A 3.4 DOHC Build then... F40 Turbo (Page 13/57)
Joseph Upson MAR 31, 12:16 PM

quote
Originally posted by Fierobsessed:
This turned into a bigger project then I anticipated. Maybe I should have just used the dual mass... It is afterall, designed for the 60 degree engines.



Not if you intend to put down more than 300 lb/ft. It's torque limited to about 10% above the engine it was rated for and I do believe I managed to make mine slip with the stock motor at about 7-8 psi.
fieroguru MAR 31, 12:30 PM

quote
Originally posted by Fierobsessed:

The more I work on this flywheel, the more upset I become with its orignial manufacture. There isn't ANY concentricity amongst ANY of the critical dimensions.




The precision of some parts is quite scary... especially when they are cast or stamped.

I would suggest using all 12 standoffs vs. the 6 to reduce the chance of the starter pushing the ring gear inwards (in the unsupported areas).

Also, what is the overall depth of that flywheel (crank face to clutch face)? Just curious.
Fierobsessed MAR 31, 01:32 PM

quote
Originally posted by fieroguru:


The precision of some parts is quite scary... especially when they are cast or stamped.

I would suggest using all 12 standoffs vs. the 6 to reduce the chance of the starter pushing the ring gear inwards (in the unsupported areas).

Also, what is the overall depth of that flywheel (crank face to clutch face)? Just curious.



I went ahead with just the 6. Done and welded. I'm actually quite pleased with it.

1.735" Crank to surface.

I still wonder if THIS dual mass can even slip. When I got it, the bolt holes affixing it to the crank and the through holes on the secondary mass were lined up, the 60 degree V6 has a bolt pattern with one odd bolt out of place, so I could easily tell that the two parts of the flywheel either didn't slip, couldn't slip, or it lined back up. They do rotate loosely a bit. Feels like it hits rubber bumpers on either end. One thing that I liked about the dual mass, I put it in the lathe, spun it to 1400 RPM and no visible wobble, no shaking, nada. It's actually machined and balanced correctly.
Joseph Upson MAR 31, 03:11 PM

quote
Originally posted by Fierobsessed:


I went ahead with just the 6. Done and welded. I'm actually quite pleased with it.

1.735" Crank to surface.

I still wonder if THIS dual mass can even slip. When I got it, the bolt holes affixing it to the crank and the through holes on the secondary mass were lined up, the 60 degree V6 has a bolt pattern with one odd bolt out of place, so I could easily tell that the two parts of the flywheel either didn't slip, couldn't slip, or it lined back up. They do rotate loosely a bit. Feels like it hits rubber bumpers on either end. One thing that I liked about the dual mass, I put it in the lathe, spun it to 1400 RPM and no visible wobble, no shaking, nada. It's actually machined and balanced correctly.



The 10% above stock application estimate is directly from a SACHS rep via email a few years back when I inquired about it. That's also one of the reasons they are swapped out on some performance cars in addition to the fact that they also tend to wear out like clutches.
Fierobsessed APR 02, 05:42 PM
I wouldn't take any manufacturers statement about something's limits too seriously. They will always tell you its good for its intended application, and perhaps just a little more. They rate the 282 higher then the F23 for a reason, they have became more conservative. Either way, I am sticking to my home modified flywheel. It has no real known limits.

Current status of the flywheel:



Because it was so poorly made, I still have todrill and tap 6 new bolt holes for the pressure plate. Then, I have to resurface it, and balance it. Nothing too difficult.

This morning I made the intercooler support bracket, this went actually pretty quick, and It holds it better then I thought it would.



I also loaded the engine back in again for what probably is its LAST test fit, now that the exhaust is done.



Everything so far is looking great, It all fit just as I had hoped that it would.
The tips were even where I wanted them to be, and they really look great! I'm going to tack weld those in place when I take the engine out.

And again, with the engine back in the car, it's time to tidy up the garage. I made myself promise, that every time the cradle was out of the way, that I would clean the garage. So far, I've managed to stick to that plan.
fieroguru APR 02, 06:36 PM

quote
Originally posted by Fierobsessed:
I made myself promise, that every time the cradle was out of the way, that I would clean the garage. So far, I've managed to stick to that plan.



Its good to have garage housekeeping rules!

Mine is if I can't find the tool/part I need in 10 minutes, stop everything and clean the place up and put everything back where it belongs.

The swap is looking good!
ericjon262 APR 02, 08:53 PM
thanks for posting the info on the fuel pump, I think I might go with one of those myself.

------------------
we're in desperate need of a little more religion to nurse your god-like point of view...

Built not bought... Because bolt-ons don't.

http://www.fiero.nl/forum/Forum2/HTML/119122.html

Fierobsessed APR 04, 05:46 PM
One more pic of the engine loaded in the car...


With the garage all cleaned up, I've decided that it is time to do the engine build. Which starts with TWO teardowns. The first, is a 97 Crate 3.4 DOHC that Iv'e had for about 10 years... just kicking around. The second is the engine that was in the car. This engine had a fierce oil leak from the front cam carrier, and the intake manifold gaskets were beginning to fail (letting air in, not coolant out)

Crate motor


One cam carrier removed


Bottom end exposed


Heads, off.


Just looking for the spot to put the oil return bung


On to the old engine! Here is where it is most obvious that the 3.4 DOHC really is just a 2.8 on steroids, with massive heads.


Cam carriers off.


Heads off


Everything looks in order here


This is what makes this engine special. But, its all VERY heavy stuff!


Gasket failure! Which as it turns out, I am totally at fault for. The bolts were never torqued, only snugged. Some were downright loose. This explains why the gasket only failed on the front head. The rear head was totally tight. No leaks. I am so disappointed with my self for this screw up. But, at least I know what went wrong. The oil leaking onto the intake manifold gasket was the reason those gaskets started to swell, and fail too.


Lastly, this is where all my hard work, and money is sitting right now...



Which, you have to admit, any engine sitting in this spot, is going to perform quite well...
That's it for now.
BV MotorSports APR 04, 05:57 PM
My best friend, Garth, would loose his mind over this setup. Its what he has always dreamed to have in a Fiero. if you ever decide to go with a different powertrain, PM me. Dead serious.
Fierobsessed APR 09, 06:30 PM
Still working away at this, in the last couple of days I...
1. Tore both my original engine and my crate engine down to their short blocks
2. Removed all 48 valves from the 4 heads
3. Cleaned the 94-95 heads.
4. Found two slipped valve guides, pressed them back into place. I don't know how I'm going to prevent this in the future.
5. Found my head studs to be too short for my heads, because the head bolt threads start 0.7" below the deck.
6. Found that my head studs fit perfectly in place of the mains bolts.
7. Ordered connecting rod studs, Flywheel bolts, and a batch of new head $tuds all from ARP. They were pricey.

Next on my list is to have the heads decked for finish only. And whenever the clutch shows up, finish the flywheel, which needs to be re-drilled correctly for the pressure plate, then surfaced and balanced.

The heads are getting the 96-97 valves. Why not? They are brand new! I checked them for compatibility, and they are 100% interchangeable. I also plan on using the cams and cam housings from the 96-97 crate engine. No sense in using old parts when I can avoid it. The lifters are improved in the later engines, but the cam profile is just a little bit tamer. I could mix match them, but everyone always says you shouldn't mix things like that. Jury is still out for me on that one. I happen to strongly believe the 3.4 DOHC cams can be interchanged, even if used, as they appear to have a flat grind, and a cutout on the base circle to provide the lifter spin. Bucket lifters are too short to accomodate a tapered grind like traditional flat tappet cams anyway. Maybe I WILL use the 94-95 cams... Still debaiting on that one. Either way. I plan on degreeing all the cams. It's actually VERY easy, I don't even need the engine!

Once this is done, it is the extent of the modifications I plan on making to the engine itself. My next goal is to make it pretty. Lots of cleaning, lots of painting. Still debaiting on colors, I'm leaning towards either silver or blue, or a combination, as my engine bay already has some polished aluminum, and blue silicone couplers. Either way, I plan on working on the intake, filling it out and smoothing it till it looks like glass.