L31 (Vortec 5700) swap

[benjaminearle]

Here's a couple pics of the new engine as I'm cleaning it. Hope i can remember where all those plugs go!

So, on the EGR, must it come off the exhaust before the O2 sensor? It may be easier and cheaper to just add a bung instead of tuning it out.

 

[Jims86]

Hmmm, interesting idea to have the manifolds drilled and tapped. Could most any machine shop do that or does someone special need to be contacted?

Anyone care to weigh in on the pros and cons of maintaining or deleting the EGR system?

I'm taking today to clean up the old engine lots of degreaser later it looks pretty nice. I wish there was a easy way to run the old chrome air filter assembly and maintain the MAF. Anyone relocated it just above the throttle or does that just not provide enough straight pipe? Not to mention nothing to secure the round filter to.

******

 

[Jims86]

Hmmm, interesting idea to have the manifolds drilled and tapped. Could most any machine shop do that or does someone special need to be contacted?

Anyone care to weigh in on the pros and cons of maintaining or deleting the EGR system?

I'm taking today to clean up the old engine lots of degreaser later it looks pretty nice. I wish there was a easy way to run the old chrome air filter assembly and maintain the MAF. Anyone relocated it just above the throttle or does that just not provide enough straight pipe? Not to mention nothing to secure the round filter to.

Yeah, any machine shop should be able to do it. you may have to re shape the pipe a little for it to properly connect to the manifold.
The up side to keeping EGR, is no tuning, and lower combustion chamber temps. You can also get ahold of a drivers side TBI manifold, and use the AIR tap, and bend a custom tube.
Air tap is at the front of the manifold.

 

[kleedus]

take a look at my crew cab build thread there is a link at the bottom of my posts

I am putting a vortec 383 in my crew with a 4l80 205 with a vss on the 205 output

you can get the egr block off plate and plug on ebay kinda cheap

after seeing the mess the egr made inside the intake I am glad I decided to delete the egr. i say delete it you should have your computer tuned for your set up anyway so its only a small cost for the block off parts

I had oneluckypops modify my harness I took out of a 96 Tahoe he gave me a awesome price and did top notch work tailored my harness how I wanted it to fit my needs

look threw my thread I can't remember all the details off hand and oneluckypops has a thread on his vortec 350 swap

 

[kleedus]

egr block off plate
http://www.ebay.com/itm/CHEVY-S-10-...Parts_Accessories&hash=item3a7c82735a&vxp=mtr

egr intake plug
http://www.ebay.com/itm/VORTEC-S10-...Parts_Accessories&hash=item3a7ba60499&vxp=mtr

you will need both the plate and the plug these are the same parts I used for mine


also look at upgrading your injectors to this type shop around this was just one I found real quick to show you and you will need the mount bracket to go with it
http://www.ebay.com/itm/Vortec-cent...Parts_Accessories&hash=item232c020cf9&vxp=mtr

 

[benjaminearle]

Out with the old...

The old LM1 cam out today. Yanked it by myself with some help from Mr chain hoist and Mr comealong. I'm very thankful to have a friend with both a crane in his backyard and a girlfriend kind enough to let me borrow some space for this project. The stipulation is that HE can't help me until his other two big car projects are complete. Both engine swaps, one an LT1 into a '96 Tahoe (and it has to remain OBD II compliant) and the other swapping german muscle around.

Anyway, here's some pics of my work today. Stupid engine hung on everything coming out - harness got looped over the throttle cable bracket, fan kept finding the radiator clip and finally the power steering hose got under a subframe bracket which i didn't notice until the steel line was almost pulled straight.

Also I finally got a good look at the "small crack in the block that [previous owner] repaired with JB Weld" I took the JB Weld off with one flick of a screwdriver. C'mon, if you're going to half-ass a repair, at least do a complete half-ass job. Guess he didn't know that JB doesn't stick to oily metal.

I would have had this done yesterday but I lost a couple hours when i move the crane and managed to send the block and tackle through my buddy's basement window. Oops. Hello glass shop.

Next up is cleaning the bejezus out of the engine bay. Why, hello Ms Pressure Washer - let's dance.

 

[benjaminearle]

Well, some progress last night. I was able to extract the EGR fitting from the L31 exhaust manifolds (thanks, portaband) by slicing off enough casting to release some compression, then add a wrench, rest penetrant and a big hammer. And, viola, save $10 on the fitting.

I'm still not 100% decided to run EGR but want to give it every option. Need to bolt the old LM1 manifold up and see what piping/drilling/welding it will take to get that fitting installed in the right place. Anyone know whether or not it will clear the firewall if installed in the stock Vortec (behind Cyl #7) location? That way I can leave the tube alone.

Also, with the engine I got the head pipes with O2 bungs so i'll cut those out by V-slicing a saddle out of the existing pipes and lay over my '79 pipes, mark it, drill it, and weld on the saddles without getting the heat-affected area into the threads.

All together, getting these three fittings from the donor has saved me about $30. That $30 will be put toward motor mounts as the '79's were a bit torn and floppy. I see motor mount sets ranging from $10 to $130. Any guidance would be greatly appreciated or I might just stroll into NAPA and say "motor mounts for a '79 GMC with a 350." Rubber? Poly? Clamshell? The steel is fine just the rubber is worn out? Is it replaceable?

Radiator will be coming up soon. Current truck has an external oil cooler (not hooked up) and external trans cooler (hooked up in series with the in-rad unit). I'll need to decide between using a radiator for a '79 (which will fit nicely, unsure of the hose fitting placements and sizes) or a '97 radiator (unsure of fit but the hose and tube connections would be right). Any recommendations for or against using in-radiator oil or transmission coolers and keeping or ditching the external units?

Also, on a side note, should this be moved to the Vortec section instead of EFI? I find it a little confusing having TBI, EFI and Vortec in different spots since one engine could be multiples of those. Vortec is actually a head design but TBI, MPI, TPI and typical Vortec injection are EFI - just want to be in the right place for the best help and honestly the most traffic.

 

[El Camino Man]

I can answer one question!

From my personal experience, an external tranny cooler is better than a stock one that goes through the radiator. On Fords, E4ODs are notoriously sensitive to heat and everyone puts aftermarket tranny coolers in place of the radiator cooler.

Reason? Simple! "Figure" 50% of the air going through the radiator is used to cool the coolant itself and the other 50% cools your tranny fluid. Install an aftermarket tranny cooler: 100% of radiator airflow cools coolant and 100% of tranny cooler airflow cools tranny fluid!

 

[benjaminearle]

OK, I have a fuel system question on this build - I was looking at the Painless instruction manual (no, I don't have their harness, just trying to glean as much info as possible). It talks about needing a regulated fuel supply to 55psi. I just did the spider assembly on an identical engine and there was what appeared to be a regulator in the spider. So, do I have to run an external regulator or just feed the spider with AT LEAST 55-58 psi and let it regulate the excess off?

 

[benjaminearle]

OK, more parts ordered yesterday - autozone.com has a special for 20% off and free shipping if you spend (pre-discount) $100. So i got a new oil pump (high volume, with screen) for about $40, a new oil pump shaft, new plugs (Bosch has a $1/ea rebate), oil filter ($8 Fram rebate if you purchase oil AND air filters together) and fuel filter. Also got new rubber engine mounts. And out of all that what was the one "special order" item? Stock engine mounts for a Gen 1 350. Go figure. So i ended up with all that, shipped, for $102.

LT1Swap.com has a basic list of what needs to be hooked up to get running (I'm hoping it's right) so my next major hurdle is fitting the EGR tube to the downpipe, fitting the O2 sensors to the pipes, installing the old motor mount brackets and spacers to the new engine and dropping it in - after I get an AC compressor to at least be a pulley and open up the bolt holes in my LM1 exhaust manifolds (they seem to be off, and were on the LM1 too, by just a hair to have all six bolts go in easily. Figure I'll ream an extra 1/16-1/8 into the hole diameter on one, or maybe every other, manifold hole - keeping at least three for lineup and the other three for pull-down. I've been advised to use the Vortec metal gaskets and will do so.

Oh, I guess I didn't make a note of this - my friend just replaced the radiator in his '96ish C2500 due to a small tank leak, so i got it for free (at least until I can afford one). It fits vertically, but is almost 6" wider than the square's rad, so i relocated the overflow bottle and the charcoal canister and it went in with stock brackets. It's 3 or 4-row (awesome) and has hose fittings that will fit my L31, trans cooler fittings that fit my TH350 once I pulled the adapter bushings out and oil cooler fittings that will fit my L31 (that has an oil cooler and came with the lines). I'll try to remember to get a picture of all this.

Also, and finally, good news - I sold my LM1 with the Edelbrock goodies to a guy who wants the Eddy stuff for an '84 Vette. Offset my L31 purchase by 50%.

Sorry for such a long post - I'm keeping notes here as much for myself as for all of y'all, but I of course welcome comments, suggestions, and to the best of my ability, questions. "42" will be my go-to answer if I don't know.

 

[benjaminearle]

"Figure" 50% of the air going through the radiator is used to cool the coolant itself and the other 50% cools your tranny fluid. Install an aftermarket tranny cooler: 100% of radiator airflow cools coolant and 100% of tranny cooler airflow cools tranny fluid!

I'm not saying it isn't better to have an external cooler but there's some flaws to the 50/50 versus 100/100 argument you present here. It's a matter of fluid heat transfer not just mass flow rate. For a given surface area (be that the rad with built-in cooler or a stack of trans cooler, AC condenser and Rad) there's only a certain amount of air moving through the heat exchangers. That air only has a certain heat capacity to absorb heat from those exhangers roughly linear with respect to the specific heats of the fluids, the thermal conductivity of the exchanger, the surface area of the exchanger and the mass flow rates of all fluids. If you heat up your cooling stream by passing it over the trans cooler first, you lose capacity to cool your engine coolant (typical stacked heat exchangers) if you reduce radiator size to make room for an internal trans cooler, you reduce surface area, SO there's a middle ground somewhere. The only truly additive solution (neglecting increased wind resistance) is to put an external cooler somewhere that it uses a completely different air stream than the engine radiator. I believe the reason you see "better" results with your external cooler is simply a function of increased surface area of teh trans cooler and the fact that the engine radiator is operating, successfully, below capacity.

Did I mention that I hold PE licenses in thermal and fluid systems design?

I'm done being a geek, back to loud pipes, big tires and grunting.

 

[Jims86]

I'm not saying it isn't better to have an external cooler but there's some flaws to the 50/50 versus 100/100 argument you present here. It's a matter of fluid heat transfer not just mass flow rate. For a given surface area (be that the rad with built-in cooler or a stack of trans cooler, AC condenser and Rad) there's only a certain amount of air moving through the heat exchangers. That air only has a certain heat capacity to absorb heat from those exhangers roughly linear with respect to the specific heats of the fluids, the thermal conductivity of the exchanger, the surface area of the exchanger and the mass flow rates of all fluids. If you heat up your cooling stream by passing it over the trans cooler first, you lose capacity to cool your engine coolant (typical stacked heat exchangers) if you reduce radiator size to make room for an internal trans cooler, you reduce surface area, SO there's a middle ground somewhere. The only truly additive solution (neglecting increased wind resistance) is to put an external cooler somewhere that it uses a completely different air stream than the engine radiator. I believe the reason you see "better" results with your external cooler is simply a function of increased surface area of teh trans cooler and the fact that the engine radiator is operating, successfully, below capacity.

Did I mention that I hold PE licenses in thermal and fluid systems design?

I'm done being a geek, back to loud pipes, big tires and grunting.

That egr tube MIGHT fit behind the manifold. I also had a thought...since you need to run at least 2 o2 sensors, that egr tube might screw into the o2 location of an 87 TBI exhaust manifold, then you can just run your sensors below the collectors. Also, if mods are needed, you could cut the tube at the straightest part...install in the exh, then the intake, and tack weld another piece of tube where needed.......any bending can be done befor the patch piece is installed. BTW, Do Not bypass the Rad trans cooler, just add the external cooler in line.

 

[benjaminearle]

That egr tube MIGHT fit behind the manifold. I also had a thought...since you need to run at least 2 o2 sensors, that egr tube might screw into the o2 location of an 87 TBI exhaust manifold, then you can just run your sensors below the collectors. Also, if mods are needed, you could cut the tube at the straightest part...install in the exh, then the intake, and tack weld another piece of tube where needed.......any bending can be done before the patch piece is installed. BTW, Do Not bypass the Rad trans cooler, just add the external cooler in line.

The only problem is finding an '87 manifold. I'd love the tank and sender from an '87 LWB too, but there's none in my local yards. I found a 89 suburban (square body) manifold, with AIR tap but it comes off cyl 1, not at the collector - not sure if that would be OK.

Out of curiosity, why would you not want to just bypass the internal cooler? I plan on starting with JUST the internal cooler from the '99 truck.

 

[Jims86]

The only problem is finding an '87 manifold. I'd love the tank and sender from an '87 LWB too, but there's none in my local yards. I found a 89 suburban (square body) manifold, with AIR tap but it comes off cyl 1, not at the collector - not sure if that would be OK.

Out of curiosity, why would you not want to just bypass the internal cooler? I plan on starting with JUST the internal cooler from the '99 truck.

The air tap will work just fine.
Transmissions need to warm up quicker than just an external cooler will allow. Some rebuilders wont honor warrentees if the rad is not used.

 

[benjaminearle]

Transmissions need to warm up quicker than just an external cooler will allow. Some rebuilders wont honor warrantees if the rad is not used.

Thanks, so initially the trans wants heat from the engine, only later does it want to shed heat. Interesting.

Found a factory gauge cluster with big speedo and tach, small voltage, coolant, oil press and fuel. VERY tempting, but it's in wood grain, not aluminum.