Addressing Internet Myths About LS Swaps

dropstep said:

The price point is a big one that usually makes me quit reading about people's cars. So many people have a 6.0 swap that claim they have 500 bucks in everything including the cam, heads, intake and nitrous package. Having done a few swaps myself, never LS but the little detail stuff seems to always catch people off guard. 

I think that what is happening with a lot of this is people ignore the costs of the radiator/headers/exhaust because "it would have needed it anyway".

I have near $500 in rebuilding my car after the last rallycross, for cryin' out loud.  $142 gearset on super mega discount on eBay, $220 for bearings and seals, $40-ish in gear oil, $20 in carb cleaner.  Add up ALL the costs involved, not just the major items.  (I am generously not counting the $40-ish bucks in fuel to get to Summit and back the first time, and the hour of detour the second time)

When I converted this same car to a different front suspension (FB RX-7, to FC RX-7 frontend) it cost me about $300 for new struts and strut mounts and misc stuff, and a $50 parts car.  However, I did the swap because I needed two new ball joints and a new idler arm and a steering gearbox, which would have cost something like $1800.  Could I go online and say I converted my car and it paid me $1500?

This still ignores the driveshaft problem.  Around here, a custom driveshaft is $500 right there, full stop.  This is exactly why I spent way too much time figuring out how to make a Ford 9" work in my Mazda while maintaining the OE driveshaft.

Knurled. said:

Keith Tanner said:

AC was the hardest thing for us to work out on a "production" swap. Mating the GM and Mazda systems involved parts that just weren't available anywhere. We did some by taking Mazda parts and having them modified, but between the PITA factor and too much variance in quality we had to have the parts machined. We did the same for the PS, there are some custom fittings in there that you're just not going to find in nature because nobody else wants to put an AN fitting on a Miata rack.

We just make our own lines.  There's a company that makes threaded fitting hose barbs for the common compressor(s) used on these engines (is there even more than one?) which makes creating generic hoses simple.  Alternatively, you could TIG up something.

Oh, the GM side is cake. But the fittings for the Mazda end do not exist. There is no company that makes them, and we had a hard time coming up with someone who could deliver on their promises. It was the last part to make production on our NA/NB swaps.

It's one of those things that's really easy to solve in a forum post but turns out to be much more difficult when you're trying to put parts on the shelf in real life. There's a big difference between working for free and having to account for your time. Pulling a rack apart, TIGing things together, drilling, tapping, new lines - before you know it, you have 5 hours in the job and that's over $500 for the customer. If you can do it with a $100 custom adapter, you've just saved money.

Keith Tanner said:

Knurled. said:

Keith Tanner said:

AC was the hardest thing for us to work out on a "production" swap. Mating the GM and Mazda systems involved parts that just weren't available anywhere. We did some by taking Mazda parts and having them modified, but between the PITA factor and too much variance in quality we had to have the parts machined. We did the same for the PS, there are some custom fittings in there that you're just not going to find in nature because nobody else wants to put an AN fitting on a Miata rack.

We just make our own lines.  There's a company that makes threaded fitting hose barbs for the common compressor(s) used on these engines (is there even more than one?) which makes creating generic hoses simple.  Alternatively, you could TIG up something.

Oh, the GM side is cake. But the fittings for the Mazda end do not exist.

We splice in to the existing lines.  Granted, this is one of those places where it is easy for a shop delivering a car, complicated for a place shipping a supply of parts.

As for the rest of your post that I deleted for brevity... we weigh parts cost vs labor cost all the time, and it is surprising how often it is cheaper to just throw money at Atech (Summit) or other suppliers, when you are charging $90-120/hour.  Even for simple things...  let's say you spend five minutes looking for a weird bolt.  If that bolt costs less than ten dollars to buy, you just wasted money.

We tried splicing on to existing lines but it was not as reliably successful as we would have liked. Again, not an issue for a one-off build but it only takes one or two do-overs to eat up a lot of profit. Getting the custom fittings made it a slam dunk every time.

When time really has a value, the cost of parts gets much lower!

SVreX said:

I can try to answer that, because I am building a 4.8L Miata. I can share my reasons...

- The 4.8 is an oversquare design. The rotating assembly is smaller. That means it revs better than it's bigger counterparts- very nice for a sports car. 

- The 4.8 has less torque than its big brothers, but still way out performs smaller displacement engines. I don't need huge torque in a 2600 lb car that is street driven.

- The 4.8 is really cheap. 

- The 4.8 is only a cam and heads away from 400hp. Ok, that's not 600 or 1000, but I am building a street driver, not a drag racer. 

- The exterior of the 4.8 is dimensionally identical to it's bigger brothers. That means all the work I do fitting a 4.8 into the car is not lost if I later choose to switch to a bigger engine. Transmission, mounts, exhaust, heads, intake, pan, hood clearance, front cradle will all still work. 

I consider the 4.8 a cheap mockup motor that may offer me all the performance I want, but is easy to switch later.

Well stated, I appreciate the reply. I had actually considered the sizing and fitment work being a likely one-time thing later that evening, glad to see I was on target there.

With the 4.8 being oversquare, how far can you really rev it? I appreciate oversquare engines (the 1jz in my Supra is a 71.5mm stroke with 86mm bore, these things REV if you set the head up right), but being a pushrod engine, what is a realistic redline? I like high rpm engines, but I get nervous about the idea of spinning a pushrod setup more than 7500...

All in all, it sounds like a sound plan for a Miata, should be a good fit, I just figured if I was going to swap mine to a v8, I would just go off the deep end. That said, it's obvious to me that I'm barely informed about the possibilities with the 4.8, I had no idea that they were capable of 400hp with the right cam / heads. I just assumed they were turds, that's on me and me alone.

Keith Tanner said:

As for when the work becomes worthwhile - if you're paying someone else for the work, my thought is that the crossover point of V8 vs turbo four on a Miata is about 400 hp. That's the over-simplified peak power number, of course, and ignoring the fact that at 400 hp the rest of the Miata driveline is a grenade with the pin pulled while the T56 and GM rear are snoozing. But if you're comparing peaks, that's where the hp/$ lines cross. If you're doing your own work and buying junkyard parts, I think it would be lower down. They're very different to drive though, just like a 200 hp naturally aspirated four feels different than a 200 hp turbo four does.

This is exactly what I was looking for. I was assuming folks who were putting in the 4.8 and 5.3 were just dropping stock engines in them, at which point, to me, a well sorted turbo approach seems to make WAY more sense. Now if we're talking swapped heads and cams, or desire to expand upon the v8 power further, then yeah, a swap totally makes sense to me.

Kinda surprised FM doesn't make an adapter to mate the T56 and Getrag diff for those guys with the mean turbo BP's... must not have made much of a business case, I would think.

DeadSkunk said:

In reply to Trackmouse :

What does it take, control wise, to get a 1UZFE up and running in a car without any computer? There's one available locally at a Challenge friendly price, complete with the harness , ECU and transmission. It's from a 1992 SC400, if that's pertinent.

If you could use the ECU from the donor SC, I think you're gonna be alright. The only thing I can think of off the top of my head, you might want to try to incorporate the ignition cylinder into whatever car you're putting the 1uz into. Those fancy keys are like many of the 90's, an integral part of the security system.

In reply to te72 :

The first 2 years of 4.8 were low rated.  From there they kept climbing in power ratings.  I picked up a 36k mile 2010 engine rated at 300hp that came with heads that are essentially ls6 spec(minus the sodium filled valves) for $600 last year.   My current challenge build has a 2003 4.8 that was $200 with harness and accessories.  Previous challenge build datsun z car weighs in at 2450 with an iron block 5.3 making an estimated 330hp with no changes other than camaro intake and exhaust manifolds. It could indeed be sub 2400 pounds with an aluminum block but the iron one fit my budget and it was sitting here doing nothing. With me in the seat the car is 50/50 front rear weight distribution.  So as long as people keep scoffing at the iron blocks i’ll keep snatching up the deals.  i can still throw a dart at Craigslist any day and get a $450 300hp 5.3 with harness and computer.  The $200 ones are harder to find.  The early 4.8/5.3 heads will support 400hp n/a but the easiest way is pretty much to slap an ls6 cam in and a set of 243/799 heads.  I’ve produced 489hp on stock camaro exhaust manifolds and single exhaust, so tubular headers aren’t a necessity either.  

te72 said:

Keith Tanner said:

As for when the work becomes worthwhile - if you're paying someone else for the work, my thought is that the crossover point of V8 vs turbo four on a Miata is about 400 hp. That's the over-simplified peak power number, of course, and ignoring the fact that at 400 hp the rest of the Miata driveline is a grenade with the pin pulled while the T56 and GM rear are snoozing. But if you're comparing peaks, that's where the hp/$ lines cross. If you're doing your own work and buying junkyard parts, I think it would be lower down. They're very different to drive though, just like a 200 hp naturally aspirated four feels different than a 200 hp turbo four does.

This is exactly what I was looking for. I was assuming folks who were putting in the 4.8 and 5.3 were just dropping stock engines in them, at which point, to me, a well sorted turbo approach seems to make WAY more sense. Now if we're talking swapped heads and cams, or desire to expand upon the v8 power further, then yeah, a swap totally makes sense to me.

 

Kinda surprised FM doesn't make an adapter to mate the T56 and Getrag diff for those guys with the mean turbo BP's... must not have made much of a business case, I would think.

The T56 gearing doesn’t work well for that application. We do, however, have a staff member who just finished installing a Getrag rear in his turbo four. I think it drove for the first time about four hours ago. 

Also, note my disclaimer about peak power numbers, then go look at that dyno chart I posted. 400 hp is not always the same. 

With LS engines as well as SBCs, "short stroke = RPM" is kind of a myth because even with 3.75" strokes, the RPM limitation is the top end, not the bottom end.  It might have been true in the 60s but nowadays, bottom end strength is good enough and valve lift and acceleration are high enough that keeping the valvetrain together is the biggest issue.

Having a lighter crank IS nice in a lightweight car, though.

In reply to wheels777 :

Those kind of deals just aren't common in my area. 

In reply to wheels777 :

Please don't assume what you do is easy for others to duplicate.  Your parts stash is a result of years of experience building Challenge cars and searching for these sorts of deals and apparently the capital to purchase parts whether they are needed or not as well as the room to store it all until needed. Most of us are building projects with an "as needed" philosophy towards parts purchasing and barely have room for what we're working on. 

Knurled. said:

With LS engines as well as SBCs, "short stroke = RPM" is kind of a myth because even with 3.75" strokes, the RPM limitation is the top end, not the bottom end.  It might have been true in the 60s but nowadays, bottom end strength is good enough and valve lift and acceleration are high enough that keeping the valvetrain together is the biggest issue.

 

Having a lighter crank IS nice in a lightweight car, though.

I think that's only half the equation, as has always been the case. 

Small bores do reduce airflow through the heads by shrouding the valves. But a short stroke still means reduced piston speed which means increased engine speed.

Combining both means big power. 

Hot Rod Magazine builds a 4.8 crank LS3- 8000 RPM, 607 hp

yupididit said:

In reply to wheels777 :

Those kind of deals just aren't common in my area. 

No kidding. I just spent a few minutes scanning Craigslist and car-part, and the cheapest 4.8 I found was $700.

In reply to te72 :

Knurled and SVRex are correct.

There are few strip cars out there running 7500+rpm on the stock bottom end with nothing more than uprated pushrods and springs; in both 4.8 and 5.3 variants. As long as the cam and heads can support higher rpms, it would happily spin. Therw's a fierce debate about what oil pumps are capable of as well.

I can't remember which year, but GM started install LS7 lifters in all V8s. Those are the same lifters used in V1 CTS-V 346ci engine (LS7 bottom end with 4.8 crank). Before PWC hobbled that engine, it was turning 8000ish rpm.

te72 said:

DeadSkunk said:

In reply to Trackmouse :

What does it take, control wise, to get a 1UZFE up and running in a car without any computer? There's one available locally at a Challenge friendly price, complete with the harness , ECU and transmission. It's from a 1992 SC400, if that's pertinent.

If you could use the ECU from the donor SC, I think you're gonna be alright. The only thing I can think of off the top of my head, you might want to try to incorporate the ignition cylinder into whatever car you're putting the 1uz into. Those fancy keys are like many of the 90's, an integral part of the security system.

With the SC's, you don't need a paired ignition cylinder. The ECU on 2JZ and 1UZ is simpler than people think, once you track down the right pins. There are maybe like 4 pins that need power, a few that need ground but are already grounded to the engine, and one for the ign switch. No security or anything to worry about. I am using an Automatic ECU with my 5-speed trans and generic relays and switches. You can see the Rice Rod thread for more info on it.

Tom_Spangler said:

yupididit said:

In reply to wheels777 :

Those kind of deals just aren't common in my area. 

No kidding. I just spent a few minutes scanning Craigslist and car-part, and the cheapest 4.8 I found was $700.

That’s just not how you find good deals on anything. It takes time and patience. And that $700 4.8 is likely to be $200 after a few months of sitting and a little negotiation. 

Ian F said:

In reply to wheels777 :

Please don't assume what you do is easy for others to duplicate.  Your parts stash is a result of years of experience building Challenge cars and searching for these sorts of deals and apparently the capital to purchase parts whether they are needed or not as well as the room to store it all until needed. Most of us are building projects with an "as needed" philosophy towards parts purchasing and barely have room for what we're working on. 

For normal builds buying as needed is fine.  For most challenge builds it works too.  For top contending challengers you really do need to be able to buy right now “because i’ll need it one day” when you’re in the right place at the right time.  This is why i have a $20 LS1 intake in my stash(with documentation of purchase), because I bought it in 2005 when everyone was throwing them in the trash to toss on ls6 intakes.  I’ve unfortunately filled my garage, a harbor freight portable garage, and part of my dad’s garage attic and barn loft with these things.  It’s a blessing to have the parts and a burden at the same time.  I’ve been tripping over a rusty $35 disc brake 9” ford rear end for 5 years because it was too good a deal not to buy.  I’ve cursed myself multiple times for buying it.  But one day it’s going to be in a challenge car and it’s hard to argue with spending so little on such a strong axle.  

Back to the topic at hand, when I absolutely needed the 2010 4.8 because it was one of only a handful of engines that would work with what i was doing, i found the best deal on car-part.  Otherwise LKQ via ebay is my go-to for engines with a warranty at a good price.  They had a few 345hp LQ9 6.0 engines last time I checked for under $1000.  

Strike_Zero said:

In reply to te72 :

Knurled and SVRex are correct.

There are few strip cars out there running 7500+rpm on the stock bottom end with nothing more than uprated pushrods and springs; in both 4.8 and 5.3 variants. As long as the cam and heads can support higher rpms, it would happily spin. Therw's a fierce debate about what oil pumps are capable of as well.

I can't remember which year, but GM started install LS7 lifters in all V8s. Those are the same lifters used in V1 CTS-V 346ci engine (LS7 bottom end with 4.8 crank). Before PWC hobbled that engine, it was turning 8000ish rpm.

LS7 bottom end with a 4.8 crank?  Since when?

Patrick said:

Ian F said:

In reply to wheels777 :

Please don't assume what you do is easy for others to duplicate.  Your parts stash is a result of years of experience building Challenge cars and searching for these sorts of deals and apparently the capital to purchase parts whether they are needed or not as well as the room to store it all until needed. Most of us are building projects with an "as needed" philosophy towards parts purchasing and barely have room for what we're working on. 

For normal builds buying as needed is fine.  For most challenge builds it works too.  For top contending challengers you really do need to be able to buy right now “because i’ll need it one day” when you’re in the right place at the right time.  This is why i have a $20 LS1 intake in my stash(with documentation of purchase), because I bought it in 2005 when everyone was throwing them in the trash to toss on ls6 intakes.  I’ve unfortunately filled my garage, a harbor freight portable garage, and part of my dad’s garage attic and barn loft with these things.  It’s a blessing to have the parts and a burden at the same time.  I’ve been tripping over a rusty $35 disc brake 9” ford rear end for 5 years because it was too good a deal not to buy.  I’ve cursed myself multiple times for buying it.  But one day it’s going to be in a challenge car and it’s hard to argue with spending so little on such a strong axle.  

 

Back to the topic at hand, when I absolutely needed the 2010 4.8 because it was one of only a handful of engines that would work with what i was doing, i found the best deal on car-part.  Otherwise LKQ via ebay is my go-to for engines with a warranty at a good price.  They had a few 345hp LQ9 6.0 engines last time I checked for under $1000.  

It’s neat that you can retain documents of deals like that.       If I could I would have a wonderful car that by the actual costs  be under $1000 but becomes too expensive if I need to use fair market value.  

In reply to Tom_Spangler :

https://flint.craigslist.org/pts/d/53-ls-motor-from-2002-chevy/6580234915.html

Deals, great deals,  are achieved through knowledge and patience. A willingness to walk away and wait.  

Maybe combing through old ads or making note of items and call after 30-90 120 days.  

I used to get a lot of great deals because I was the go to guy on Jaguars.  When someone would give up on selling it at the price he wanted, he’d call me and ask if I was still willing to buy it at my price.  

Then storage is involved.  Deals come not when you are ready for them but when they are ready for you.  

stylngle2003 said:

Strike_Zero said:

In reply to te72 :

Knurled and SVRex are correct.

There are few strip cars out there running 7500+rpm on the stock bottom end with nothing more than uprated pushrods and springs; in both 4.8 and 5.3 variants. As long as the cam and heads can support higher rpms, it would happily spin. Therw's a fierce debate about what oil pumps are capable of as well.

I can't remember which year, but GM started install LS7 lifters in all V8s. Those are the same lifters used in V1 CTS-V 346ci engine (LS7 bottom end with 4.8 crank). Before PWC hobbled that engine, it was turning 8000ish rpm.

LS7 bottom end with a 4.8 crank?  Since when?

My bad! It's a LS2 based engine with a LS7 sized bore.

KAT-A4725 Crate Engine - Sneak Attack LS7 5.7L

With an 8000rpm redline, this crate engine is ideal for that “sleeper” ride. Package includes a Katech sleeved LS2 case, Katech forged piston-rod assembly, forged crankshaft, LS7 cylinder heads, and an LS7 derived valvetrain coupled with Katech specified camshaft. 

PN Name Displacement Bore Stroke

KAT-A4725 Sneak Attack LS7 5.7L / 346ci 4.125 3.268

In reply to wheels777 :

I never had a FB; didnt even know they had a market???

I have a decent amount of searches saved, and I never see anything that is as good as you state. But, I see yall are soaking them all up. So, that mystery is solved.

yupididit said:

In reply to wheels777 :

I never had a FB; didnt even know they had a market???

I have a decent amount of searches saved, and I never see anything that is as good as you state. But, I see yall are soaking them all up. So, that mystery is solved.

facebook marketplace is the new craigslist.  Its simpler to post and, as a result, gets more traffic.