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Vortec questions

metalneverdies

metalneverdies

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Is there any reason why I couldn't buy a used stock Vortec Thottle body, intake manifold and EGR port then slap them on a Vortec crate motor?

The only other things I would need to run that setup in my 87 K5 with TBI would be a proper tune and a higher psi fuel pump? I should be able to put my factory exhaust manifolds back on too corect?

Am I missing anything or is it really that easy to get a proper running Vortec swap and avoid the stupid high costs of the GMPP conversion manifold?

There is a guy locally selling Vortec upper and lower intake manifolds and throttle body, distributor, alternator, starter, EGR valve and fan/clutch for pretty cheap. Just not sure if I should pick them up. If they will work out for the Vortec swap that would be awesome. :dunno:
 
that system basicly sucks for real performance . and the spider injector unit has its problems also .

the intake gaskets bad design . aftermarket has beeter ones.

eat dist gears and break the 2 tabs on the plastic housing that hold the cap to the dist body a lot . even reman units have the tabs glued on and break soon after you try and install the screws.

96-00 or -03 in van vortec sbc use egr tube on driver side exaust manifold specific to that motor style .

not much in the way of performance tunning out there I have seen .

there is a guy here just listed a edelbrock tbi multi port kit for vortec heads in the sale section . just a idea to use what ya got :whistle:

I know its said a lot but ls swap is dam great bang for the buck these days and close to bolt in .
 
Gah. I had seen the same complaints on other sites but was hoping they were exaggerated.

I was hoping that it could be essentially drop in and go if I used all tbi sensors and exterior parts.

Ls motors have a few problems I have read about too.

Plus every one who wants CC and AC seem to dump ~4k if they do it without cutting up the frame. I guess I can just go with drive by cable and not have CC to cut down swap costs.
 
the info I gave is from years as a mechanic working on lots of vehicles.

what do you mean cut up frame ?

holley has a/c high mount brackets .

and 03-up dbw is 4 extra wires for cc use
 
Ignoring the LS option, what about a GMPP intake? It sounds like you want basically a crate motor, but a Vortec motor is little more than a standard one piece main, roller small block, with Vortec heads on it. The heads are the real difference outside of the as-mentioned, crappy Vortec injection setup.

Absolute worst case, you buy a carbed vortec intake, carb to TBI adapter (all available on summit, etc), bolt the TBI on, get it tuned, and you are done.

EGR is a royal pain on Vortecs, and honestly, Vortecs aren't worth the hassle if you must run EGR for emissions. There are other/better options for heads in that case. Even on the head side itself, you can be into a set of Dart 23*(?) AL heads for $900, although I'm not sure they are available in the '86-95 intake manifold bolt pattern you have. But there are tons of aftermarket heads out there that will take your stock manifold, and the ~$150 savings on the intake could be spent on more expensive (than Vortec) heads.
 
dyeager535 said:
Ignoring the LS option, what about a GMPP intake? It sounds like you want basically a crate motor, but a Vortec motor is little more than a standard one piece main, roller small block, with Vortec heads on it. The heads are the real difference outside of the as-mentioned, crappy Vortec injection setup.

Absolute worst case, you buy a carbed vortec intake, carb to TBI adapter (all available on summit, etc), bolt the TBI on, get it tuned, and you are done.

EGR is a royal pain on Vortecs, and honestly, Vortecs aren't worth the hassle if you must run EGR for emissions. There are other/better options for heads in that case. Even on the head side itself, you can be into a set of Dart 23*(?) AL heads for $900, although I'm not sure they are available in the '86-95 intake manifold bolt pattern you have. But there are tons of aftermarket heads out there that will take your stock manifold, and the ~$150 savings on the intake could be spent on more expensive (than Vortec) heads.
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Extra power is always good. The main reason I was looking at vortec crate motor was that it had a full roller setup. If I was able to find a tbi full roller 350 with a warranty I would go that route for sure. If I have to drop 2k on a vortec crate then another 300-400 in adapters plus a tune, then that kills the deal for me.
 
trucks have roller setup ready blocks in the tbi era .

cars had the roller cams in the era from what I have read.

and as said if vortec motor you can get intake and or adaptor to make it tbi .

don't forget tho tbi and different cam = chip burn to run the best.
 
Roller cam was '86-up in cars...so whenever cars stopped getting small blocks that used the same cams.

Roller cam setups (takeoffs) can often be found in various places (craigslist, ebay, etc) complete. Being rollers, realistically even used doesn't matter that much.

From what I understand, the roller cam gets you far less than say, better heads, or better exhaust. They have benefits, and if able to run, for me it's a no-brainer, but they aren't worth spending a ton of money on because you think they will net you a ton more power.
 
metalneverdies said:
Is there any reason why I couldn't buy a used stock Vortec Thottle body, intake manifold and EGR port then slap them on a Vortec crate motor?

The only other things I would need to run that setup in my 87 K5 with TBI would be a proper tune and a higher psi fuel pump? I should be able to put my factory exhaust manifolds back on too corect?

Am I missing anything or is it really that easy to get a proper running Vortec swap and avoid the stupid high costs of the GMPP conversion manifold?

There is a guy locally selling Vortec upper and lower intake manifolds and throttle body, distributor, alternator, starter, EGR valve and fan/clutch for pretty cheap. Just not sure if I should pick them up. If they will work out for the Vortec swap that would be awesome. :dunno:
Click to expand...
You forgot the PCM change as well as wiring... Vortec has a crank sensor and the cam sensor is in distributor.

Although it's not a perfect system it runs well. New spider injection fixs the major flaw. Intake gaskets would have been fine from factory if they had used anti freeze instead of Dex (Death) Cool.

Mine runs fine! Not sure what all the hate is about? I wouldn't choose the system to build a modified engine but it still does well to 350 HP...
 
Mark, for all the "complexity" of Vortec, as far as I can tell, GM managed to not get much more than about what you get out of a small block by just changing to Vortec heads from the older style.

Obviously every engine build is going to respond to Vortec heads differently, but the 1991 truck TBI 350 was rated at 210HP, the Vortecs were rated at ~255HP (I can't find anything definitive beyond the 255 number) but need 600 more RPM to get there.

So they had better heads, a "dry" intake, I'm guessing a larger throttle body, probably more compression, and a roller cam (among other things). 45HP sounds like a lot initially, but when testing has shown Vortec heads alone good for around 40HP, it makes the additional 5HP gain vs. cost and complexity hard to justify IMO.

I see reference to 350HP L31 motors, but don't see anything explaining what they were installed in. As far as I can tell though, that is in reference to the Ramjets, but that's apples to oranges.

FWIW, the iron-headed TPI L98's, TPI being much maligned for weak flow on the 350's, were getting 245HP in 1990, 6 years before the Vortecs. GM managed to add 10HP in 6 years with the same displacement, completely different heads, in vehicles with lower emissions requirements. I suppose the cost of the Vortec setup was less than the TPI's, so GM has that excuse. :)

I'm not busting your chops, I have always found (or did, not sure how the new vehicles stack up) it odd that GM was so cheap that they stuck truck buyers with antiquated technology, when the performance could have been MUCH better.
 
GM was not trying to get HP out of a truck motor. The newer design was to meet emissions standards. Design of the engine alone changed how much EGR was needed, it only comes on during acceleration 1st, 2nd gear and then no more.

The 350 HP was not one of their engines just what could be done and still use spider, actually I think it's more like 320 with cam and headers then tune. Always have to look to get all HP in before the 5800 RPM range because that is where the PCM stops. Still don't know anyone who has broken that barrier, it's in the PCM code somewhere.

I understand it was a cheap new design using new tech, not upgrade-able because of the design and had some issues. But still works well.

I think if the Vortec came with spider injector with individual injectors instead of the poppets? It would have ended up with a better reputation today...

Intake gasket issues were not only a Vortec problem of the era, it was all GM vehicles along with all the other cooling system issues caused by Death Cool.

If your throwing vortec heads on a SBC? The Vortec intake is a low dollar way to run a newer OBDII system MPFI and not TBI. Dave W makes an external Crank Trigger so the entire EFI system from 96-00 can be used in conversions without the need of the internal crank trigger and plastic timing cover.

Then it's even a simple repin of PCM to run the 0411 LS PCM.

I think sometimes engine building done on internet is all about what is absolutely the best and what is capible of the biggest HP numbers? When in real world those big HP numbers are not needed and vehicle needs so much more money for mods to keep up.... real world dollars are also involved...

Thinking real world dollars the intake alone from JY is about $75 and injector upgrade $169 if the intake did not already have it... beat those numbers to run MPFI on Vortec heads? :dunno:
 
Yes, for multi-port Vortec is probably hard to beat $$-wise. But looking at it from the standpoint of HP (which IMO is the only apples to apples way to compare motors outside of torque) how much HP would you get out of the plain-old TBI system if you converted it to roller cam, vortec heads, and re-tuned? You think there is another 45HP there? I suspect there is, and then some.

GM had to meet emissions standards, and be cheap. Always the cost angle. TPI was meeting car emissions standards and producing nearly the same HP as Vortec on un-arguably antiquated equipment 6 years earlier. But I guarantee, cost of the TPI components for GM FAR exceeded what the Vortec stuff cost them.

The Ramjet I suspect is the "L31" people are saying made/makes 350HP, but its obviously not a Vortec induction system, just Vortec heads http://www.chevroletperformance.com...350&engine=Ram Jet 350&sku=12499120&engCat=sb
 
I'm not disagreeing but...

You can't compare GM costs between a Vortec truck engine and a TPI muscle car engine. Apples to Oranges and no argument the TPI was better engineered for the day.

But the TPI was part of the sale of the vehicle too!!! Those vehicles were designed for HP and all that was part of the sale. So production cost was up but it made sales up as well. Or you could get a plain TBI engine...

My only point was a stock Vortec intake works well, it's no where near as bad as people constantly advertise, not a design for a highly modified engine or good choice to start with there. But for mild mods and a very cheap cost to run Vortec heads it's great.

It's got a bad rap! Just like a LT1 OptiSpark Distributor... it was so far ahead of it's time and maintenance on it was to replace the distributor at 100,000 miles! If you did that even a leaking water pump seal leaking all over it would not matter. But if you had a leak on old unit it would fail. Was not a cheap unit and manufactures made cheap replacements, that failed and did not run right. Train Wreck! :doah:
 
Well, apples to apples would be a torque for a truck, and TPI made 345ft lbs, L31 was 330ft lbs. (LO3 was 245 apparently) I suppose I'm thinking along the lines of the newer trend of whose truck makes the most HP, or TQ, or is rated to tow the most. Times aren't the same I suppose. Just seems odd to me that GM didn't spend the money to dump the TPI into the full size trucks, at least limited like they did with the Syklone/Typhoon's.

Aren't there kits out there that convert the Vortec "spider" setup to a more conventional system that doesn't use the poppet valves?

As I understand it they are somewhat problematic as well.
 
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