Just about ready to fire
Just about ready to fire My LQ4 swap is just about ready to fire. Unfortunately, I recently lost my dad to cancer, and he was the technician in the family. So, I might need to lean on y'all a bit more for some help.
The engine is as follows: LQ4 bored. 40 over, L92 heads (70cc combustion chambers, I believe), flat top pistons, asa high lift hot cam (from ws6store.com) and LS3 intake/injectors.
I'm thinking about a mail order tune to get it running. Any recommendations as to who does them well? It looks like I'll need the static compression ratio as well. With the info provided, can it be calculated? Also, I'm thinking about going with the cartridge style maf. are they supposed to be mounted at any particular angle into the intake tube?
I'm sure there will be more, but thanks in advance!
The engine is as follows: LQ4 bored. 40 over, L92 heads (70cc combustion chambers, I believe), flat top pistons, asa high lift hot cam (from ws6store.com) and LS3 intake/injectors.
I'm thinking about a mail order tune to get it running. Any recommendations as to who does them well? It looks like I'll need the static compression ratio as well. With the info provided, can it be calculated? Also, I'm thinking about going with the cartridge style maf. are they supposed to be mounted at any particular angle into the intake tube?
I'm sure there will be more, but thanks in advance!
TECH Fanatic
Joined: Dec 2017
Posts: 1,460
Likes: 265
From: Bossier City, Louisiana
I can't answer most of your questions but I can still provide a little guidance. Check all of your fluids before that first start up. Engine oil. Power steering pump fluid. Transmission fluid. Radiator fluid. Brake fluid if you are going to drive the car. Differential fluid . . . same.
Rick
Rick
Sorry to hear about your dad man. Almost lost mine to colon cancer several years back.
Nothing wrong with a mail order tune. Do some research and figure out who you want to use. Then call them and ask exactly what they need to know about your ride to make it run right. I’ve personally done four with Vengeance, and each one ran great. I’m about to start the fifth one this coming week.
As mentioned above, check ALL your fluids. I always pre-fill my oil filters every time I change oil. I never start an engine with a dry filter. Pretty much assures instant oil pressure. Watch your gauges at start up. If something doesn’t look right, kill it. If something doesn’t sound right, kill it.
Ask all the questions here you want. Plenty of people here to help!
Nothing wrong with a mail order tune. Do some research and figure out who you want to use. Then call them and ask exactly what they need to know about your ride to make it run right. I’ve personally done four with Vengeance, and each one ran great. I’m about to start the fifth one this coming week.
As mentioned above, check ALL your fluids. I always pre-fill my oil filters every time I change oil. I never start an engine with a dry filter. Pretty much assures instant oil pressure. Watch your gauges at start up. If something doesn’t look right, kill it. If something doesn’t sound right, kill it.
Ask all the questions here you want. Plenty of people here to help!
TECH Resident
Joined: Jul 2007
Posts: 967
Likes: 53
From: Winter Haven FL
Che70velle makes a great point. Don't be afraid to shut it down if anything seems off. Anytime I do a first start on an engine I've had open I make it a 2 person job. I man the key and watch the gauges while someone else is up front looking for liquid or smoke. If you get fixated on the oil pressure gauge you may not see fuel spraying on the manifold.
Thanks guys. I'm pretty familiar with cars in general, this is just my first LS build and dad was my efi go to. I'm gonna start it up for a few seconds just to ensure no catastrophic failures, then put the front of the engine and car together. Figured it would be a good idea to get the maf in place and a decent tune in before I do. I was trying hard to get the thing running for my dad, but he took a hard turn for the worst. Now I gotta start it up with open headers so that he can hear it.
Sorry to hear about your dad. Cancer is a merciless bitch.
If the tune guy is good then the mail order tune could be spot on. Not sure if the static compression is really all that important. That’s more for you to know what gas to run and perhaps take a few degrees out in timing in the tune. You should be able to get an idea of what it is with a few numbers but not sure the tune guy will care too much as long as it’s not stupid high.
I just started running my engines on a test stand I built for cheap. First JY Engine was my dads 5.3 filled with sludge and we put a LQ9 cam in it, LS6 springs and new timing set, fbody pan and melling pump. Ran it for a few min and walked around looking for leaks, just look at the oil pressure first and verify it has oil pressure. I like to prime the engine by disconnecting the fuel pump and coil harnesses without spark plugs and crank it a few long times to get oil into the pump etc since it was new and empty. I let it sit for a few min and looked everything over and then went to crank again and it was stuck. No good. Pulled the plugs and the rear driver was filled with gas. Removed the fuel rails and tested them hanging off the engine and sure enough the injector was partially stuck open and just pouring fuel into the cylinder. Fixed that issue and it ran good.
I just put my JY 5.3 on the stand yesterday. I learned from that one and did all the same things but put a fuel pressure gauge on the fuel rail and verified it was holding pressure before cranking so I knew all the injectors were closed. Ran like a top so now I’m pulling it apart.
Fluids, prime the engine, verify fuel pressure and that it’s holding. Electrical is all plugged in and everything is tight. Drop the tune in and crank her over. Depending how long the engine has been sitting it might be a good idea to squirt a little oil in the plug holes and spin the motor over my band a few revs to get oil on the rings and cylinders.
If the tune guy is good then the mail order tune could be spot on. Not sure if the static compression is really all that important. That’s more for you to know what gas to run and perhaps take a few degrees out in timing in the tune. You should be able to get an idea of what it is with a few numbers but not sure the tune guy will care too much as long as it’s not stupid high.
I just started running my engines on a test stand I built for cheap. First JY Engine was my dads 5.3 filled with sludge and we put a LQ9 cam in it, LS6 springs and new timing set, fbody pan and melling pump. Ran it for a few min and walked around looking for leaks, just look at the oil pressure first and verify it has oil pressure. I like to prime the engine by disconnecting the fuel pump and coil harnesses without spark plugs and crank it a few long times to get oil into the pump etc since it was new and empty. I let it sit for a few min and looked everything over and then went to crank again and it was stuck. No good. Pulled the plugs and the rear driver was filled with gas. Removed the fuel rails and tested them hanging off the engine and sure enough the injector was partially stuck open and just pouring fuel into the cylinder. Fixed that issue and it ran good.
I just put my JY 5.3 on the stand yesterday. I learned from that one and did all the same things but put a fuel pressure gauge on the fuel rail and verified it was holding pressure before cranking so I knew all the injectors were closed. Ran like a top so now I’m pulling it apart.
Fluids, prime the engine, verify fuel pressure and that it’s holding. Electrical is all plugged in and everything is tight. Drop the tune in and crank her over. Depending how long the engine has been sitting it might be a good idea to squirt a little oil in the plug holes and spin the motor over my band a few revs to get oil on the rings and cylinders.
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If the motor has sat for awhile I would at a minimum prime it with a piece of 3/8 fuel line. Example of how to do that is here.
What I have different from the example there is I’ve used an old differential oil bottle full of engine oil and slipped the nozzle into the 3/8 hose end and given it a squeeze to force the oil into the various passages etc.
What I have different from the example there is I’ve used an old differential oil bottle full of engine oil and slipped the nozzle into the 3/8 hose end and given it a squeeze to force the oil into the various passages etc.
I just fired my build up Friday for the first time.
I would use the garden sprayer method to prime. I put 5 quarts through it, took about 2 hours. Admittedly I could not get oil out of the pushrods. But I topped off the pan, then cranked it with the FP fuse pulled. I'd say within 3-5 seconds of cranking I saw ~20psi on my factory oil pressure gauge. Put the FP fuse back, primed it, checked my injectors and connections. Found a significant leak on the AN fitting to my fuel rail for my pressure gauge. Tightened it up, reprimed, no leaks. Held my breath and fired it up. Had oil pressure almost instantly. No notable valvetrain noise at startup. So priming definitely helped.
I would use the garden sprayer method to prime. I put 5 quarts through it, took about 2 hours. Admittedly I could not get oil out of the pushrods. But I topped off the pan, then cranked it with the FP fuse pulled. I'd say within 3-5 seconds of cranking I saw ~20psi on my factory oil pressure gauge. Put the FP fuse back, primed it, checked my injectors and connections. Found a significant leak on the AN fitting to my fuel rail for my pressure gauge. Tightened it up, reprimed, no leaks. Held my breath and fired it up. Had oil pressure almost instantly. No notable valvetrain noise at startup. So priming definitely helped.
If you don't know what the out of hole measurement is, if you know what brand of piston you used that would give us a good idea of where to guess. Example: Sealed power pistons are notorious for being about .010 shorter than they should be. If you used Sealed power pistons and didn't deck the block your pistons will be about .005 in the hole vs .005 out of the hole. Not a huge deal but your compression ratio would be about 10.0 or so if your dad used those pistons.
Last edited by kossuth; Apr 9, 2018 at 08:13 PM.
I can't remember the piston brand. They were purchased at ws6store.com. I'll have to track down the order. The head gaskets were the mls gaskets, and the block was not decked. I think the ballpark estimate is good tho. Thank you. I appreciate that!