Ultimate Chevrolet V8 help thread - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

g6civcx · 08-13-2010, 12:11 PM

OK, let's cut the BS. Over the years I have only seen a handful of Chevrolet V8 engines successfully swapped into an S-chassis. I have seen even fewer people who can offer credible info on this swap.

I want this thread to be about informing and educating people who want to do this swap. It's a very long and hard road. Ask anybody who has ever completed one.

I have seen way too many V8 swaps fall by the side due to unrealistic expectations, lack of budget, lack of skills, lack of know-how, etc.

You should jump in with eyes wide open so you know what to expect.

Having said that, I'm now on my 5th season with my Chevrolet V8 swap. Please feel free to ask any question. If you have useful info please feel free to contribute as well.

Please keep non-constructive comments out of this Tech thread. You can PM me with your criticism.
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Step 1: picking the engine

The very first thing you will want to decide is which engine families you will want to use.

Now keep in mind that when I say engine families, I am talking about exterior dimensions. Each engine family has slightly different exterior dimensions and mounting options.

Internally, any engine can be built to any specs. Don't limit yourself to what you think is possible. An engine from any family can be built to any specs: aluminium block and heads, 10,000 RPM rev limit, high boost/low compression, or anything you can think of. All these things are possible. The exterior dimensions is really just a mold and they can build the block to whatever specs you want.

Keep in mind though that the difference between the engine families (other than dimensions) is price. You can build an LT-series to the same spec as a stock LS7, but you'll likely spend more trying to build up the LT-series.

I'll talk about some of the popular swaps.

Big block: Big Block Engines | 454 Engine | 502 Engine | 572 Engine

I can tell you from personal experience that the big block is too wide to fit between the frame rails of a stock 240. Only consider this swap if you're willing to tub out your front end. I won't comment any more on this swap.

Small block - Generation 0/I/II, sometimes referred to as "small block" per se
Small-Block Engine - Crate Engine | GM Performance Parts

I lump all of these together due to their similar external dimensions.

This is a very good budget build. Externally they're a little larger than the newer GenIII/IV engines, but you can pick up parts very cheaply.

FYI, in the US (and probably the entire world), this is the most commonly built passenger car and light truck engine. So chances are you can find used and replacement parts very easily.

Most of the Gen0/I run on carbs, but there is ample aftermarket support for FI conversion kits. You can also build aluminium blocks and heads, high/low compression bottom ends, high rev top ends, etc.

The problem with this swap is that there too MUCH aftermarket support. You can find dozens if not hundreds of manufacturers for any part you need.

This is the engine I chose due to cost and availability of parts.

The only comment I have is that you may want to avoid the GenII/LT-series engines. These tend to have a lot of problems and don't perform quite as well as the other Gen0/I engines for the same budget.

Even if I can get a free LT1 I wouldn't even do it, but do your own research. There is a lot of literature on the LT-series engine.

Small block - Generation III/IV V8, "LS-series", "LS", or colloquially "LSX"
http://www.gmperformanceparts.com/Pa...l.jsp?engine=0

This engine family is a little slimmer than the Gen0/I/II, and is considered to be a little bit more modern than the old Gen0/I/II design.

This is also a fairly popular engine in terms of production, but keep in mind that FI parts tend to run a little more expensive than carbureted parts. You can convert any LS-series back to carb if you want. There is plenty of aftermarket support for either application.

My only problem with this is price and availability. Since these engines came in newer cars, you can't find as many GenIII/IV in junkyards as older engines. Also since they are modern and have more parts, they tend to be a little pricier if you do find them.

This is a good choice if you want good power in stock trim. Lightly modded they make a lot of power, if you don't mind paying a little more.

g6civcx · 08-13-2010, 12:21 PM

Step 2 - picking the transmission/gearbox

There are really only a few transmissions worth running with this swap. Keep in mind that any transmission can mate to any small block chevy. There is a lot of aftermarket support. You can even get a high-performance automatic if you wanted. It all depends on what you want.

I'll just briefly comment on the most popular and straight forward choices.

Borg-Warner (World Class) T5

This is probably the most popular transmission used in pony cars in the 80s and earlier 90s. They came in the F-body and Mustangs. You can probably pick one up fairly cheaply since they're only 5-speeds.

The only problem is that they tend to be weaker. If you're putting down serious torque on slicks the T5 may not be able to hold all that torque.

On the good side, the T5 is very light and simple. There's not much to go wrong.

Just make sure you get a T5 out of a V8 car if you want it to fit. The T5 also came with V6 engines but the spline count is slightly different. Internally they are similar so you can use them for spare parts if needed.

This is a good choice for mild roadracing, autocross, or daily.

I chose the T5 for my car because of cost and availability. If you plan on putting down a lot of torque you may want to step up to a T56 or aftermarket T5.

Borg-Warner T56

Everybody knows about this so there's not much to say. It comes in Mustang, Camaro/Firebirds, and even Vipers.

They're beefy in stock form, and you can get custom gearsets pretty easily. Just make sure you get the ones for Chevrolet application.

Other choices

There are many other options, but the T5/56 are by far the most popular ones. You can do research on your own.

TIP: the stock clutch master cylinder bore is too small to push the slave cylinder on the T5/56. Clutch travel is excessive because the bore is too small. Sikky makes a nice kit that comes with a new Wilwood 3/4" clutch master cylinder for good pedal travel.

g6civcx · 08-13-2010, 12:45 PM

Step 3 - picking the engine mounts

IMHO, this is the most important step. As of right now I'm only familiar with a few kits.

Mounting options

Before selecting a kit, decide how you want to mount the engine. Ideally the best setup is to notch the firewall and shove the engine back as far and as low as possible for better weight distribution. This is what I did.

Now keep in mind that most drifting sanctioning bodies no longer allow notching the firewall.

Hinson Supercars - Hinson Super Cars

Back in the early 2000s Hinson was pretty much the only company offering swap kits for 240s. They only support GenIII/IV though. They don't have a kit for Gen0/I/II.

Pros:
* technically sound kit
* no modification to the vehicle body (other than subframe)
* they offer turnkey installation
* good support

Cons:
* price!
* you have to chop up your subframe, which means you'll have trouble going back to KA/SR if you wanted to
* No T5 support

I avoided Hinson mostly because they don't support Gen0/I, and because of price.

Sikky: High Performance Auto Parts :: SIKKY Manufacturing

They've only been around a few years. I've only seen one of their car in action in person so I can't comment much. Just from what I've seen:

Pros:
* price
* no subframe modification
* good support
* no firewall notching

Cons
* awkward engine placement. The LS1 I saw sat really high compared to the Hinson kit. This may be an early pre-production kit so I didn't know if their actual kit was going to be that bad.
* no T5 support

McKinney Motorsports: 350 Chevy 240sx Products McKinney Motorsports

I really like this kit because they support Gen0/I/II. You can search the Tech forum for the build thread.

Pros:
* support for Gen0/I/II
* price
* no subframe modification
* decent engine placement
* good support
* no firewall notching

Cons
* no GenIII/IV support
* only supports Tremec TKO, B/W, Muncie. T5/56 support still in development

I would love to see more products from McKinney. Their pieces look really high quality with good R&D.

I would not hesitate to use their kit in my car.

Custom

This is the best but most expensive way to go. You can design your engine placement, but make sure you know what you're doing or you have a good shop backing you up.

This is the route I went because back when I did this swap, no one offered support for the Gen0/I/II.

I wanted the mounts to do the following:

1. Place the engine as far back and as low as possible
2. No modification to the subframe.
3. Minimal modification to the engine.

This is the shop that did my engine mounts: B&T Motorsports Online

They cut the firewall and shoved the engine a good 6" back. The subframe remains unmodified. The only other body mod was slight relocation of the windshield wiper connecting rod.

The only modification that I had to do to the engine:

* oil filter relocation kit, oil filter hits the frame rail
* custom oil pan to clear the subframe. I started with a Moroso 7qt oil pan. I had the shop cut out the bottom of the pan and reweld a new bottom to clear the subframe. The final result ended up with a stock capacity oil pan of 4.5 qt and no subframe modifications.

No other mod was needed to fit the engine and transmission into the car.

Some pix for comparison.

This is a stock single cam KA. The front of the block is 12.25" from the radiator support and the valve cover gasket is 2" below the ledge on the firewall.

This is the V8. The front of the block is actually 15" away from the radiator support. The top of the valve cover is actually 4" below the ledge on the firewall.

Approximate dimensions of the Gen0/I: http://www.enginefactory.com/chevdimensions.htm

Height from front sump to top of valve cover: 20.5", dimension C
Length from back of block to front of block: ~25", dimension B minus pulley

Go measure your own KA length and height and see how my custom mounts measure up.

g6civcx · 08-13-2010, 03:11 PM

Step 4: Picking the rear end.

Of every V8 240 I've seen, all the owers say that the stock 4.083 rear diff is no good. You spin the first 3 gears without trying and freeway cruising is an unacceptable 3,000 RPM.

Most people with this swap go with something around 3.5-3.6. I have the lowest R200 diff which is 3.133 from the Pathfinder. You guys with high power builds can search my posts or PM me for info on this swap.

Drag racing guys may want to think about an R230 upgrade.

You can skip this step until later, but you can save a little bit of money if you can take care of the rear end before you spec the driveshaft.

You should get together with someone who has a lot of experience tuning race cars. Pull out your engine dyno sheet (or the closest thing you have), your gear ratios, and the wheels you want to run. Have them help you pick the best rear end for you.

Unfortunately there are only 5-6 ring gear choices for the R200. You can do research on that.

tip: swap the magnetic transmission drain plug with the non-magnetic diff filler plug.

g6civcx · 08-13-2010, 03:16 PM

Step 5: Building the driveshaft

After you have the engine, transmission, and rear diff driveline lined up perfectly, I recommend you calling the DriveShaft Shop and have them build you a custom spec driveshaft for your specific application: The Driveshaft Shop | 2010 Website Coming Soon

I've worked with DSS guys on over a dozen projects and they are VERY nice guys. Don't be afraid to call them and pick their brains. They can help you get the correct driveshaft for your application.

The price is actually not that bad. A custom shaft costs about the same as a stock-spec shaft. Talk to them.

You can talk to them about steel vs. aluminium while you're at it.

g6civcx · 08-13-2010, 03:25 PM

Step 6: exhaust

Sikky makes conversion headers. Hinson also sells a kit.

I prefer to use universal block hugger headers and custom Y-pipe that feeds into the stock cat. This allows me to use a regular 240 catback to save on cost.

Step 7: engine accessories

If you're lucky you'll be able to reuse all of your engine accessories if your engine came with them. Most likely you'll find that all the accessories are in the wrong place.

If you buy a crate engine, I recommend that you don't buy many of the kits that get sold. The reason is that most of the kits are meant for American cars, and you'll have clearance issues with the 240.

Instead, I recommend: Jones Racing Products, Inc.

They have pretty much every configuration for every chevy engine, and can help you get the right kit for you.

So instead of trying to ghetto rig something, you can get all of your accessories at one place and they're guaranteed to work. Pretty good guys when you need support as well.

TIP: You can mount a Chevy power steering pump to the stock rack high pressure line. You need custom high pressure fittings for the pump. I got my fitings and braided line from Harp @ Taka Motorsports. The return line is low pressure and can use a regular clamp-on type.

g6civcx · 08-13-2010, 03:33 PM

Step 8: HVAC

For a street car you may want to think about having AC. For a race car you should run a heater as a backup radiator.

You can reuse the stock AC with new compressor and lines. Or if you want, you can build a complete system. Vintage Air can help you with whatever you need: Vintage Air - Inventors of Performance Air Conditioning - www.vintageair.com

They sell cooling/heat units, as well as a complete line of compressor and all electrical accessories. They send you the lines. You cut and mockup the lines. Send the lines back to them and they'll crimp the lines for you for free.

jham4x4 · 08-13-2010, 07:35 PM

Step 9: Visit silviav8forums.com -Tons of cars tons of info....everything you need and more.

all4bspinnin · 08-17-2010, 05:58 AM

if this isnt a sticky then it should be.... thanks for the writeup! i was thinking about doing an lt1 swap in my s14 the other day so its funny you post this at this time.

g6civcx · 08-17-2010, 08:10 AM

Quote:

Originally Posted by jham4x4

Step 9: Visit silviav8forums.com -Tons of cars tons of info....everything you need and more.

You can if you want to. This is all information I learned first hand from my own experience. I know the Gen0/I and T5 swap the best. As of right now knowledge of this combo is still not as developed as the LS-series.

babillaracing · 08-18-2010, 02:32 PM

nice write up man

g6civcx · 08-18-2010, 02:40 PM

Step 9a: Wiring

Carbureted setups with manual choke requires only 3 wire hookup:

1. Key activated starter solenoid (15A if stock, 40A if using high torque aftermarket starter).
2. One thick 4 AWG, and preferably at least 2 AWG, power wire for the alternator and starter.
3. Key activated ignition (10A for most aftermarket HEI ignitions).

No other wiring is needed to make the engine run.

There are so many standalone engine harnesses for the Gen0/I carbureted setup. Pick the one you like most, or make your own.

Siberian Husky · 09-03-2010, 10:39 PM

i'd like to see this thread grow.

GSXRJJordan · 09-03-2010, 11:36 PM

I've swapped a few V8's into a few different cars, and have taken it upon myself to become a subject matter expert since doing my LSx FD3S.

The SBC (small block Chevy, AKA Gen0/1) is cost effective, but certainly not ideal in any respect. They're almost all iron block and about half have iron heads as well, and unless you're boosting >10psi, iron block sucks. When you factor in partial-throttle response and fuel economy with the ease of GenIII/IV (LSx) wiring, running carbs on your street car becomes a little ridiculous as well. Obviously, I'm not a fan.

As far as kit companies go, Hinson's in some hot water right now and although their products are generally pretty good, they're backed up. I have nothing but warm fuzzies about Sikky's swap kit, and Daft has some good stuff as well (I think they're cheaper but not as complete). With the multitude of engine mount options, headers is really the thing you want to buy rather than fab yourself, and you can't go wrong with either of those.

That brings me to headers - block huggers to use stock cat and catback? Get serious. You're leaving 30hp+ on the table, after all the work to get a v8 in your car? Get some legit longtubes for a few hundred bucks and do true duals with an X-pipe (street) or H-pipe (race).

The real 'sweet spot' (budget-wise) in my opinion is to find a LM7 (GenIII 5.3L Aluminum block out of Silverado 1500's) engine with relatively low miles (50k or less is common) with harness, PCM (that's powertrain control module, GM-speak for ECU), and accessories for less than $1000 and slap a T5 or T56 on it. 300hp stock, high revving, FUN FUN FUN, and cheap.

If you've got a few grand more to spend, you get a 2001+ LS1 drop-out from a Camaro or Firebird. They've got the best OEM header/cat config for trying to pass smog, no EGR, and the LS6 intake manifold stock.

If you've got somewhere around $10k, a forged 402ci shortblock using a brand new GenIV block and 4" bore x 4" stroke (that's block + rotating and reciprocating assembly, no heads and no trans) runs about $4k, slap some 243 heads (C5 Z06 and all LS2's) on there for $500 or some L92 heads (LQ9 and LS3) for $1k or so with a cam/pushrods/springs/retainers and pick up an accessory kit and T56 for 500+rwhp all day.

I'll admit that I play in the higher-end V8 builds more often than the budget stuff, but I'll be helping a few Pro-Am guys reach their V8 goals on some tight budgets this year, and of course I do all the electronics.

g6civcx · 09-04-2010, 12:34 AM

I'm getting tons of PMs on this topic still (to the point of clogging my inbox). So I'm putting the info here for searching. But you all heard it, non-LS-series engines suck and carbs suck so don't ask me any more.

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