C4 + LS1 + T-56 = Good times! by subtlez28

24 minute(s) of a 50 minute read

C4 + LS1 + T-56 = Good times!

Compliments of subtlez28 @ www.pro-touring.com

10/20/2009

Now, it occurred to me a couple years ago that some of the modern performance cars (C4s, C5s, C6s, newer F-bodies etc) just don't scare you the way old muscle cars did or do. Largely because of sound deadener and better suspension, you just don't get that: "I'm gonna die" feeling anymore (adrenaline). This project is about going back to basics. No creature comforts. Deleted radio, sound deadening, HVAC, power windows/mirrors and almost anything else that doesn't help it go faster.

I've always liked Corvettes for there well designed chassis, light weight, brakes, etc.. etc.. So, when I realized early C4s were getting cheap, and old/worn enough that I wouldn't mind stripping one down I started seriously shopping.

I have High Speed Auto-crossed (one solo timed lap on an open road course) an 02 Z28. I love the LS1 and T56! But it has some inherent deficiencies, and I just didn't want to diminish its street car status. Time for a purpose built, lighter, better chassis to put an LS1 T56 in.

The car I ended up with was an 84 that already had an LS1 swapped in. I'm told this car was put together around 2001. When I got it though, someone had swapped out a built LS1 for a stock 98 LS1, backed it with a 4L60E, but it was a non running basket case.

The good news was it already had a stand alone harness, C5 accessories (except the balancer...), C5 seats, newer black interior, C5 Z06 rims, Konis, good springs/sway bars, and upgraded brakes.

Again, with my less is more, street legal race car build theme, some of the parts (4L60-E, C5 seats, Z06 wheels) went up for sale and the transformation began. Then it stalled for a while, life got in the way, but I'm back on it again.

I put 17x11s all around, and have mostly disassemble the HVAC, deleted most of the interior, power locks/mirrors, and cut out a lot of unused wiring. I picked up a nice aluminum, laser cut dash w Auto-meters gauges. It definitely works w the street legal race car theme, and allowed me to ditch alot of the interior plastics.

I'm not real proud of these photos, as it is a work in progress. Complete with messy garage and parts piled on the car (don't worry I have the carpets on the roof protecting it). But I thought some of you would get a kick out of it, and I wanted to prove I actually have this project I keep talking about.

I don't know why the previous owner painted the valve covers blue, but they will go gray or black soon.

I'm thinking carpet delete and fabricated door panels. Pretty much all business and flat black inside. I may black out the dash, but it is so pretty...

I also removed the Hooker shorty headers it came with as I intend to go with Melrose Header's long tube headers built for LS1 swapped C4s.

Right now, I'm continuing disassembly. I plan to remove the LS1, inspect it, and clean up some engine bay issues (scary fuel and brake lines). I have an under-drive balancer to put on that will work with the C5 accessories. It currently sports an F-body balancer, and the accessories are spaced out from the block (w buts and washers...) to make everything line up.

It is hard to measure things now as it is pretty crowded. I also want to check the position of the engine to see if it offset (front to rear or side to side) appropriately. Because this was an early swap, simple adaptor engine mount brackets were not used. In stead some metal was welded in and C5 stands were used. I'll post op some pics of that when I get the engine out.

Here are some more engine pics:

Gratuitous (subtle) Z28 shot! 

10/24/2009

Who wants to see some scary stuff?

This had a complete drive line when I received it (though non-running). The ebay add said it just needs a battery and spark plugs to run... yeah right!

Anyway, I took the trans out a while back and left the drive-shaft hanging. Last night I went to take out the DS and saw this:

No strap on one side!! Had I got it running... I'm pretty sure the LS1 would have snapped this u-joint off and... big problems.

But that is not all. This I knew about, but last night I tore it out:

1st of all, why the external fuel pump when the car comes with an in tank FI pump? 

Yes, that is hose clamped, spliced in braided line!

Yes, that is inner-tube wrapped around and hose clamped to the pump. 

Not to mention this is mounted just behind the rear end. It was held in with 3 sheet metal screws that were literally finger tight! And the atrocity that was the multi-spliced wiring...

Best part is they cut the factory hard line, so now I'm not sure what I will do. I wish it was in tact as it is nice, safe, and reliable. I may just run a push-lock line all the way up, but the factory stuff would have been my preference. Any idea where I could get a replacement factory line?

I have a Racetronix kit to put in tank. I hope the factory pump and assembly is still in place in the tank. 

10/30/2009

I got to work on the C4 last night and again today. One great thing about C4s... they are easy to pull an engine out of! I was worried about going after it without an extra set of hands, but, no problem.

Getting the LS1 out of the way will allow me to clean up the engine bay some, and more importantly, go through some questionable mods.

The front brake lines are kind of a mess, since I received the car modded, I don't know how they looked stock, but I'm not happy w how they sit.

It also let me get a good look at the sections welded in to run the C5 mounts. They are partially bolted together (along with a weak, and now broken weld). I'm open for input here. Start over? Fix this?

Oh, and lets not forget the fuel lines I am so fond of...

More troubling news on that front... The hot wire for the fuel pump relay (for the external pump covered earlier) was run along the fuel lines! Zip tied nearly 100 times, but still managed to be chafed to bare wire! Am I being nit-picky again, or does running a power wire physically attached to the fuel lines strike others as a bad idea? You can see it in the pic, its the one without the weather pack connections, kinda just dangling there. It ran (past tense, gone now) all the way from the firewall to the tank. Though it changes color and wire type at a crimp slice 1/2 way.

Today was a mix of good progress and heartache. I rolled it outside and pressure washed the grime from the engine compartment.

I noticed some fuel was dripping from the return line (the pressure line is disconnected over the diff-where the external pump was). So when I rolled it back in the garage I put a pan under it as I assumed it was just the fuel in the line (it had been sitting nose up for so long). I even used a big antifreeze pan to be safe... WRONG! Apparently a lot of fuel can siphon from the return line. I smelled gas in the house... ah oh.. Go into the garage to find gas all over the floor.

I did a lot of cleaning up with the hose, but the smell lingers. Luckily most of the area effected was clear, but some boxes and wood blocks got tossed. I wonder how long the smell will last.

Back to good news, Classic Tube sells a complete fuel line. Though I imagine I will have to drop the tank and rear suspension to install it. They also offer brake lines. 

HELP WANTED:

Does anyone have pics of a stock 84 engine compartment without an engine? I'm wondering how the factory fuel and brake lines route, and terminate. I'm also curious how the old SBC mounts, and how my cross member has been modded. 

10/31/2009

Decisions, decisions... My 1st plan was to leave the engine together so I could focus time and energy on the other areas of the swap. Then go through the engine next winter.

But, with all the 1/2-@$$ stuff I'm finding, I wonder how much could be wrong with the engine. I noticed the rear of the engine is abnormally oil covered (was an auto car) and the rear cover is missing a bolt... Also, the driver's valve cover is missing a bolt...

I picked up:

LS6 heads

LS6 cam (and springs)

Ported Oil Pump and TB (by Drag Werks)

LS6 Intake

Katech rod bolts

and I'm considering an Improved Racing F-Body Trap-Door Race Baffle (oil pan baffle) 

So I'm strongly considering going through the engine now, rather than gamble. Not to mention more power is a beautiful thing!

Tomorrow I'll clean this thing off and ponder...

Input is welcome here.

Also, does anyone have an extra rear cover or 98 Valve cover bolt? 

11/1/2009

Trey, I haven't located pics of the LT1 C4 set up yet, but..

A member of another board who is doing a similar project suggested fliping the C5 stands.

Flipping the stands moves the contact spot ahead ~4.5". The bushing lines up with the bosses on the block, so flipping to the front mounting bosses is easy to calculate even without C5 stands.

The bad news is on the passenger side the stand interferes with the C5 A/C bracket. The good news on that is the part of the A/C bracket it contacts doesn't seem necessary. It is that furthest back ear, I don't yet know why it couldn't be ground off, or even what it is for...

That far left hole is just kind of floating back there.

Not an issue for me, as I do not intend to run A/C.

Now, moving my mounting location ahead 4.5" puts me just behind the flat surface of the cross-member. This would be an easy location to add a plate. 

Only down side it the flat surface of the crossmember is 2.5-3" higher than the current mount location. I want to raise the engine, but not quite that much. Although I would think using something other than the C5 bushings would solve that.

The C5 stands bushing location is about even with the top of the pan. My f-body pan hangs ~5.5" below (a C5 pan ~5" according to the conversion pan sticky). The C5 bushings are ~3". So if the cross member hangs 2.5" below the bushing, I'm set.

More good news is that by moving the mount back 4.5", I can run flat between the 3" bushings and not hit the pan (no cut out required).

4/5/2010

Wow, time has flown. Not much progress over the winter except some parts gathering.

I picked up 4 17x11s and 315/35/17 Kumhos from DTD. I will run these on all four. The 36 mm offset is close, but it looks like I will need to run a small spacer. I went with the Kumhos as I intend to run street tire class.

I also picked up some other cool and surprisingly expensive parts like LS1 ARP head bolts, crank bolt and flywheel bolts. A road race oil pan baffle from Improved Racing. A Fel-pro gasket set. Clutch hydraulics. A used T56 bell housing and mini starter. New water pump, tension pulley, and idler pulley for the C5 accessory drive.

Over the last couple days I finished grinding off the old mount system (this was an early LS1 conversion). I plan to make new mounts from angle iron coming off the crossmember, and C5 stands flipped forward. This will be similar to LT1 mounts, and have been successfully used by other swappers. I cannot use the speed hound conversion mounts as my original mounts were cut off during the previous swap.

The old cut off mounts were plated welded to the cross braces and frame:

It took more time and effort to grind these off than I expected...

I also dug the Liberty Face-plated T-56 out of its crate. Face-plating is a process where the syncros are removed (except for 5th and 6th). This will allow for extremely fast upshifts (think motorcycle or Jerico trans).

I bolted on a stock f-body hurst shifter. Then I mounted the C-beam adapter bracket... This was no easy feat. I had to batter it into position. I tried using a rubber mallet but eventually resorted to beating it into place with a BFH... So much for the pretty powder coating. Once in place I had to use this C-clamp to torque it into a position where the 3 bolt holes lined up.

Hopefully I will make more progress as in the next couple days. 

4/8/2010

I had an impressively engineered and fabricated car drop by. Jim Nilson's "Cormaro". This is a 67 Camaro with complete 85 front and rear Z-51 Corvette suspension installed (along with a custom subframe, firewall and floor). He even kept the Corvette engine set-back. This car was completely fabricated in his home garage!! He stopped by, I drooled over his car, and he gave me some pointers on my project.

I also took some measurements on engine placement. I was wondering how offset the original SBC was offset to the passenger side. My factory engine mounts were cut off by the previous swapper. Looks like ~2" offset to passenger. Crank centerline was 15 1/4" from the frame driver, and 13 1/4" to passenger frame as measured along the cross bar in front of the engine (the pic is taken from an angle).

Any one have differing info?

Also, not sure if I mentioned, but I picked up a D44. So lately I dropped out the 3.73 geared D36 (for sale). Now the vette sits on stands entirely w/out a driveline...

I'll get picks of the new driveline on the floor next time I get garage time.

Oh, and my Melrose headers are in the mail. I cannot wait to get those! 

4/14/2010

I received some more goodies in the mail over the last couple days.

My Melrose LS1/C4 swap headers came in. I am impressed. Build quality and hardware are top notch! I ordered mine uncoated. I want to go flat black with them. I intend to use header paint. If that fails, I can always get them coated later.

I also received my C5 front brake brackets. I got them from a forum member. Again, build quality and hardware were impressive. I mounted them on some 85 spindles I picked up (because 84s have smaller/weaker mounting bolts). Although I do not yet have my new rotors or hub/bearings so a full mach-up will have to wait.

Spindles came shockingly clean, and cleverly bolted together for shipping.

Also, since I have the D36 (and entire rear suspension) out... I have been drooling over Banski Motorsports' C4 rear suspension parts.

http://www.banskimotorsports.com/C4_...spensioin.html

What can I say... I have a soft spot for quality USA made parts! 

7/12/2010

Thanks! Sorry for the late response. 

I recently sold my (subtle) Z28. So the rush is on to finish this build. I have done a bunch of work. When I get a little free time I will update my progress w some pics.

Here is a teaser:

I have the entire rear suspension out (actually the entire drive-line) along with the rear facia, bumper support and gas tank. The New (to me ) D44 was checked out at the shop. Banski rear suspension is in the mail.

I have finally started the re-assembly process by installing the new Classic Tube fuel line.

The rush is on. I hope to race the car at 2 events in September. 

7/28/2010

Well, I have been working on it some lately. I haven't had as much time as I'd like for photos and posting, but here is an update:

The Good news:

I have finally started reassembling things!

I have the new Classic Tube fuel line in (which required the whole rear of the car off give or take).

I took off the rear facia (nightmare). Lots of hard to reach bolts and sweat and blood involved...

And dropped the rear bumper/gas tank assembly:

More on the gas tank in the bad news section...

I have had some help in the garage today in form of my 7 year old son Patrick!

So I was able to get all rear suspension back in. I replace all the consumables: new SKF hub/bearings, ARP wheel studs, Spicer U-joints. I picked up the whole rear kit from Banksi: rod ended camber rods, toe kit, and trailing arms.

I deleted the dust shields on the rear brakes, and I think I'll leave the rear wheel wells off.

Bad news:

When I dropped the tank I found the sending unit rusted to the tank. Two of the bolts snapped off. The sending unit was *******ized like the fuel line (pump replaced w hose). If you remember from early posts they also cut up the factory hardline to put an external pump under the rear axle...??? I have no idea why when the car has an internal pump. I intend to replace it with a nice Racetronics kit.

I do have a new sending unit from Corvette recycling. I just have to clean up the fuel tank 1st. Oh, and did I mention my local radiator/gas tank place stopped boiling tanks two months ago?! 

7/30/2010

I did some work on the gas tank today. I drained it as much as I could and washed it out w water days ago. It still smells like gas but is dry. I was worried about going after the rust (explosion). Today I bit the bullet and hit it with a plastic media wheel on a drill. It cleaned up well, and no sparks...

I threw a quick coat of paint on:

Down side is the cheap bolt extractor kit I bought at AZ did not help w the two broken bolts. However I did bust several drill bits... Those tank bolts are hard!

I switched over the wiring on the late C4 sending unit. I just pulled the factory wires from the old 3 plug connector, the new 4 conector, and put the new unit wires in the old (3) connector. The new sender didn't even use the 3rd place, so I think I'm good.

I also put in my Racetronics pump and sending wiring (just 2 splices - it was for the 84 sending unit).

8/1/2010

I got my new (to me) harness in yesterday! I originally had an S&P harness for the LS1 and 4L60E that came in the car. I was going to modify it for the T56. But then I found a great deal on a used S&P harness for an LS1/T56 combo, so I jumped on it.

For anyone doing a similar swap with an auto, my other harness is currently in classifieds.

$650 shipped.

11/29/2011

I'm sure I'll regret this later, but the truth is I have not made this car a priority in too long...

Would anyone who has followed this build be interested in taking over?

I'm fairly close to completion. Things that come to mind it still needs:

1- Engine mounts or plate

2- Wiring, keep in mind I have a nice plug and play engine/trans harness and ECU

3- Clutch hydraulics (have the parts)

4- Seats (the only part I really do not have at the moment)

I have new:

-Melrose Swap headers

-Dewitts LS1 Swap Radiator

-Water pump, balancer etc

-Laser cut Aluminum dash w Auto-meter Guages

Completed:

-D44 inspected and installed new rear hub/bearings and ARP studs

-Full Banski rear suspension

-Racetronics fuel pump , new classic tube fuel line

-Liberty Face-plated T56 six speed with C-beam bracket

-98 LS1 with LS6 intake and stand alone harness/ECU

-C5 front brakes

-17x11 front and 17x13 rear wheels/tires

$10k would take it home with the LS1, T56 and all mentioned parts. I have much more in it!

I would consider trades up or down (plus or minus cash). Manual trans C5, G8, GTO, CTS-V or LS1 F-bodies come to mind.

I've been pretty candid with this thread. No surprises.

I don't "need" to sell it, but I have been facing the reality I don't have time for this project at the moment...