Need some Vortec 350 info/help please
04-16-2012, 01:36 PM
#1
Need some Vortec 350 info/help please OK, so I'm not quite sure if this is the right place, but I'm posting it here anyways. If it's not, I'm sorry, please direct me to where I should be posting.
I'm about to pick up a '97 Cheyenne 2500HD (8600 GVWR) extended cab 8' bed. Truck currently has a Vortec 5.7l w/4l80e in it. Truck will mainly be used for work-like purposes and towing a racecar, but overall won't see a ton of heavy use.
I'm having a hard time finding go-fast parts for the Vortec motor. Seems the intake mani/throttle body setup is different enough from everything else SBC that there aren't any aftermarket intake manifolds for it (not sure if the stocker is a restriction, I know it's not really on the LS motors, but on the older SBC's good gains can be seen with a nice aftermarket mani). Cam kits seem expensive (since it's a roller cam motor from the factory, means I can't use a $150 non-roller cam kit, right??), etc., and I'm trying to figure out which would be more economical, assuming the Vortec is in good shape - mod the Vortec 5.7l, or do a 6.0l swap. I'm not new to swaps, last year I swapped a 5.3l LM4 into my Volvo wagon, and a 2.8l m52 into a BMW 318ti.
Thoughts? Opinions? I have access to HPTuners, so tuning won't be an issue either way, and if I do the LS swap, I'll have Brendan @ lt1swap.com flash the base file for me like he did in my Volvo. Keeping the stock motor is obviously WAY easier, but it seems like a lot of work to make mediocre power. My otherwise stock 5.3l with blockhugger headers and a stock '01 LS6 cam made 300 hp/311 ft./lbs of torque to the wheels, so a 6.0l should make plenty more when intelligently modded. Seems these Vortec's only put down ~200 hp/275 ft./lbs stock from what I've found.
Thanks for your time everybody, and appreciate the input!
I'm about to pick up a '97 Cheyenne 2500HD (8600 GVWR) extended cab 8' bed. Truck currently has a Vortec 5.7l w/4l80e in it. Truck will mainly be used for work-like purposes and towing a racecar, but overall won't see a ton of heavy use.
I'm having a hard time finding go-fast parts for the Vortec motor. Seems the intake mani/throttle body setup is different enough from everything else SBC that there aren't any aftermarket intake manifolds for it (not sure if the stocker is a restriction, I know it's not really on the LS motors, but on the older SBC's good gains can be seen with a nice aftermarket mani). Cam kits seem expensive (since it's a roller cam motor from the factory, means I can't use a $150 non-roller cam kit, right??), etc., and I'm trying to figure out which would be more economical, assuming the Vortec is in good shape - mod the Vortec 5.7l, or do a 6.0l swap. I'm not new to swaps, last year I swapped a 5.3l LM4 into my Volvo wagon, and a 2.8l m52 into a BMW 318ti.
Thoughts? Opinions? I have access to HPTuners, so tuning won't be an issue either way, and if I do the LS swap, I'll have Brendan @ lt1swap.com flash the base file for me like he did in my Volvo. Keeping the stock motor is obviously WAY easier, but it seems like a lot of work to make mediocre power. My otherwise stock 5.3l with blockhugger headers and a stock '01 LS6 cam made 300 hp/311 ft./lbs of torque to the wheels, so a 6.0l should make plenty more when intelligently modded. Seems these Vortec's only put down ~200 hp/275 ft./lbs stock from what I've found.
Thanks for your time everybody, and appreciate the input!
04-16-2012, 02:58 PM
#2
Staging Lane
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Ive seen a 5.3 with ls6 cam, ls1 heads, and ls6 intake with TB in a z28 walk all over a stock ls1 ss. Both were m6. I am working on a 5.3 turbo set up now and should reach around 700 HP when all set and done. They are easy to find and about half the cost of a 6.0. So i would go with the 5.3.
04-16-2012, 03:04 PM
#3
I can't help you with hop up info but I can give you alittle advice before you buy this truck. I own a '98 c1500 with the 5.7 vortec that I bought new. These engines have a intake manifold gasket problem. The gasket deforms and cracks letting coolant leak, if your lucky. outside the engine. If you're not lucky it leaks inside the engine. I've had to change the intake gaskets twice, the first time at 63k and then again at 102k. Felpro makes a rubber coated intake gasket p/n MS98000T thats supposed to be the fix.
Unscrew the oil fill cap from the valve cover, if it has scum in it or if it smells like antifreeze stay away from that truck. One guy I work with knew he had a leak and didn't fix it right away and he ruined his short block.
Hope this info helps, good luck
Unscrew the oil fill cap from the valve cover, if it has scum in it or if it smells like antifreeze stay away from that truck. One guy I work with knew he had a leak and didn't fix it right away and he ruined his short block.
Hope this info helps, good luck
04-16-2012, 03:42 PM
#4
The LT1 section here in general wont be a lot of help, the Vortec heads are based on the iron LT1 heads released on the 94 Caprice but the Vortec you have is basically a gen 1 engine, the LT1 is a gen 2 and the later "vortec" LS variants are gen 3+.
The LT1 shares a lot with your engine but our intake manifold is very different.
I would start with headers/exhaust for the truck, being a gen 1 motor that is a good place to start, figure something out to make sure the engine is getting cold air if it isn't already.
I would go back and look at your data far as the HP and torque figures and I would expect the engine in your truck to make peak torque sooner than the 5.3l so for towing use it might still feel better despite lower peak number. I also think some exhaust mods will help numbers nicely closing the gap.
Not saying the 5.7l you have is better than the 5.3l just saying I think with a few tweaks you can close the gap some and make it work pretty well with a lot less hassle.
Far as cams and towing you are going to need to stay really small, if you want to try and stay "budget" maybe look into a ZZ4 crate motor cam, they are pretty cheap and a nice little upgrade. I had one in My LT1 Caprice for awhile and the stock cam in my Caprice was really close to the cam in your motor.
The LT1 shares a lot with your engine but our intake manifold is very different.
I would start with headers/exhaust for the truck, being a gen 1 motor that is a good place to start, figure something out to make sure the engine is getting cold air if it isn't already.
I would go back and look at your data far as the HP and torque figures and I would expect the engine in your truck to make peak torque sooner than the 5.3l so for towing use it might still feel better despite lower peak number. I also think some exhaust mods will help numbers nicely closing the gap.
Not saying the 5.7l you have is better than the 5.3l just saying I think with a few tweaks you can close the gap some and make it work pretty well with a lot less hassle.
Far as cams and towing you are going to need to stay really small, if you want to try and stay "budget" maybe look into a ZZ4 crate motor cam, they are pretty cheap and a nice little upgrade. I had one in My LT1 Caprice for awhile and the stock cam in my Caprice was really close to the cam in your motor.
04-16-2012, 04:07 PM
#5
The LT1 section here in general wont be a lot of help, the Vortec heads are based on the iron LT1 heads released on the 94 Caprice but the Vortec you have is basically a gen 1 engine, the LT1 is a gen 2 and the later "vortec" LS variants are gen 3+.
The LT1 shares a lot with your engine but our intake manifold is very different.
I would start with headers/exhaust for the truck, being a gen 1 motor that is a good place to start, figure something out to make sure the engine is getting cold air if it isn't already.
I would go back and look at your data far as the HP and torque figures and I would expect the engine in your truck to make peak torque sooner than the 5.3l so for towing use it might still feel better despite lower peak number. I also think some exhaust mods will help numbers nicely closing the gap.
Not saying the 5.7l you have is better than the 5.3l just saying I think with a few tweaks you can close the gap some and make it work pretty well with a lot less hassle.
Far as cams and towing you are going to need to stay really small, if you want to try and stay "budget" maybe look into a ZZ4 crate motor cam, they are pretty cheap and a nice little upgrade. I had one in My LT1 Caprice for awhile and the stock cam in my Caprice was really close to the cam in your motor.
The LT1 shares a lot with your engine but our intake manifold is very different.
I would start with headers/exhaust for the truck, being a gen 1 motor that is a good place to start, figure something out to make sure the engine is getting cold air if it isn't already.
I would go back and look at your data far as the HP and torque figures and I would expect the engine in your truck to make peak torque sooner than the 5.3l so for towing use it might still feel better despite lower peak number. I also think some exhaust mods will help numbers nicely closing the gap.
Not saying the 5.7l you have is better than the 5.3l just saying I think with a few tweaks you can close the gap some and make it work pretty well with a lot less hassle.
Far as cams and towing you are going to need to stay really small, if you want to try and stay "budget" maybe look into a ZZ4 crate motor cam, they are pretty cheap and a nice little upgrade. I had one in My LT1 Caprice for awhile and the stock cam in my Caprice was really close to the cam in your motor.
Thanks for the info! As far as torque goes, no way - my 5.3l makes WAY more torque everywhere than that 5.7l does (just a guess, can't say for certain). The 5.3l is bone stock except for block-hugger headers and an early LS6 cam. I would imagine an intelligently modded 6.0 making substantially more power, with .7 more liters of displacement, and better flowing heads from the factory. The 5.3 graph below was intended as a nice DD. I could put a much bigger cam in a 6.0 for a tow rig since DD smoothness and drivability aren't as much of a concern.
FWIW, I think I've already made up my mind though. Seems there's just not a lot out there for these Vortec motors, and they seem to pull a reasonable amount of money used. Would me the swap probably $1500 or less.
04-16-2012, 05:08 PM
#6
kendogg, If you've already made up your mind, you can disregard this...
But... the hp/tq numbers in your original post that you "heard" are overly pessimistic. With my '98 Vortec bone stock except for LT headers and 3" single exhaust, it put down 254 hp/ 325 tq to the wheels on the dyno tune. You won't find many 5.3's that can beat the L31 for torque from idle to 4000 rpm.
I've since swapped to a ZZ4 cam, never dyno tuned it, but it did pick up from a 14.9 ET to 14.3 ET, along with a converter change. mph went up by 3-4.
I've put 370,000+ miles total on two different L31's and had no intake issues like was mentioned above. and I run the DogP!ss out of them! towing, nitrous passes at the track....
The stock intake manifold/injection system is limited to about 350 rwhp, and will limit rpm more than the stock 5800 PCM cutoff will. One person is getting 375 from his, but he's done some porting to it and running a plenum spacer.
Used roller cams for it are cheap; I've bought two zz4 cams for $75 in the past few years.
But... the hp/tq numbers in your original post that you "heard" are overly pessimistic. With my '98 Vortec bone stock except for LT headers and 3" single exhaust, it put down 254 hp/ 325 tq to the wheels on the dyno tune. You won't find many 5.3's that can beat the L31 for torque from idle to 4000 rpm.
I've since swapped to a ZZ4 cam, never dyno tuned it, but it did pick up from a 14.9 ET to 14.3 ET, along with a converter change. mph went up by 3-4.
I've put 370,000+ miles total on two different L31's and had no intake issues like was mentioned above. and I run the DogP!ss out of them! towing, nitrous passes at the track....
The stock intake manifold/injection system is limited to about 350 rwhp, and will limit rpm more than the stock 5800 PCM cutoff will. One person is getting 375 from his, but he's done some porting to it and running a plenum spacer.
Used roller cams for it are cheap; I've bought two zz4 cams for $75 in the past few years.
04-16-2012, 05:22 PM
#7
kendogg, If you've already made up your mind, you can disregard this...
But... the hp/tq numbers in your original post that you "heard" are overly pessimistic. With my '98 Vortec bone stock except for LT headers and 3" single exhaust, it put down 254 hp/ 325 tq to the wheels on the dyno tune. You won't find many 5.3's that can beat the L31 for torque from idle to 4000 rpm.
I've since swapped to a ZZ4 cam, never dyno tuned it, but it did pick up from a 14.9 ET to 14.3 ET, along with a converter change. mph went up by 3-4.
I've put 370,000+ miles total on two different L31's and had no intake issues like was mentioned above. and I run the DogP!ss out of them! towing, nitrous passes at the track....
The stock intake manifold/injection system is limited to about 350 rwhp, and will limit rpm more than the stock 5800 PCM cutoff will. One person is getting 375 from his, but he's done some porting to it and running a plenum spacer.
Used roller cams for it are cheap; I've bought two zz4 cams for $75 in the past few years.
But... the hp/tq numbers in your original post that you "heard" are overly pessimistic. With my '98 Vortec bone stock except for LT headers and 3" single exhaust, it put down 254 hp/ 325 tq to the wheels on the dyno tune. You won't find many 5.3's that can beat the L31 for torque from idle to 4000 rpm.
I've since swapped to a ZZ4 cam, never dyno tuned it, but it did pick up from a 14.9 ET to 14.3 ET, along with a converter change. mph went up by 3-4.
I've put 370,000+ miles total on two different L31's and had no intake issues like was mentioned above. and I run the DogP!ss out of them! towing, nitrous passes at the track....
The stock intake manifold/injection system is limited to about 350 rwhp, and will limit rpm more than the stock 5800 PCM cutoff will. One person is getting 375 from his, but he's done some porting to it and running a plenum spacer.
Used roller cams for it are cheap; I've bought two zz4 cams for $75 in the past few years.
Well, the dyno numbers I 'heard' were from a forum of dyno graphs, I forget which one though, maybe gmfullsize.com?? Regardless, if those zz4 cams are really that cheap used, perhaps I'll just grab one of those from the get-go, a set of LT's, and call it a day. See how it is, and if it's still not enough power, then I'll swap it. HPTuners will tune these ECU's, right?
You mentioned about the stock intake limits.....are there any aftermarket intakes for these engines, or is it probably not worth it for my uses? Thanks for the continued input!
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04-16-2012, 05:25 PM
#8
Pat I had no idea you had put a ZZ4 cam in your's.
I did expect the torque thing though. The OP is comparing a mildly modded 5.3l to an L31 completely choked with stock exhaust. I know the LT1 responds well to exhaust and in that regard I expected similar things from thew L31.
I did expect the torque thing though. The OP is comparing a mildly modded 5.3l to an L31 completely choked with stock exhaust. I know the LT1 responds well to exhaust and in that regard I expected similar things from thew L31.
04-16-2012, 05:34 PM
#9
I've heard that stock SBC exhaust manifolds are pretty bad, are they really that bad? And realistically, I was comparing my mildly modded 5.3l to similar mods on the 5.7l - mild cam, and headers. Just didn't think the numbers I had read supported the gains that I guess you can get. FWIW, the 5.3l is also breathing thru the stock Volvo single-in muffler too.
Where can I find these zz4 cams? What engines/cars were they in?
Where can I find these zz4 cams? What engines/cars were they in?
04-16-2012, 05:48 PM
#10
This is one of the dyno's I was referring to:
http://www.youtube.com/watch?v=BfLru8jEC3k
Similar truck to what I'm getting, except mine is a 2500HD. And is it worth it to get the marine intake if I can find one reasonably, or is it not worth it for the power I'm trying to generate?
http://www.youtube.com/watch?v=BfLru8jEC3k
Similar truck to what I'm getting, except mine is a 2500HD. And is it worth it to get the marine intake if I can find one reasonably, or is it not worth it for the power I'm trying to generate?
04-16-2012, 06:30 PM
#11
You probably already realize this, but just so I don't mislead you - along with the need for better valvesprings to run any more than the stock cam, you'll also need different retainers to avoid retainer-to-seal interference with lift such as the ZZ4 cam on the stock Vortec heads. There are numerous spring/retainer kits out there to do the job.
I have a 2nd-hand JET DST (ex- Tunercat) for mine. I don't know what your HP Tuners covers.
Regarding the intake, yes, there are upgrades available. Probably the most popular is the GM marine intake; it uses conventional type injectors and is popular for those running boosted L31 setups and needing more fuel. Do a search for it on www.fullsizechevy.com/forum
But if I'm reading you right, I don't think it's money well spent if you still want to use your truck as a truck. You'd probably pick a cam that isn't going to peak at 350 rwhp anyway. The guy putting down 375 is running a GM LT4 Hotcam in a stroker.
The ZZ4 cam (same as ZZ3) comes in ZZ4 (ex ZZ3) GM crate engines.
But honestly, for the weight of your truck and the 2.48 low in that 4L80E, the stock cam can perform pretty darn well if you just let the engine breathe and tune it. The stock tune on those leaves a lot to be desired.
Another possibility is the GM cam that comes in their HT383 crate motor.
Without changing the torque converter, I'd want either the stock or the HT383 cam in that heavy truck.
I have a 2nd-hand JET DST (ex- Tunercat) for mine. I don't know what your HP Tuners covers.
Regarding the intake, yes, there are upgrades available. Probably the most popular is the GM marine intake; it uses conventional type injectors and is popular for those running boosted L31 setups and needing more fuel. Do a search for it on www.fullsizechevy.com/forum
But if I'm reading you right, I don't think it's money well spent if you still want to use your truck as a truck. You'd probably pick a cam that isn't going to peak at 350 rwhp anyway. The guy putting down 375 is running a GM LT4 Hotcam in a stroker.
The ZZ4 cam (same as ZZ3) comes in ZZ4 (ex ZZ3) GM crate engines.
But honestly, for the weight of your truck and the 2.48 low in that 4L80E, the stock cam can perform pretty darn well if you just let the engine breathe and tune it. The stock tune on those leaves a lot to be desired.
Another possibility is the GM cam that comes in their HT383 crate motor.
Without changing the torque converter, I'd want either the stock or the HT383 cam in that heavy truck.
04-16-2012, 07:16 PM
#12
I am thinking of using that HT383 crate engine to replace my 170k L31. Cant beat it for the money and the simplicity. Bolts right in and a BB tune will make it drive like the stock L31 until you put your foot in it. Comes with a forged crank and a warranty lol.
04-16-2012, 09:07 PM
#14
You probably already realize this, but just so I don't mislead you - along with the need for better valvesprings to run any more than the stock cam, you'll also need different retainers to avoid retainer-to-seal interference with lift such as the ZZ4 cam on the stock Vortec heads. There are numerous spring/retainer kits out there to do the job.
I have a 2nd-hand JET DST (ex- Tunercat) for mine. I don't know what your HP Tuners covers.
Regarding the intake, yes, there are upgrades available. Probably the most popular is the GM marine intake; it uses conventional type injectors and is popular for those running boosted L31 setups and needing more fuel. Do a search for it on www.fullsizechevy.com/forum
But if I'm reading you right, I don't think it's money well spent if you still want to use your truck as a truck. You'd probably pick a cam that isn't going to peak at 350 rwhp anyway. The guy putting down 375 is running a GM LT4 Hotcam in a stroker.
The ZZ4 cam (same as ZZ3) comes in ZZ4 (ex ZZ3) GM crate engines.
But honestly, for the weight of your truck and the 2.48 low in that 4L80E, the stock cam can perform pretty darn well if you just let the engine breathe and tune it. The stock tune on those leaves a lot to be desired.
Another possibility is the GM cam that comes in their HT383 crate motor.
Without changing the torque converter, I'd want either the stock or the HT383 cam in that heavy truck.
I have a 2nd-hand JET DST (ex- Tunercat) for mine. I don't know what your HP Tuners covers.
Regarding the intake, yes, there are upgrades available. Probably the most popular is the GM marine intake; it uses conventional type injectors and is popular for those running boosted L31 setups and needing more fuel. Do a search for it on www.fullsizechevy.com/forum
But if I'm reading you right, I don't think it's money well spent if you still want to use your truck as a truck. You'd probably pick a cam that isn't going to peak at 350 rwhp anyway. The guy putting down 375 is running a GM LT4 Hotcam in a stroker.
The ZZ4 cam (same as ZZ3) comes in ZZ4 (ex ZZ3) GM crate engines.
But honestly, for the weight of your truck and the 2.48 low in that 4L80E, the stock cam can perform pretty darn well if you just let the engine breathe and tune it. The stock tune on those leaves a lot to be desired.
Another possibility is the GM cam that comes in their HT383 crate motor.
Without changing the torque converter, I'd want either the stock or the HT383 cam in that heavy truck.
Ya, I know I'd need springs. I've never heard of Jet DST, and support for TunerCats seems to be dead. HPTuners doesn't support the '96-'97 'black box' ECU's, and seems a lot of the guys on the HPTuners forums are recommending to swap to a later, tunable ECU. Hardest part now is just trying to decide if any of this is really worth the trouble to 'test' and see if it's enough. Or just do maintenance on it and drive it for awhile until I gather the parts to yank the motor and post it for sale for $500 and drop a 6.0 in instead and call it a day.
Thanks everybody!
04-17-2012, 06:33 AM
#15
Ya, I know I'd need springs. I've never heard of Jet DST, and support for TunerCats seems to be dead. HPTuners doesn't support the '96-'97 'black box' ECU's, and seems a lot of the guys on the HPTuners forums are recommending to swap to a later, tunable ECU. Hardest part now is just trying to decide if any of this is really worth the trouble to 'test' and see if it's enough. Or just do maintenance on it and drive it for awhile until I gather the parts to yank the motor and post it for sale for $500 and drop a 6.0 in instead and call it a day.
Thanks everybody!
Thanks everybody!
If you're not near a good dyno tuner that knows these trucks, www.pcmforless.com (Bryan Herter) has an excellent mail order tune for the stock cam that he developed with my truck on the dyno. 87 octane. The Vortec heads are a modern fast-burn chamber and don't need much timing.
