Discussion
I think like many of us trying to pick the bones out of the discussions on this site regarding engine choice, its a bit daunting, and I for one seem to shuttle back and forth between wanting a 'more modern' engine, and wanting ease of build (ref the Factories line).
From what I have read about engine choice, one thing seems to stand out at the moment!
You U.S. based bretheren seem predominantly to be going for the LS style engines from the Ls1 to the 7 derivative for your ultimate Ultima!
Here in the UK, it seems most choose the SBC iron or ally block units, I guess because of the emissions testing avoidance, and of course its easier to fit!
BUT - do you guys in the States know something that we don't?
Apart form the emissions regulations, are there advantages in going for the LS derivatives?
What about cost for a reliable Road and track useable configuration? 5-600bhp
What about build issues?
gearbox?
cheers
brdee
There are a lot of US guys looking into LS motors which is really gaining popularity. I was one of the first builders here in the states, and I chose a pre-1968 engine b/c that is what Texas required at the time if you didn't want to run cats or have emissions standards to follow. I thought this to be the safest route, however, you would probably be safe without cats if you selected an engine of a later year that didn't have cats. Every state here in the U.S. has different standards for registering kit cars. Some of the guys here on the board can fill us in on their requirements. The LS engines are an improvement in design over the older engine and are aluminum, lightweight, and can be cheap to buy from a junk yard. I was always cautioned about going for too much hp with the original LS1 motors that came in the vette, but GM has beefed up the bottom end of these motors now. Jeff Schwartz and Mark Koch are making plenty of hp with their motors!
I think it comes down to how much extra work you want to do figuring out the exhaust which will need to be custom done.
Cheers!
-Mack
I think it comes down to how much extra work you want to do figuring out the exhaust which will need to be custom done.
Cheers!
-Mack
I was forced to go the LS route because I have to pass EURO4 emissions, if I didnt have to pass emissions I probably would have gone the old carbies and distributor route 'cos that's what I was brought up on.
However, after being forced to go with the modern engine, I am now very glad that I had to. It forced me to research the dark and mysterious witchcraft of computer operated systems..
They are much more efficient, thereby giving better performance from a stock engine. When I say more efficient/better performance, that includes better power, cleaner running and more fuel efficient.
There's a great book that I have been reading that explains the whole EFI thang…
www.pistonheads.com/gassing/topic.asp?h=0&t=244664
The book explains how car makers were forced to go EFI in order to meet emissions standard, about the early years of turbo cars and how they were generally the Jap cars and frowned upon by the hot rod fraternity who were generally against this new technology. Gradually, as the younger Jap-car drivers grew up, the EFI/Turbo technology made its way over to the US V8 market – and now is “mainstream” in the USA hotrod scene.
Then it dives into the technical end and explains EFI from grass roots level. I would thoroughly recommend reading this book if you are (like many of us) one of those brought up on carbies and distributors….. Using a factory crate engine with a computer is not as daunting as it sounds. The computer need be set up properly ONCE – and all you need to do is change plugs and maintain systems……the car tunes itself, and even tells you when something is not working properly….
You mention ease of build being a deterrent to using an LS engine. These are the challenges:
1. Getting the computer to run the engine outside of the car it was designed for. The computer will have a whole load of sensors that were designed for the original car that will need to be disabled. This is simply a matter of using someone who knows what they are doing to set up your engine. I used Jeff Schwartz in the USA because he knows LS engines AND has one in HIS Ultima….He used a 2002 Camaro computer on my 2005 Vette LS2 - The 02 Camaro uses a cable throttle body. I have a Magnacharger so Jeff had a programmer modify the tables to suit the blower, and larger injectors etc. I had Jeff put the engine on a dyno before he shipped it to me to make sure it all worked. The car ran first try, but was not running at its optimal. He changed the pulley on the blower and a few settings and the following day it was all sorted.
2. Getting the car to pass emissions. We are using the stock manifolds and stock Vette cats. Given that the car is running the same A/F ratios as the stock car, the same cats etc, then the engine should give the same emissions performance. The way emissions is tested here in Hong Kong is on a rolling road where the car is put through a drive cycle. Its gonna pretty much be at idle through this, so there should be no problem there. If you use a stock LS engine (no blower) there should be zero risk for emissions problems. I am not sure how you would go about the testing in the UK – I imagine there is govt test centres? I recommend going and talking to someone there to find out how they do the testing – I did that in Hong Kong and was definitely worth it.
3. Engine mounts – they are different- but there are adaptor plates available.
4. Transmission – as far as I know you can only get adaptors for G50 boxes – I could be wrong though. There was a small amount of machining done on my adaptor plate – I think for the starter.
5. Exhaust – I am gonna use the stock manifolds and cats for emissions testing. I am also having a set of headers made that will run down under the chassis, rather than over the top like the factory ones. The mufflers will go in the stock position, the cats will go in the vertical section of the pipe between the collector and the mufflers.
6. Fuel Tank – get bigger fittings installed – I got -12 fittings as I only want to run one pump, and I want the fuel to be able to level out between the tanks easily, thereby making filling and fuel return easier to deal with.
Personally, given the advantages of the LS in terms of efficiency , I don’t see the above challenges as any more daunting as putting in an SB and having to maintain it.
If you asked me 9 months ago I would not have given you the same answer.
>> Edited by crafty on Monday 27th February 01:08
However, after being forced to go with the modern engine, I am now very glad that I had to. It forced me to research the dark and mysterious witchcraft of computer operated systems..
They are much more efficient, thereby giving better performance from a stock engine. When I say more efficient/better performance, that includes better power, cleaner running and more fuel efficient.
There's a great book that I have been reading that explains the whole EFI thang…
www.pistonheads.com/gassing/topic.asp?h=0&t=244664
The book explains how car makers were forced to go EFI in order to meet emissions standard, about the early years of turbo cars and how they were generally the Jap cars and frowned upon by the hot rod fraternity who were generally against this new technology. Gradually, as the younger Jap-car drivers grew up, the EFI/Turbo technology made its way over to the US V8 market – and now is “mainstream” in the USA hotrod scene.
Then it dives into the technical end and explains EFI from grass roots level. I would thoroughly recommend reading this book if you are (like many of us) one of those brought up on carbies and distributors….. Using a factory crate engine with a computer is not as daunting as it sounds. The computer need be set up properly ONCE – and all you need to do is change plugs and maintain systems……the car tunes itself, and even tells you when something is not working properly….
You mention ease of build being a deterrent to using an LS engine. These are the challenges:
1. Getting the computer to run the engine outside of the car it was designed for. The computer will have a whole load of sensors that were designed for the original car that will need to be disabled. This is simply a matter of using someone who knows what they are doing to set up your engine. I used Jeff Schwartz in the USA because he knows LS engines AND has one in HIS Ultima….He used a 2002 Camaro computer on my 2005 Vette LS2 - The 02 Camaro uses a cable throttle body. I have a Magnacharger so Jeff had a programmer modify the tables to suit the blower, and larger injectors etc. I had Jeff put the engine on a dyno before he shipped it to me to make sure it all worked. The car ran first try, but was not running at its optimal. He changed the pulley on the blower and a few settings and the following day it was all sorted.
2. Getting the car to pass emissions. We are using the stock manifolds and stock Vette cats. Given that the car is running the same A/F ratios as the stock car, the same cats etc, then the engine should give the same emissions performance. The way emissions is tested here in Hong Kong is on a rolling road where the car is put through a drive cycle. Its gonna pretty much be at idle through this, so there should be no problem there. If you use a stock LS engine (no blower) there should be zero risk for emissions problems. I am not sure how you would go about the testing in the UK – I imagine there is govt test centres? I recommend going and talking to someone there to find out how they do the testing – I did that in Hong Kong and was definitely worth it.
3. Engine mounts – they are different- but there are adaptor plates available.
4. Transmission – as far as I know you can only get adaptors for G50 boxes – I could be wrong though. There was a small amount of machining done on my adaptor plate – I think for the starter.
5. Exhaust – I am gonna use the stock manifolds and cats for emissions testing. I am also having a set of headers made that will run down under the chassis, rather than over the top like the factory ones. The mufflers will go in the stock position, the cats will go in the vertical section of the pipe between the collector and the mufflers.
6. Fuel Tank – get bigger fittings installed – I got -12 fittings as I only want to run one pump, and I want the fuel to be able to level out between the tanks easily, thereby making filling and fuel return easier to deal with.
Personally, given the advantages of the LS in terms of efficiency , I don’t see the above challenges as any more daunting as putting in an SB and having to maintain it.
If you asked me 9 months ago I would not have given you the same answer.
>> Edited by crafty on Monday 27th February 01:08
Must admit that were I to put a new engine in my car it would be an LSx of some description. The SBC may be well supported and comparatively simple but you need the complexity of EFI to get an engine running as well as it can *all* the time. The LSx clan would appear to be a lot better built and having taken an Gen I to bits and messed with silicon on intake manifolds, etc I can appreciate having o-ring gaskets and well located parts. Of course with things like COP ignition and a built in dry sump in the LS7 your not exactly short of performance features either.
Would be interested to find out how an LSx engine would fair in the SVA emissions test. As far as my docs are concerned newer engines only have to pass the post-95 regs for actual emissions and no mention is made of having all of the emissions equipment. Would be interesting if anyone happened to have a de-catted LSx and happened to get an emissions test done somewhere... What we're shooting for is:
200 ppm of HC at idle
0.5% CO at idle
0.3% CO at fast idle(2.5-3k rpm)
0.97-1.03 lambda at fast idle
Would be interested to find out how an LSx engine would fair in the SVA emissions test. As far as my docs are concerned newer engines only have to pass the post-95 regs for actual emissions and no mention is made of having all of the emissions equipment. Would be interesting if anyone happened to have a de-catted LSx and happened to get an emissions test done somewhere... What we're shooting for is:
200 ppm of HC at idle
0.5% CO at idle
0.3% CO at fast idle(2.5-3k rpm)
0.97-1.03 lambda at fast idle
Gassing Station | Ultima | Top of Page | What's New | My Stuff