LS7 Conversion
#182
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The shims showed up yesterday, so I assembled the engine tranny using two .090” shims. No binding, and the converter had to come out .120” to contact the flexplate. That is damn close to 1/8”. I also installed the starter and cranked until I saw 50 psi on the gauge. 50 psi at crank speed, damn good I think. I also installed the headers. I’m getting close to start. I need to install spark plugs and plug wires. Fill the fluids, hook up fuel and fuel pump relay, and crank. Maybe this weekend.
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Metalhead140 (05-30-2019)
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#186
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First problem, the alternator is not charging. Yes I put the 85 ohm 5watt resistor in the power on line. Maybe it needs a full 12 volts to get the alternator to charge. But I’ve read several warnings against that. The alternator is brand new. Any ideas?
Second problem, the engine overheated very quickly. I filled the radiator with two gallons of anti freeze and water a week ago, not a drop got into the block. I disconnected the steam vent line on top of the water pump, and poured water in to fill the block. The temp stays at 190 degrees now.
Second problem, the engine overheated very quickly. I filled the radiator with two gallons of anti freeze and water a week ago, not a drop got into the block. I disconnected the steam vent line on top of the water pump, and poured water in to fill the block. The temp stays at 190 degrees now.
#187
Melting Slicks
Here is a schematic for a 2010 LS7. This may help. The overheat probably was due to an air pocket in the cooling system. Do you have a fill point above the top of the radiator?
#188
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I am fairly sure my thermostat has a small hole in it, allowing coolant to get into the block no matter what. Couldn't find a picture however. I am now on the opposite side of this problem, I would like to flush seven year old coolant and refill. I would assume I would just warm the motor up and drain, and for new fluid, I am open to suggestions as I don't remember for sure what I did the first time. I might have filled from the top hose regardless of the hole in the thermostat. Or the steam line as BeeJay says.
Last edited by ignatz; 06-02-2019 at 01:50 PM.
#189
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Problem solved. The switched exciter wire for the alternator goes to the third pin from the right. Not the second, like earlier GM alternators. I have to keep reminding myself that everything about the LS engine is different. Better maybe, but different. Now I need to make an appointment with my local muffler shop.
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Metalhead140 (06-03-2019)
#190
Racer
I had to replace the water pump just after I got my LS2 going.
When I did, we used a thermostat that had three or four small in the lower disc that separates the two sides of the pump. I believe this allows a little bit of flow through the motor, even when the thermostat is closed. It was a Napa P/N 506-186.
The first time we filled the system on the test stand, we did disconnect the steam hose to allow air out of the block as we filled the radiator. However, when we put the motor in the car, and again when we replaced the water pump, we left the steam line connected and filled through the radiator, but would squeeze the upper radiator hose to burp out the air. This let us add about another gallon.
We also filled the overflow bottle about half full and I noticed that by burping it when we were filling, it used very little from the overflow.
ADDED: I forgot to mention, I have a funnel that fits snuggle into the radiator fill opening, which allowed us to slightly overfill the radiator into the funnel. Then when we squeezed the hose to burp the system, it would push the air out and the "extra" fluid from the funnel would go into the radiator. It actually worked really well and I surprised that I never thought to do it that way before.
-Chris
When I did, we used a thermostat that had three or four small in the lower disc that separates the two sides of the pump. I believe this allows a little bit of flow through the motor, even when the thermostat is closed. It was a Napa P/N 506-186.
The first time we filled the system on the test stand, we did disconnect the steam hose to allow air out of the block as we filled the radiator. However, when we put the motor in the car, and again when we replaced the water pump, we left the steam line connected and filled through the radiator, but would squeeze the upper radiator hose to burp out the air. This let us add about another gallon.
We also filled the overflow bottle about half full and I noticed that by burping it when we were filling, it used very little from the overflow.
ADDED: I forgot to mention, I have a funnel that fits snuggle into the radiator fill opening, which allowed us to slightly overfill the radiator into the funnel. Then when we squeezed the hose to burp the system, it would push the air out and the "extra" fluid from the funnel would go into the radiator. It actually worked really well and I surprised that I never thought to do it that way before.
-Chris
Last edited by CA_WxMan; 06-03-2019 at 01:36 PM. Reason: More info
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ignatz (06-03-2019)
#191
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First Drive!
It’s running very rough. I think it’s because the open headers have the fuel injection all confused. Muffler shop tomorrow to connect the new engine and headers to the old exhaust system.
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Metalhead140 (06-05-2019)
#193
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The car is back from the muffler shop. It’s not as loud as I expected. I guess the stick LS7 Cam is a lot milder than the LT4 Hit Cam I had in the 383. The LS7 does not like the 750 rpm idle, so I may increase it to 900-950. I drove it 10 miles to let the Sniper FI learn. I’m trying to behave and keep it under 4000 rpm and 50% idle for a few miles. Only one problem so far. This #%^** Mr Gasket adjustable thermostat housing is leaking. It leakes running and sitting. Maybe I installed wrong. Does anyone make a housing that points down instead of right?
Last edited by Bee Jay; 06-09-2019 at 11:04 AM.
#194
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I would see if the one housing bolt thats not visible is bottomed out and not clamping down on that side. I can see the bolt thats visible is a through hole but the other bolt may not be. That was a common problem with aftermarket water necks as the bolts didn't match the waterneck thickness and would hit bottom causing many owners to over-torque and strip out the bolt hole threads. I never liked the O-ringed swivel water necks until we figured this out. Now that's all I use.
Hope this can help.
Hope this can help.
#195
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I would see if the one housing bolt thats not visible is bottomed out and not clamping down on that side. I can see the bolt thats visible is a through hole but the other bolt may not be. That was a common problem with aftermarket water necks as the bolts didn't match the waterneck thickness and would hit bottom causing many owners to over-torque and strip out the bolt hole threads. I never liked the O-ringed swivel water necks until we figured this out. Now that's all I use.
Hope this can help.
Hope this can help.
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Metalhead140 (06-10-2019)
#196
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Now I bet you always use the O-ringed swivel water necks. Hey that problem was found as joint discovery on this forum. Sorry but now you owe the whole forum a beer.
#197
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The car is back from the muffler shop. It’s not as loud as I expected. I guess the stick LS7 Cam is a lot milder than the LT4 Hit Cam I had in the 383. The LS7 does not like the 750 rpm idle, so I may increase it to 900-950. I drove it 10 miles to let the Sniper FI learn. I’m trying to behave and keep it under 4000 rpm and 50% idle for a few miles. Only one problem so far. This #%^** Mr Gasket adjustable thermostat housing is leaking. It leakes running and sitting. Maybe I installed wrong. Does anyone make a housing that points down instead of right?
#198
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They totally reinvented the wheel. And DO NOT install this gasket that ships with the housing. The O ring gasket on the thermostat is all you need. It will cause a slight leak and the guys at NAPA will laugh at you. Ask me how I know.
Last edited by Bee Jay; 06-12-2019 at 12:04 PM.
#199
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New Hood
I installed the hood I got from J&D Corvette. The intake manifold and sniper fuel injection is so tall, I could only fit a 3” filter under this new hood. I also have to get a lower MC.
This one sits too high. Anyone got experience/advice with the Wilwood MC?
This one sits too high. Anyone got experience/advice with the Wilwood MC?
Last edited by Bee Jay; 06-13-2019 at 08:39 AM.
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Metalhead140 (06-13-2019)
#200
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I drove the car today for the third time. Just short 20 mile trips to work or to town, to give the fuel injection a chance to learn this new engine. Tomorrow I’ll drive it to the Pismo Beach Coffee and Donuts. A couple of observations. The engine runs a lot hotter than I’m used to, around 200 degrees. I checked and that is where my LS 6.0 in my truck runs and so does my 427 Convertible, so I guess I gotta get used to it. What I don’t like is as the engine temp rises, the oil pressure drops. I have Shell Rotella 5W30 oil in for break in, and at 200 degrees water temp, the oil pressure drops to 15psi at idle and about 30psi at 2000rpm. The Truck never goes below 40psi, even at 200 degrees and idle. After the cruise tomorrow I’ll drain the oil and put some heavier 20W40 or 50. I have not gone over 4000rpm or 50% throttle yet, but I did break traction once accidentally, so it is making good power. Any advice on oil pressure?