Broken crank! What swap? (Page 1/2)
Modesto APR 14, 11:34 PM
As some of you have already read I bought this '88 less than a week ago for $2800. The seller was very upfront that he didn't know exactly what was wrong but that it was probably going to need major work. It only has 57k and is in really nice shape. Already has the kevlar racing clutch kit from The Fiero Store and KYB suspension.



I'm 99% sure the crank is broken. I have a thread in the tech section if you want to read about it. So here are my options as I see them;

1) 3.4 bottom end swap.
Modest power increase but most importantly I can keep it looking like a completely stock car (except for the starter location of course). Also the cheapest, fastest, and easiest swap.

2) 3.4 DOHC swap.
Arguably the most fun to drive from a standpoint of rev range and the whole "it's more fun to drive a slow car fast, than a fast car slow" thing. I have a lead on a 0 mile reman engine with a '93 z34 harness and ecu for like $350.

3) Series II 3.8SC swap.
Obviously the most power, and I don't think much more involved than the 3.4 DOHC swap. Cost is going to be more, but not a significant amount. My concerns here are the domino effect of then needing/wanting bigger tires, brakes, etc. Also they just plain don't sound as nice as the 60* engines, at least not without a lot of work.

I know this has been rehashed a million times on this forum but I'm really most curious about how the value will be effected. Almost my exact same car (had 1k less miles and not a broken crank) sold for $8300 on BAT sometime in January and people were talking about how good of a deal it was, so the market seems to be there, even if none of us would pay that. What say ye?

[This message has been edited by Modesto (edited 04-15-2020).]

RWDPLZ APR 15, 12:18 AM
3.4 bottom end swap if you have any kind of emissions testing with a visual inspection in your area, it'll look completely stock. Otherwise the 3.8 Series II SC.

Post-swap value depends on the quality of the work and how well it functions. Some swaps that look like a bad science experiment scare off most potential buyers, but something like Skitime's old car would increase the value, at least for someone not looking for a stock car.

http://www.fiero.nl/forum/F...3/HTML/000073-4.html
cvxjet APR 15, 12:50 AM
The 3.4 F-body swap will actually give you more performance gain than the "20 HP" it brings- the power is at a lower RPM so it is like having a better final drive ratio. My car is 0-60 in 6.5 seconds and quarter in 14.8....This info comes from my G-meter...and I will admit that I am not a great Launcher.....(Slow enough to have a lot of fun on windy roads without going 100)

You have to drill holes for the starter in the F-body Block to mount in the (Fiero) stock location...the engine looks dead on stock unless you look at the sides of the block down low. And, at least in CA, it is the certified replacement engine from GM for the 2.8.

The Twin-dual-cam 3.4 is substantially heavier than the PR engines, as is the 3800s.....The best engine for the Fiero in my (Nutty) opinion is the 3900 or 3500 later 60 V6 engines...they are lighter and better....the 3500 has 210-220 HP and the 3900 has 240 HP. They both will turn to 6300 rpm but pull really hard from 2500.

The best V8 is the LS4- that is the LS V8 that is set up for transverse mounting- it only weighs approx' 15-25 lbs more than the 2.8.

And my dream engine is the NEW 4.3 all aluminum V6- 300 lbs (70 lighter than the 2.8) and 285 HP and 320 Lb/Ft of torque- all at low "R's" which really frustrates the Honda-8000 guys when you beat them only turning 5000 max (I have heard a 4.3 L thru the stock Fiero exhaust- it sound just like the 2.8 V6 only meaner....
engine man APR 15, 06:46 AM
it is tough to pick a engine i have only had 3 the 2,8 , 3.4 dohc & my current 4.2 Audi V8 i will say i loved my 3.4 dohc it was easy to put in and i used the 4:10 4 speed as i knew it didn't have a lot of torque so it needed gear and it was great sounding where the 3800 is a great engine but the sound it makes when reved up sounds flat farm tractor-ish to me the Ls4 looks like the best V8 for the dollar but looks like allot of work & sone $$ to do i would look at Fieroguru's build as he was the first or one of the first to do that swap good luck the car looks great now it just needs a great engine if you can take a ride in fieros that have engines you are thinking of that would be a great help to you so if you have access to them would do that first .
I just want to add one more thing a Good engine with the wrong gearing can feel like a slug so do your homework on the whole driveline so it is the best it can be with whatever engine you chose.

[This message has been edited by engine man (edited 04-15-2020).]

sourmash APR 15, 07:48 AM
I'd agree with the first response.


quote
Originally posted by cvxjet:
And my dream engine is the NEW 4.3 all aluminum V6- 300 lbs (70 lighter than the 2.8) and 285 HP and 320 Lb/Ft of torque- all at low "R's" which really frustrates the Honda-8000 guys when you beat them only turning 5000 max (I have heard a 4.3 L thru the stock Fiero exhaust- it sound just like the 2.8 V6 only meaner....



What bellhousing does it have? Hadn't looked it up until now, but note that it has a forged crank.
Rickady88GT APR 15, 12:23 PM
I searched the 4.3v6 and found an all aluminum version in the Silverado. Is this the engine you are talking about?
engine man APR 15, 01:28 PM
the problem with that 4.3 it has not been done yet . i think it has the same as all truck Ls engine bellhousing so it is pretty much like sticking a ls in and at that point the Ls4 i feel is a better option

[This message has been edited by engine man (edited 04-15-2020).]

Rickady88GT APR 15, 02:59 PM

quote
Originally posted by engine man:

the problem with that 4.3 it has not been done yet . i think it has the same as all truck Ls engine bellhousing so it is pretty much like sticking a ls in and at that point the Ls4 i feel is a better option




I do not know the emissions laws in other states but here in CA it will be impossible to certify a truck engine in a car. So if the goal is to make it "smog" emissions legal than at least check to see if such a swap can be certified.
Otherwise, the newer the engine is the more difficult it will be to swap it into a Fiero. Because of the sophisticated electronics and software that incorporate so many "seemingly" unrelated systems and components. Not all drive trains can be reflashed or edited to delete unnecessary systems from the ECM.
So I recommend that if you want the new 4.3 and want to swap it in your Fiero, that you get an entire donor vehicle and swap in the entire drive train and systems. Obviously you would need to do a lot of work and can't use some of the stuff like the transmission and exhaust system. For stuff like that you will need to do research and swap skills.
I like the idea of doing this engine but I doubt that it is a simple swap by any measure.
87convert APR 15, 03:19 PM
I really feel your pain on this. My 86 suffered a broken crank and after lots of searching and thought I went with the 4.9 Cadillac with 4 speed auto. This is not a race car swap but it is a blast on the street. Just enough to be killer in the 60ft grand prix (across the intersection) and a great cruiser on the freeway with 30 mpg and A/C. It is not a quarter mile killer, but is a lot of fun and a fairly easy swap.

Rolland
cvxjet APR 15, 05:26 PM

quote
Originally posted by Rickady88GT:

I searched the 4.3v6 and found an all aluminum version in the Silverado. Is this the engine you are talking about?



Yes- That is the one; The LV3. The beauty of it is that it is almost 100 lbs lighter than the LS4 V8 but has almost the same power...and will sound like a beefier "Fiero V6".....Yes, you would need the bellhousing adapter plate, and have to play with the electronics to run right without a BCM, etc.

Not exactly sure about Utah smog laws; Here in CA any >>Later<< engine can be swapped into earlier cars, provided it will correctly run the computer- But I hadn't thought of the Truck vs Car detail (Back a few decades ago, cars were smogged while trucks were not- but I believe that little problem has gone away.)

Another possible light-but-torquey engine swap would be the Buick 3.5 V8- it is all aluminum and the Brits did FI versions of it- once again, tho, you need an adapter between it and the trans.....

[This message has been edited by cvxjet (edited 04-15-2020).]