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Which means "Evil Twin". Lets see your projects where you change boring into fun or create the fun from scratch.
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PostPosted: Thu May 28, 2020 10:01 am 
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A little off the engine subject....I'm remembering that the 87/88 fieros got better front suspension after the chevette they lifted it from went out of production in 86. Do I have that right? Or was it only the GT that got updates? Have you done any additional suspension work?, sorry if you said and I missed it.

What kind of timeline have you got in your head for this build? Fall? Spring?


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PostPosted: Wed Jun 03, 2020 11:25 am 
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The Colorado block arrived... I spent the prior weekend deburring, porting the bay-to-bay breathing windows, had it cleaned at the local basic rebuild machine shop during the week, then shined it up last weekend.

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Right now it's at the local custom gun shop getting Cerakoted with MC5100

My plan is to have the local race shop line bore it with the heads on, going for minimal change to the crank centerline, then take it up to ProMar in Jersey to have the bores honed and inserts installed. I'm not sure if I'll have the race shop or ProMar clean up the decks.

Then I can assemble the short block!

ETA:
I wore out a LOT of wire brushes... here's the ones I would recommend using:

Code:
McMaster
PN        Short Name      McMaster Nomenclature/Description
4916A13   5/16 End Brush  Stainless Steel Brush with Shank for Tight Spaces, 5/16" Brush Diameter (1/8" shank for Dremel)
4911A79   1/2" End Brush  Brush with Shank for Tight Spaces, Long-Lasting, 1/2" Diameter with 0.01" Diameter Stainless Steel Bristles
4797A32   1.5" Wire Wheel Brush with Shank for Angles and Corners, 1-1/2" Brush Diameter with 0.012" Diameter Stainless Steel Bristles
4797A33   2" Wire Wheel   Brush with Shank for Angles and Corners, 2" Brush Diameter with 0.014" Diameter Stainless Steel Bristles
4797A55   3" Wire Wheel   Brush with Shank for Angles and Corners, 3" Brush Diameter with 0.014" Diameter Stainless Steel Bristles


For a whole block, I recommend getting 3 of each wire wheel, 2-3 of the 1/2" end brush and about 20 of the 5/16" end brush. You'll need a die grinder to take 1/4" shank tools and a Dremel for the 5/16" end brush. The 5/16" end brush doesn't last long as it only uses 0.005 wire, while the others use tougher wire.
The 1/2" end brush is actually a really cool design; it has three plastic rings around the bristles stacked from the end of the crimped shell. As the protruding wires wear, break and bend, which would normally be the end of the brush's service life, the plastic rings protect lengths of the bristles. You can pull off one of the rings and get some more wear out of the brush; and even do that twice more since it starts with three rings. It's a cool idea.


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PostPosted: Thu Jun 04, 2020 8:57 am 
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you've been busy! It looks great but I'll bet doing it absolutely sucked :(


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PostPosted: Thu Jun 04, 2020 11:16 am 
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Great work Will!

Let us know how the Ceracoat works/looks when it's finished. I may change directions on my 550's block and go that way.


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PostPosted: Mon Jul 06, 2020 5:50 pm 
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mk e wrote:
you've been busy! It looks great but I'll bet doing it absolutely sucked :(


Blew aluminum oxide out my nose the next day and was covered in welts where broken wires had stuck into me. Yes, I did wear safety glasses and ear plugs.

cribbj wrote:
Great work Will!

Let us know how the Ceracoat works/looks when it's finished. I may change directions on my 550's block and go that way.


I got the block back last weekend, but didn't have time to set it up on the stand and get some glamour shots. It looks... pretty much like it did before. The luster might be a little different. It looks and feels like it's been clear coated. We'll see how it works.


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PostPosted: Mon Jul 06, 2020 6:04 pm 
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TheDarkSideOfWill wrote:

I got the block back last weekend, but didn't have time to set it up on the stand and get some glamour shots. It looks... pretty much like it did before. The luster might be a little different. It looks and feels like it's been clear coated. We'll see how it works.

Well where the heck are the pictures man! My GOD! we can't live like this!

:)


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PostPosted: Tue Jul 07, 2020 9:55 am 
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mk e wrote:
A little off the engine subject....I'm remembering that the 87/88 fieros got better front suspension after the chevette they lifted it from went out of production in 86. Do I have that right? Or was it only the GT that got updates? Have you done any additional suspension work?, sorry if you said and I missed it.

What kind of timeline have you got in your head for this build? Fall? Spring?


I'm thinking I can get it running by the fall.

The Fiero team developed a bespoke suspension during the Fiero's development. GM's bean counters said no, and the team had to pull the Chevette's front suspension for the front and the Citation's front suspension for the rear.
For 1988 production only, the car finally got the suspension that was originally designed for it, which is MUCH better than the '84-'87 suspension.

The '84-'87 suspension has pro-dive, huge scrub radius and tiny brakes up front. 9 3/8 x 3/8 solid rotors... At least GM put aluminum calipers on the Fiero, but since they used the same mold as the iron calipers, the aluminum calipers were flexible and soft. The rear suspension had anti-dive when it was in the front of a Citation, but that turned into pro-squat when they moved it right into the back of a Fiero without geometric changes. It ended up with bump-steer due to the fixed inner tie rod end location. Also, the tiny 5x100 hub cartridges in that system can't take much hard use.

The '88 fixed the pro-dive, has much better alignment adjustments, has a great scrub radius and light effort for manual steering. Both front ends are short/long A-arm. The '88's got 10 1/2 x 3/4 vented rotors all around. Both rear ends are strut, but the '84-'87 has an A-arm and toe link, while the '88 has parallel lateral links and a trailing link. While the roll center is not adjustable from the factory, modifying the system to raise the rear roll center is not difficult and is a phenomenal improvement to a system that's already pretty good. Camber at both ends can be adjusted to ~ -1.75 degrees without any mods. Installing rod end lateral links is also really easy and results in a good improvement in path accuracy and camber control with zero negative effects on ride or NVH.

I think that if the '88 GT/Formula had been the Fiero that debuted in '84, the Fiero would have been in production a LOT longer and might even still be part of GM's model portfolio.

The '88's only weakness are the '88-Fiero-only front hubs. They're reasonably tough, but they're small OD have a shallower flange offset than any other hub, so there's nothing that can be swapped in. I have geometric data on the knuckle, and just need to get enough other things out of the way to CAD up a knuckle that will accept C5/6/7 Corvette front bearings. With the Corvettte wheels offsets, packaging the '88 knuckle with the same scrub radius as stock actually results in a LARGER hub flange to kingpin axis offset, which makes the new one easier to package than the original.

The Northstar car is an '87, but I also have a stock V6 '88.
The '87 ("The Mule") has spherical bearing rear control arm pivots, rear hub end components from a Pontiac 6000 with larger hubs, brakes and outer CV joints (27 spline), Koni struts and coil overs, 11" front brakes, UHMW PE front suspension bushings, Koni front shocks and an anti-dive mod in the front suspension that works wonders.

Coming soon:
Rear: fabricated rear knuckles to accept C7 Corvette rear hubs with 33 spline CV joints, raised rear roll center, improved toe link geometry, 12 3/16 brakes, hot rod drum-in-hat parking brake, strut clamp extension plates to fit 18x11 rear wheels.

Front: spherical bearing lower control arm pivots, fully adjustable upper control arms, aluminum lowering spindles with aluminum hubs, 12 3/16" brakes and 17x9 wheels

Eventually:
Rear: Custom valved Bilstein inverted struts, custom fabbed subframe
Front: Custom wide-track control arms to use the same fabbed knuckles as the I'm developing for the '88; coil overs on custom valved Bilsteins.


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PostPosted: Thu Jul 16, 2020 11:36 am 
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I was playing with the Cerakoted block last weekend... I'm seeing some weird shit.

I torqued up the bottom end and measured the main bores.
Then I bolted on the heads and measured the main bores again.
Then I split the bottom end, installed the replacement bearings, retorqued the bottom end and measured the bearing IDs.

I pulled the new set of Clevite bearings out of the box and found that the shrink wrap had ruptured and the bearings had been banging eachother up in shipment for who knows how long. They looked like they'd been media blasted in places. I polished them carefully on a veratex wheel, then cleaned and installed them. They measured out weird with a bunch of out-of-round and poor consistency from one to the next.

In looking at the numbers, I see that the Colorado block main bores are ~0.002 larger than the rusty bore block main bores in which the bearings ended up at -0.0025 main clearance. I figured that was a step in the right direction, so I split the bottom end again, installed the coated bearings and measured them. They still come up with negative bearing clearance, but it's improved from -0.0025 to about -0.0012... which is effing weird, because that's an '06 block and '06 crank... why are the bearings coming in like that?

Between the beat up set and the coated set, subtracting the bearing ID from the bore ID gave me a total shell thickness number. This is 0.3164 for the beat up bearings and 0.3170 for the coated bearings, so there's not enough variation between the bearing sets to account for the delta in bearing ID.

Once I had installed and measured the coated bearings in the Colorado block, I pulled the heads and measured them again.

I need to bolt up the bottom end on the '93 block that came out of the car and see WTF it does. I took those measurements when I built that engine, but they didn't get into my Google drive, so I may not be able to find them now. I need to check for the hard copy notes in my filing cabinet.

I also need to measure the thickness of the factory bearings that came out of the rusty bore block to see if they are different from my coated Clevites

//

When I measured the rusty bore block with and without heads, the average main bore and average out of round each increased by 0.0001. The average out of round increased from 0.00026 to 0.00038, which seems a little high.
In the Colorado block, the average main bore increased by 0.0001 and the out of round was consistent at 0.0001.

The rusty block deltas are barely worth considering and the Colorado block numbers are in the noise, so I no longer think that the mains should be bored with the heads on. If the situation evolves to the point of boring the mains 0.002 to get the bearing clearances right, this will be handy knowledge.

The average main bore in the rusty block is 2.8523 and the average main bore in the Colorado block is 2.8542. Both blocks are 2006 units. 0.0019 difference seems like a lot of variation in what should be a very consistent and precise feature.

Pics to follow.


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PostPosted: Fri Jul 17, 2020 8:03 am 
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what are you measuring with Will? I don't have equipment to even start to play this game....my best bore measurement is piston and feeler gauge :(


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PostPosted: Fri Jul 17, 2020 9:40 am 
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I'm lucky enough that I have access to some pretty nice metrology equipment. I've been using tripod bore mics to measure all the IDs.

//

Oh wait... I just compared the journal ODs of the cast crank that came out, the forged crank I bought new and the forged crank that came out of the rusty bore block. The crank from the rusty bore block came out at 2.5385 average, while the new forged crank and old cast crank came out at 2.5335 and 2.5338... so my used crank, that came out of a running engine is 0.005 larger than the other cranks.

That's fishy... I need to go back and make sure I didn't blow those measurements by reading the mic wrong.


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