A MAF will work and its a better system than the MAP, but the MAP is less prone to water or dust or vibration issues.
5.3, versus 6.0, versus 5.7
- Thread starter workingdog
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agree...I forgot about the powerhouse 305's and the corvette. I've never been a fan of the 305 in any flavor.
workingdog
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- #23
Finally got the 5.7 home. Although it was covered and indoors, it looks pretty bad. Input on what I've got would be great.
One big difference between it and the vortecs is the distributor. I assume it's a traditional distributor - no PCM controlled timing.
Peter
One big difference between it and the vortecs is the distributor. I assume it's a traditional distributor - no PCM controlled timing.
Peter
Very much PCM controlled timing. The distributor has no vacuum advance. The PCM gets the signal from the cam position sensor (pick up coil in the dizzy) and it triggers the coil to fire with any advance or retardation the PCM thinks the engine requires.
The secondary part of the ignition system is the same as any distributor ignition.
Thats a late 90s 5.7L Vortec. It's a good gen II motor. Very good flowing heads, but prone to cracking. Be sure there is no coolant in the oil. The injection spider pintles are prone to plugging as well. Early ones had to be replaced as a unit. Later ones could be replaced as needed.
The secondary part of the ignition system is the same as any distributor ignition.
Thats a late 90s 5.7L Vortec. It's a good gen II motor. Very good flowing heads, but prone to cracking. Be sure there is no coolant in the oil. The injection spider pintles are prone to plugging as well. Early ones had to be replaced as a unit. Later ones could be replaced as needed.
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workingdog
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- #25
Thanks for the information. I'm trying to wrap my head around how that would work. Are there points in the distributor? I'm giong to have to go to Wikipedia.
No points. magnetic pickup coil sends a pulse to the PCM.
workingdog
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- #27
So, the distributor is just acting as a cam sensor? Not triggering the spark?
Now I'm beginning to see why the vortec was such a big change. At least on the 5.7 the thermostat is still on top of the block.
Then the cap on the distributor is just to keep the dust out? (as opposed to providing contact points for the rotor).
I assume there's just one injector on the throttle body and that 'tuned port' refers to the fancy shape of the intake.
Peter
Now I'm beginning to see why the vortec was such a big change. At least on the 5.7 the thermostat is still on top of the block.
Then the cap on the distributor is just to keep the dust out? (as opposed to providing contact points for the rotor).
I assume there's just one injector on the throttle body and that 'tuned port' refers to the fancy shape of the intake.
Peter
The distributor does not trigger the spark itself.
The top part of the distributor is the same. The cap gets the spark from the coil and sends it to the rotor that is still on the distributor shaft. The rotor then sends it to the terminal on the cap connected to the appropriate ignition wire. The part under the rotor is what's different.
There are injectors in the center and they send fuel down eight little tubes to each cylinder just before the intake valve. That system is very unique to that engine.
Tuned port does refer to each runner being tuned. All intakes that are port fuel injected are tuned. The first port fuel injected GM motors were marketed as Tuned Port Injection. That is not a TPI engine. That engine is better. GM marketed that engine as a Vortec. Unfortunately, they called a number of different engines Vortec. GM aficionados refer to that engine as a "true" vortec. It has excellent flow characteristics. I have those heads on a earlier block.
The top part of the distributor is the same. The cap gets the spark from the coil and sends it to the rotor that is still on the distributor shaft. The rotor then sends it to the terminal on the cap connected to the appropriate ignition wire. The part under the rotor is what's different.
There are injectors in the center and they send fuel down eight little tubes to each cylinder just before the intake valve. That system is very unique to that engine.
Tuned port does refer to each runner being tuned. All intakes that are port fuel injected are tuned. The first port fuel injected GM motors were marketed as Tuned Port Injection. That is not a TPI engine. That engine is better. GM marketed that engine as a Vortec. Unfortunately, they called a number of different engines Vortec. GM aficionados refer to that engine as a "true" vortec. It has excellent flow characteristics. I have those heads on a earlier block.
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workingdog
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- #29
Wow, the plot thickens. Is this the very last iteration before the modern vortec (no distributor)?
Anything else interesting I should now about it? When I'm ordering parts (I need at least a distributor cap, PCM, and a heater from first inspection), what should I say I"m ordering for?
Did the AC compressor go in the empty bracket on top of the accessory loop.
Peter
Anything else interesting I should now about it? When I'm ordering parts (I need at least a distributor cap, PCM, and a heater from first inspection), what should I say I"m ordering for?
Did the AC compressor go in the empty bracket on top of the accessory loop.
Peter
The AC goes on top. You can buy an AC eliminator pulley so you can run the belt if it had AC. about $40.
That motor came in Silverado and Suburban. It might have a VIN number stamped on it. I know on the GEN I motors it was on a pad right at the parting line of the right head in the front. With a VIN you should be able to get really close to the original application. I think you'll be good if you go with a 98 Silverado 2500.
You need a MAF and the air hose from the intake to the MAF.
Do you have the wiring harness?
That motor came in Silverado and Suburban. It might have a VIN number stamped on it. I know on the GEN I motors it was on a pad right at the parting line of the right head in the front. With a VIN you should be able to get really close to the original application. I think you'll be good if you go with a 98 Silverado 2500.
You need a MAF and the air hose from the intake to the MAF.
Do you have the wiring harness?
workingdog
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- #31
Here's what I found on the block
Lift side
5.7LG SGI 0098 with the little clock thing at 2pm.
right side
1024388C (C must be a 0).
I found this online - 10243880 96-up 350 2 & 4-Bolt Vortec Roller
Pictures of MAF and harness attached.
Appreciate the help.
Lift side
5.7LG SGI 0098 with the little clock thing at 2pm.
right side
1024388C (C must be a 0).
I found this online - 10243880 96-up 350 2 & 4-Bolt Vortec Roller
Pictures of MAF and harness attached.
Appreciate the help.
workingdog
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- #32
Will Summit's block hugger headers work in an FJ40 with these heads?
Those are great engines
Yes. As well as they work with any sbc.
Take the intake off and replace the intake gaskets, most likely you have a large amount of crap that needs to be cleaned off under the intake (carbon), You can fab up your own EGR block off, and they make a dedicated plug to use to replace the EGR Pipe that feeds the exhaust manifold (that is if you don't have to play with emissions). You have a 5.7 vortec from a GM pickup or suv.
You don't set the timeing with the distributor...you set something called crank offset as I recall and you need a scan tool to do it.
I have the same engine expecet mine is a 1999 version. If you need any picutures let me know (PM).
The PCM controls everything.... Unless you convert over to carb.
Better check the big plug on top of the manifold for damage...that's what controls the fuel injection. GM also has a "upgraded" fuel injection syder harness. I'm not a big fan of the fuel injection setup under the top cover of the intake manifold but it is wha it is...
Look up 5.7 fuel injection sypder upgrade on google I'm sure you will come up with some pics...
I use teh matching GM fan and fan clutch on my 60.
You don't set the timeing with the distributor...you set something called crank offset as I recall and you need a scan tool to do it.
I have the same engine expecet mine is a 1999 version. If you need any picutures let me know (PM).
The PCM controls everything.... Unless you convert over to carb.
Better check the big plug on top of the manifold for damage...that's what controls the fuel injection. GM also has a "upgraded" fuel injection syder harness. I'm not a big fan of the fuel injection setup under the top cover of the intake manifold but it is wha it is...
Look up 5.7 fuel injection sypder upgrade on google I'm sure you will come up with some pics...
I use teh matching GM fan and fan clutch on my 60.
workingdog
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- #36
Thanks for that information. I had read about the problems with the spider, but had not been able to find the kit. I did a lot of reading about the marine intake, but that seems like a lot of work. I suppose while I have the engine out I should do the spider replacement. I heard that it's better to buy it from GM as some of the aftermarket spiders are suspect - any thoughts on that?
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It improves the poppets and makes them replaceable as individual parts rather than the whole thing.
workingdog
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- #38
So, I followed your lead and did a little more research.
The replacement spider actually replaces the poppets with injectors - so it is true MPFI after installation. From the dealer it's $420, from Amazon ACDelco it's $330, from Summit not from ACDelco it's less than $300.
Apparently the original poppets were being destroyed by the gas being used in CA and GM came out with this 'fix' for CA trucks. The original poppet system is not very reliable.
My understanding is that the injectors in the new spider are much more liable, but still only 19 pounds and that they can't be changed. So, although there are lots of things you can do to this engine, upgrading the injectors for more flow isn't one of them.
I'm hoping to get a chance to install the next spider in the next couple of days and will post.
Peter
The replacement spider actually replaces the poppets with injectors - so it is true MPFI after installation. From the dealer it's $420, from Amazon ACDelco it's $330, from Summit not from ACDelco it's less than $300.
Apparently the original poppets were being destroyed by the gas being used in CA and GM came out with this 'fix' for CA trucks. The original poppet system is not very reliable.
My understanding is that the injectors in the new spider are much more liable, but still only 19 pounds and that they can't be changed. So, although there are lots of things you can do to this engine, upgrading the injectors for more flow isn't one of them.
I'm hoping to get a chance to install the next spider in the next couple of days and will post.
Peter
No kidding? That's the first I've seen those. That's a great upgrade.
spotcruiser
Geezer
As noted before, get the FelPro intake manifold gasket kit and replace those while you're doing the spider replacement. Use Brendan at lt1swap for any pcm programming that you need. He's a good guy. His website has the wiring diagrams for the engine. The OEM service manuals are a big help also.
I have the A/C compressor and hoses, if you're looking to use the A/C. If not, you can use the compressor mount for a York compressor, as I did. It's a fairly easy mod.
Ping me if you have any questions.
I have the A/C compressor and hoses, if you're looking to use the A/C. If not, you can use the compressor mount for a York compressor, as I did. It's a fairly easy mod.
Ping me if you have any questions.