89 Corvette Mostmint #39

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MostMint
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Re: 89 Corvette Mostmint #39

Postby MostMint » Sat Oct 27, 2018 3:43 pm

^ I now have a place to add ballast if needed lol

Tom came over and with some thrashing we were able to get it started today. Still a ways to go before its ready to move under its own power.

Looking for engine pics I came across this so I'll just leave this here for now:

https://www.barrett-jackson.com/Events/ ... UPE-133130

It fetched $19k.
[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 Nov 01, 2018 12:31 am

After getting the car started I went to work to make it actually run. I set the timing. With the electronics for timing advance connected it would start. Without it it would not. So I set the timing cranking with the starter. It worked.

The next problem was the crankcase vent hose was missing. I figured no big deal leaving it to open air it pulls in air anyway but this was totally wrong. After hooking it up the car started idling. Took a while to realize I actually had it so it could be installed.

I also noticed the cooling fan is running when the engine is running, even at cold water temps. Made attempt to resolve this by replacing the relay to no avail. ECTS resistance checks out also so not at all clear what is happening here.

The other bigger problem is the sound from inside the engine. I reasoned it might have been mal adjusted rockers arms. A quick trip to pull-a-part netted a valve cover I cut open so I could adjust while running. As I adjusted the first one and compared the sounds I knew that was not the problem. After some conversation with Fred32v I decided to finish up adjusting the other side, listen underneath, then pull the plugs, check compression and see if the sound was there with a free spinning crank.

Remarkably putting my hand on the oil pan while running I could feel the knock near the 5-6 rod journals.

Then I did a compression test. Ugh there was one at 50, two at 85, another at 130 and the others were 155 and up. This is not going to be good for a performance test. Our replacement valves helped but we must not have them seated properly. This engine has to come out.

In the meantime I started locating parts. I am going to see Tony soon as he has many of the parts I need from his engine rebuild, and I located a guy with a spare bottom end in pieces for $75 which I plan to get this weekend.

Kinda bummed the chance to get this thing on the street and/or on a track is basically done for the season.
[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 Nov 01, 2018 9:53 am

Upon further thought going to redo compression test with oil in cylinders to isolate between valve or ring compression problem.

Deciding also maybe get a mule engine and swap over the tray and intake could get back online quickly. Would like 245 hp to get true performance test so have some learning to do about heads and cams. Like why does the TBI version in Suburban make 210 hp and the Vette makes 245hp
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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Maverick
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Re: 89 Corvette Mostmint #39

Postby Maverick » Thu Nov 01, 2018 10:21 am

Probably not telling you anything you don't already know but, a leak down test will tell you if the compression leaks are intake valves, exhaust valves, rings and/or head gaskets. A simple test to nail it down without swapping parts.
Maverick

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MostMint
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Re: 89 Corvette Mostmint #39

Postby MostMint » Mon Nov 05, 2018 7:33 pm

The fuel line rusted out from the inside
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Should read 1.1 something
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parts is parts
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I went on a parts acquisition odyssey last weekend I now have a short block, and extra crank rods and pistons and other stuff. I am also getting another running engine and possibly a TPI intake and heads from a Camaro.

Tiresmoker suggested I run the trans through the gears before pulling the engine. I moved the rayostat off the shifter boot and now I can’t get it to start. I wondered if I moved the knob and tried to check it but the range I am getting is nowhere near the resistance I need. I tried my VATS bypass but no success yet. It resists.

At this point I have to give up on the likelihood I will get to any track and just focus on getting it running and basic street tests for now.
[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 » Sun Nov 11, 2018 8:02 pm

I was able to get the VATS bypass to work successfully. The Vette ECU needs a 30 hz signal which required an additional ground wire to be connected.

Once again Fred32v came by. This time we put the backup engine on a stand, then were able to start the car and confirm the transmission will go through all the gears. We then proceeded to remove the wounded engine from the car. We managed to spill some oil draining the spare engine other than that this was a fairly clean job.

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We also got to the bottom of the oil pressure sensor leak - it appears to be an internal leak of the sensor itself my guess it trauma from prior owner rebuild attempts.
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Oh and by the way the speedo was working so my earlier repairs must have been OK
[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 Nov 15, 2018 9:34 pm

[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 » Sat Nov 24, 2018 8:27 pm

After some deliberation I decided to put Loren's engine in the car without a rebuild. So we started down that path. That engine is a 4-bolt main so my newly created windage tray will not work without additional fabrication. Nonetheless we can use the factory windage tray. This engine used to have one and it still has the factory bolts. While apart we looked at the bearings. Mains are .030 under and rods are .010 under. We're thinking this was rebuilt once before. Beside the bearings the windage tray bolts are in the wrong place and the #4 intake valve seat was machined incorrectly.

While changing the valve seals today we used air to keep the valves up and noticed the #4 intake valve leaking. This required removing the head where we discovered the valve seat problem. I plan to send this to a machine shop to get this one seat corrected.

The bores look good and the valve seat I checked looked very good.

The mains we checked showed some copper which I was willing to live with til I started thinking about it more. With the valve problem I will spend the extra time and $40 to change out the bearings.

Also learned that the truck balancer pulley has the wrong depth, the truck flexplate is larger diameter than the Vette, the truck harmonic balancer is larger diameter than the Vette, and the truck oil pan is smaller than the Vette pan. Unfortunately the reduces the # of spares I can get from the truck engines.

Did some research on the camshafts.

Was able to locate specs for the Vette cam and the 96 engine (Evan's) roller cam.
Also - for reference here are some cam specs:

Corvette stock roller cam L98 10066049
Lift (w/1.5) .415"/.430"
Int/Exh Dur@.050" 207'/213'
LobSep 117'

1996 L31 truck roller cam (Evan's engine):
Intake lift- .414" Exhaust Lift- .428"
Intake duration @.050"- 191 Exhaust Duration @ .050" - 196
Lobe Centerline- 111
I confirmed the lift with the dial indicator

1995 truck flat tappet cam (Loren's engine)
I had to do measurements to get specs for this. At .373 intake and .399 exhaust this cam is no good it has to go.

With this information I decided to replace the flat tappet cam with the truck roller cam. At this point the cam, lifters, dog bones, and spider are installed.

Nothing easy with this project right now.

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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 Dec 06, 2018 12:11 am

So the head went back on and the valvetrain. These ports on the truck heads are odd and I think they stink but I resisted spending a lot of time redoing them I want this thing running.

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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 Dec 13, 2018 7:11 am

Update:

Last Friday Tom, Joey and Kurt helped and we got the engine assembled and back in the car. We also removed a bunch of connectors from the wiring harness as they were no longer needed. On Sunday I made progress connecting everything back up to the engine. Finally on Monday evening I had a chance to start it.

Through these work sessions we learned:
* why the Vette uses a smaller harmonic balance - the larger one hits the subframe.
* fitting the engine to the transmission and motor mounts is tricky. We will want to devise an easier path
* the Vette uses three bolt holes that the prior application did not. All of them required tapping to clean out the rust etc. This would have been much easier to do on the engine stand
* truck heads have straight plug holes, using them with the Vette headers puts the plug really close to the heat shielding
* I tried grounding a couple of the A/C wires but the fan still runs when the engine is running

I have done some research and I think I know what I need to do to get the fan off. All the A/C switches are closed when fan assist is not needed, which means the circuit has to be complete to ground. I can bypass all of it by grounding the correct wire into the ECU. That is next. Some care required finding a ground on a fiberglass car!
[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 » Sat Dec 15, 2018 8:52 am

Last night I bypassed the fan request input from the A/C pressure switches. The fan is still on.

The other obvious problem is the engine temp sensor. This gives high resistance when cold. I had already tested resistance of the sensor it looked OK so I just disconnected it for good measure - no luck.

There are some lower probability items:
- there is an AC request wire from the AC controller - the described purpose is so the ECM can increase the idle when the compressor is cycling. I wonder if it is really doing something else in there so I will disconnect that wire. Positive voltage in the wire signals the request
- the ECU is bad
- there is a short in the wiring
- there is a "fuel back-up" mode the ECM can operate in which turns on the fan. I believe this only happens when you trigger it by grounding a wire in the diagnostic port, but it is a way the fan can come on.
[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 Dec 26, 2018 6:26 pm

From last weekend:

Replaced the brake booster. The studs are just a bit too far a apart and the master cylinder will not fit. Did not check this until after installing. Will probably open up the holes just a bit. Ordered new master cylinder since the disassembly uncovered the master cylinder leaking a bit also.

Tom went to work on repositioning the alternator. Can't really get it to a good spot with appropriate supporting brackets. Ordered a bypass for the EGR which will add an idler pulley but I am willing to undergo that expense right now to keep this moving.

Removed the shifter knob and cleaned up all the rust there and reinstalled. Much easier to press the button than a thin piece of metal to get it in gear.

Still have one leaky fitting in the fuel line. Tried cut and reflare but no luck. Ordered a Rigid flaring tool I think my old tool is the problem.

Replaced the engine coolant temp sensor. It still giving a code. Re-read the manual I think there is a break in the wires that will be next.

Confirmed the 84 Vette had straight plug configuration so the 84 headers should work with the truck heads on the backup engine.

Removed unused wires from the wiring harness on the engine side. The plug for the main harness uses a 1/4" bolt to hold the two halves together. I simply separated them then pulled the unneeded wires through the plug side. About 8 wires removed most were for cruise control. Going to remove as many as possible from the underhood to reduce complexity in there.

Weighed the car as it sits now it is as 2962. This is with steel heads. BP says that aluminum heads will save 70 lbs. If I want this car at 2700 fighting weight there is a lot of weight to take off to get there. About 1700 of that is on the front - not as good as I had hoped, but it does improve with a driver in the car.

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From the weekend before the car went out of the garage under its own power
IMG_3203.JPG
[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 Jan 03, 2019 9:10 am

Aftermarket gauge panel request!

At this point planning to put the following gauges in the car:
Air fuel ratio
Engine oil temp
Transmission oil temp
Engine oil pressure
Engine water temperature

I have a 3-gauge panel but as you can see I need another 2-gauge panel. These gauges are 2 1/16. I will get one from Summit just wondering if anyone had an extra to donate to the cause?
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

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GMJohnny
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Re: 89 Corvette Mostmint #39

Postby GMJohnny » Fri Jan 04, 2019 6:04 am

I might have some gauges from the 442. I gave AK the oil pressure gauge to use
for his Nissan. I should have water temp and volts. I'll check this weekend and
let you know.

GM

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MostMint
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Re: 89 Corvette Mostmint #39

Postby MostMint » Tue Jan 08, 2019 11:32 pm

I am all over the place with this project. I joined corvetteforum.com, made some contacts, asked some questions and have acquired a lot of information.

One of the topics I have been exploring is roll cages. Summit has one for $599: https://www.summitracing.com/parts/rhc- ... l/corvette

I posted a question on there to get specifics. One challenge with the Corvette is that the cockpit really is a bit height limited so you have to tuck the bars up practically into the space where the top goes. My roll cage guy is charging $2500 to fabricate one.

I've been around roll cages long enough to know a good one when I see one. The bars run right along the pillars, and the door bars are "NASCAR style" where they come out into the door cavity for an extra margin of safety and ease of access.

The Summit cage looks like this:
Rhodes-Race-Cars-13-0531-DOM-201918153014286.jpg
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Ugh. I don't think I can do this cage. Many thanks to Jim in MN who answered my question on the Summit page with these pics. I suspected the door bars would be inadequate - could have fixed that having my fabricator do just the door bars, but the bar is nowhere close to the A pillar and I'm thinking the top hoop could be higher than it is in these pics.

Going to sit in the car and measure heights but odds are at 10%

This past weekend I finally connected with a local guy selling Vette parts. He was parting out the cars, using the suspensions in classic trucks (think 40s and 50s). Got a great price on several parts I needed. I'll probably see him again

I also connected on the forum with a local guy who has a late model C4 - he knew several people I knew from Bridgestone anyway he has been helping me loading me up with lots of practical info.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]


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