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Jerry
Jerry PowerDork
8/18/22 9:41 p.m.

In reply to John Welsh :

Ooof.  That's a fun looking car.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
8/19/22 7:49 a.m.
Tony Sestito said:

I, for one, WANT Crossfire Injection. That setup has fascinated me since I was a kid, and it's weird as hell. From what I've read and researched, it was a good design, except they made the lower plenum runners too small which restricted flow for some dumb reason like federal noise regulations. I think someone made a better lower plenum at some point, but those have to be rare these days. Either way, I dig them. 

Crossfire works really well if it is adjusted properly.  There are two TPSs, and you have to get the throttle bodies synced properly for anything to work right.

 

The runners are kinda small because it's a sub 200hp V8, it doesn't need a whole lot of area.  GM revisited the "low crossram" style manifold with the Vortec engines, the ones with the "spider injectors".  The Vortec and Crossfire lower manifolds look really, really similar...

 

Older page on Crossfire manifold design theory, and conversion to 4 barrel carb.  What is interesting is that the owner noted that the new manifold was noisy.

SKJSS (formerly Klayfish)
SKJSS (formerly Klayfish) PowerDork
8/19/22 8:09 a.m.

The prices are getting crazy high, but I'd love a restomod '80 or '81.  Drop an LS and 6spd in it, leave the rest stock looking...mmmmmm, tasty.

Cousin_Eddie (Forum Supporter)
Cousin_Eddie (Forum Supporter) Dork
8/19/22 8:11 a.m.

I'm the same way about the Cross-Fire cars. I'd like to goof with one and see how it works. 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
8/19/22 8:21 a.m.
SKJSS (formerly Klayfish) said:

The prices are getting crazy high, but I'd love a restomod '80 or '81.  Drop an LS and 6spd in it, leave the rest stock looking...mmmmmm, tasty.

You'd have an easier time putting the 6 speed in an older car.

I say this, because I was involved in debugging a T56 swapped '71-ish car.  Definitely from before the Endura era.  To get the transmission to fit under the floor, the trans crossmember had to be lowered significantly, which caused huge issues with driveshaft angles, which is where I came in.

'80-81 do not have crossmembers, they have what Mazda calls a powerplant frame, which looks like a whole fresh level of hell to work with for a trans swap that also requires some judicious drivetrain angle adjustments.

 

Or you could, I dunno, keep the automatic.  The benefit of the V8 is the OMG teh torrrrrque, right?  That seems to be at odds with having a manual transmission.

Jerry
Jerry PowerDork
8/21/22 8:08 a.m.
Jerry said:

https://www.facebook.com/marketplace/item/461598932116817/

Only an hour away, I like the black on black and T Tops for hot days because I'm sure the air doesn't work. Tempted to see it this weekend.

So I looked at it last night, only an hour away.  It looked really nice in person, but driving was another story...

First it stalled 4 times before I got out of the Meijer parking lot.  The steering had A LOT of play in it, I felt like I was driving an 80s Cadillac.  The tach didn't work.  The fuel gauge didn't work.  It was getting late & I tried to flip up the headlights, you could hear the vacuum running but no flip up.  He didn't have much more on the coolant leak other than to say the same thing, shop said they added a bottle "of something" and charged him $160.  He said it was on the passenger side but had no other info.

He seemed like a nice guy, younger, said he wanted to get his $10K he paid back for it since grandpa couldn't help him "build it up" since the cancer started.  I wasn't sure I'd like these cars and think I actually might if it were a better example.

It had some newer components I could see, radiator, a bit of engine work already.  This thing in the console that he wasn't sure what it was.  Oh well, search continues.

EvanB
EvanB MegaDork
8/21/22 8:25 a.m.

Looks like that is a MSD atomic fuel injection system to replace the carb. 

https://www.summitracing.com/parts/msd-2900

eastpark
eastpark HalfDork
8/21/22 8:27 a.m.

TIL that MSD has a EFI kit similar to the Holley Sniper:

https://www.holley.com/brands/atomic/
Jerry, I'm watching this with interest. I'm thinking the same in regards to getting a C3, but I'm still very much "fence-sitting" for a while. 

 Cheers, Paul 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
8/21/22 9:45 a.m.

The steering is always kinda sloppy on those by modern standards.  By 1960s standard they are awesome.  1980s Cadillacs were much tighter by comparison, so you were driving a good one smiley

 

The trick is they have Ford style power steering where it has a manual steering box, and a separate assist ram.  The assist control comes not from a spool valve in the box but a control valve on the center link.  The Pitman arm attaches to that, all steering forces from you go through it.  So there is a guaranteed amount of play there, plus the play in the box, and the inherent flexiness of the tinkertoy steering linkage, and also you have a bunch of power steering hoses that move with the steering and leak all the time.

 

I think GM did it this way so steering forces did not put twisting forces on the frame, which is amazingly willowy.  The main steering loads on the chassis are from the ram, which pushes and pulls side to side, doesn't put a torque on the frame.

 

A 401 CJ
A 401 CJ SuperDork
8/21/22 10:24 a.m.
SKJSS (formerly Klayfish) said:

The prices are getting crazy high, but I'd love a restomod '80 or '81.  Drop an LS and 6spd in it, leave the rest stock looking...mmmmmm, tasty.

That's the modern way to make a late C3 run like it looks.  When I was coming up, 90's, the recipe was disco-era Vette, truck 454, a set of the then new Edelbrock aluminum heads, and that's a home brewed roll your own big-block Vette that will run proper for not a huge outlay. Cam it to your liking but milder is better in my opinion...most of the auto cars are 3.08 so you need torque to overcome that.

Jerry
Jerry PowerDork
8/21/22 11:16 a.m.
EvanB said:

Looks like that is a MSD atomic fuel injection system to replace the carb. 

https://www.summitracing.com/parts/msd-2900

Is there a chance this unit just needed tuning?  Like would there have been controls within that display to adjust?  He drove it to the Meijer, says he drives it on weekends.  After I went a few miles and came back it didn't seem to want to stall nearly as bad.  He mentioned "that noise you hear I was told is because I'm not using 93 octane", referring to the pinging under throttle...

The listing said fuel injection, but when he popped the hood my brain went "sure looks like a carburetor".

And the steering was like Fred Flintstone, turning the wheel back and forth did nothing.

EvanB
EvanB MegaDork
8/21/22 11:24 a.m.

I would imagine it's very likely they just installed it and didn't take the time to get it set up correctly. But I know zero about those systems and what the setup/initial tuning is like. 

I've been offered a free 76 that has been sitting outside for years. I'm still not sure if I want to spend the effort to retrieve it, the only reason I would is for rallycross hilarity. 

eastsideTim
eastsideTim UltimaDork
8/21/22 11:25 a.m.

In reply to Jerry :

Sounds kind of like if you want to spend the fall and winter futzing with it to have it ready for next spring, it might be an option, although the price seems high to me.  If you want something ready to roll, best to move on.  The FI system is throttle body injected, so it can look (and fit) like a carb.

A 401 CJ
A 401 CJ SuperDork
8/21/22 11:53 a.m.
EvanB said:

I would imagine it's very likely they just installed it and didn't take the time to get it set up correctly. But I know zero about those systems and what the setup/initial tuning is like. 

I've been offered a free 76 that has been sitting outside for years. I'm still not sure if I want to spend the effort to retrieve it, the only reason I would is for rallycross hilarity. 

It may have been mentioned already but check out Thecorvetteben on YouTube.  Him rebuilding that dumpster-fire '72 is a motivator.

 

 

Dusterbd13-michael
Dusterbd13-michael MegaDork
8/21/22 12:32 p.m.

The msd stuff predates the sniper a little. Its VERY susceptible to E36 M3ty install issues with emi noise, etc. They were pretty ok, and almost as good as the current spec holley spec.

If i remember correctly, there a borgeson box to replace the current stuff.

Look for rust in the birdcage

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
8/21/22 12:40 p.m.

If the Sniper is at all like the Holley setup, it is best repaired by throwing it away and installing a decent carb from Quick Fuel.

vwcorvette (Forum Supporter)
vwcorvette (Forum Supporter) UberDork
8/21/22 1:24 p.m.
Pete. (l33t FS) said:

The steering is always kinda sloppy on those by modern standards.  By 1960s standard they are awesome.  1980s Cadillacs were much tighter by comparison, so you were driving a good one smiley

 

The trick is they have Ford style power steering where it has a manual steering box, and a separate assist ram.  The assist control comes not from a spool valve in the box but a control valve on the center link.  The Pitman arm attaches to that, all steering forces from you go through it.  So there is a guaranteed amount of play there, plus the play in the box, and the inherent flexiness of the tinkertoy steering linkage, and also you have a bunch of power steering hoses that move with the steering and leak all the time.

 

I think GM did it this way so steering forces did not put twisting forces on the frame, which is amazingly willowy.  The main steering loads on the chassis are from the ram, which pushes and pulls side to side, doesn't put a torque on the frame.

 

Best explanation I've ever heard about the steering.

I joke with my wife that the two inches of play in the steering is a no cost option from the factory. 

A 401 CJ
A 401 CJ SuperDork
8/21/22 4:48 p.m.

My '76 was very tight in the steering.  That car drove very well after I finally had a competent shop align the rear end.  I drove a meticulously restored '68 and by comparison it felt like a '54 Scenic-Cruiser with bad ball-joints.  On ice.  Something had been lost.  A C3 is never going to feel like a modern BMW, Porsche, or even Corvette but it will drive as well as anything domestic from that period if it's right.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
8/21/22 5:04 p.m.

In reply to A 401 CJ :

Recirculating ball steering can get very, very bad if it has been screwed with by someone who didn't know what they were doing or what to expect.  I have worked on a lot of "restored" cars that were cosmetically great, but whoever did them should stick to cosmetics and have someone competent do the mechanicals.  Lot of scary stuff, loose front end parts, cracked arms (freshly bead blased and painted!), clutch linkage assembled from loose hardware found from the bolt bins at Home Depot... and steering boxes that had their gear mesh adjuster cranked all the way down in an attempt to make a '69 Chevelle have steering as tight as an MR2.  The gear mesh is not where (most of) the play actually comes from.

Competence is not gonna happen at $8/hour at a resto shop.

Alignment is, as you note, also crucial, and aligning the rear of a C3 is a huge pain.  I went to try it once, and couldn't see how to do it without pulling the body off the frame, to be able to get to the trailing arm bolt to juggle shims.

vwcorvette (Forum Supporter)
vwcorvette (Forum Supporter) UberDork
8/21/22 11:42 p.m.

In reply to Pete. (l33t FS) 

The shims are slotted on one end to fit over the bushing pivot bolt. Actually  come out rather easily.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
8/22/22 9:50 a.m.

In reply to vwcorvette (Forum Supporter) :

That is great.... how do you get a wrench on the bolt? 

 

Disclaimer: when I tried this, the C5 was not out yet, so my memory is a tad fuzzy.  But I remember the body wrapping around the area where the bolt was.

A 401 CJ
A 401 CJ SuperDork
8/22/22 7:45 p.m.
Jerry said:
Jerry said:

https://www.facebook.com/marketplace/item/461598932116817/

Only an hour away, I like the black on black and T Tops for hot days because I'm sure the air doesn't work. Tempted to see it this weekend.

So I looked at it last night, only an hour away.  It looked really nice in person, but driving was another story...

First it stalled 4 times before I got out of the Meijer parking lot.  The steering had A LOT of play in it, I felt like I was driving an 80s Cadillac.  The tach didn't work.  The fuel gauge didn't work.  It was getting late & I tried to flip up the headlights, you could hear the vacuum running but no flip up.  He didn't have much more on the coolant leak other than to say the same thing, shop said they added a bottle "of something" and charged him $160.  He said it was on the passenger side but had no other info.

He seemed like a nice guy, younger, said he wanted to get his $10K he paid back for it since grandpa couldn't help him "build it up" since the cancer started.  I wasn't sure I'd like these cars and think I actually might if it were a better example.

It had some newer components I could see, radiator, a bit of engine work already.  This thing in the console that he wasn't sure what it was.  Oh well, search continues.

I dunno.  That car presents really well and if it has good bones that's worth something.  Bunch of little stuff wrong with it.  Sure.  But it's basically a C10 pickup truck.  How hard can it really be?  I do get that some parts are unique and there's a Corvette tax on them.  But a good chunk of it is the same stuff that ran 100's of thousands of miles in work trucks.  What's the joke about running poorly longer than most cars will run?

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
8/22/22 7:50 p.m.

Heh... I just noticed in the pics that the air injection tubes are still there, but the check valves are not capped off.  This will introduce an astounding amount of air into the exhaust system.... which will fake out an O2 sensor to read leaner than the engine is running, so anything with closed loop fuel control (like one of those "self tuning" EFI-in-a-box kits) is going to run pig rich.

 

Tony Sestito
Tony Sestito UltimaDork
8/22/22 9:25 p.m.

On the MSD EFI...

That's the older, original Atomic EFI. It's a step below the Sniper and two steps below the newer Atomic 2 setup. All the tuning is done on the handheld, and I believe it's a returnless system. They do work OK when set up properly, but they don't have the flexibility the Sniper and Atomic 2 have. I have the Atomic 2 on my truck and I love it so far. Like any of the out-of-the-box EFI systems, they only work well when they are installed properly. A lot of the issues I see with them are due to ham-fisted installs. 

On the rest of the car, it sounds like a good starting point for a project, but at that price, one could do better. 

vwcorvette (Forum Supporter)
vwcorvette (Forum Supporter) UberDork
8/22/22 11:22 p.m.

In reply to Pete. (l33t FS) :

The nut should be outboard. It's a castle nut with a cotter pin. 

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