: 4.6 caddy vs. olds 4.0



cart69
03-09-06, 12:38 PM
just wondering the differences between these two, got a buddy that needs help on his aurora and i know they are much the same engine as my sts. just wondered how much the same?

auroradude
03-09-06, 03:00 PM
50hp less and much slower. virtually the same motor though, just as bulletproof as the big daddy is.

parts68
03-09-06, 08:54 PM
so as anyone put a 300HP 4.6 in a 'rora?

auroradude
03-09-06, 11:19 PM
well. people bullshit back and forth about it, but i dont think anyone has had balls enough to do it just yet. apparently the electronics arent gonna add up. the Aurora DIC is completey different than the caddy's although it does have a lot of features. different set of warning lights etc (no service emissions soon for example, like the STS has). wire harnesses obviously wont work.

my mechanic said he is POSITIVE he can do it and the estimate was $6500. Thats just an estimate. It could be several thousand more he cautioned. To me it isnt worth it, just turbo the damn 4.0.

However I would very seriously consider it if my engine ever heads south. Add to that boring it 0.30 over, bulletproof connecting rods and pistons, all motor reworked etc,,, forged crank etc. then a bulletproof trans when that goes.

Aurora40
03-10-06, 01:14 PM
just wondering the differences between these two, got a buddy that needs help on his aurora and i know they are much the same engine as my sts. just wondered how much the same?
I'd think from a working-on-it perspective, you'd find they are virtually identical. I also wouldn't call one "much slower"... ;) I bet many STS's don't run much better than my 14.8...

parts68
03-10-06, 07:02 PM
My thought is just using the 4.6 long block and retaining all the Olds specific stuff.
I cant imagine long blocks not being interchangeable.
I have a couple of 4.6s but dont have any of my rora 4.0s out to compare side by side.

Zorb750
03-10-06, 11:37 PM
14.8 would be unusual out of an Aurora. They usually run low 15s from the guys I know with them.

auroradude
03-11-06, 12:16 AM
40man's isnt stock though. I'm pretty sure his ran 14.8 stock too but I forget. Thats an example of a perfect break-in though and I believe Mobil 1 was used since new.

parts68
03-11-06, 11:02 PM
so are we just going to talk about this or is someone going to do it?
Im thinking a 95 is the best bet as the PCM can be reprogrammed if needed.
I may actively seek a nice 95 with bad motor(and no other problems)
to do this.
I currently have 2 95 project cars that I need to sell first.
Hopefully neither will need a motor soon so moving on.

infin1ty
03-12-06, 03:14 PM
I have both and yes, they are very similar. They were built in the same factory. If his Aurora has the Autobaun package, it will be a little faster.

parts68
03-13-06, 09:09 PM
I have 2-95 (currently for sale)and a 96.
All 3 have autobahn and sunroof.
Hopefully none will need a motor soon.
I have a 4.6 long block ready and spare upper end of a 99 4.6.
I may need a tranny for one of these tho. Not so good is that 3.71
trannys are harder to find.