Possible Chevy LS4 (5.3 FWD LS) swap?

Jackets64

Member
Theoretically, if I got a F40 trans with a metric bellhousing and mounted it with the normal F40 trans mount mod and attached an LS4 V8 to it and fabricated some engine mounts, would it fit? Maybe if I relocated the fuel tank?
 

Gtstorey

Goblin Guru
"Would it fit" is sort of open ended. It likely could go within the limits of the "frame" but nothing would likely bolt up. If you can fabricate enough to get things to bolt in, it likely would be easier to replace the entire rear "cage" to make it work.
 

Jackets64

Member
"Would it fit" is sort of open ended. It likely could go within the limits of the "frame" but nothing would likely bolt up. If you can fabricate enough to get things to bolt in, it likely would be easier to replace the entire rear "cage" to make it work.
Ok, would it fit with no modifications to the size and general structure of the standard chassis? I’ve seen people say it could fit, obviously with some fabrication but I’m interested in owning a Goblin in the future and I think it would be awesome to have a V8 Goblin. It would be a similar concept to an LS4 Fiero except with less chassis modification.
 

Gtstorey

Goblin Guru
My guess is that it would fit but the subframe wouldn't bolt in and none of the mounting points would be close and more than likely rear suspension would be difficult. For v8 kit car I would look at the Stalker.
 

escapepilot

Goblin Guru
Could it be done? Probably. But why? With the ability to get insane amounts of horsepower out of the Ecotec 4, what would be the point? If you list the pros vs cons, I don't see how an LS could win.

Pros of LS - V8 sound, V8 torque (only a minor plus in a 1600 lb car)

Cons of LS - significantly increased complexity of build (fabrication to fit, integration of electronics...), increased rear weight bias, decreased fuel economy, increased cost.

Even a NA LS based Goblin will be quicker than just about anything else on the road. Add the SS/SC or SS/TC as a donor and you'll likely never encounter another vehicle you're not quicker than.
 

Desert Sasqwatch

Goblin Guru
Once per year someone gets on the forum with an idea of building a V8 Goblin. Do a search and please take a look at those discussions. If you believe you are serious and have deep pockets, talk with Dale E and get his input. He has already researched this option.
 

Rauq

Goblin Guru
Unfortunately the tough reality with these questions is, if you have to ask, you probably can't pull it off. If it were a straightforward build, it'd probably already have been done. If you're willing to venture into uncharted territory and figure it out for yourself, you'll find support here in the community, but it would probably require substantial rework of the subframe and the rear 1/3 of the chassis. I'm sure it can be done, but then you're really only buying the DF kit for the design work that's been put into the front half of the chassis.

Is an LS capable of making more power than an Ecotec? Yes, but Ecotecs have already made more power than is useful in 99.9% of builds, and with less effort than it'd take to get an LS4 into a Goblin. Mounting a starter on an LS4/F40 combo requires more fab work than building an entire Goblin.
 

Dale E

Well-Known Member
Oh no, not this again!!!! Yes it can be done. No it really isn't any harder than the Cobalt/HHR engine mounting to chassis/subframe. All the parts are available already (know your resources), No one has actually done it --YET! Read the discussions in other builds @ Classy. and another one that opened the stage floor for discussion and no one danced! If you want to do it - do it! If you don't want to do it, then don't. You can spend a lot of money building the Cobalt platform to insane power.

No one needs insane power in the Cobalt to win a race. Read Lotus history. Why did the SCCA stick 70 horsepower Lotus cars in the same class as a Corvette? It wasn't because of insane power the Lotus was winning, it was handling!

I'll just say, that the 3800 V6 supercharged engine I put on a HHR/Cobalt subframe fit and mounted all to the subframe. Gas tank remains in stock place. So.

A final thought. The desired Cobalt is a SC or TC and they are nearly unobtainable. The Goblin chassis may eventually have to be re-imagined for another power train donor that is available.

All I have to say here!

Dale
 

Jackets64

Member
Okey dokey. I’ve got the general consensus. Thanks anyways! (I may still try in the future just to try. I very much like the idea of having a uniquely powered Goblin. Maybe if the LS4 doesn’t work out I’ll try the 3800 V6.)
 

Rauq

Goblin Guru
For my money I'd go with a Saab LP9 2.8T V6 over a 3800 ;)

I always feel bad giving my input that these alternative swaps are unlikely to pan out, but you've taken it better than most. You should definitely build a traditional Goblin first, you'll receive only support in that initiative. Then see if the swap itch has been scratched... you'll also get more encouragement and support to complete a swap if you've already built your Goblin.
 

Jackets64

Member
For my money I'd go with a Saab LP9 2.8T V6 over a 3800 ;)

I always feel bad giving my input that these alternative swaps are unlikely to pan out, but you've taken it better than most. You should definitely build a traditional Goblin first, you'll receive only support in that initiative. Then see if the swap itch has been scratched... you'll also get more encouragement and support to complete a swap if you've already built your Goblin.
Ok. Sounds like a good idea, I may have to check it out. It’s gonna be a while til I get my hands on a Goblin but I’m a big fan of speculation XD
 

Dale E

Well-Known Member
Everyone has their reasons for doing something. One of your greatest powers is choice. The power to choose whatever you want in life, be it car, house, job, family.

So I chose to go down the path of Lotus themed cars some 60 years ago. I like everyone in the Goblin family, has wanted to build a car since I was young. Papers are in boxes of various drawings, of cars, parts, mufflers, suspensions.

Lonny and the DF Kit team designed a great foundation in their chassis, and even they are designing modifications you builders asked for. The builders - choice - is build on that solid chassis foundation and create their work of art. The Goblin family is supportive and helpful, since each member has a skill set that lends expertise to others.

Encourage a potential new family member to come and join in the excitement, the passion. If something isn't what you would do, encourage another to expand his desires. Sit back, and watch the flow of energy. Examples of that are displayed here on the forum in the build logs.

Dare I say!! How many Goblin builders have modified their builds? How many builders have added tabs, run the water tubes without hoses, drilled holes for some reason, added scoops, and side pod radiator mountings, and even suspensions?

There is no difference in doing those things than fabricating up a different motor mount. The Goblin engine and transmission are held basically by the rear chassis members. The subframe is there for bracing the rotational torque roll of the powertrain components. Oh and something to mount the suspension to so you can drive your Goblin versus just starting it up and playing race-man while it is on jack stands.

As for the starter on the LS4, that has been solved and a part is available. A flywheel is available to mount to the F23/F40 transmissions. Lonny already has modified the foundation chassis for the F40. If you can do all the modifications you have already done , as mentioned above, then a little chassis tweaking to get an extra half inch or inch to fit in a different power train isn't going to be harder.

Empower, encourage!!

Dale
 

Jackets64

Member
Everyone has their reasons for doing something. One of your greatest powers is choice. The power to choose whatever you want in life, be it car, house, job, family.

So I chose to go down the path of Lotus themed cars some 60 years ago. I like everyone in the Goblin family, has wanted to build a car since I was young. Papers are in boxes of various drawings, of cars, parts, mufflers, suspensions.

Lonny and the DF Kit team designed a great foundation in their chassis, and even they are designing modifications you builders asked for. The builders - choice - is build on that solid chassis foundation and create their work of art. The Goblin family is supportive and helpful, since each member has a skill set that lends expertise to others.

Encourage a potential new family member to come and join in the excitement, the passion. If something isn't what you would do, encourage another to expand his desires. Sit back, and watch the flow of energy. Examples of that are displayed here on the forum in the build logs.

Dare I say!! How many Goblin builders have modified their builds? How many builders have added tabs, run the water tubes without hoses, drilled holes for some reason, added scoops, and side pod radiator mountings, and even suspensions?

There is no difference in doing those things than fabricating up a different motor mount. The Goblin engine and transmission are held basically by the rear chassis members. The subframe is there for bracing the rotational torque roll of the powertrain components. Oh and something to mount the suspension to so you can drive your Goblin versus just starting it up and playing race-man while it is on jack stands.

As for the starter on the LS4, that has been solved and a part is available. A flywheel is available to mount to the F23/F40 transmissions. Lonny already has modified the foundation chassis for the F40. If you can do all the modifications you have already done , as mentioned above, then a little chassis tweaking to get an extra half inch or inch to fit in a different power train isn't going to be harder.

Empower, encourage!!

Dale
Thank you for the message and the info. From the way a lot of people were talking, it sounded like the LS4 was way too big. Maybe the LS4 has a chance after all! Either way, it won’t be happening with me anytime soon. It’s gonna be at least three years before I could possibly get my hands on a Goblin.
 
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Rauq

Goblin Guru
Thank you for the message and the info. From the way a lot of people were talking, it sounded like the LS4 was way too big. Maybe the LS4 has a chance after all! Either way, it won’t be happening with me anytime soon. It’s gonna be at least three years before I could possibly get my hands on a Goblin.
Well stick around, maybe between now and then someone will reveal that they bought a kit and got an LS4/F40 combo up and running! There's been folks that have built cars with cool features without posting about them until they're done, and I'm sure folks that have built things and never posted about them at all. I was interested to see the active aero wing on @Paulh24 build- the first the forum saw of it (to my recollection) was when they posted their Goblin for sale. Where are you at? I'd be down to wrench on someone else's V8 Goblin project.
 

escapepilot

Goblin Guru
For my money I'd go with a Saab LP9 2.8T V6 over a 3800 ;)

I always feel bad giving my input that these alternative swaps are unlikely to pan out, but you've taken it better than most. You should definitely build a traditional Goblin first, you'll receive only support in that initiative. Then see if the swap itch has been scratched... you'll also get more encouragement and support to complete a swap if you've already built your Goblin.
I really like this idea also. Build it with minor mods, learn it, determine what you want to change. The experience and knowledge from building close to “stock” will make modifications later much easier to tackle. Forging a new path can overwhelm most people. Having experience to build on will make it seem more manageable.
 

ccannx

Goblin Guru
Yes ! With enough money you can make it fit. Most likely will have to move the fuel tank up front, fabricate your own subframe, widen the rear frame box, get custom driveshafts, standalone ecu higher spring-rates, custom shift linkage and possibly additional cooling for the v8.
 
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DCMoney

Goblin Guru
Had lunch with a friend and we were BSing about how in the future I'd start to look at swapping a hayabusa or Kawasaki H2 engine out for the LSJ. Do it at the time I'm ready to repowder coat the frame so any modifications could be done at the same time.

Engines smaller, less weight, probably drop close to 200 pounds instantly vs the LSJ and F35. Use a chain drive diff with a starter motor on a ring gear for reverse, with custom axles off the diff to use the existing hubs. There's not a huge electrical draw coming off the goblin, dont think an alternator would be necessary, stator and RR should provide enough charging power. Motorcycle wiring is pretty basic. I've stripped harnesses before on dedicated race bikes and it was 100x's easier than the goblin wiring. Air shifter or simple push/pull linkage for the shifter with a quick shifter setup so no lift up/down shifts (paddle shifters for +100 to rep). No torque from a I4 motorcycle engine but you'd have the ability to play around with the gearing, turbo kits are readily available for the busa engines. Best of all the sound of 10K+ rpm.
 

Jackets64

Member
Had lunch with a friend and we were BSing about how in the future I'd start to look at swapping a hayabusa or Kawasaki H2 engine out for the LSJ. Do it at the time I'm ready to repowder coat the frame so any modifications could be done at the same time.

Engines smaller, less weight, probably drop close to 200 pounds instantly vs the LSJ and F35. Use a chain drive diff with a starter motor on a ring gear for reverse, with custom axles off the diff to use the existing hubs. There's not a huge electrical draw coming off the goblin, dont think an alternator would be necessary, stator and RR should provide enough charging power. Motorcycle wiring is pretty basic. I've stripped harnesses before on dedicated race bikes and it was 100x's easier than the goblin wiring. Air shifter or simple push/pull linkage for the shifter with a quick shifter setup so no lift up/down shifts (paddle shifters for +100 to rep). No torque from a I4 motorcycle engine but you'd have the ability to play around with the gearing, turbo kits are readily available for the busa engines. Best of all the sound of 10K+ rpm.
If I was to do this I might do it with a Yamaha R1 for that cross plane sound. That would be sick.
 
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