car since I'm in the middle of the process now.

A few may have seen my previous build on a 1992 740 turbo wagon, it was hit by a car that was parked behind it that was hit by a Uber Eats driver who feel asleep at the wheel. the rear wagon area was sagging and when we got it up in the air it was def a loss as with frame damage and the frame cracked at the lower portions of the bend. the build thread on that one is here.

http://forums.turbobricks.com/showthread.php?t=346900

I picked up this 1991 740SE wagon from thelostartof after my red wagon was destroyed and this is how it looked the first day I picked it up and swapped the rims on it for my Propus C's. You can actually still see the powder they put down in car accidents from the Uber Eats driver. This was literally the next day after the accident.





Like usual i drove it around completely stock and got bored so I started cleaning up things and changing things out. I eventually pulled the radiator and intercooler and swapped them with the ones from my wrecked red wagon (92 740). The change was nice but still wasn't enough, so I was originally going to swap in this 93 RedBlock I found and tossed some h-beam rods in. I was also going to drop this AGP 5457 turbo.





It was at this point that I started looking at what I spent and what else I needed to do which included oversized valves, then I'd have to have them installed and I'd want porting. After that point I'd need to look into a custom tubular manifold. Looking at the pricing I distinctly remember thinking out loud to thelostartof "For the price of porting, installing the OS valves and what I'm going to spend on a tubular exhaust manifold. I could just use those v8volvos mounts and swap in a v8...." of course the response was "you could do that."




So I ended up buying this giant(LM7) with trans(4L60E)/harness/ECM for less then the cost of porting my head. And slowly sold off all the Volvo related performance parts aside from a few things that will probably take longer.



It sat in front of the SE for a while until I got a different DD to roll around in for a few months and then the removal of the old engine happened. Took about a night to do and its already gone off to its new home to help a fellow AZ TB'er get their ride back on the road.






After this it was time to test fit the new engine in, since I was using the v8volvos mount its supposed to allow you to use the truck accessory mount and oil pan and while the oil pan has great clearance the hood won't close. Temporarily I have a solution to that I'm just hoping I can pull it off and make it look good.




Don't have pictures of this part but I had to take the trans off so I could get the engine in for the test fit. The rest of these images the transmission is not in.



The oil pan clearance, its almost at the same level as the frame rails so its useable but I may still grab a h3 oil pan or a newer Silverado oil pan.



It's in and fits, lots of space for activities and I'm going to wait till I have some c6 manifolds to do anything.





I took a week off to go on vacation and went to California with the family to enjoy some time on the beach. Once I was back I started working on the wiring which was pretty straight forward. I made main power and ground wires using welding wire and then started mocking up other lines. I think at this point ac is almost figured out along with cooling.




Mocking up the location for the ECM and fuse box, I am going to see if I can make a mount that floats the fuse box in front of the abs module and places the ECM in the old battery tray.




Just a note, the electrical is mocked up right now, that means that this will all be shielded and in protective sheaths once its completed.

And that catches us up to where I am this week, next week I'm going to start making fuel lines. the todo list feels like its making progress finally which makes me happy.

To Do:
Fuel lines
power steering lines
AC lines
Radiator lines
intake
Electric power steering pump
alt relocation bracket
make space for the transmission
Run Trans cooler lines
Measure diff to trans eyelet to eyelet distance and install
Make adapter for DBW pedal
Install TAC module

I'm sure I'm missing things and I'll add it to the list but the major things are all almost done.

Edit:

you know something I never added any of the other things I did other the go fast additions, so here I'm adding this.

so once I started doing power adding I really wanted the car to be able to stop esp if I was going to put a built redblock in. Afterall this is my DD that my daughter will be in and car seat or not every thing safety wise I can do will be done. So the first thing to tackle was my brakes, I converted them using this walkthrough from thelostartof. https://forums.turbobricks.com/showthread.php?t=344357

The install was very simple and about the only thing I did was paint the calipers white so as to see all the dirty and make me compulsively clean my calipers once a week when doing the rims.





That said I went through the suspension which was actually all upgraded with poly bushings and rubber bushing. I had a rebuilt kit that I was going to use on the red wagon but those will sit for now.



On top of the upgraded poly bushings where needed and rubber bushings, the rear springs were swapped out with overload springs with a coil cut out. That's about it for external upgrades to the car.

Also to add just in case anyone follows along for guidance, I've used a lot of other builds here to get me to this point. lt1swap.com has also been a huge help here's the main point of wiring setup for the gm ecm to control things volvo side.

From lt1swap.com:
Feed c1-b11 (red) to the ignition switch. (From the Volvo fuse box Red Wire)
Run a wire from the ignition switch to c1-A9(pink). (From the Volvo Fuse Box Blue/red wire)
Run a wire from c3-f1(Grey) to the fuel pump. (Pink wire from volvo fuse box)
And finally connect C100 pin C(Pink Wire) to a 12v+ run/start source (haven't run this one yet will update later)

AC 12v request is being fed from the stock harness at the (GREEN bullet) connector on the firewall to Pin 17 on the C2 connector

Looking good!

Do you now have to replace the entire DS with something more substantial, or just the front half to go from Volvo to whatever that is?

Are the V8 mounts intended for a different (shorter overall height) drivetrain than what you used, that is causing the hood interference?

It's nice that newer drivetrains typically have all the EMS right up front - makes transferring the whole system easier , for sure.

lookforjoe said:

Looking good!

Do you now have to replace the entire DS with something more substantial, or just the front half to go from Volvo to whatever that is?

Are the V8 mounts intended for a different (shorter overall height) drivetrain than what you used, that is causing the hood interference?

It's nice that newer drivetrains typically have all the EMS right up front - makes transferring the whole system easier , for sure.

Click to expand...

I'm just going to replace the front half with the gm end and have it rebalanced. not going for huge power for the first year so I think it'll be safe with this setup for now. I will be looking at a stronger driveshaft and rear end once I start adding more power.

Based off the for sale thread it seems like it was intended for either the car or truck ls setup along with the stock transmission, so I think its not a operator error but I wouldn't count that out. And it seems that much like all the other mounts out there the intake and accessory mounts are a bit to high for the hood to close properly.

I am very happy that its all in a centrally located area, its makeing setup for a lot of things much easier. thats not to say I won't be doing some custom wiring here and there. hopefully I don't have to do too much. From what I've been researching and asking questions on it seems a lot simpler then I thought it would be.

Nothing huge today, just beginning to mock up my fuel lines to go from the Volvo filter to the gm fuel rails. I'll be keeping the inline fuel pump but the in-tank fuel pump will be swapped out with my AEM 320lph e85 compatible fuel pump that I ran in my previous Volvo wagon. The fuel tank will be switched out to the larger capacity 20g fuel tank out of a 9 series along with the accompanying gauge cluster.




While making this fuel line I do wonder where people split the line to feed both sides of the fuel rail. I was thinking of just doing a T as close as possible to the fuel rail and calling it a day unless there's a reason not to do that?

Fuel feed and return lines are completed, next up is to make power steering lines. I have never played with power steering before outside of "yep that's leaking take it to someone." So hopefully I can find a walkthrough on which side is high and low on both the rack and the gm PS pump. I decided to use the gm lines and adapt an a/n fitting to the end of the rubber hose line.



Oh look a sneaky shot of the tac module and whereabouts its going to go. Also I'm using the OEM Volvo return line.


also to add, I still need to run a vacuum line from the intake to the FPR but at this point if I had a starter on and at least some exhaust manifolds I could actually test start the engine....

Not a big update time but any progress is progress right?

Last week I ran the power steering lines and tested for leaks and found none which is awesome.




So today I got the a/c lines made by an a/c shop locally and got them installed.






So now at this point I have fuel, electrical, power steering and a/c lines done. I'm going to order some hose so I can run custom cooling lines. I was going to switch over to a car water pump but it puts the angles at weird harsh points.

Here's some pictures showing the clearance I have between the radiator and wp there's a lot of space for it so I think I can get away with a few 90* silicone hoses and a pipe for the lower and it'll be creative to get the upper hose done.






And I started mocking up placement of the trans cooler but I'm not loving this location so I think I might do something a bit different.



This week I'm going to work on pulling the engine back out of the engine bay and making space for the transmission. Thanks to the v8volvos fb group I have some pointers on how much and where to make space. once that's complete it'll be time to get the trans in and measure for the driveshaft.

I'm hoping in a week or 2 from now I can do my first test start. I'm not dead set on that as it seems most people take about 3 months to do a v8 swap and I'm only at my 4th week. So its probably good to just pace myself instead of running this like a 100 yard dash.

Definitely pace yourself, you are way ahead of the curve. Haste makes waste etc. Nice job! I've been working on my 242 swap for a few years.

Very nice looking wagon, love it.

yeah thanks man, I just have to keep telling myself its only been 4 weeks and lots of other have spent a lot more time. It may also help that I'm staying NA for now and possibly going turbo a year from first run date.

Mechanically this seems great

And the headlights and corners and grille look like jewelry

But the true way of the SE desires a full grey grille and big gaps to the headlights

A 240 boi would advocate for the correct front end of a special 240

A 740 boi must do the same

*bows before thee*

S70T5fivespeed said:

Mechanically this seems great

And the headlights and corners and grille look like jewelry

But the true way of the SE desires a full grey grille and big gaps to the headlights

A 240 boi would advocate for the correct front end of a special 240

A 740 boi must do the same

*bows before thee*

Click to expand...

just say no to hockey sticks

I almost forgot to add these pictures, just routing cables that aren't going back to the transmission and also mocking up the cooling lines. Used a wire hanger and my baseboard angle tool to figure out what bends I'll need to make for the rad hoses.




Also thinking I really should mount the fuse box up higher but I need to figure out some sort of stand off that doesn't just look like a block of wood under it. This position makes it so I don't need to modify the harness coming out of the TAC module for the pedal so I have less points of failure.



Has anyone considered actually removing the whole Volvo fuse block and just running it all through the gm fuse block before? I'm kinda contemplating it but part of me feels like that's probably not the best idea for time sake...

Once the transmission is done it looks like it'll be a lot of little things left to do aside from tuning and exhaust...

Another update the transmission is in! its actually awesome to be looking at all this and seeing that its so close to done. I am going to be going nuts when I have to wait for the driveshaft to be finished.

Ignore the transmission fluid, but the gm transmission now fits, gonna see if I can get the stock trans mount to fit for now to hold the transmission in place. I may also look at maybe making a skid plate for both pans since they are kinda low. while I'm at stock springs in the front and have overload springs in the rear I don't want to take chances.




The engine is tipping a bit farther back now that the transmission is in but I need to get the mount in and see if it'll level out a bit more. Also the hoist is only there because I don't have another place for it to go for now.




Pretty close to stock location for the tailshaft so the fitment is pretty good, I cleared out about 2" - 3" on the passenger side about 7" back and nearly none on the driver side since I didn't want to mess with pedal clearance to much. it seems to fit ok, but I may make some more space depending on how much space I have between the trans and tunnel. I'll check that tonight since the fam is home and I have a trans fluid spill to clean up.

Nice! I wanna hear it when it runs.

there will totally be start up vids and sounds part of me really wants to do an open dp start up but I know I will likely be yelled at for days if I do that.

Nice Build! These motors sound pretty good.

I actually miss the sound of a healthy v8, though I grew up on big block mopar's this will work to

Update time:
Tried to get to this yesterday but ended up having something I've always wanted for a birthday... peace and quite and a day to wrench on my own project. So it was today that I got a chance to work on my build. So to start off with the engine is in place fully, no more weird angles and sorta fit but 100% in and fitting. I have about an inch of clearance between the firewall and the transmission. but about 2-3 inches of clearance from the firewall to the engine which is great. I wanted to do more but shoulder injuries are preventing that.





Also test fitting the hood so I can mark some things down as the same person that is painting and fixing the SE bumper is gonna make the hood work with the truck intake. obv I'm going to be playing with the intake and shaving it down. I don't want to have to mess with the harness to much but it would be nice to have something that looks a bit cleaner.





I had a friend come this week who is into cars but not the Volvo scene, he was a ton of help getting this all together this week. Gonna help him get his v8 upgrade done as well hopefully next week or the one after.

I can't stop turning around and staring at this thing in the garage its just so amazing to see it all in place.

edit because I don't want to post again:

I also started trimming up the intake, which no longer hinders the closing of the hood for now, the alt and tb are in the way at the moment which was the main thing I was looking for so I can start trimming. This is also how




I really want to redo how all the wiring and vac hoses route but for now I'm ok with how its routed, in the future though I want it to be cleaner.

Update time:

So I kinda wanna redo the wiring and a lot of other small things like my suspension, cooler lines, vacuum lines etc. That said I started with what I know, wiring, and pulled apart the harness. I'm gonna need to extend some grounds but I think I can make the harness route out so most of this runs under the fuel rail pipe and the vac hose.


Once that was done I started measuring up where my new found body shop friend will need to cut up the hood. this has changed multiple times since then.


while doing that I realized that the engine was tipping back a bit to much so I made a temp trans mount. Getting it back in space I have around 4" of space from the back of the engine to the firewall. Hopefully this will make it so most of my measurements aren't to far off. if anyone wants to chime in about this I'm all ears.




So today I decided I would finally get everything wired in. I started off with cutting and "capping" every wire I'm not using for now with marine grade heat wrap.




Once that was done I just wrapped it all with electrical tape.




After that was done I wired in the ignition and fuel pump fully. I feel like 6 wires(main ground/positive, fuel pump, ignition in and out) isn't much to make a engine run but hopefully that'll do it once I try to start everything.

Still need to measure for the driveshaft but need to wait till I have help as it is a lot more accurate with another person to help. that said I may have to bribe thelostartof with fixing some paint on one of his rides. Though is it a bribe if I enjoy doing it?

Alright its back up in the air again, I did a solo driveshaft measurement and while I feel like I have it I don't feel its spot on so I'm waiting for thelostartof to have some free time to help me measure everything. I don't want this to end up wrong. My solo measurement for future reference to myself was 58 9/16" with a lm7/4l60e and the stock 91+ 7 series rear end. I don't think I've seen anyone post measurements but I would not go by this on your own build, measure according to what the driveshaft shop tells you.





I also test fit the c6 exhaust manifolds that I got from another member here and the passenger side is gonna fit perfect, however the driver side will be interesting. I'll have some help coming in the form of some exhaust jig stuff. this should work just fine for what I'll need I hope. The biggest issue comes in that the opening of both the truck manifold and the c6 manifold gets real close to the steering shaft in different spaces. I still need to measure the clearance I'll get from the truck manifold on that side but I think I'll be using the c6 manifolds.




I should add that I have about 3 inches of space between the downpipe start and the steering column at max and 2 1/2" of clearance at the high point. using the LM7 intake I get 2 1/2" no matter what position the column is at.






I also realized when I had my a/c lines made that I included my junk line so they made the line with a cross threaded fitting that i could not repair, so $18 later I had the correct fitting reattached. the a/c lines are now on and fully seated to the dryer. the line going from the compressor to the condenser is obviously not hooked up since I still need the space so I can square away my wiring.






Once I got this all done I started poking at the wiring and decided to leave that for another day and hooked up and torqued down all my power steering fittings. This probably took the longest due to all the space restraints but hey I got PS now. I also made sure all the fuel fittings are completely tight so there won't be any leaks but I'll do a leak test just in case. Also for some reason my phone hates focusing on the actual ps lines and its a tight squeeze with my hands so these will all be slightly blurry.






Also just for the curious here's a few shots of the space in the actual tunnel with the trans all the way in its final position. I have so much space for all the activities... though I'm not sure what those will be, also need to start figuring out what I'm doing with my trans linkage so I can actually shift...





All that said my to do list is getting incredibly short(ish) now:
Driveshaft (measure, order, install)
Cooling hose fabrication
Shifter Linkage
Intake piping and filter
exhaust fabrication
transmission dipstick install (Lokar flex setup)
Mount for fuse box and ECM
Possibly steering shaft modification
ac 12v+ signal from Volvo ECC to gm ECM at pin 17 on c2 PCM connector
tie Volvo accessories back to 12v signal
wiring cleanup
tuning
Hood modification

Did I mention that I want this to run already.... it'd be nice to be driving this in Nov so I can take it to my 20 year reunion but not sure that will happen...