I have formed a team to explore racing a C4 Corvette in the ChampCar Endurance Series. We are going to build a track ready car for evaluation then assuming all goes well finish the prep work for racing.I already have a team where we have successfully raced a 1992 Saturn SC in the same league. We have three trophy weekends in the past five races with this car. To get to P1 there is more work, and we made a decision to switch platforms from the Saturn to the C4.


Purchased car for $1500 in May 2018.
My son and I picked up the car in central Ohio in May of 2018


I will update you with the story on the car as time permits. Quite a bit of progress has been made but we are probably 10-15% of the way to being ready to race.

 

What are the features on the donor car and what is the build target platform?

 

The car is about as plain Jane as you get for an 89 Corvette. The relevant features are as follows:
automatic transmission
rear gear 2.59
FE1 suspension
ABS

Edit: here are the RPO codes for my car

AC3 AR9 AS8 BGR CC3 C68 DL8 D7B D9A E5Z E9Z FE1
GM1 JL9 K68 L98 MD8 MX0 NA5 NK4 QA1 UQ4 UU8 V73
XAU YAU 1AY 1SB 24S 81U 90I 902 909

The aluminum head L98 with one piece rear main seal and the ability to put a ZF6 factory option in the car were important considerations when selecting the 89.

I reason that the Corvette in stock form is going to perform quite well so what I need to do is make necessary preparations/modifications to make it last for a 24 hour race.

 

I would advise you to be careful with the C4 as I have a 1988 and my ABS system doesn't have a pump and it does not work like the standard modern ABS. On my 1988 C4 the two front wheels have ABS type action but the rear of the car is treated as one axle and not two separate wheels. The 1988 is a primitive ABS system at best, I think the 1989 is different as the 1988 uses a one year only master cylinder. I hope it is able to provide you with a good braking system for racing. Classic Tubing makes the sets of new Brake lines in Stainless if you want to go that way. I bought a set of brake lines for my 1988 C4 and it came as either 9 or 11 pieces. Being a unique year I even bought a good working ABS unit as a spare for when I need it.

If I were going to race one of these engines I would probably use an aftermarket head Gasket set that is tougher than the ones that the factory used. In the past thirty years they have made some real improvements in head gaskets.

You have chosen a great platform to race in the C4's, the engine is out and in the open and easy to wrench on when necessary and the cars look great. There are a lot of things that you can do to improve on the original design!

Happy New Year and I wish you the very best in getting your C4 ready to race!

 

There is a complete Dana 44 setup available here on the forum. Pedals, tunnel, batwing, driveshaft and c-beam. Even the ZF is available from the same vendor. All came from the same car. Mark Mirrock (Mirroc Corvette in Pa) also has complete setups.

If you have a need for a spare set of rims, a friend over off Krumroy has a set (all 17x9.5) from his 90 that you could pick up for a very attractive price (assuming you would want to run stock width).

Besides Kubs, there is a wealth of C4 racing experience local here. One of the club members of Tiretown Corvette Club (the one I belong to, Kubs belongs to Corvette Cleveland) just won the SCCA ITE, ITR, ITS class championship for the NE Ohio area.

Others in the club have experience racing automatics.

If you ever want to get in touch with some of them just shout.

 

Summary of 2018

Car condition:

Bought the car in May not running. It would crank over but not start.
It had a key but like a backup door key that had no resistor
Came with 61k miles
Tires were from 1992, and were leaking from dry rot
Plates were last renewed in 2010

Car had been left out with the fuel sending unit not bolted to the tank. Significant amount of water in the tank and between the tank and liner
Fuel pump connected to sending unit with hose only no clamps
Missing parts: alternator, one of the frame supports, water pump pulley, fuel sending unit bolts, chip in the key, engine belt, battery tie down and bolt
Rust was found in the engine crankcase, water mixed in with the oil, oil pickup had slight crimp, harmonic balancer key peened over slightly
Engine had Summit crank, new bearings, high volume oil pump, pistons and rings. It also had six bent valves, and two rods installed backwards on the piston
Only one fuel injector was working, rust came out of all of them
Fuel line rusted from the inside out after the fuel filter
Speedo wiring harness connector was gone
Lockup converter connector was damaged and poorly wired back together
Wire to engine coolant temp sensor had a break in it
Tach wire missing connector to distributor
Brake booster and master cylinder leaking
Sensor for temp gauge not working
Sensor for oil pressure leaked
Header exhaust studs were stripped due to use of wrong bolts and some rust
Found rust chunks in the water pump, considerable rust in the water jackets and radiator. Overflow reservoir had lots of junk in it
Exhaust hanger in front of rear end broken
Hood release on passenger side cable seized up - looks like small fire as several items are slightly melted
All cats were hollowed out
No key for center caps

Work done so far:

Drain the gas tank. Clean it out – literally with a vacuum and Windex. Flush fuel lines.
Replace the flexible fuel line in engine compartment with braided stainless hose
New fuel injectors (well remanufactured), new fuel filter, fuel pressure regulator
Replaced all brake hoses with braided stainless steel hose, flushed the brake fluid, replaced brake booster and front pads
Install VATS bypass enabling removal of pass key and VATS modules
Headers: removed EGR pipes, cleaned up weld spatter, did some porting, replaced exhaust studs, heat wrapped
Removed: most interior panels, carpet, radio, air conditioning underhood components, air pump
Replaced power steering hoses and fluid
Removed all non essential wires from wiring harness on engine itself
Removed spare, jack, all equipment and the clamshell
Removed cruise control mechanism
Acquired and freshened a running truck engine and installed in the car
Set up belt configuration without A/C and using air pump bypass pulley. Convert tensioner over to grooved pulley
Bypass heater core
Acquired a scrub set of tires so we could move it and do basic road tests
Acquired two extra sets of rims
Changed transmission fluid and filter
Other purchases: New battery, alternator, ECTS, O2 sensor, passenger motor mount, plugs, wires, factory service manual, transmission front seal, engine gaskets, thermostat
Fabricated custom windage tray from fabricated sheet
Installed oil temp sensors in transmission and engine oil pan
Installed wideband O2 sensor bung for AFR gauge
Replace missing exhaust hanger with chain
Closed off EGR ports in bottom of intake and external ports, removed excess material from bottom of intake
Studied other Vette finishes, found them to be basically poor, and made appeal to ChampCar to lower VPI
Current vehicle weight: 2960
Learned a ton about Corvettes and late gen 1 small blocks
Car is moving under its own power in the driveway, and capable of smoking the tires

Major milestones:

Get the car running – done
Basic road test – start, stop steer, shift
Basic performance tests: drag race, autocross
Get on the road course for a track day
First race

Other:

The current to do list has 114 items on it and I am quite certain it is not complete.

Key tenets of my plan include oil management, heat management followed by reliability, simplification and weight reduction.

I have penciled in the first race for late August or early October. I have a busy year ahead as the Saturn will be doing two races as well.

 

Thanks will be in touch.
Problem with the ZF6 setup is its expensive. I found an entire 92 car with the ZF6 (presume blue tag) for $2500 which I did not want to pay, so I can't really see spending that much just for the parts. With the 89 we have that option, but for now we are starting with the automatic. I think it can help us prove out the viability of the platform and maybe a race or two before we make the additional investment for the ZF6.

 

The racing experience I mentioned above is regarding C4's. Jerry (the guy that took the SCCA position) is running a 1985 if I remember correctly. He runs a stick car with a Dana 44 rear. He also crews for Ruman Racing.

http://rumanracing.com/

The member that raced with an auto put a fan cooled transmission cooler back where the spare tire is put. Heat is the enemy of the 700R4/4L60/4L60E transmissions.

$2500 and being able to part out the rest of the car was a bargain. A Dana 44 setup will go in the $1000.00'ish range with batwing, driveshaft and c-beam (not the transmission). I just bought one. Another member that autocrosses runs his Dana 36 and when they blow up just replaces them because they are cheap. Alternative manual trans are more expensive, such as the Tremecs.

Is that 92 local and still available for $2500.00 ?

Which shocks does your car have. In the spring I will have a low mileage (19K) set of Z51 Bilsteins you can have (yes have if you want them). I will also have a low mileage 3.07 geared Dana 36 that I will be selling for a decent price (complete unit, batwing, driveshaft, c-beam).

One of the shortcomings of the Dana 36 (besides the size of the gears -vs- the Dana 44) is that the bearing retaining caps are left unsupported. Zip Corvette is working on version 2 of the batwing they used to sell that had blocks welded in and machined (along with the bearing caps) for a .002/.003 crush fit to support those caps. Jerry above cracked a bearing cap in half while racing but the support blocks of the Dana 44 kept his differential together. If you have someone that can fabricate, machine and weld similar blocks in, it will help hold the D36 together if you are going to stay with that unit).

 

The 92 was not local and now is not the time to make that investment. I saw it a few months back I doubt its still out there

The car still has the factory Bilsteins on it they have 61k but they are now 30 years old. Would appreciate the extra set thanks.

This car is going to make 240-250 HP at the wheels max so I am curious what kind of power is breaking the Dana 36? Also is there a weight difference between the 36 and 44? I was planning to do my homework on this but we're not far enough along yet. Up to this point my plan is to get a parts car which should come with all these spare parts. The whole car I find to be cheaper than the parts. In November I passed on a complete 89 for $1500 (automatic car) I think that was a mistake.

 

Only the stick cars come with the Dana 44. Of the power level and what is breaking them (D36's) in autocross, etc, I will ask and find out the next time I see the folks. That will be sometime in Feb March time frame.

The Bilsteins I will give you are the heavy duty Z51 option shocks from 1996.

Fine Lines over on Hartman by the High School has rolls of stainless and such for making break lines, etc. for decent prices.

In the future if you continue on with the '89 and need to rebush it without the binding that poly does, here are some bushings that just came on the market this year. They are in between OEM rubber and poly. Notice they are 1 piece press through bushings as opposed to 2 piece poly.

https://corvettesalvage.com/product/...kit-1984-1996/

https://corvettesalvage.com/product/...set-1984-1996/

I am buying the batwing bushings today/tomorrow myself

In the extended future, (and I realize that there is a points penalty) Banski Motorsports has a Heim Joint rear suspension. If you would like to see what they look like, I have a set that I will be installing in the spring. You could go to lunch with myself and our mutual friend Dan and I would bring one of the bars with ends if you would like to see them for future reference or on Tuesday nights there is a group of Corvette people that get together at the Burger King on 94 (by Tractor Supply), I could bring them there one evening once I start going back after knee surgery. In the winter they eat inside, during good weather they get together out back. It is another set of folks to tap into regarding Corvettes.

As far as the weight penalty of the D44 -vs- D36 I can't say. The difference is in the diff/gears themselves. The batwing/c-beam/driveshaft are going to be reasonably comparable in weight.

If you want to get the u-joints redone professionally (ie: done on a dedicated press, not a vise) the guy that does the driveshafts for Summit Racing's teams and Mongoose Motorsport's cars is over on Mogadore Rd, near where Skelton (close to where the jet went into the apartment buildings) crosses to Gilchrest, I am going to have him do mine. I saw his setup, it is a purpose built u-joint press. He is trying to retire, so I am going to have him do mine soon.

He has access to (and carries) a brand of u-joints that are way above the quality NAPA etc carries and are priced not too bad. I will get his name and number from my boy and PM it to you so you have it for future reference.

Napa carries SKF rear bearings under their name. That is where I got the set I put in mine. You need to take a flashlight and look inside the knuckle at the back of the bearing(s) and see if they are leaking grease. Even though my car only had 11,800 miles on it when I bought it in '96, the bearings were leaking due to sitting and age.

I am going to have to replace my fronts soon also (ouch). If you do some searches here on the forum, other members have come up with less expensive alternatives such as front bearings from Camaros (I believe) that the only difference is the way to run in the bolts. The price differential is very significant.

 

Thanks. I agree about the ease of access to the engine, though most of the dropped wrenches etc tend to land on things and not make it to the ground.
Gaskets - agree totally and kinda wish GM through the decades would have spent a little more on head and intake gaskets for many of their models
The brake lines are super clean as is the rest of the underside of the car so hoping what is under there will be good for a long time, but will keep this in mind in case I find any bad spots
Good info on ABS I will check into it further as to how the 89 unit works. If it turns out to be any real trouble we will run without.

 

Picture time.

ET phone home

Tires from 1992 week 43

Whoops when its raining insert the PCV and close the hood.

brand new Summit crank with a little surface rust due to water in the crankcase

oil in the crankcase, water in the water jacket please. if not you get this.

 

Round 2 of pics. "discovery" uncovered many things needing help
this came out of the water jacket

how not to treat your oil pan - previous owner installed option!

That's about 95% done cleaning the junk out of the tank

How not to treat your TCC connector

This is about half the water I found between the plastic gas tank and the metal liner

rust came out of every one of these like a pepper shaker

 

More pics. Starting to fix things.
What kind of quality control is this?

Small restrictions but the pipe is small!

Still room for improvement but definitely better.

If your intake manifold has small holes in it for EGR, you close them up. It's what you do.

Yes weld the oil pump pickup to the pump also. big TIG made quick work of this

In ChampCar it is highly recommended to use chain for exhaust hanger. Doing it for this one.

 

Thank you for sharing the pics!! This is going to be a fun build!! You found some cool stuff already it seems. You're not that far from me so I'm hoping to see the car around some time!! Will look forward to more pictures and progress!!

 

It is great that the brake lines are in good shape! Judging from your pictures I would say that it is likely that you will need to order a set of fuel lines for your car. If you had that much rust in the fuel system it had to come from somewhere. Classic Tubing is a company who makes the new fuel lines if you want original style. I found installing the original type lines would require lifting my body off or major dis-assembly. I simply cut the section off that was difficult and ran it in (Fuel Injection, Pressure type) rubber hose and hooked it all up. On my 1988 the fuel return line is still open so I am using it. My fuel line was rusted shut internally on the supply line along the section under the passengers door. That was a real PIA to figure out....

IF you decide to get rid of the ABS system the folks at Classic Tubing offer the brake kits in Steel or Stainless and with or without ABS. They do beautiful work at Classic Tubing... They also have the stainless braided DOT approved Brake Hoses that are used at all four wheels to connect the caliper to the brake system.

Thanks for the pictures, that Engine sure needs some TLC and a healthy wallet! Good Luck and I look forward to hearing about your New race Car as you build it.
CTMcCloskey

 

Upon first attempts to start the car we uncovered a leak in the fuel line

Cutting up the leaking fuel line shows a hole that has every appearance of coming from the inside. All the flare nuts loosened up without any trouble. This was an unexpected turn.

After the first discovery of water in the crankcase my son took the whole thing apart and this also uncovered the six bent valves and lack of honing of the bores despite the new pistons and rings that came with the engine. These wrongs we fixed

In order to improve oil control I want a full length windage tray.

After installing the cleaned and repaired original engine, we were greeted immediately with a rod knock. So I bought a backup plan which is a 95 truck engine that had been powering a 1980 Monte Carlo. It needed new crank bearings, an intake valve seat recut, and umbrella seals. Also converted it over to roller cam which came from another truck engine.

Lost in the shuffle was the fact that the truck heads are straight plug which puts the plugs precariously close to the header. I'm using the junky wires that came with the car right now so if I cook them I am not losing anything of real value. The truck engine accessories are generally incompatible with the Vette.

 

Here are the last round of pics to bring you up to current.

So I heat wrapped the exhaust manifolds instead of using factory tins to actually have a little space between the plugs and the header. Looking to acquire a set of 84-85 headers to put on the mule engine

Removed several wires from the engine side of the wiring harness - all the way back to the plug at the firewall. There is a lot more wiring work to do.

We eventually bought a VATS bypass, but to get it started we used this rheostat out of an old radio to change resistances until we found the right one.

The mule is installed. this is what the engine compartment looks like today

A look under the hood at the passenger side. We replaced the factory rubber in the fuel line with braided stainless hose.

Some significant interior delete options - I better check those RPO codes again. Still a long way to go in here

And here is a 3/4 rear view from this side. You can't see the melted rocker panel from the prior owner - apparently torpedo heater got too close.

Still a lot of weight to come off but its a start. If you look at the wheel wells you can see the car is already riding high 28.5" in back and 27.5" in front

The original tires were leaking so I picked up a free set of 245/45/17 that are 10 years old to make the car moveable. Once I got the mule running I had to test the posi. With the truck cam and heads and TPI intake this thing has a lot of low end torque.

 

Keep up the hard work. Its nice to see some more vettes in Champ. We did our initial build a couple years ago. We had some back luck at our first few races, but had success at Sebring this December.

We we went through all of the same things as you are doing. I have a build thread here as well.

 

Aaron, heard you had finished a race. There was another thread a week or two back we were discussing it. Keep at it.