240sx LS>VQ build thread.
If you are planning on going turbo then I would say a 4.8, 5.3, LQ4 or LQ9 is the best bang for the buck. 4.8's can be found for $300-400.
Will an inaccurate timing cause it to not start?
Last edited by laurentj23; Feb 20, 2015 at 06:20 PM.
The Best V8 Stories One Small Block at Time
If you have or can rent a leak down or compression gauge you can determine if you bent some valves, but you'd also hear backfiring if it were trying to start. I had some bent valves, but with the right tools that's a pretty easy thing to fix. Did you put the heads on with GM TTY bolts or reusable ARPs? If the latter then you're only out the cost of a head gasket and an hour to pop a head off and take a look.
If it isn't too tight in the engine bay, popping the front cover off to see if the dots are lined up isn't a huge ordeal in and of itself, and if they are off it's pretty blatant.
What is the noise at the 26-second mark in the second video? If it is the cam/crank randomly ending up in sync and sparking while a valve is open that's probably not the best sign. Random "puff" of pop noises coming out the front of the motor aren't reassuring. If it is just a random noise from you moving then disregard. Just my experience, I'm sure someone else will chime in.
Anyway, as far as trading motors goes, I think getting your motor to run in my car would be fairly simple if time consuming, but getting my motor to run in your car would be more difficult, since so far we don't know if the platform itself is even viable.
Where are you in GA and which shop are you at? There is a pretty well-regarded shop near Lawrenceville, I think the guy posts here as Trojan or something like that.
If you have or can rent a leak down or compression gauge you can determine if you bent some valves, but you'd also hear backfiring if it were trying to start. I had some bent valves, but with the right tools that's a pretty easy thing to fix. Did you put the heads on with GM TTY bolts or reusable ARPs? If the latter then you're only out the cost of a head gasket and an hour to pop a head off and take a look.
If it isn't too tight in the engine bay, popping the front cover off to see if the dots are lined up isn't a huge ordeal in and of itself, and if they are off it's pretty blatant.
What is the noise at the 26-second mark in the second video? If it is the cam/crank randomly ending up in sync and sparking while a valve is open that's probably not the best sign. Random "puff" of pop noises coming out the front of the motor aren't reassuring. If it is just a random noise from you moving then disregard. Just my experience, I'm sure someone else will chime in.
Anyway, as far as trading motors goes, I think getting your motor to run in my car would be fairly simple if time consuming, but getting my motor to run in your car would be more difficult, since so far we don't know if the platform itself is even viable.
Where are you in GA and which shop are you at? There is a pretty well-regarded shop near Lawrenceville, I think the guy posts here as Trojan or something like that.
The motor is currently in the car. Its at my mechanic shop in jonesboro. He builds race car on the side and works at the nissan dealership as his main job so, im sure he will take care of the issues. And hopefully not a bent valves.
When i tried to crank if before, inhad plenty of backfires. Does that mean i bent some valves? I heard it mostly a thump sounds mostly on the header but it doesnt happen all the time. I havent had the chance to get a compression test prior to towing it to the shop.
Im using brian tooley head bolts so im guessing its tty bolts.
The ls3 motor will fit in the car. Just need to have extension for the wiring harness ect ect.
I don't think the backfires have to mean valves are bent, but it would likely (someone correct me if I'm wrong) at least mean that it is sparking while a valve is open. Cam and crank might not be syncing, and I'd guess - guess - that either the cam is misaligned, a sensor is bad/miswired or you have the wrong cam gear.
No idea what your mechanic will do but if it were in my garage this is what I'd do (from easiest to hardest) -
Noid light/ spark checker (just because it's literally the easiest thing in the world)
See if the guy tuning it can show you what the cam/ crank sensors are seeing.
Compression/ leak down test. If nothing else pull a plug and stick your finger on the hole while someone turns it over.
Pop off front cover.
Pull a head.
Pull motor/ start from scratch.
Put known good motor in car and see if it runs.
I don't think the backfires have to mean valves are bent, but it would likely (someone correct me if I'm wrong) at least mean that it is sparking while a valve is open. Cam and crank might not be syncing, and I'd guess - guess - that either the cam is misaligned, a sensor is bad/miswired or you have the wrong cam gear.
No idea what your mechanic will do but if it were in my garage this is what I'd do (from easiest to hardest) -
Noid light/ spark checker (just because it's literally the easiest thing in the world)
See if the guy tuning it can show you what the cam/ crank sensors are seeing.
Compression/ leak down test. If nothing else pull a plug and stick your finger on the hole while someone turns it over.
Pop off front cover.
Pull a head.
Pull motor/ start from scratch.
Put known good motor in car and see if it runs.
Thanks for the advise.
My mechanic kinda keep me in the dark on what he's going to do. But, I told him that Ill get the car if it's not fixed by the end of the month. I towed the car end of Jan and from there, Im gonna troubleshoot according to your suggestion.
Alpha auto works pick the car up using their trailer and take it to their shop.$125. Apparently the first mechanic didn't even do any kind of work. Car has been on the same spot since I dropped it off in the middle on jan. So, now the car is at another shop. I'm hoping they will get it run sometime this week or next.





