Best Choice engine
Discussion
LS3 has less plumbing to do.
LS 7 probably easier to tweak for less ££ but you pay an extra 8K in the first place
LS3 is probably better value £ for £.
Better still build your own and save a bundle.
There are plenty of able engine builders over here that would be seriously competitive and give you an "enhanced" build.
LS 7 probably easier to tweak for less ££ but you pay an extra 8K in the first place
LS3 is probably better value £ for £.
Better still build your own and save a bundle.
There are plenty of able engine builders over here that would be seriously competitive and give you an "enhanced" build.
ls 3 is already pulled with the power. struggling to make more horsepower if not spending many additional EUR
ls7 is to be developed and will always equal more torque .... and the subtleties such as dry sump, titanium connecting rods, etc. etc.
pull out more horses at this stage is cheap
definitely higher quality and refinement
ls7 is to be developed and will always equal more torque .... and the subtleties such as dry sump, titanium connecting rods, etc. etc.
pull out more horses at this stage is cheap
definitely higher quality and refinement
Just buy a stock Ls3, get yourself on the road ... room to grow for most drivers ability in that unit .
7 is a very nice unit too but perhaps less growing room in its back pocket.
Built units can be equally tough, durable and flexible .. worth talking to local builders. FC's unit seems reliable for its potential output. ;-)
Always bear in mind a current production unit will be much closer to optimized all-round than motors of yester-year.
And finally don't be drawn in by aftermarket peak HP figures, current Engine Manufacturers use a different method (slightly more conservative) to that of the majority of aftermarket dyno software .. hence the aftermarket often demonstrates higher readings on paper . The bottom line is an engine manufacturer has to produce to their minimum quoted figure .. often they exceed.
The aftermarket dyno software finds this easy to exploit !!
G luck.
7 is a very nice unit too but perhaps less growing room in its back pocket.
Built units can be equally tough, durable and flexible .. worth talking to local builders. FC's unit seems reliable for its potential output. ;-)
Always bear in mind a current production unit will be much closer to optimized all-round than motors of yester-year.
And finally don't be drawn in by aftermarket peak HP figures, current Engine Manufacturers use a different method (slightly more conservative) to that of the majority of aftermarket dyno software .. hence the aftermarket often demonstrates higher readings on paper . The bottom line is an engine manufacturer has to produce to their minimum quoted figure .. often they exceed.
The aftermarket dyno software finds this easy to exploit !!
G luck.
Edited by 738 driver on Monday 28th October 22:43
You would probably not be disappointed with either but the LS7 is a pretty much standard engine. It comes with a simple dry sump (not suitable for racing but OK for track days) and will pump out far more HP with a decent exhaust.
Mine is 577hp on GM ECU straight from the GM crate. Cost me about £12k with ECU. I sourced all the other ancillaries from the states for less than £2k so about £14k ($21400).
Had it dyno set up so know what she produces. American HP tends to be a bit less than English HP....
There is no substitute for cubes!!!!!!!
Paul
Mine is 577hp on GM ECU straight from the GM crate. Cost me about £12k with ECU. I sourced all the other ancillaries from the states for less than £2k so about £14k ($21400).
Had it dyno set up so know what she produces. American HP tends to be a bit less than English HP....
There is no substitute for cubes!!!!!!!
Paul
gerradiuk said:
As your talking about engines in Ultima's, don't they suffer from heat soak? The Air filter must be getting roasted .
Depends where you put the air filter, mine is in the LHS side vent feeding the supercharger, the air here is close to ambient as attested by a temporary thermocouple rig I put together.The intercooler however is a different matter.
heat soak would indicate that the motor has been run, shut off, let stand for 10 or 15 minutes than restarted. I think it is worth while for anyone driving a turbo-supercharged-or high output N.A. motor to consider having the discipline to let the motor run a minute or two at normal throttle down the road to let excessive heat buildup to be dissipated from intercoolers, hot spots in the heads ect before jumpimg on the throttle. I bring this from my 25 years of driving my Renault R5 Turbo you can not expect a air to air inter-cooler to not suffer from heat sink while stuck in traffic. I believe that all heads have their spots that tend to run a bit hotter than the rest of the head. I would assume that heat soak could be a problem to these areas for a few minutes after a hot start also even the best insulated of cold air box's and air plumbing are going to see some heat pickup. Maybe 45 years of flying helicopters has caused me to be overly mechanically sensitive to equipment but when your life depends on it..............lee
The Schwartz LS7 730hp Package. 730 HP and 518 ft lbs torque @ 7400RPM
I like the higher RPM especially if the transaxle gearing is stock.
http://www.schwartzperformance.com/gm-ls-engines/
I like the higher RPM especially if the transaxle gearing is stock.
http://www.schwartzperformance.com/gm-ls-engines/
2001ultima said:
The Schwartz LS7 730hp Package. 730 HP and 518 ft lbs torque @ 7400RPM
I like the higher RPM especially if the transaxle gearing is stock.
http://www.schwartzperformance.com/gm-ls-engines/
Got to say the Schwartz LS7 730hp looks nice, if it is emissions friendly then maybe a goer.I like the higher RPM especially if the transaxle gearing is stock.
http://www.schwartzperformance.com/gm-ls-engines/
However at $6395 the LS 3 looks stunning and gives you the opportunity to throw $16,000 odd at it
For me the LS3 would be a no brainer.
You could even buy that and get a local builder to mod it and fit it for you and keep the change.
First question has to be what is the application?
If this is a new build then any of the breathed on engines are going to be a nightmare to get through IVA.
If this is a replacement engine then what was in before and is there anything stated on the V5 as to what emissions have to be achieved? The reqd. emissions may be in note form on the front page of the V5.
Steve
If this is a new build then any of the breathed on engines are going to be a nightmare to get through IVA.
If this is a replacement engine then what was in before and is there anything stated on the V5 as to what emissions have to be achieved? The reqd. emissions may be in note form on the front page of the V5.
Steve
I originally thought I MUST have 700hp minimum, then had to accept I couldn't afford it reliably, so plumped for a standard LS7. Reasons were I wanted a 427, and a stock one not built cos of emissions.
3k miles later I don't regret it, it has been perfectly reliable and makes a nice balanced package, it's fast enough on the road for most tastes, 0-140 in around 11secs. Not fast for an Ultima, but hard to beat for a stock engine, that starts and idles like any production car.
Only thing I'd like to change is make the power delivery a little more exciting, but a cam will sort that.
If I was logical, I'd have bought an ls3, 90% of an ls7 for 60% $$$
3k miles later I don't regret it, it has been perfectly reliable and makes a nice balanced package, it's fast enough on the road for most tastes, 0-140 in around 11secs. Not fast for an Ultima, but hard to beat for a stock engine, that starts and idles like any production car.
Only thing I'd like to change is make the power delivery a little more exciting, but a cam will sort that.
If I was logical, I'd have bought an ls3, 90% of an ls7 for 60% $$$
Best is entirely subjective.
I looked long and hard at this as well. In the end the choices came down to the pragmatic choice of how much power I wanted and what I planned to do with the car.
In the pub bragging rights 700+bhp and LS7 win, but from all i've read an LS3 and 500 odd bhp is plenty enough for British roads. Swings and roundabouts, but as I plan to keep the car, it made sense to get a proven engine that will do high mileages without the potential cost dramas surrounding expensive engine items that have been known to go bang in the LS7.
For me at least, the bragging rights etc were not 'worth it'.
I looked long and hard at this as well. In the end the choices came down to the pragmatic choice of how much power I wanted and what I planned to do with the car.
In the pub bragging rights 700+bhp and LS7 win, but from all i've read an LS3 and 500 odd bhp is plenty enough for British roads. Swings and roundabouts, but as I plan to keep the car, it made sense to get a proven engine that will do high mileages without the potential cost dramas surrounding expensive engine items that have been known to go bang in the LS7.
For me at least, the bragging rights etc were not 'worth it'.
Also remember that torque is what produces acceleration in the real world. High Hp may be great when you get above 5000rpm but when you boot it out of a corner/roundabout it is torque at 2000-3000rpm that kicks you in the back.
I understand the LS3 thinking as good value for money but if you want nearer to 600hp and (semi) dry sump then the LS7 is great as a standard engine. Problems only show themselves if you stretch it too far or abuse it.
Tryst me, you don't need to abuse it.
7000 miles in 17 months and no issues.....except a few trouser cleaning bills!!!
Paul
BTW. Had 400hp in the form of an LS2.........no where near enough for road use!
I understand the LS3 thinking as good value for money but if you want nearer to 600hp and (semi) dry sump then the LS7 is great as a standard engine. Problems only show themselves if you stretch it too far or abuse it.
Tryst me, you don't need to abuse it.
7000 miles in 17 months and no issues.....except a few trouser cleaning bills!!!
Paul
BTW. Had 400hp in the form of an LS2.........no where near enough for road use!
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