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LTX and LSXPutting LT1s, LS1s, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects including repairs, swap info, and performance upgrades.
Dirty dingo motor mount plates came in. These will set the gen v in ls motor position. Their adjustable plates wouldn’t work with low mount a/c so I’m hoping everything is just going to fall into place.. If the trans ends up being too far out of wack or the compressor too close to the idler arm/k member, plan B will be to go for a mid mount compressor and the dd adjustable mounts. I also have the Holley pan ready to go on. I have to finish putting together my buddy’s charger’s nag 1 tomorrow, but if I have time left over I’m gonna try to test fit this thing!
I can give you some information that may save you quite a bit of frustration related to the mounting of your engine and transmission. The engine mount bosses on the side of the LT block protrude 3/8" further outward than the the mount bosses do on the LS blocks. That means using any sort of adapter plates between the motor mounts and the block is going to exacerbate that issue even further and ultimately raise the installed height of your engine. If they do put you in a geometric bind, you may wish to take a look at the Hooker Blackheart 71221018HKR LT engine clamshell bracket, which was specifically designed as an LS type clamshell for the LT engine and draws the mount poly inserts up closer to the block to provide the same installed crankshaft centerline height as an LS engine using the stock 4th-gen F-body mounts you have in your photo. I've posted an image of this clamshell in use on another LT swap application so you can get a visual depiction of how it draws the mount insert up closer to the sides of the block.
What engine control system will you be using and will it be compatible with the 6l80 TCM ? They are from two different GM generations and it would suck to get to far along this road only to find they won't play well together.
What engine control system will you be using and will it be compatible with the 6l80 TCM ? They are from two different GM generations and it would suck to get to far along this road only to find they won't play well together.
My 6L80 is factory attached to a L83. Do some 6L80s use different inputs?
I under stand that the 6l80 carried over to the gen V engines. But the trans in question is a 2013, and was behind a gen 4 engine. The engine in question is a 2016, a gen V engine. It should not be taken for granted that the EMC from a gen V will be compatible with a gen 4 TMC. If it is , great. I'm just saying it would be best to be sure now.
What engine control system will you be using and will it be compatible with the 6l80 TCM ? They are from two different GM generations and it would suck to get to far along this road only to find they won't play well together.
I'm in talk with PSI Conversion and they're probably going to help me out with a harness. For the TCM/ECM they said I can send them over and they'll be able to match/unlock them. If you get your engine and trans from the same doner then this isn't required. Also I just figured its worth mentioning that I'm trying to do the base swap on some kind of a budget, being most guys aren't aiming for the moon on power and just want a fun daily driver. I have a Terminator X in my Camaro and it's great for that car, but once again not everyone wants a race car. My point being a gen V Holley kit starts at 2299.00 with transmission control, where a PSI or most "stock" conversion harnesses are around 800.00, plus ECM of course. Sure you get a lot of extras with the Holley, but if you're not building a race car why spend an extra $1000+ for features you won't need. And obviously the factory stuff has been beyond proven with hp tuners, so I have no problem using the stock stuff for the Trans Am, even when boost comes into play eventually.
I can give you some information that may save you quite a bit of frustration related to the mounting of your engine and transmission. The engine mount bosses on the side of the LT block protrude 3/8" further outward than the the mount bosses do on the LS blocks. That means using any sort of adapter plates between the motor mounts and the block is going to exacerbate that issue even further and ultimately raise the installed height of your engine. If they do put you in a geometric bind, you may wish to take a look at the Hooker Blackheart 71221018HKR LT engine clamshell bracket, which was specifically designed as an LS type clamshell for the LT engine and draws the mount poly inserts up closer to the block to provide the same installed crankshaft centerline height as an LS engine using the stock 4th-gen F-body mounts you have in your photo. I've posted an image of this clamshell in use on another LT swap application so you can get a visual depiction of how it draws the mount insert up closer to the sides of the block.
Thanks for the info, I might have to go this route especially with the 6l80e now. I need to keep the motor as low as possible to clear the tunnel.
I finally found some time this morning to dig into the l83. Aside from looking like it came out of a river, everything seems to be there. The valves are actually pretty gunky and I have no plans of pulling the heads so I’m not sure how I want to clean them. I’m considering throwing some seafoam through a vacuum line when it’s back together. I also removed the vacuum pump and it won’t be going back on as I’m not keeping afm. The Holley pan comes with plugs for the oil feed and drain ports, but I found an adapter from erl’s that steps the 12mm feed port down to a 1/8 so that seems like a good spot for the 3rd gen oil gauge sender. Tomorrow I’m putting on the mounts and oil pan then dropping it in for a test fit.
Do you know what application it came out of? How does the bottom end look? Or are you waiting for the new pan? That is kinda gunky. Must have gone a ways between oil changes and used crappy gas.
Do you know what application it came out of? How does the bottom end look? Or are you waiting for the new pan? That is kinda gunky. Must have gone a ways between oil changes and used crappy gas.
It came out of a 2016 Yukon. I’ll be pulling the pan tomorrow so hopefully it doesn’t look like that inside. Its common for DI engines to get gunky on the intake valves as they’re not getting constantly sprayed with fuel. A catch can will probably help, but I think sea-foaming every few oil changes is probably the better option.
It came out of a 2016 Yukon. I’ll be pulling the pan tomorrow so hopefully it doesn’t look like that inside. Its common for DI engines to get gunky on the intake valves as they’re not getting constantly sprayed with fuel. A catch can will probably help, but I think sea-foaming every few oil changes is probably the better option.
Agreed. I'd take a small pic and knock off the heavy stuff and shop vac it out. Rotate each valve closed. The sea foam should work. Catch cans are good for any LS/LT. I know you're going N/A at first but use -8 for future boost plans.
I'm surprised at 65k and 4 years old that the aluminum looks as scaley as it does but it doesn't matter much if the insides are good.
I'd look into walnut shell blasting those intake ports. They don't look terrible but look a little worse than mine with 50k more miles on it. Easy insurance to do now.
Last edited by aliceempire; 10-29-2020 at 09:08 AM.
I'm surprised at 65k and 4 years old that the aluminum looks as scaley as it does but it doesn't matter much if the insides are good.
I'd look into walnut shell blasting those intake ports. They don't look terrible but look a little worse than mine with 50k more miles on it. Easy insurance to do now.
An old-school trick (carbureted & no catalytic converter) for cleaning that gunk from the intake ports and valves was to use brown (not Minute) rice. You would rev the engine and pour some brown rice down the carburetor. The rice would "sandblast" the ports and valves and go right out the tailpipe. It's "hard" enough to do the cleaning, but not so hard to damage parts. I have done this in the past. It works.
Well the engine is technically in the car, but no where near mounted in place. Unfortunately the mounts I got sit the motor waaay too far back, and while the a/c compressor clears beautifully, the motor sits on the firewall..You can see the heater core is impossible to get to, and there’s no way the a/c box is going back in, plus yeah it’s literally wedged against the firewall. I’m gonna try flipping the mount adapters backwards as it seems it will push the motor about an inch and a half forward. Not sure if this will be enough, but its a start. I also screwed up and basically got the wrong adapters. After taking another look at dirty dingo’s site, they don’t actually have these mounts under the 3rd gen swap section. The only 3rd gen, gen V adapters they sell are the adjustables which use the old stock sbc mounts.
The issue now is that I have an ls swap k member, so essentially the mounts are backwards. All the swap stuff seems to have the fork end on the block and the rubber on the k member. I need 4th gen mounts on the block for this to work. I new I had the wrong stuff when the 4th gen mount was too big to clear the bottom of the block. The bolt holes still lined up though, so I just cut the bottoms down and I’m planning on welding the seam if I get them to work. Also the inside of the motor looks NOTHING like the outside or intake valves. This is very good news
Boy that thing sits high. You going to be able to get the wiper motor back on?
Hopefully. The back isn’t down all the way so its sitting higher back there. I think there will be enough room once I get the correct mounting and get it off the firewall.
It's neat that you're doing this build thread. I think this is the first documented Gen V swap on the forum. I remember another swap that was finished but it wasn't documented. (maybe just paid for it and didn't do the work) I know for sure you'll do the work and tell the whole story!
You're making good progress. Based on your images, I would venture to guess that the Hooker Blackheart LT clamshell brackets I referenced previously would lower your engine 3/4" from where it is now and move it forward by the same amount. The torque of that LT engine is also going to eat up those rubber motor mounts in pretty short order. We've had a couple of guys here at Holley try to use them in mild LS swap builds and they don't seem to last beyond a few months.
You're making good progress. Based on your images, I would venture to guess that the Hooker Blackheart LT clamshell brackets I referenced previously would lower your engine 3/4" from where it is now and move it forward by the same amount. The torque of that LT engine is also going to eat up those rubber motor mounts in pretty short order. We've had a couple of guys here at Holley try to use them in mild LS swap builds and they don't seem to last beyond a few months.
Thanks for the tip with the mounts. I ordered the lt clamshells from Holley along with their poly inserts.
Well just for fun I decided to pull the motor back out and try flipping the adapter plates from driver to passenger side. This helped greatly and moved the motor forward about an inch and a half, and I was able to slide the bolts through. Its no longer touching the firewall, and the a/c compressor has miles of space. It’s still sitting high though, and the truck intake still seems like a no go at this point. I talked with Matt at Tunetime Performance and he gave me an lt1 intake to play with and it clears a little better...
The Holley lt clamshells came in today, so after I swap them in the height SHOULD be the best its gonna get. My only real concern at this point is the bell housing clearance with the bottom of the firewall. After the new mounts are in I’m planning on tearing the trans apart so I can test fit the case, or at least just the bell housing.
Ok I’ve really been dragging *** on this, but mostly because I was prepping my Camaro for the track a few weeks ago. Anyway I installed the Holley LT mounts but its a no go. The engine sits substantially lower but the bell housing is so close to the firewall that its literally impossible to put the bolts in with the engine in the car. Plus the wiper motor BARELY fits and the a/c box is going to need a huge chunk of it cut out just to clear the cylinder head. It sits way too far back and high. So it looks like I need to ditch the tubular k member and go back to the stock unit. Aside from hacking the ls stand offs off, there’s no way to get this thing to sit how I want it. The Holley mounts are designed for a 4th gen so I knew it wasn’t going to be a guaranteed fit. I don’t really mind because I can put the tubular k member in my Camaro now. I ordered a set of ict billet mounts made for the stock k member and a gen V, so that should be a good fit. I also called them up and was told I can run the low mount a/c if I cut the unused overhang of the plate off once the engine is in it’s final position. The funny thing is the transmission seems like its going fall dead on with the k member. The new mounts will move it forward more, but I think using a 5th gen camaro mount will make up for this. I also pulled the trans apart and it seem’s like its not going to “shift perfect” like the facebook marketplace man said. Glad I paid core price. More to come soon.
Just so you are aware, Hooker Blackheart has an LS swap system that is based on the use of the stock K-member. The system moves the engine/transmission mating plane forward from the stock SB Chevy position by about 5/8"- 3/4". The Hooker Blackheart LT clamshells and inserts you have will install right into them also and place the crankshaft centerline in the same stock position it sits at with the LS swap installation. Aftermarket LS swap K-members are known to deviate from the stock engine/transmission mating plane position by various amounts, which is why we based our swap system around the use of the stock K-member (the fitment is reliable and repeatable).
Is it a stand off fork that bolts to the stock k member to accept the 4th gen style holley motor mount?
Yes, the brackets were designed to use 4th-Gen F-body motor mounts. There is a Hooker Blackheart 3rd-Gen F-Body LS swap system thread in this forum that you can search for to find photos of the engine mounting brackets if you want to see them.
71221003HKR is the part number of the Hooker Blackheart 3rd-Gen F-Body LS swap engine mounting brackets. I tried searching for the thread on this forum I mentioned to you and it doesn’t come up. I’m not sure why that is, but if it’s gone it will be valuable lost resource to members here I think.
Yes, the brackets were designed to use 4th-Gen F-body motor mounts. There is a Hooker Blackheart 3rd-Gen F-Body LS swap system thread in this forum that you can search for to find photos of the engine mounting brackets if you want to see them.
Found the mount adapters but I’m going to give the ict billet pieces a try first being I already have them in hand. Need to swap the stock k member back in and go from there.
Sounds like a reasonable plan since you already have them. Pay close attention to the change in your engine height compared to where it’s at currently as you may end up at a higher mounting position, which may create non-optimized U-joint working angles, or hood clearance issues for you further down the line.
I believe you could significantly improve your motor fitment if you went with a UMI k member. From my experience the BMR k member sits the engine higher and farther back which is what you are fighting. The UMI k-member allows you to position the engine fore/aft with some adjustment due to its mounting plate design. It is set up to position at basically the stock height. I have successfully utilized the UMI k member with the Holley trans cross member with both LS and SBC set-ups. Anyways just something to think about.
I believe you could significantly improve your motor fitment if you went with a UMI k member. From my experience the BMR k member sits the engine higher and farther back which is what you are fighting. The UMI k-member allows you to position the engine fore/aft with some adjustment due to its mounting plate design. It is set up to position at basically the stock height. I have successfully utilized the UMI k member with the Holley trans cross member with both LS and SBC set-ups. Anyways just something to think about.
I’m really trying to keep the low mount a/c. Umi states that you can’t keep it with their k member.
Ok I’m finally started to get somewhere! I pulled the motor and put the stock k member back in. I mocked everything up with the worn out 30 year old mounts and it still fits perfect. The motor is sitting substantially lower and far enough forward that I can get to the bell housing bolts from inside the bay. The oil pan has plenty of space around the k member, and its only going to get better when I swap in the poly mount inserts. I can get the compressor back on by trimming the unused section of the mount adapter off, and ict billet confirmed this as well. With the motor this far forward it seems like the transmission should tuck up pretty well. I’m gutting the case next week then I’ll be mocking the trans up to see where it falls. The wiper motor will also clear now, and the a/c box fits as well. It might need a small amount of trimming to ensure the valve cover doesn’t rub, but its in there!
I’m really trying to keep the low mount a/c. Umi states that you can’t keep it with their k member.
yes you are correct, if that is an objective the UMI will not work for that.
I am not sure what bmr's objective was in regards to how they placed their motor mount positioning, as you have verified it goes up and back, neither which are helpful
Great job so far! I'm interested to see how the LTx works in our cars, I think you've now proven that it will physically fit. Curious to see how many hoops need to be jumped through to get the computer happy/gauges working etc.
Ok the engine is in it’s final position. I ended up moving the motor mounts one position forward on the ict billet plate. This moved the engine back another 1/2 inch. Doing this gave me a little more space between the accessories and radiator, as well as allow for some more up and down wiggle room with the oil pan and crossmember. This is also the furthest I can mount the motor while still fitting the truck compressor. I still might ding or notch the k member by the hose connections being I don’t know how big the hose bulkhead is going to be. The best part is I can still EASILY remove the compressor with the motor bolted in. The a/c box clears as well, but I might notch that connecting flange a little being it will sit slightly higher with the new mounts that won’t be 34 years old.. Also theres a small connector on the very back and bottom of the compressor. Its not for the clutch so I’m assuming its a pressure switch/sensor. I’m planning on cutting away the plastic from the pins so I can bend them at a 90 and solder on some extension wires. It comes straight out and is almost touching the clamshell, so there’s no way the normal connector will work, assuming I use it.
Finally I gutted the trans and got the case into position. The bell housing clears without an issue, and the trans mount is only an inch or two forward from the old t-56 hawks crossmember I had on hand. I need to get driveline angle measurements before making/modifying a final crossmember, but for now the trans is centered in the tunnel and I’m very happy with space I have around the tail shaft. A crossmember mounted torque arm doesn’t seem like it would be an issue. For the height, she is a bit low.. Keep in mind its nowhere near its final position, and there’s still some room to move it up, I just couldn’t clear another tooth on the jackstand. I heard somewhere that a G8 pan is shallower so I will look into that. I’m probably going to ding the tunnel in a few places as well, but honestly I’m just going to be aiming for as close to 0 degrees I can get on the tail-housing. I have no plans for lowering this thing, so I won’t be stuffing it up as high as possible. I just want to get it to the point where the angles are correct and everything is happy.
Next step is to yank the motor, clean it up really nice and spray the bay. After that I’m moving onto the wiring and fuel system, and finally I’ll finish up the trans crossmember, driveshaft, and torque arm.
Wow, the 6L80 hangs down low. I had one for my '66 but I was going to have to tunnel the car to bring the driveshaft up enough (because air ride). Ended up bailing it and going with a 4L80. Good luck! The LTx content is great.
It looks like you are going to have too much down angle on the engine/ trans. A shallower trans pan would help ground clearance but not the drive line angle. also, the Camaro and G8 trans mount have two mount to crossmember bolts where the truck mount only has one. I tried both and I liked the Camaro better. It is heavier construction and slightly taller.
It looks like you are going to have too much down angle on the engine/ trans. A shallower trans pan would help ground clearance but not the drive line angle. also, the Camaro and G8 trans mount have two mount to crossmember bolts where the truck mount only has one. I tried both and I liked the Camaro better. It is heavier construction and slightly taller.
Yea that truck mount is toast so I'll probably replace it with a Camaro unit. I'm pulling the trans down again tomorrow so I can see where the close spots are and shape the tunnel to fit better.
If possible you may want to try and see if you can use a 5th gen Camaro trans pan as it's slightly deeper than an SS pan but still more shallow then the stock truck pan. I believe it holds about a quart more than a G8/SS pan. The extra fluid provided from the Camaro pan will probably help the longevity of your transmission.
Pulled the trans and shaved down the ribs on the case that were making contact in the tunnel. I saw another thread on here where someone did the same and it seemed to work out. I also had to remove the hold down for the fuel lines, and I’m probably gonna re-route them as well. I slightly dinged in a few spots in the tunnel and got the angle under 3 degrees. I leveled the car out on jackstands, so this number should be pretty close. Ground clearance already looks way better and with a camaro or g8 pan it looks like it will be the same height as the engine k member. There’s about 1/4 of an inch of space between the top of the trans and the tunnel, so before the finally assembly I’m going to ding in a few spots a bit more just for insurance. Really happy with the fitment so far, I’m gonna pull the motor next week and start the bay resto as well as clean up the block.
If you still have tunnel clearance that is great. It's been a long time since I put an angle gage on mine but if I remember right I was at 4 degrees down. Looks like it's going well, good work!
Ill keep watching your build, i have been toying with swapping the L83 into the wife's '92, btw i also noted all the aftermarket K members need mod for the LTs ,, still the only hold back for me is having to mod the trans tunnel for the 6l80 that and hiding the car from the wife wile i cut up her baby, it only has 58K on the clock , i think she might hurt me
10-20-2020, 04:27 PM
