89 Corvette Mostmint #39

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MostMint
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89 Corvette Mostmint #39

Postby MostMint » Thu May 17, 2018 10:48 pm

This has been coming for some time. Watching ChampCar Endurance Series evolve it has become exceedingly apparent that the platform upon which you start can determine your ultimate performance. As we have demonstrated with the Saturn it is entirely possible to be competitive at the right venue and the right preparedness. However I see this league evolving making it exceedingly difficult to be competitive.

Furthermore there is a large disparity in competitive levels of classes. At VIR last year we broke an engine and after 7+ hours we were back on track. We run in class A. The leading class D car was just a few positions ahead of us.

I have seen precious few Corvettes in ChampCar which does confuse me. With sometimes 40% of the field being E30 and E36 platform vehicles, how could there be practically no Corvettes. ChampCar allows them and actually values them above the E30 points wise.

And finally my son has interest in building this car. I had planned to make the buy in October but he has this summer and expressed interest, so here we are!

I have contemplated many facets of building a car. For a car to be competitive in this series it comes down to three things:
1) horsepower to weight ratio
2) gas tank size
3) handling characteristics

(Teams must add driving skill and reliability for to be successful)

The Saturn lacks the necessary power to weight ratio, and has some disadvantages in handling due to FWD. It has been an amazing car and have enjoyed it thoroughly. For now it stays.

With all this brewing in my head I have been kicking around a few ideas. On the Corvette option spent a good bit of time browsing them in the fall and decided next fall was the time to move since prices are low.

In the meantime I've still been casing them in my free minutes and came across this car.

It is an 89 with 61k miles, the TPI L98 and automatic transmission. The underside looks clean, no signs of damage repair, a couple cosmetic flaws nothing major. It is not a running car at the moment. The prior owner had the engine rebuilt and has it reinstalled in the car. It is mostly reconnected except for all the accessories driven by the serpentine belt. The fuel system has been gone through and the gas should be good. There was a long story about how his brother in law was the original owner and somehow the drain plug came out after an oil change. Whatever. I'm figuring the car is probably worth close to $1500 with the engine in pieces.

The tires on the car are from 1992, and the plates were current as of 2010. Suffice it to say the car has not moved much recently. The guy kept it in his garage for like 20 years. He is moving to Florida and is not taking the car which is why he decided to sell.

The reason it is not running is he no longer has the key with the chip to satisfy the anti-theft system and so the ECU will not deliver fuel to the engine. Kurt is looking into this already he knows what to do just has not bypassed it yet.

I have the RPO codes from in the glove box but have not decoded them yet.

Kurt and our new toy - try not to look so excited
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Sitting out waiting for combat robot projects to get out of the garage
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The 2 tells me this tire was made in 1992!
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[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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MostMint
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Re: 89 Corvette Mostmint #39

Postby MostMint » Thu May 17, 2018 11:00 pm

The first order of business is to get it started which means the VATS needs to be addressed. After that we need to get all the parts to install the accessory belt, get some usable tires (right now two of the tires do not hold air for very long probably dry rot). This will make it a whole lot easier to move the car around.

I am forming a to do list which is quite extensive.

Planned milestones:
1) get the engine running
2) get it roadworthy to test out the current systems
3) make necessary preparations and do a track day. This may include a roll cage to satisfy Rhonda about safety. If the performance is good we will continue
4) complete preparation of the car for safety and reliability. Targeting under 2700 lbs
5) first race - if all goes well this will be at Gingerman in August 2019

I have to work on building a team. At least two of my current team members are dead set against racing an automatic car. Last time we all agreed ahead of time how to go, this time the challenge will be finding people who can buy in to my idea.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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MostMint
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Re: 89 Corvette Mostmint #39

Postby MostMint » Thu May 17, 2018 11:30 pm

Looking for a water pump pulley, alternator for L98, also 275/40/17 tires or close so I can move it around. I have a line on 245/45/17 but we will need to stretch them to get it to seat.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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MostMint
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Re: 89 Corvette Mostmint #39

Postby MostMint » Wed May 23, 2018 9:04 pm

Kurt has figured out the resistance for the VATS, replaced the fuel filter and the fuel pressure regulator. The regulator was rusty. Still not starting on its own fuel supply. Up next is fix the fuel supply in the tank.

Most of the interior is out of the car. I have some 10 year old 245/45/17 with good tread which will replace the dry rotted tires we have. Also noticed it appears to be down to the liner on left front brake pad.

We have replacement alternator and water pump pulley. Also picked up 88 service manuals from my friend Joey and have a CD on order for 89 manuals.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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Re: 89 Corvette Mostmint #39

Postby MostMint » Sat May 26, 2018 11:27 pm

The engine is coming out.

Kurt got fuel pressure to the injector rail after fixing the fuel pump (the hose from pump to steel line was missing hose clamps). Engine would catch but not start. Did compression test found #3 at less than 5 psi, #1 at 65 psi, others between 110 and 160. Also found at least six of the injectors were not delivering fuel. The catching was #4 cylinder which was only one firing. Pulled a valve cover and found water and surface rust.

Top end is now off the engine. I can only guess the guy pressure washed it with the PCV out or something so there is some rust in there now, and there was some mixing of oil and water. The pistons were definitely replaced with these: https://www.summitracing.com/parts/slp-h345dcp

It appears however the bores were not honed in any way. There is some scoring and a little evidence of rust. Basically the guy's engine "builder" replaced the pistons and rods, crank and oil pump (according to the story) and nothing else. Actually glad we found something because if we ran it like that we might have ruined the new parts.

#3 exhaust valve is definitely not seating I believe it is slightly bent.

Funny thing is that 8 pistons for this car are less than 4 pistons for the Saturn.

Looks like Michael's going to get more business soon.

Tires mounted on rims, we got a new battery, new alternator, and replacement injectors and top end gasket kit en route.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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Re: 89 Corvette Mostmint #39

Postby MostMint » Sun Jun 17, 2018 1:14 pm

We found more oil water milk in the bottom of the pan. There were dead insects on the inside of the pistons. Gasket surfaces had paint on them.

We decided the #'s matching L98 is going to be the spare engine. What this means is we will use it to get the car going, do baseline tests, and plan to build another before the first race. With this in mind we are putting it back together with an actual rebuild but not super concerned about special internal treatment for a 24 hour race. Checked the bores they look to be between 4.001 and 4.002". None of the mains had turned in whatever happened to this engine prior to previous owner "rebuild" attempt. Found 6 bent vales, so we bought 6 replacements which Kurt installed and lapped in. All the valves came out for inspection and replacement of 29 year old seals. Kurt did a fair amount of cleaning inside the block to remove the surface rust (non-machined surfaces). Honed all the cylinders. Short block is now reassembled. And Kurt learning how to changes valves and hone cylinder bores.

After $1500 purchase price, the next $1k has been spent in parts: taxes/transfer title, new radiator hoses, brake pads, injectors, gasket kit, piston rings (upgraded to moly top ring - $33 for ring kit for 8 pistons), alternator, battery, mount and balance tires (this was $90! oops), fuel pressure regulator, O2 sensor, transmission filter.

We could definitely use another roller cam gen 1 small block (casting 14093638) if anyone has a line on one at a good price. There is no rush on this.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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Re: 89 Corvette Mostmint #39

Postby MostMint » Wed Jul 18, 2018 8:12 pm

At this point, Kurt has the long block assembled, but there has been no activity in the past several weeks.

Last weekend I did my first project on the car - I went to work on the exhaust manifolds. Plan was to remove EGR valve, clean up the threads on the studs, and clean and paint.

That plan fell apart on first inspection. The prior owner had welded the small EGR pipes shut but they protruded into the header pipe. These I ended up grinding out.

I tried running a die on the studs but since they had been cross threaded with American thread (these are metric 10x1.5) I could not get satisfactory thread. This led to removing and replacing the studs. With heat and candle wax I was able to remove four of the studs but broke the other two. This led to quite a bit of monkeying around to drill out the old studs. In neither case was I 100% satisfied with the threads I tapped so I added a metric nut at the top and had Kurt weld it on.

The exhaust port of the header was another thing. First off the factory header is 1.5" OD which I find small. Second where the flange attaches to the pipe is between 1.2" and 1.3". Yikes I went to work with the die grinder cleaning up these welds to improve flow. The 4 into 1 end was also quite sad there was weld splatter and the openings are even smaller. I spent over an hour grinding out extra metal on each one before I got burnt out. Maybe more on another day.

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[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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MostMint
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Re: 89 Corvette Mostmint #39

Postby MostMint » Mon Jul 23, 2018 1:54 pm

Item #1: The factory serpentine belt includes the A/C and the air pump. Neither of them are needed for this application, so the challenge is how to handle that!

The A/C hangs off the passenger side. Choices there range from adding an idler to changing the pulley on the tensioner and running the belt on it opposite side. I like the latter but now need to get the right pulley (allegedly Chevy Beretta has one that will work).

The air pump is on the driver side and the alternator is beyond it. Choices are to put an idle pulley in there, or possibly fabricating a bracket to move the alternator closer. This one will require some mock up to get right.

I still have more work to sort this all the way out but seems like something that needs fixed

Item #2: With no EGR what can I do to simplify the intake manifold?

The EGR appears to be let into the intake by the EGR valve straight into the top of the TPI, but also through small holes in the base of the manifold. I'm seriously considering having Kurt weld these all shut then I can avoid having multiple plates blocking EGR openings and possibly removing some weight from the bottom of the intake manifold. The intake is a maze of pathways and so I'll need to spend a little time mapping them before I get started.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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Basement Paul
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Re: 89 Corvette Mostmint #39

Postby Basement Paul » Mon Jul 23, 2018 5:01 pm


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Re: 89 Corvette Mostmint #39

Postby MostMint » Mon Jul 23, 2018 11:15 pm

ChampCar is likely to charge me points for these things since they are not stock parts. I think I have to be more subtle. Plus eliminating those pulleys will eliminate two more possible points of failure.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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Fred32v
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Re: 89 Corvette Mostmint #39

Postby Fred32v » Tue Jul 24, 2018 9:43 am

I understand why ChampCar might not consider the air pump eliminator to be stock,
but what does Chevy do if you order without air, might it not have that idler there?

Your Grandfather removed the fins in the smog pump so it became an idler,
I think that was on Paul's Cadillac.
Fred32v
GMC Canyon Crew Cab Short Box 4x4 V6!

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Re: 89 Corvette Mostmint #39

Postby MostMint » Wed Jul 25, 2018 2:19 pm

I assumed AC is standard like they never made a non-AC C4 but I will check the RPO codes to confirm.

Making the air pump an idler is plausible idea if I can eliminate it will be one less point of failure
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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Re: 89 Corvette Mostmint #39

Postby TireSmoker » Wed Jul 25, 2018 10:33 pm

this might help, semi-serious question -- how many BMW E30s came w/o AC? I'm guessing its a no-points mod to have an idler pulley in its place.

-Dave

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Re: 89 Corvette Mostmint #39

Postby MostMint » Thu Jul 26, 2018 12:34 am

It's a good question to ask and I will check with Tom. It is possible the belt configuration is different and easier to bypass. Like the Saturn you can bypass AC with just a shorter belt.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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Re: 89 Corvette Mostmint #39

Postby TireSmoker » Thu Jul 26, 2018 8:02 am

I didn't read it all, but there's a few pics here. Talked about removing AC and air-pump. Had to convert to a standard rotation water pump, because the normal serpentine setup requries reverse rotation.

https://www.corvetteforum.com/forums/c4 ... ulley.html

funfact: poster Anesthes in that thread is the guy I bought the Saturn's megasquirt from.

-Dave


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