EFI SBC vs LS Motor

[redefined]

Just looking for some specifics on why to do one vs the other. Currently I have a 350 SBC & T-10 with the following mods:

• Eldelbrock TEC 200 Aluminum Heads
• COMP Cam 12-612-5 Solid Lifter Cam
• Roller Rockers
• Ceramic Coated Headers
• Holley Competition 750 cfm
• MSD Ignition
• Super T10 4 Speed Transmission
• Center Force Clutch
• Scatter Shield
• Hurst Comp Shifter
• OEM Forged Crank
• OEM polished rods
• TRW pistons w/ floated wrist pins
• Balanced rotating assembly
• ARP Head Bolts & Fasteners

So I've been really interested in doing an LS swap, even have tossed the above setup for sale, but a friend says since I've already got some decent parts on this motor why not just EFI it?

Now my goal is 700whp with a blower - granted this will be a while down the road, one step at a time.

From what I've read, with no specifics other than newer technology, the LS motor does everything better. From fuel economy to making power and the important one drive-ability. A big one for me is the reliability and turning the key and having it start, without pushing the pedal 4 times etc. Yes the 350 has never let me down but I'm nervous every time it cranks for a min, ha!

So why not do an intake manifold and EFI on the 350 SBC? Why should I swap to the LS?

To you guys that have done the EFI on the 350, what parts have you used?

Thanks!!!

[ProTouring442]

I am no expert, but from what I have read, it seems to me that when it comes to breathing, the LS engines are really more akin to a Big Block, and that's the big difference between the old Small Block and the LS engines.

[Vegas69]

You can make the same power in a more reliable package with an Ls.

[TheJDMan]

The irony is that with all the interest in LS conversions, the SBC parts are becoming very inexpensive. While I continue to monitor LS conversions, at least for the forseeable future I will be running a SBC. I am considering a throttle body EFI to replace my Holley double pumper at some point.

[redefined]

Originally Posted by TheJDMan

The irony is that with all the interest in LS conversions, the SBC parts are becoming very inexpensive. While I continue to monitor LS conversions, at least for the forseeable future I will be running a SBC. I am considering a throttle body EFI to replace my Holley double pumper at some point.

I've thought about it. If you do this you still have to do all of the other 'fuel' parts. Tank/pump/regulator/lines etc. At which point if you decide to go LS it'll already be done, ya? Or am I missing something here?

I thought about converting my built SBC over to fuel injection too, or even procharging it but my compression is a little to high at 10:1

[WSSix]

It's like Todd said, the LS does it more reliably. Even with your goal of 700whp, the LS will be more reliable though it's arguable what constitute reliable at that power level. If you were wanting a lower power level, say 500 or so at the wheels, I'd say stay SBC because with a blower that's not difficult or really even pushing limits and a good EFI system will allow for good drivability.

The other thing to keep in mind when building a forced induction car is where the power comes on. As an example, to me, a Procharger is a terrible choice for a pro-touring car or really any car not being drag raced. Go drive one and you should realize very quickly that it does not produce a linear power band and they have terrible lag(I know nothing about their new intelligent design so maybe that's changed) which is not enjoyable when going on and off throttle and around corners. So achieving your goals with boost and how much boost will be needed also has to be taken into consideration. At 700whp, the LS will do this better as well needing less boost which will allow for an engine that isn't piss poor when not under boost.

I would recommend building towards the ultimate goal from the get go or else you'll be redoing lots of stuff. If going for 700whp is required to you, get an LS now and call that part done.

[redefined]

Thanks for the response.

However, I'm not sure about your 'lag' description. Superchargers are far more linear than a turbo is, am I missing something here? Is it the that style supercharger, a Procharger that's not as linear?

I've own supercharged and turbocharged vehicles, mostly BMW's and the supercharger on that one was far more linear and constant than the turbo. On a road course you better know exactly when that turbo will spool or you'll be going sideways.

Correct me where I'm wrong! Thanks!

[camcojb]

Originally Posted by WSSix

It's like Todd said, the LS does it more reliably. Even with your goal of 700whp, the LS will be more reliable though it's arguable what constitute reliable at that power level. If you were wanting a lower power level, say 500 or so at the wheels, I'd say stay SBC because with a blower that's not difficult or really even pushing limits and a good EFI system will allow for good drivability.

The other thing to keep in mind when building a forced induction car is where the power comes on. As an example, to me, a Procharger is a terrible choice for a pro-touring car or really any car not being drag raced. Go drive one and you should realize very quickly that it does not produce a linear power band and they have terrible lag(I know nothing about their new intelligent design so maybe that's changed) which is not enjoyable when going on and off throttle and around corners. So achieving your goals with boost and how much boost will be needed also has to be taken into consideration. At 700whp, the LS will do this better as well needing less boost which will allow for an engine that isn't piss poor when not under boost.

I would recommend building towards the ultimate goal from the get go or else you'll be redoing lots of stuff. If going for 700whp is required to you, get an LS now and call that part done.

I've had three Procharged builds, none of them had any lag. Instant boost on WOT, maybe not max boost immediately, but enough to blow the tires off. Definitely not laggy like a turbo setup with the wrong or improperly sized turbo would have. And far less heat management issues than a front mounted turbo setup. Personally, I'm sold on the roots type blowers now for true instant boost and driveability. They may not make as much HP as turbos, but far easier to package and maintain, far less heat issues to deal with.