LM7 need help picking parts for 500+ hp N/A build.
11-12-2015, 02:38 PM
#21
TECH Addict
I just don't think that the 383 is the proper choice for the OP's stated goals. His original power goals were a little over optimistic for a 5.3L, but the OP has already shown that he is willing to settle on a more realistic power goal... So throwing another liter of displacement at it, via a $2000 stroker kit and another $1000 in machining labor just doesn't seem necessary when he clearly states that this is to be done on a budget.
He can do a head/cam/intake on the stock lm7 shortblock, and achieve the more realistic 400's the OP brought up in post #3...
If he wants more after the h/c/i, there's absolutely nothing stopping him from adding displacement later... And he will have a better top end to support the extra cubes if he does decide to bore/stroke it.
He can do a head/cam/intake on the stock lm7 shortblock, and achieve the more realistic 400's the OP brought up in post #3...
If he wants more after the h/c/i, there's absolutely nothing stopping him from adding displacement later... And he will have a better top end to support the extra cubes if he does decide to bore/stroke it.
11-13-2015, 09:34 AM
#22
Ah missed the part that he is willing to lower his target hp.
In that case, the crank and rods in the motor can be used again. Get some LS1 spec pistons and have the block bored to match them. Have those 243s refreshed with better valvetrain, clean up castings if necessary. Then a custom cam for your truck.
In that case, the crank and rods in the motor can be used again. Get some LS1 spec pistons and have the block bored to match them. Have those 243s refreshed with better valvetrain, clean up castings if necessary. Then a custom cam for your truck.
11-13-2015, 11:04 AM
#23
TECH Addict
Again, why involve the possibility of paying money to potentially destroy the block? Why pay money to add displacement, at all, when the unmolested shortblock that the OP already has is plenty capable of producing the power he desires?
To the OP: Everyone sure is willing to spend your money for you, man.
To the OP: Everyone sure is willing to spend your money for you, man.
11-13-2015, 02:58 PM
#24
Again, why involve the possibility of paying money to potentially destroy the block? Why pay money to add displacement, at all, when the unmolested shortblock that the OP already has is plenty capable of producing the power he desires?
To the OP: Everyone sure is willing to spend your money for you, man.
To the OP: Everyone sure is willing to spend your money for you, man.
Since the engine is already taken apart, it's a good time to do it anyways and start with a completely fresh engine.
11-13-2015, 03:32 PM
#25
TECH Addict
I'm not going to argue that more displacement would be beneficial, especially in a truck. But the lm7 shortblock is a very robust and capable platform that could be rebuilt in its original glory for much cheaper than getting it machined for ls1/6 pistons. And it is plenty capable of reaching the OP's goals with its original displacement and a typical h/c/i swap, with absolutely no risk of hitting water during the overbore and ruining the block.
Would you rather have a 5.7 with stock truck heads, or a 5.3 with stage two cnc ported heads?
Plus, you could take the money you didn't spend on having your block bored, and spend it on some cometic head gaskets.
Would you rather have a 5.7 with stock truck heads, or a 5.3 with stage two cnc ported heads?
Plus, you could take the money you didn't spend on having your block bored, and spend it on some cometic head gaskets.
11-13-2015, 03:37 PM
#26
I don't trust an engine pulled 5 years ago. That alone requires full disassembly and a hot tank bath to flush rust, spiders, critters, dried sludge, and anything else in the galleys. Getting bores punched out is pretty cheap considering it needs machine work anyways.
Use the crank and rods in there now or use the same crank with gen4 rods and ls1 spec pistons. No power adder means hyper pistons will be fine, forged anything will be a waste of money.
Use the crank and rods in there now or use the same crank with gen4 rods and ls1 spec pistons. No power adder means hyper pistons will be fine, forged anything will be a waste of money.
11-13-2015, 06:02 PM
#27
Ok I am a complete noob on motor building so please take it easy on me.
I manage a body shop and one of my mechanics in our GM service shop said he would be happy to put my engine together for me. I already have a 5.3L LM7 engine out of a 2002 Chevy Silverado. It had a 109K miles on it and ran fine when I pulled 5 years ago and has been sitting on an engine stand since.
My goal for this motor is to be in the 450-550hp range naturally aspirated for of course the least amount of money possible. I am going to be putting this into a 68 short wide bed chevy truck I am currently restoring as a dedication to my brother who just passed away in February.
I would like to maintain the fuel injection and have an engine that is reliable with good street manors as I plan to cruise this truck plenty and drive it to the shows.
So what is the most common and economical way to achieve my goals, remember I work at a GM dealership so I get employee pricing on GM parts, but other then that fact I don't care what brand as long as they are of reputable quality.
I manage a body shop and one of my mechanics in our GM service shop said he would be happy to put my engine together for me. I already have a 5.3L LM7 engine out of a 2002 Chevy Silverado. It had a 109K miles on it and ran fine when I pulled 5 years ago and has been sitting on an engine stand since.
My goal for this motor is to be in the 450-550hp range naturally aspirated for of course the least amount of money possible. I am going to be putting this into a 68 short wide bed chevy truck I am currently restoring as a dedication to my brother who just passed away in February.
I would like to maintain the fuel injection and have an engine that is reliable with good street manors as I plan to cruise this truck plenty and drive it to the shows.
So what is the most common and economical way to achieve my goals, remember I work at a GM dealership so I get employee pricing on GM parts, but other then that fact I don't care what brand as long as they are of reputable quality.
Thanks for the info. I am not looking to go crazy wild on the build or super expensive. I am looking for best bang for the buck and a reliable motor that i can light the tires up with every once in a while. It's gonna be a cruiser but I want enough power to light the tires up of I'm feeling frisky lol.
So it sounds like 400's is a more realistic goal for what I want to do...
So it sounds like 400's is a more realistic goal for what I want to do...
Now you just have to decide how rowdy of an idle you want the truck to have and what rear axle gear you have or need and then you can select your camshaft.
05-14-2018, 03:23 AM
#28
TECH Enthusiast
would an asa cam 226/236 be ideal for a l33 or flat top 5.3 with 799s, went to the machine shop for my 370" build, if my cylinder walls look good I'd like to stay away from the machine shop and see if I can swap out to 4.8s, going into an lm7 with 799s.....iron l33
05-14-2018, 06:35 AM
#29
Restricted User
And how do you plan on getting a 5.3 to a 370?
05-14-2018, 09:09 AM
#31
TECH Enthusiast
05-14-2018, 09:21 AM
#32
TECH Enthusiast
05-14-2018, 09:39 AM
#33
Restricted User
You honestly can't expect anyone to somehow derive you're using a 6.0 from this...
05-14-2018, 11:52 AM
#34
TECH Enthusiast
05-14-2018, 11:53 AM
#35
TECH Enthusiast
05-14-2018, 12:07 PM
#36
TECH Enthusiast
why does it bother some of you guys so much when old threads get brought up.....do you have nothing better to do than to monitor my activities on out dated threads and then feel like your doin something by calling me out on it......I'm gonna continue to comment on 5/10/15 yr old threads I also would like to know the out come on some of these disasters. .....I know the original OP may not answer but then again who is to say he/she would be right, so any other suggestions , even 10 yrs later may actually be better........DO YOU FOLLOW ME!!!
05-14-2018, 12:10 PM
#37
TECH Enthusiast
why does it bother some of you guys so much when old threads get brought up.....do you have nothing better to do than to monitor my activities on out dated threads and then feel like your doin something by calling me out on it......I'm gonna continue to comment on 5/10/15 yr old threads I also would like to know the out come on some of these disasters. .....I know the original OP may not answer but then again who is to say he/she would be right, so any other suggestions , even 10 yrs later may actually be better........DO YOU FOLLOW ME!!!
Last edited by KCS; 05-14-2018 at 12:18 PM. Reason: Deleted profanity and inflammatory remarks
05-14-2018, 01:02 PM
#38
TECH Senior Member
05-14-2018, 01:19 PM
#39
TECH Enthusiast
nah....I'm done now.....sorry everybody else for having to wittiness all that! CARRY ON....... ! Till I find another 3+yr thread.....lol, u can pull ur panties out the bunch. ....I know some of you fellas hate me! But we're all here for the same reason (most of us) answers. .......not all of us work at machine shops or ase certified mechanic's. .....we just wanna learn off of others mistakes without ,,,,,,feeling like we're a burden to you because of your losses''''
