Jack-C

Hello fellow members,

I would like your advice on engine choice for a conversion. The engine has to be light, I want around 400bhp naturally aspirated. I am planning on stripping the stock engine down and doing a complete rebuild after the block has been machined.

The car choice is possibly one of the following: s2000, MK2 RX7, BMW E30.

If you could reccommend an engine and give some pros and cons of it, that would be great.

Thanks
Jack

usdmholden

Based on your two requirements of 400 hp after rebuild and light, basically any aluminum LS will do that, since they all weigh nearly the same. An LS2 will do it with basically zero mods.

superdave84

I suggest the LS2 as well. Super Chevy did an article on LS2 and LS1 upgrades and with just a set of long tube headers they dynoed the LS2 at 462 hp. That's a huge jump from the 405hp factory rating.

You can get just about any other engine to run 400hp too, but you'll need to swap the cam and most likely heads. Probably cheaper to just get the LS2 in the long run. I just bought one for $3200 from LKQ.

usdmholden

No need to swap heads for only 400 crank hp. Even then, in most cases, still no need to swap heads for 400 wheel hp.

Any aluminum LS engine, (LM4, L33, LS1, LS2, L76, L92, LS3, etc) with small cam, valve springs, pushrods, long tube headers, aftermarket tune, more than 400 hp unless you really screwed something up. The bigger then engine, the more power it will make over 400. Don't buy an LS4, it is an aluminum 5.3 but it is also a front wheel drive engine. Everything on that list to the right of the "LS2" including the LS2 really won't need anything additional for 400 hp once you get headers installed for your swap.

Of them all, the LM4 and LS1 have the "worst" heads (806, 853, 241, 706, 862), which however are still very good in comparison to most other engines, and the LM4 and L33 has the smallest displacement (5.3L).

The best engine would be the LS2 since it comes as a car engine and will be the cheapest 400 hp car engine you can get which requires zero modification. Obviously the larger displacements make more power but they also cost a lot more than an LS2. Frankly though, an fbody LS1 dropout with a cam installed will get you where you want and be cheaper than an LS2, but I don't put it as #1 because the cam will have to be swapped.

Jack-C

Cheers guys for all your advice. Depending on my finances at the time, I will be wanting to up-rate the pistons, crank, con rods, valve gear etc. What is the major difference between the LS2 and LS1 engine, Do they both have an Aluminium block and head? Is it the cam which UDMHOLDEN mentioned?

Living in the UK sucks for trying to buy a used Chevy V8!!

Jack-C

Are the wiring looms and a manual transmission for the LS2 easy to get hold of? And in your experience, which company do you guys recommend for each component?

superdave84

The LS1 is a 5.7 liter engine, and the LS2 is a 6.0. Heads will be aluminum on all of these engines, except I think there were some iron heads on some of the early truck motors, but those are extremely rare.

I am not sure of the exact horsepower rating of the LS1, but I believe they can be as low as 300hp, or as high as 350hp. I know the 2004 GTO came with an LS1 rated at 350hp, but I don't think the earlier LS1s from the Vettes were rated that high.

The LS2 has much better heads, a better intake, and larger displacement. They are rated at 405hp stock, but as I mentioned before, the LS2 is extremely responsive to simple upgrades like headers and/or a cold air intake.

For transmissions, all car and truck motors have the same bolt pattern to attach the transmission, and you can even use transmissions older than the current engines (TH350, TH400, 700R4, Powerglide, and all the manual variants). The only exception is the LS4, which will not bolt to any transmission except the front wheel drive version. Any of these transmissions should be about as common as the engines, although I have never been to the UK and I have no idea how many GM cars/trucks there are to choose from over there.

Jack-C

Thanks for that, it has made it much clearer for me now. LS2 it is! In your experience how much can I pick a running LS2 engine with a manual transmission incl all ancillaries for in America, I might look at shipping costs.

superdave84

It depends on the mileage. I just picked up an LS2 for $3200 (USD). It was complete, but there was no transmission. Mine has 111,000 miles on it.

You'll find several LS2s with everything attached, plus a transmission starting at about $5500, and going up a little from there, depending on the mileage. Keep searchign for "GTO engine", along with "LS2". Most LS2s came in Corvettes, and a Corvette engine would work fine, however the Corvette transmission is way different than a normal transmission, and will not work for a swap. It has part of the trans in the front (behind the engine) and part of it at the rear of the car between the wheels. So, I would suggest looking for GTO engines/transmissions if you want the LS2.

Look on ebay. I'm sure many of the sellers are willing to sell internationally for the right price. Keep in mind that you will need to send your computer out to a programmer as well, to remove VATS (vehicle anti-theft system), remove the rear O2 sensors, and make a few other changes in order for your car to run and function properly. I chose to use the guys at PCM Performance. Cost me $300 and I got to reprogram everything exactly how I wanted...plus they retuned it to add about 20 more horsepower.

Pop N Wood

iTrader: (1)

You might do well to spend some time reading about these motors. You are drinking from a fire hose right now. Lots of information on this site and others.

Not sure why you have decided to rebuild the motor. LS motors easily go 200k miles without rebuilds. The bottom ends are very stout, especially with only a 400 HP goal. You shouldn't need to upgrade unless you are looking for much more. If you are set on having a new bottom end, look into a new crate motor. Scoggin Dickey is a sponsor here and they ship internationally. Buy a GM crate motor and you will even get a warranty.

https://sdparts.com/category/crate-e...ms_per_page=48

By the way, if you do go with a crate motor consider a carb'd version. With new stuff it should save you some serious money, no computer to tune and carb'd crates are generally rated 30 to 40 more HP than the EFI variants.

Jack-C

I appreciate all of your advice you are giving me thanks, I think your eBay is much better than the UK eBay for picking up these kind of parts.

I just want to strip it down, so I know how it is all put together and I wouldn't mind adding some aftermarket parts to it!

Thanks for that superdave84, I completely forgot about getting the ECU flashed to remove immobiliser. Any other advice you guys can tell me?