Jump to content

LQ9 engine swap questions?


ss4ever

Recommended Posts

Hey guys I am looking to replace the engine in my 1972 Monte. I was thinking of buying a LQ9 Escalade/Silverado SS 6.0 engine. I found a decent price on one complete with everything including the harness but not a transmission. My plan was to buy the LQ9 and a 4L60E trans and stick in my Monte along with a set of headers and some better exhaust. I have seen several posts about guys here doing the swaps but I need to ask a few questions for myself.

 

I was wondering what everyone that is doing LS swaps is using for a fuel tank and pump? I saw someone mention a 94 Caprice tank.

 

How well do the truck intakes clear a stock first gen hood? I know I have seen a few people swap them in fourth gen Montes and have to clearance the underside of the hood to clear the throttle body.

 

What all has to be done to use a factory GM Escalade or Silverado SS harness and ECM? I am guessing the ECM will have to be reprogrammed to get rid of the VATS or do they still have that?

 

Which 4L60E trans should I use? I didn't know if one from a F-body would fit better or if the ones in the trucks were better. Not really planning on doing a 4L80E but if it weren't too much work to do I would consider using one instead of the 4L60E.

 

My car currently has a electric fan on it and a custom fan shroud. Does the factory run a electric fan or mechanical on the LQ9?

 

Thanks in advance.

 

Randy

Link to comment
Share on other sites

My Denali has that motor, I can help you with any minor questions. Scott (Footballubet) is the one to talk to probably, as he deals with that stuff everyday in his job that he loves kicking

Ill check the fan in the AM, I thought it was mechanical but Ill check

Link to comment
Share on other sites

Thanks for the help guys. I am no stranger to a fuel injection swap as I did a TPI swap in my old 88 Monte Carlo SS along with a nice aluminum head roller cammed 355 and a T5 trans. Looking back at the time I should have just done a LS1 swap but nothing ever fell in place for it. I am a full time automotive mechanic, rather be called a mechanic than a technician just the terminology I grew up with. I have access to my shop's Snap On Shopkey system(Mitchell) so I can get all kinds of wiring diagrams and specs and I have a 1972 Monte Carlo service manual(repop).

 

When I did my TPI swap in the SS there were a handfull of VERY informative writeups showing what parts were needed as well as what parts to get from the donor vehicle and which wires to hook to where. I haven't really found much here on this site but maybey I just don't know where to look. Got any suggestions?

 

 

Here is a picture of the engine I will be pulling to make the swap:

 

300465_1933364822519_1494259209_31756756

 

Thanks again

 

Randy

Link to comment
Share on other sites

Thanks for the link, I checked it out some but from what I have seen on the links on this site about the engine oil pan is that the Montes set the engine back a little farther than on the chevelles so there is not as much trouble with the oil pan clearing. I was hopeing to hear more from the members here on the site that have done an LS swap to hear what fuel tanks they have used and what engine mounts ecct. I gotta admit I am fairly dissapointed in the lack of responses here.

Link to comment
Share on other sites

It happens, sometimes the expert you are looking for is not on line for a while. I've had this happen myself on other fairly specific type topics. I came back a few weeks later and brought the topic back out and fortunately attracted the attention of the right people.

 

Sorry I can't help you on this specific topic, but best of luck.

Link to comment
Share on other sites

I have a 6.0 in my 03 Silverado SS.Amazing truck.The fan is a thermal clutch style.A tank from a 86-87 Gramd National will work and is almost a bolt in.Used originals are tough to find.If you pull the sending unit and look in you will see a white plastic barrel that is part of an intrakit baffeling system made so the pump does not run out of fuel when the tank is low on corners.Some of the cheap aftermarket tanks had a saucer type sump stamped in them and didn't work too well.The better tanks have the baffeling so make sure yours does.There's tons of info on doing these swaps and almost every part for every car to make everything bolt in.GOOGLE.

Good luck.

Link to comment
Share on other sites

The engine in your Silverado SS IS an LQ9, glad to hear you like it so much. I was not aware that the G-body fuel tank was such a close fit. I run across an occasional TBI Monte fuel tank around here, I have seen the aftermarket tanks before with the pan in the bottom and they roll the metal out pretty thin on them, I will be keeping an eye out for a factory tank with the plasic baffles.

 

Some of the stuff I am still not sure on is stuff like the oil pans, there seems to be several different oil pans depending on the mounts used. I was hoping to hear from some members here as to which accessories they used and how the clearance was on them. Also wondering what everyone has used for mounts. I kind of like the look of the BRP mounts but they are so pricey for no more than there is to them. I keep seeing the cheap EBay mounts but I would hate to buy them and they not work the best for my aplication.

 

I have actually been thinking about getting a LS1 or possibly a LS6 intake manifold and headers to put on the LQ9 before I stick it in the car but then again not sure on that.

 

I don't mind Google but I would rather talk back and forth in an open forum and get different discussions about the swap.

Link to comment
Share on other sites

I just completed the swap of a LY6 and 4L80E in my 72. Need to do some tuning still as I swaped to a LS3 intake and injectors from a Camaro and my off idle fueling is a little off. I used swaptech multi position mounts from nookandtranny. I could have slid the motor farther back but was able to use my stock cross member and minimize the notching of my frame for the A/C compressor. I went with a holley pan and have plenty of room I also used Fbody headers (pacesetters) and they fit really well. The drivers side collector exits at a angle but it actually gave me more room for the o2 sensor and transmission linkage on that side. I swapped in a steering box from a Grand Cherokee and was able to bend the truck power steering lines and bolt them up. I used a harness from PSI as the only LY6/4L80E combo that I am aware of was in 2007 and 2008 vans. I got tired of looking and got a LY6 from a 2008 truck that had a 6L80E which uses a different TCM which the new harness simplified.

I needed a lot of little things like a brake switch to get the TCC to unlock correctly and adapters to make my guages work the way I wanted and countless other things.

The stock 2.73 posi is going to have to go one of these days but I wanted to see what it was like since the 4L80E has the same ratios as the stock TH400.

I still think it was a cheaper way to go than rebuilding the 402/TH400 that was in the car the way I would have wanted. You also just can't beat fuel injection from a driveabilty and mileage standpoint. Let me know if you have any questions and I will try to help.

Link to comment
Share on other sites

Why did you swap the steering box? I called PSI today and talked to them about their harness and ECMs and they sound like they know what they are doing. I keep going back and forth about the intake though, I have thought a lot about switching to a LS1 intake but now I hear that if I go with a LS1 intake that I will have problems clearing my accesories.

 

I talked with BRP today as well about their kit, the guy I talked to was very helpfull answering my questions as best he could. He was thinking(not 100% sure) that the truck accesories would clear the frame and hood with their kit. I mentioned being a member on www.montecarloss.com and he mentioned that since they are a authorised vendor there I would recieve a 10% discount(NICE!) I asked if I get a better discount since I am a moderator there LOL, I had to try.

Link to comment
Share on other sites

I swapped the box because it gives better road feel and is not over powered like the stock unit. I thought I would just mention it so that if you plan to do both you dont have to deal with converting standard fittings to metric to bolt up the lines.

Not the prettiest install but it is functional.

DSCN1295.jpg

DSCN1294.jpg

My AC compressor would not clear unless the motor was slid way forward and then I think you will hit the pan. The alternator clears the hood fine. I would like to change the accessories to clean up the top of the motor but my goal was to get it running first. I started with this.

Start.jpg

Link to comment
Share on other sites

What is everyone using for radiator hoses?

 

What is everyone running for guages and speedometer? I had thought about getting a Cable-X box but after checking the price of everything I am considering just buying a digital dash conversion. By doing that I won't need a cable-X box or an adapter to hook up my tach and sensors.

Link to comment
Share on other sites

383825_2485022973628_1494259209_32088899

 

I got the engine and transmission pulled tonight. The buyer is coming to pick the engine up wednesday night. I hope to get the engine and transmission bought and here next week sometime.

Link to comment
Share on other sites

Well guys I did buy the 16,000 mile LS1/4L60E from a wrecked 99 Camaro SS. I wasn't really planning on buying a LS1 to start with but after finding this one that was local from a friend I decided to buy it. I brought it home monday night and started stripping off some of the parts I won't be needing.

 

405391_2526491290310_1494259209_32104212

 

I bought a set of adapter plates off Ebay, they are VERY nice pieces.

 

402176_2531424453636_1494259209_32106281

 

Right now the plan is to modify the factory harness to use as a stand alone harness(either do this myself or pay someone) and get the factory ECM programmed to get rid of the VATS and the rear O2 sensors. Not sure if I am going to get rid of the EGR or not at the moment(any opinions on this?).

 

I am hoping the factory F-body oil pan will clear my crossmember with the engine set back to the farthest position on the adapters.

Link to comment
Share on other sites

Sorry I didn't see this earlier.

 

I kept the motor mounts in the stock location on the frame. Replaced the block motor mount with a polyurethane one and used 1" setback plates attached to the block as well. By doing this I was able to use the F-Body oil pan. I am using the 4L60E so I had to relocate and modify the trans cross member. I also need to take ~2.5" off the driveshaft (likely going to have a chromemoly one made). I am using trailblazer SS exhaust manifolds for now (headers later). I had to relocate the brake line distribution block as the exhaust manifold hit it. So far it looks like I can keep the stock column shifter if I want (sleeper look). I need to mount the fuel system and finish up the wiring yet. I may run a clutch fan for a bit before switching to electrics.

Link to comment
Share on other sites

The F-Body pan fits good with the 1" setback plates, but i suggest using an engine leveller when installing the motor and trans together as I had to have it at quite the angle to get the pan past the crossmember. It may actually be easier to just put the trans in after the motor from underneath.

Link to comment
Share on other sites

I had to notch the top of the crossmember as well. I just cut it and welded in a piece of plate. In the future i might just make one out of tubing to give it a bit cleaner look.

Link to comment
Share on other sites

All my electronics are from Howellefi. I would consider PSI next time, better pricing. I'm going to try and put the ecm in the car up under the dash if it all works out as planned.

Link to comment
Share on other sites

Well lastnight I set the engine/trans in the car for the first time. Using the plates I bought I set the engine mounts in the first position mounting the engine farthest forward but the drivers mount wouldn't clear the alternator. With the mounts in the middle postition the alternator wouldn't clear the crossmember. I set the engine mounts at the farthest back position(engine farthest forward) and the alternator clears the frame and the oil pan clears the crossmember perfectly.

 

418995_2555622778579_1494259209_32113309

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...