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2002 L31 5.7L out of chevy express/freshen up/build?

14K views 51 replies 5 participants last post by  Rinny 
#1 ·
I was wondering if you guys could help me out with my 2002 L31 out of a chevy express
It has 100,000 miles on it.
I am putting it in a 2003 awd astro van that I use for surf fishing up here in rhode island (putting that motor quite a feat in itself for me, but with in my capabilities!!)
I want to do the smart things before I install it,I am going to go with electric fans
thinking about an EFI intake upgrade
can the fuel injection be improved upon, I would like to keep it.. Not racing it just want responsive driving on the high way and sand.
any input is welcome.
I don't mind spending some money but don't want to do things that are not nesc for my application
cold air intake also?
water pump
timing chain
oil pump?
Cam ( mild and which one?)
what head work is requires if I do a cam?
valve covers?
headman headers?
Should I put new pistons in and should I do any head work on the vortec heads?
crank bearings?
Hone cylinders or bore? (how much over?)
I am going to have the machine work done and probably lower end, pistons, heads, EFI intake assembled by the same shop if I go that far into it.
I can wrench but have limited abilities. Nothing like the people on here, some of the stuff you guys talk aboul is like looking at a forign language. Especially when it comes to measuring travel and internat engine parts.
Thanks
 
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#2 ·
Whenever I've built anything from scratch I've left the motor rebuild until last. Get it shoehorned in there, running with all the stuff you want, make any changes you need, and use it for awhile.
THen pull the motor out and rebuild if needed.
You'll be time and money ahead and likely smilin' longer.
 
#3 ·
This swap has been done at least 30 times that have been documented. I appreciate the suggestion to get it in then build the motor but I think if I take my time and don't cut corners I can do it one time. There is much support out there to do the swap but getting the motor all good to go part is what I am not so sure about. You guys are way beyond anby wrenching I will ever be capable of doing but perhaps you can give me options on components and what to expect for my application? Thanks again
 
#4 ·
At 100,000 miles with fuel injection there should be very little bore wear, and I'd expect the lower end bearings to all look great also. If visual inspection of those areas proves this out, I would not change a thing, leave the pistons and rings alone. You could put new bearings in if you like, but if they look good now they will easily go another 100,000 miles if oil changes are timely.

Honing and/or boring, piston and ring replacement, crank regrinding and rod resizing can all be done if the condition warrants it.

Same with the oil pump, if unhurt there is no reason to change it.

The timing chain, on the other hand, I would definitely replace, as the chain stretches and at 100,000 miles is probably rather loose.

Cam you could change if you want a more performance oriented grind, but that is your choice.

Heads will likely need a valve job, possibly some new valveguides, maybe new springs(especially if you go to a performance cam), milling to correct surface flatness for head gasket seal, and new valvestem seals.
Most important thing with the heads is to get them crack checked, as they have a history of cracking, especially if the engine is ever overheated.

Re-seal it with fresh gaskets and seals and you're good to go.
 
#5 ·
Needs to pass emissions. Same fuel delivery system as was in the donor vehicle.


I am going to do a visual inspection of the lower end and go from there. The heads are coming off so I guess I should get them redone and if I am going to do that I should do a mild cam. Any suggestions on the cam and what has to be done with the heads to match them up to the cam?
 
#7 ·
If motor has been maintained well,at 100,000 miles,it's not likely hurt all,but,if you wanna rebuild,then that's understandable.The Vortec efi is a good system for the uses you state & will work fine up to approx. 350 HP.I would install a new spider assembly while it's apart.
I've seen these motors come apart with 200,000 to over 300,000 miles & have very little cylinder wear & visible cross hatch.I'm running 1 now that has 396,000 miles on it.
For cams,keep in mind that just about any changes you make will need computer tuning.You will want to stay below .450" lift,unless you have the guide bosses machined for more clearance,or,use a spring/retainer set that offers more clearance.
 
#8 ·
For what you are gonna be doing,GM's Ramjet cam(#14097395) is really good choice.It won't require any headwork,however,I would use better springs than the stock set.The GM LS6 springs with Comp 787 retainers would be a good budget friendly choice.The cam runs approx. $170 new,or,you can often find them on Ebay as new pullouts for approx. $125.Springs are $60.Retainers run approx. $55.
This cam will give you great lowend torque (approx. 400 ft/lb) from 1800 out near 4800 rpm.It will run ok on the stock Vortec tune,but,tuning will really bring a lot better perfoirmance & not cause codes in the system.
 
#9 ·
I'd run that L31 as is, its only 100,000miles.
Going into an AWD vehicle will be cool.

Sounds like you will be wailing on that AWD system, a stock L31 will do what you want and more. A good tune will help as well, esp WOT power. The stock calibration is too rich for max power.

If you really want more WOT power, I suggest going to a 5.3 or 6.0. If you can install a L31, you can install an LM7 or LQ4/9. That's comning from a person who is actually running a marine intake. IMO Its hard to beat the marine intake dollars wise, its a complete injection setup that is a GM part. The lower is iron though, while the upper is aluminum.
Once you crack into a GEN 1E Vortec 350, the well, if I', changing the timing chain, I might as well change the cam, If I'm changing the cam, I might as well get new lifters, well I might as well use new springs, it goes on and on, and it makes sense, but very soon you are way beyond bang for buck of the GEN 3/4 engines. Trust me, I love these GEN 1E Vortec 305/350 engines.

peace
Hog
 
#13 ·
What the heck is that big hose coming off the intake,lol. I don't think it would fit under my hood.


The newer motors than the 2002 5.7 is much more complicated to go in my van. I don't think I have the capability to get it done.


I am 80% sure I can get the 5.7 in .


I am going to get the truck on a dyno when I am done so it can be dialed in.


200 to reflash my PCM or 400 to put it on the dyno. No brainer, rite?
 
#20 ·
So this is where I am at 5.7 Build. Some one has been in motor or at least replace one valve cover gasket. It was a different color.
Under the intake was bad lots of sludge, the motor has not been taken care of. This is what I am thinking
2002 5.7L vortec L31 out of a Chevy Express
Remove crank/rods/pistons
Check and dip block and paint (Chevy orange) when ready
Bore 30 over
Polish crank and install with new bearings
Install new pistons don't want to change compression/rings/bearings/wrist pins?
Check heads for cranks and flatness
Install GM Ramjet cam #14097395 and bearings
Install GM L56 springs with Comp 787 retainers
Install heads
Chrome valve covers
Install new oil pump
Install new performance intake (not specked)
Install new Spider assembly
Install new timing gears and chain
Install new water pump
Install oil pump to spec
Install modified oil pan
any input more than welcome.
Any idea on how much it will run to do what is listed?
Thanks again
5.
5.7 Build
5.7
 
#21 ·
For $2000, you can buy a brand spanking new L31 Vortec.LOL.
There are no "performance intakes" for the vortec efi system that uses the spider.For the power level you are looking at the stock system will be fine.The newer style spiders are alot more dependable than the old poppet style & have very few problems. The intake is a 2 piece.The upper is easily removed for spider replacement if needed.Tuning is also not complicated at all, especially for your 2002 controller.Lots of support out there for it & easy to get tuned.Only the 96/97 black boxes have limited tuning options.Give Bryan a call at PCM For Less, or there several others that can fix you up.
Also, you don't have to have an expensive GM scan tool to set the distributor.You can do it for about $30 with a Bluetooth plug in adapter($25) & $5 app called Car guage pro. It will read the CMP retard to get the distributor set accurately.
 
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#23 · (Edited)
Just to say it the fi tech system is self learning and only cost 900 bucks sounds like a lot but once you buy new injectors and all the other parts to get the stock stuff right you will have that much into it along with dyno tuning and setup. With the fi tech all you need is a regular 4 barrel intake for the vortec which can be had for cheap if buying used. Then you can use a dizzy that allows the fi tech setup to run the timing as well. SO in the end the engine will have a good free flowing intake system and not need any tuning to make it happy. So pretty cheap and can be done at home without going to the dyno for tuning. Might save you money in the end and also support any mods that you end up making.


Dont like the cam later on just change it no worries about tuning it again every time you make a change. this is whats going on my truck once the spider setup finally craps out.



So the intake for the spider is a regular 4barrel intake?
Why don't you like the cam?
What did you guys think about the 383 stroker kit post?
This is going to take me a while to figure it all out but I am confident with all the knowledge here I can do it. Just a lot of reading and research which is cool to become a little more knowledgeable about the mechanical side of the l31, great stuff, lil confussed but all good stuff. Thanks a bunch
 
#24 · (Edited)
I'll try not to write a long winded book here,but,to clear up some of the misinformation supplied above


The FITech is a great system,especially for an older vehicle where you are converting to EFI from a carb,but,in your vehicle,not really a good option as it can't control the transmission,or,communicate with about 1000 other things that you will need the vehicle PCM for.Everything on your vehicle from the brakes,radio,instrumentation,etc is tied into your PCM,so,it will need to be used.It's also still a TBI system,not,MPFI as your current setup.For the power level you are proposing,your current setup will perform just as well & be easier to setup.Your engine cam combo is a very common setup & tunes that can be reflashed are abundant.The 2002 PCM is no more complicated to tune than any other EFI system.Since you are putting into another vehicle,you will need to have VATS disabled,or,worked around anyway.
As for setting the distributor the $25 adapter from BAFX Electronics is available from Amazon & the Car Guage Pro app from Google PLay.For $30,it allows you to read & reset any codes.It will read CMP retard to set the distributor.Something that a lot of $300 scanners can't do.It allows you see,capture,send,& print live data.It also has a function called "dash board,that lets you set up a custom guage panel on your android phone/tablet for all your outputs,TPS,MAP,O2 reading,timing,etc in real time.Hard to beat for $30.I have used it to set several Vortec distributors.CASE relearn is not always necessary & it's main function is to detect engine misfire & determine the actual misfire location.Worst case,you will get a random misfire code.Any modern shop can do the relearn if it needs it for minor cost.Usually 1 hour labor charge.This often gets out of whack as parts wear & timing chain stretches anyway.
If you want to do your own tuning,then,buying a high $$$ programmer may be an option for you,but,not necessary.Again,you don't need a dyno to tune this thing.Certainly an option,if you wanna spend the money,but,not necessary.
 
#25 ·
A new updated spider runs about $300 if needed.Your 2002 should already have it,as,I think it went across the board by 1998.You can get the PCM tuned & delete VATS for about $200.To me that's way cheaper & a lot less headache than paying $900 for a fuel system,another $200 for the intake,along with all the hassle & headache involved with converting into your vehicle.Your current PCM will still need to be retained & reprogrammed anyway for transmission control & other various functions the FITech can't do.
 
#28 ·
I am going to replace the spider and seeing there is not a better intake than the one I have unless you go with the marine one, (too complicated for my limited skills) I think I will clean up the one I have and ust it? Yes I can get my computer reprogramed for 200 all I need to do is give them the specs on what internal parts I used I believe?
 
#29 ·
The problem with rebuild kits is that 90% of off the shelf kits will come with pistons that have a shorter pin hgt.This causes the piston to sit lower at TDC lowering compression,power,& detonation resistance.Make sure you get pistons that have a 1.56" compression hgt,unless you are having the block decks cut.
They are higher,approx $300 a set but the best piston for your application,IMO,is the the KB-193.It is a hyper D cup piston.It has 12cc of volume as the stock piston does,but,has a large quench pad,offering the performance benefits of a flat top without excessive compression.It also has a 1.561" compression hgt.
The Car Guage Pro app I mentioned above will allow you to capture live data to send to your tuner,if needed.
 
#34 ·
Not sure how much you know about the motor,but,you already know at least some disassembly has been done based on the different valve cover gasket. 1 of the very 1st things you should do is,once you have the heads off,measure the piston to deck hgt @ TDC on all 4 corners of the block.This will give you some idea if it has stock hgt pistons & wether the block has been previously machined,along with knowing how square the decks are.In stock form,this measurement should be approx. .025".
 
#36 ·
Not sure what problems Hcompton is referring to with tuning,etc.Maybe he could be more specific about it,so,that we know,but,just an FYI,the 96 PCM black box for Vortecs has virtually no support,or,options that I know of other than Jet's DST unit.97 is only slightly better.As far as I know,Bryan at PCMforLess was still supporting the 97 black box.98 & 99 have decent options & support.2000 & up such as you have are greatly supported & easily tuned as they use the same controllers that any Camaro,or,other modern LS EFI system uses,except with different programming.Your 2002 may very likely be the 0411 controller,or,1 of it's equivilants.
The Vortecs EFI is great for it's designed & intended purpose in applications of up to 350 HP.Some have went slightly higher,but,that gets really tricky as fueling becomes inadequate at that point.At your level & cam choice,tuning will be a breeze.
Even the older poppet design worked well for many miles as long as you used a quality fuel injector cleaner regulary to help prevent varnish from building up & either causing leakage,or,failure to open fully.The other problem,which I experienced myself at 475,000 miles,is that,the hoses that run from the spider to the injector would in time from the fuel & heat become brittle & crack,letting fuel leak into the intake & puddle.If bad enough,the intake charge would pick this fuel up,running the PCM crazy trying to adjust.It would also,again if bad enough,leak into the rear 2 cylinders causing hydrolock.The newer design with mini jectors solved most of these problems & is somewhat less psi sensitive,as the injectors open via electrically vs psi alone.The injectors are also better shielded & better hose material is used.
 
#37 · (Edited)
No,the app can not do a case relearn.I said it was capable of CPM reading for setting the distributor which is a must.CASE relearn is not always required when changing parts,but,is not a big deal if it is needed.It's about a 10 to 15 minute process in most cases.If he isn't getting a P0300 code for random misfire it will fine.The computer uses this info to detect & identify a misfire by slack & distance vs time from slack in the timing chain.As parts wear & the chain stretches,this is often done to get rid of a P0300 code in higher milage vehicles.


The FITech is a good option in the rite application,but,this is far from the rite application.It does use a TPS,so,that is not an issue,but,the transmission needs a lot more than the TPS to function properly.Another problem is torque management in the transmission.This will have to be disabled,(which is a very bad idea),along no telling how many other functions that the PCM looks for inputs from such as timing,fueling,etc that is now being controlled thru the FITech.Torque mgmt is 1 of those.It is normally adjusted for performance apps to a lower setting,but,not completely removed.During shifts,timing is reduced among other functions to help the transmission live longer.You never want completely remove it.Trying to make this work will be the proverbial can of worms x 10 & in the end,you will gain no performance,or,any other benefit,other than the necessity to retune,IF,you decide later to change cams,etc.Just the system & intake alone are gonna run you $1100.Plus,the intial programming to your PCM to remove VATS & to get all the bugs ironed out,if,even possible.Most tuners,won't charge you full price for changes to a tune that they initially sold you anyway.


As for controllers,it wouldn't surprise me if both vehicles have the same controller.The 0411 & it's varients, was used widely across the board from 99 to 2004.It's very likely,if so,that you can load the bin file for the 2002 Chevy Express in to your 2003 controller & then just make changes as needed for your setup & still be able to retain full function of everything else without problems.
 
#38 ·
The reason I purchases a 2002 motor is that is is compatabble with my computer. I should have bought a crate motor but was afraid of the stuff it did not come with. I just got a price yesterday of 2500 to get the motor completely redon 20 or 30 over. what ever is required to clean it up. The only extra thing I have to pay for is a new spider. That is with the reamjet cam and a respectable piston. The builder did not like the KB pistons for 3 reasons. 1 they build mor heat, 2 the top ring sits lower than normal, 3 the top ring has a wider gap? Really respectable race shop in my area and really nice guys. He said he will use any piston I want it was just his opinion. so I am probably going to be a thousand dollars behind because I am doing my own motor but they are close and I trust them. As far as the tuning goes I will continue to read what is posted and educate myself. Joker seems to understand my application and what I want for performance and milage results. Thanks again for the tremendous help with this prodject. I can start to talk intelligently about some of the aspects of what I am trying to do.
 
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