[Rinny]

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

 

[RWENUTS]

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.

 

[Rinny]

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

 

[ericnova72]

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.

 

[Rinny]

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?

 

[Rinny]

Trans is the 460L
Thanks for the input guys!!

 

[jokerZ71]

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.

 

[jokerZ71]

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.

 

[Hogg]

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

 

[Hogg]

Heres my lowbuck marine intake setup mocked up on the bench

I did the entire swap for just under $1000 including PCM recalibration equipement.

peace
Hog

 

[Rinny]

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.

This is exactly the type of info I was hoping for.
Thanks for the info guys.
The marine head is the best bang for the buck? I see different ones from summit and jegs.
Is it nesc to replace the injectors or just a wise move?

 

[Rinny]

oops I ment the marine intake. DUH!!

 

[Rinny]

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?

 

[jokerZ71]

This is exactly the type of info I was hoping for.
Thanks for the info guys.
The marine head is the best bang for the buck? I see different ones from summit and jegs.
Is it nesc to replace the injectors or just a wise move?

The 2002 should have the upgrade spider that uses mini jectors vs the older poppet style.These were more reliable & worked much better.At 100,000,they may,or,not be fine,depending on how they were maintained & had regular injector cleaner used.The suggestion to replace was more of a wise move,than,necessity.
The marine intakes,from what I'm told are getting really hard to find.If you're not planning on going over 350 HP,the stock unit will work fine.

 

[Rinny]

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?

DUH, the cold air intake.. stop laughing, this isn't easy fer me!!

 

[Rinny]

350 ponies would be kick *** for my application. Even 325

 

[jokerZ71]

350 ponies would be kick *** for my application. Even 325

With the cam I listed above & proper tuning,along with a decent exhaust,will set you rite around 325 to 330 HP.

 

[Rinny]

Should I do electric fans for added HP gain? It is not an easy mod but doable.

 

[jokerZ71]

Should I do electric fans for added HP gain? It is not an easy mod but doable.

If it's a real PITA, not sure it would be worth any gains you'd realize.

 

[Rinny]

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