Random engine swap questions (Page 1/1)
shemdogg MAY 28, 01:05 AM
So I got a kit car and I want a v8 ls4. Big problem is they dont fit well. And custom axles have to be made. Could I mount the motor and trans a few inches over to the driverside and toward the rear of the car to give more room? Itll bolt to my 4 speed right? lol Granted I could cut the cars fiberglass body in half to make space for the motor. Would like to avoid cutting frame rails but open to lengthening the cradle a few inches. Tips, advice, insight, name calling all appreciated

shem
olejoedad MAY 28, 09:04 AM
The front cross member of the cradle will need to be moved forward.

As the cradle/drivetrain is installed from the bottom, if the car has stock dimensions in the engine bay, everything should fit with no o body mods.

Fieroguru has posted some very excellent information regarding the LS4 swap.
olejoedad MAY 28, 09:07 AM

As you can see, it's tight but there is plenty of room.

[This message has been edited by olejoedad (edited 05-28-2022).]

V8Steve MAY 28, 12:31 PM
Why not buy a V8Archie LSX kit?

------------------
88GT 355 CI, AED HO 750 Double Pumper, AFR milled 180, Dyno'd at 427 HP, 360 WHP, F40 6-Spd
anderson@gdsconsulting.com

shemdogg MAY 29, 10:57 AM
I took your advice and started fierogurus thread from the beginning, tons of great info. Im no machinist tho and Id have a hard time fabbing up parts like that. Seems like some of the drawbacks are cradle width, I will have to make a custom cradle. For the archie kit, I want the newest engine for reliability so a ls4 its gonna be. Seems like a fortune for just a few of the bigger parts, the small stuffs easy and cheap to find. And I really dont want a 1/3 of the motor stuffed under the passenger side. I wanna be able to get tools all around when I have to work on it, not pull the motor every time something happens. Just found a 3.8sc at a local boneyard, might throw that in for now. One of the main goals is to get this car to have some funky engine trans combo that wasnt offered by the factory so I can get rid of the smog requirements on this car. Once thats done I can throw whatever I want in the car and be able to modify it later. And save a fortune and hassle of smogging the car. The 3800 should bolt to my 4 spd, gonna start digging into 3.8 swaps now. But if anybody knows if I need a custom flywheel and clutch for the 3.8 to my 4spd(muncie? it was an 86 gt once upon a time) or if the stock stuff will work lemme know. Thanks in advance

Shem
fieroguru MAY 29, 02:09 PM
When I started my build thread 11.5 years ago, there wasn't anything for the LS4 and the LS4/F40 swap hadn't been completed (everyone was saying it could not be done), so there was a lot of trial/error and fab work that now can be resolved with $$$.

The LS4 will be much more expensive than the 3800, but it will likely draw a larger crowd and be considered more impressive when done (and done well). One of your biggest issues will be keeping the 4 speed with the LS4, if you do that then you are signing up to spend $1000 on an oil pan/starter combo as my bolt on starter solution will not clear the clutch release lever on the Fiero 4 or 5 speeds).

The LS4/F40 fits nicely between the stock frame rails and strut towers:
shemdogg MAY 30, 11:52 PM
Hey Guru thanks for the reply, I didnt wanna blow you up w emails lol. I know the ls4 will fit, but its tight. When I do do the ls4, itll be w the f40. I think it may be a challenge to find the trans. Got my buddys dad who owns a boneyard looking for one. 3.8sc it what its gonna be for now. I told my wife just last night when pick n pull has some motors(there was 2 I found) and has a 50% off sale(usually 4th o july), im gonna go get some goodies. Started browsing their website again this morning and found 2 more 3.8sc and 2 g6 with 6 speeds! Just for chits n giggles I clicked the specials page, and theyre having a 50% of sale this weekend ending today! The gods must be sending me a signal! I got my wifes friend to watch my kid n hit the place up at 10:30. The g6 were both autos dag nab it, 2 of the sc motors were disassembled a bit, one was majorly robbed for parts, but there was one complete. Covered in oil and looking like it had old coolant in it. Car wasnt crashed so im a lil worried about the health o the motor. But pulled everything but one bolt for the motor/trans in a few hours, then got an amigo to help me drop the cradle as take em apart. I didnt wanna go under a car propped up by 2 sets of space saver wheels welded together in the front and 1 out back. Anywho got home at 5pm w this

$300 out the door, $100 for the amigo who did the dangerous parts. Got the whole harness and fuse boxes. Injectors were missing, got em ordered. A new starter and intake manifold gasket set are on the way too.

Been digging deep into the ls4 and 3800 swap threads on here, I read I need a 96 maro flywheel and it needs to be milled down. Got lots more reading to do, thanks for all the replies so far!

One of the g6 I looked at musta run into a horizontal beam or something, the firewall is pushed in a good 18"


went in right at the top of the hood, total carnage!

shem