LS Swap update

[78Bu88SS]

Well its beel awhile since I've worked on the swap. Had other projects come up (LT1 swap into my truck, house addition, etc). Anyways, I finally got back to it and figured I'd throw a few pieces of info out.

I just dropped the motor in this afternoon. For mounts, I used the Transdapt motor mount adapter plates and used the stock chevy engine side mounts. I positioned the motor by bolting up my transmission and aligning the trans mount in the stock location. I unbolted the stock frame side mounts and dropped the motor in position. The mounts ended up being moved back about 1.25". I still have adequate clearance between the firewall/heater box and the heads. I am using a non a/c heater box. Putting the motor in this place allowed me to run the stock truck PS pulley. It clears the steering box just fine. Now the biggest problem to over come was the oil pan. The stock truck oil pan cleared fine, but hung way too low. Its been mentioned the Moroso LSx pan fits fine, but is quite pricey and requires a remote oil filter setup. I ended up buying the CTS-V oil pan and pickup. Fits perfect. No issues at all. Only 1/2" or so below the crossmember. Now the earlier 78-81 Gbody guys might have a little different front crossmember (so I've been told) and might not have the same clearance. Once I get the trans in (next weekend), I'll snap some pics of the motor sitting in place.

For headers, Scholenfeld headers are junk and do not fit. Do not buy them. With the motor in this location, the stock truck manifolds do not fit. The passenger side clears fine but the drivers side collector hits the frame. There is a new company that can be found on LS1tech that finally made Gbody LSx swap headers. I will be ordering a pair this week. Pricey, but really no choice.

Also, I ran into clearance issues with the #8 coil and heater box. I ended up turing the coil 90* and made a right angle bracket. I bolted it to the #6 coil. Looks clean and clears the heater box now.

Like I said, hope to have more pics next weekend. Once the trans is in (awaiting my Precsion 4000 stall), I can finish up a lot of things.

 

[Horsepwraddict]

awesome dude, keep us updated.

 

[78Bu88SS]

Got the BRP hotrods 1 3/4" coated long tubes installed, primed the motor, and fired it up. Started up the first turn of the key and idled nice and smooth. Open headers sounded awesome.

Hooked the exhaust up and wired up the 2-step. Car is done except for replacing the alternator (bearings are toast). Took the car around the block and its got some balls for sure. Should go good for a relatively mild motor.

Its getting plates this week and then is getting some miles on it. I plan on racing it come August since I have a few weeks off. Can't wait.

I'll snap some finished pics and maybe a vid this weekend.

 

[Tony_SS]

:worthless:

 

[78Bu88SS]

Heres a full write up with pics I did on LS1tech.

Finally wrapped up my LQ4 swap this past weekend. I figured I'd make a long post with the parts I used and issues I ran into. Overall, it wasnt that bad once I had all the parts. Although others had done it, I did some things different for my own reasons and overall, I'm very pleased.

Here is a quick overview of the car before I started. Its an 88 Monte SS with about 115k on it. It had a mild 357 SBC with a built 2004r, 3200 stall, and a 8.5" 4.10 GN rear. After washing the thrust surface on the crank due to a bad converter, I decided to go with an LS swap instead of rebuilding the gen 1 motor.

I picked up a 2005 LQ4 from a 2500HD chevy with 40k miles for $1250. I originally planned on going with fuel injection by using the truck intake, MSD 6010 control box, and Megasquirt. After figuring out the added expense of a cable driven TB, TV cable geometry, and the fact the injectors will probably be too small, I decided to start with a carb and go back to FI at a later time.

I mocked up the motor by using stock GM SBC frame and engine mounts. Using Transdapt motor mount adapter plates PN 4592, I bolted the stock engine side mounts to the block. On my initial test fit, I found the truck power steering pump pulley hit the steering box by quite a bit. To remedy this, I decided to place the engine in a location that put the 2004r in the stock position.

To do this, I unbolted the frame side mounts and bolted them to the engine. I then bolted the engine/transmission in as a unit, bolting the transmount in the stock location. Letting the motor down, I marked the new frame side mount hole locations and drilled new holes. The mounts are now 1.25" or so further back. Doing this, I was able to run my original driveshaft and the power steering pulley cleared just fine. I have about 1.25-1.50" between the drivers side head and the firewall, and I have adequate clearance between the engine and the non a/c heater box. The only modifaction I had to do was unbolt the #8 coil, flipped it 90*, and bolted it to the #6 coil with a small angle bracket I made.

With the motor in place, the truck oil pan cleared but hung way too low for my liking. To remedy this, I picked up a CTS-V oil pan, windage tray, and pickup tube. I test fit the motor with it and it cleared beautifully. Only 0.5-0.75" lower then the crossmember.

At this point, I removed the motor/trans and cleaned it up, along with doing the cam/spring swap, etc.

For the motor, I installed a small 216/226 Comp Cam. I went with this cam for two main reasons...one I picked it up for $75 with not many miles and two, I didnt have the extra money to spend on a full hardcore valvetrain package. I also installed yellow LS6 GM springs, and Thunderracing 7.400" hardened pushrods. At the same time, I installed an LS2 timing chain and new GM oil pump.

For induction, I opted to go with a 750 Holley vacuum secondary carb with rear metering block conversion (already had, just rebuilt it) ontop of a Edelbrock Performer RPM intake. I used an MSD 6010 control box to fire the coils.

To bolt the 2004r to the motor, I used a stock GM F-body flexplate with a GM crank spacer sandwiching the flexplate to the crank. Now the Fbody flexplate is curved, while the truck flexplate is flat. Because the truck flexplate is flat, GM places the crank spacer between the flexplate and crank. Because I went with the Fbody curved flexplate, I placed the crank spacer on the outside, which now only functioned as a crank extension to support the snot on my standard SBC converter.

The last hurdle was the exhaust. I tried the Scholenfeld LS1 "Gbody" headers with no luck. I moved the motor forward and back, and they fit like junk. Even after reworking the passenger side header, they still did not offer a good fitment. I also tried the stock 6.0 truck manifolds but the collector on the drivers side runs right into the frame. I decided to go with a set of headers I knew that would fit...BRPHotrod coated 1 3/4" coated longtubes.

I was very pleased with the headers. Because the headers arrived after I sat the motor back into place, I was afraid I was going to have to lift the motor up to get em in. But that was not the case. With the car 6-8" up in the air, the passenger side header slipped right in from the bottom. Now because BRP fitted the headers with the motor roughly 1.5" forward from my location, I knew there was a chance I'd run into clearance issues. I had a slight interference with the front LCA mount. I was able to trim the mount slightly and that was it. Nothing major. To install the driver's side header, I had to have the car a good 2.5' in the air. Again tho, I was able to slip the header in from the bottom. The spark plug access is great. Only thing I had to do was trim a small amount off a few of the plug wire boots to keep them from interfering with the primary tubes, again not an issue at all, not even noticeable. I mated the exhaust with band clamps to my 2.5" xpipe setup.

The car started with the first turn of the key. I was quite pleased. I've put about 100 miles on the swap and its run great so far. I havent even tuned it yet and it will spin them to the top of 2nd gear. It gets right up to 6500 very fast and has a lot of pull, I'm quite impressed with the power, untuned. I plan on putting my wideband on it in August to dial in the A/F ratio. Tuning with the MSD is real easy. The 2 step works great, as does the rev limiter. Changing the timing real time is a great feature.

Car specs:
88 Monte SS
2005 LQ4 with a Comp 216/226 112, LS6 springs, TR 7.400 Hardened pushrods, Edelbrock Performer RPM, 750 Holley Vac Secondary carb, MSD 6010 ignition box, BRPHotrods 1 3/4" coated long tubes, 2.5" xpipe, PI Vigilante 4000 stall converter, built 2004r, 8.5" 4.10 GN Rear.

 

[78Bu88SS]

 

[78Bu88SS]

 

[Tony_SS]

=P~ =P~ =P~

Thank you for the write up and Pics!!!

AWESOME Monte!

 

[78Bu88SS]

=P~ =P~ =P~

Thank you for the write up and Pics!!!

AWESOME Monte!

No problem. I think with a person not running a/c, this is the best position for the motor. Using the motor mount adapters, CTS-V oil pan, and BRP Hotrod headers, the motor swap should go pretty smooth.

 

[Roller406Bu]

congrats, good to see....