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86 Corvette engine upgrade

Posted: Sun Mar 03, 2019 4:15 pm
by Sjordan
Got the Corvette in and getting started. Looks like previous owner really took care of it. Everything still original. After I started taking it apart I found where my vibration problem was coming from. The dampener had come apart, outer ring slid back up against the timing cover. Still working on disassembly and will add some pictures as I go. Took a couple of pictures before I got started.

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Re: 86 Corvette engine upgrade

Posted: Sun Mar 03, 2019 4:16 pm
by Sjordan
Here's that damaged harmonic dampener. It was toast, good thing I found that before it caused a lot more damage.

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Re: 86 Corvette engine upgrade

Posted: Sun Mar 03, 2019 7:47 pm
by Sjordan
Pulled everything that needed to come off. Was a lot, but it's ready to clean up and start putting back together. Actually was a stock, all original Corvette. Someone took pretty good care of it along the way. The heads had been rebuilt not to long ago. Still had the stock cam. Bottom end still looks like new, it's a two bolt block.

Not much left.
Not much left.

Here's what it had and where it's going. Removed stock heads with 76cc combustion chambers and 1.94/1.50 valves, replacing with a set of Sportsman II Heads with 72cc combustion chambers and 2.02/1.60 valves. The stock cam with duration 202/206 @0.050 Lift .403/.415 114.5 Lobe separation, replacing with duration 214/224 @0.050 Lift .444/.466 112 Lobe separation. Should make it a little more spunky. Will include roller rockers and the intake I have all the work in porting.

Waiting on parts till tomorrow anyway, I'll add some more as I get it going back together.

Re: 86 Corvette engine upgrade

Posted: Tue Mar 05, 2019 7:42 pm
by Sjordan
Spent most of Monday in Wichita so didn't get back to really getting any work done till Tuesday. Got the cam swapped, timing chain and cover on. Got the oil pan bolted back up. Before that I chased all the threads in all the bolt holes in the block for the heads, etc. Heads cleaned up installed and torqued. So far removing the oil cooler. Hoses were pretty soft and since the price is pretty high for the hoses that are supposed to be on there I just decided to put that up and the hard line and save it for later. The air pump has already been gutted, so all the rest of that system will be removed. From the looks of the valve covers the roller rockers are probably going to hit the tabs inside the valve covers. Those things are rather high dollar even used. So they going to be saved till later when I can replace the emblems, the paint has all worn off.

I ended up using a chrome timing cover as the stock one was worn pretty bad from the dampener. It was much heavier than the stock ones I had laying around and none of them had the stock timing tab, so I just went with the better piece.

Where I'm currently at.
Where I'm currently at.

Now that the heads are on I will be working on the headers, removing the lines for the air pump and welding that up. Keeping the stock headers, as I'm sticking with a close to stock look.

Here's what the headers started looking like. I'll add finished picture as soon as I get them done. Probably be putting the rest of the car together before I get to those.


Kinda small, but I think they will look ok after removing the tubes from the top of them.
Kinda small, but I think they will look ok after removing the tubes from the top of them.
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Re: 86 Corvette engine upgrade

Posted: Sun Mar 10, 2019 4:49 pm
by Sjordan
Didn't get out to the garage Saturday, but I'm trying to make up for it today and get this thing all back together. Starting to look promising. Here's progress up to now. Hopefully I'll be posting some pictures of the car finished in a few more hours.

I'll list everything that has been done when finished.

Just bolted the bottom of the intake on.
Just bolted the bottom of the intake on.

Re: 86 Corvette engine upgrade

Posted: Sun Mar 10, 2019 8:48 pm
by Sjordan
Couldn't pull it off in one day. Got most of it back together. Get back to it as soon as I can.

Here's what it currently looks like.
Here's what it currently looks like.

Re: 86 Corvette engine upgrade

Posted: Tue Mar 12, 2019 10:04 pm
by Sjordan
Here is one of the headers after removing the air lines for the air pump. I forgot to get a picture of the passenger side till after I got it back on the car. I just cut them off, welded the holes up and ground it back down smooth.

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Re: 86 Corvette engine upgrade

Posted: Tue Mar 12, 2019 10:16 pm
by Sjordan
Got the upgrades done. Engine all back together and car is running. Will probably need some tuning done later. Still using the stock tune and it's doing just fine. Like to modify the air filter and I have a descreened MAF from the Camaro, but that will require re-calibrating the ecm. So I'll get that later. Drivable now and I can take time on weekends to pull some things like the brackets for the alternator, AC, etc and clean and polish them up. See how nice I can make this look before it gets a paint job.

Here's the pictures of the engine finished. And I think it's sounding better, not that it sounded bad to start with.

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Re: 86 Corvette engine upgrade

Posted: Wed Apr 03, 2019 6:25 pm
by Sjordan
The Corvette is doing great with nothing but the engine mods. Opening everything up did lose some of the low end torque, but it makes up for it pretty quick and don't sound like it's trying very hard. My next plan after I get the time is to do some tuning on it and open up the air box and MAF sensor.

So far I have been very happy with how the tune port idea has been working out. Everyone has always dismissed then as not good for any real power. So I wanted to prove that is not the case. I will be getting some prof on this after a while and I will keep sharing everything that has been done along the way.

When it finally gets finished I will do a whole write up on how it could be repeated.