355/ls1 piece by piece opion....

[JBA05]

Ls1 is a better engine I will say it here first, but this is only part of my question....

Ls1: 10.1 compression
355: 10.1 compression..... Can choose whatever but will say the same for a fair comparasion....

So what I want to know is if I build a 355 stroker with 10.1 comp will it make similar power to a ls1 say 225 kw... With a cam same specks as a ls1... Heads flow very similar in my research 20 CFm difference... Now the manifold is the restrictive part most people say.... So will a 355 with factory manifold make 225 kw (they come restrictive after this power level I've read).. now the other combo would be to add a tp dual plain manifold with throttle body.. would this be as good as a stock ls1 intake or better...

Yes I know we could go single plane but looking at a rpm range to only 6500.. with the widest torque curve possible.... So probably cams under 230/50 will be where I'm aiming at....

So to put it short will a 355 with a tp manifold be as good as a ls1 up to 400 Rwhp??

[ucntry]

dont know the answer but dont forget the waight diffrence inbetween engines and bang for you buck can get a ls1 on ebay for around $3500 to stroke a holden engine for 355 turn key will be 6k plus

[VK55]

Depends whats its going in.. If conversion costs been to be taken into account then that will change the outcome, but if its straight up LS1 vs 355 its an easy one.

LS1.

[cava454]

Stock v stock

I preferred my 5oh. Something about I just liked more.

[JBA05]

Yes I know the ls1 is better and will be cheaper... But what I want to know is will a tp manifold remove the restriction and say make 300 hp with a stock cam??? And 10.1 comp....

[Soopy]

LS1 isn't necessarily better.
The bottom end is stronger, 6 bolt mains. The heads have a better clamping force too.
They have a 3.9" bore and 3.62" stroke.

Holden 355ci has two bolt mains unless you convert it and less head bolts IIRC.
It has a 4.0" bore and a 3.62" stroke. (Correct me if I'm wrong).
From what I've squized quickly VN heads don't flow quite as much as CFM wise as 241 LS heads, but I would look to find air speed figures under .550" to get a better idea of how they will perform.

Over all, I think its horses for courses. If you like the 355 holden engine and its going into an early girl then I'd do it over an LS1. There is nothing you can do to an LS1 that you can't do to a Holden motor. The main bolts and head clamping force is the only downside IMO. That and the cost of go fast parts, but that's more or less redundant given the LS conversion costs.

Forget the over inflated dyno figures quoted by dyno racers. Its a dream world they live in.

[JBA05]

The car in question is a vt 5oh... And the aim is a tuff streeter and not worried about dyno figures at all... If it runs 12's I will be happy...

[Soopy]

You should be able to make a 355ci run 12's. There is no reason why you shouldn't.

[njmartin]

You could just sell the car and buy a VT II for a tiny bit extra and spend all the money on the ls1 straight up without worrying about the conversion costs etc

[Soopy]

Originally Posted by njmartin

You could just sell the car and buy a VT II for a tiny bit extra and spend all the money on the ls1 straight up without worrying about the conversion costs etc

But VT LS1's aren't all that flash. They have a crappy intake manifold, poor heads and small injectors. The cam is also not all that crash. Basically its no better if not worse then the series 1.

[JBA05]

Yeah I could do that but Im a sucker for doing things the hard way... This is my first v8 and I'm in love with the sound yes I know its crazy...

[Soopy]

In all honesty, you'd be wasting your time doing that. Buy another 5ltr block and stick a stroker kit in it. Then just swap your heads over come time to do the transplant.

I own an LS powered car, I've driven the arse off it and had a tinker. They're just another motor. As I said earlier, the only real upside is that go fast parts are cheaper. Aussie motors can and have gone just as fast.

[VrolliN]

Savage has a good story about an ls1 and 355 comparison, basically his mate ended up thinking his 355 was a real slug in comparison, cant remember how so but if he pipes up in here im sure he can tell you

My thoughts, why go 355? I mean you have to pay to stroke it out, and then where do you go for more power? For the same $$$ throw a cam in an ls1, its killing the 355 AND theres so much more head room for power gains....

[Soopy]

It would be interesting to find out what his mates 355 combo was. I've driven Holden motors that would obliterate a bolt on LS1.

Where do you go for power with a 355?
Umm... Same place as an LS1? They both work in exactly the same way, on exactly the same principles. Stick a big cam in a 355 and it will do exactly the same job for exactly the same reasons. The benefit to building a motor is you can tailor the compression ratio and piston design to suit what ever application you choose.
He will also have a brand new motor, as opposed to something touching 200,000km (going to be the case with another VT or a replacement motor.)

What do you think the LS1 has over a Holden 355 to allow it such drastic gains?

[cava454]

Turbo your 5oh and make everyone else cry.

[JBA05]

Yes its something I'm used to doing played with a few turbos and the gains r good... On the computer side is a bit difficult up here not many tuners will tune for boost.. and then u gotta trust the one u go to.. the ls1 computer upgrade sounds good tho...

[Soopy]

Originally Posted by JBA05

Yes its something I'm used to doing played with a few turbos and the gains r good... On the computer side is a bit difficult up here not many tuners will tune for boost.. and then u gotta trust the one u go to.. the ls1 computer upgrade sounds good tho...

Hit up delcohacking.net and search for the NVRAM mod.
It basically allows real time tuing via a USB > ALDL cable and the use of Custom operating systems. The COS allows for easy(er) tuning with forced induction.

Similar functions to an LS1 PCM conversion but for about 1/4 the price and plugs straight in.

[MYT05]

Since it has turned into a 5L vs LS1 debate (like always) I'll throw in my 2cents (as always).

MOTOR vs MOTOR - LS1 wins hands down always $ for $ investment. Your already starting with a 5.7L that is lighter, more economic and parts are cheaper believe it or not.

STROKE HOLDEN V8 to 355 vs LS1 CONVERSION - Stroke your Holden V8. It is going to be well under HALF PRICE of the full cost of conversion I promise you. With that money left over you could throw in a supercharger on top of the 355 and piss all over your converted LS1 anyway...

You want a cruiser, just stay with your trusty Holden 8 and take her out to 355 IMHO. Its going to be more reliable that an LS1 conversion and half the price to achieve a similar result. Remember that the 5L are a lot more punchy down low, and that's where a lot of your 'cruising' will probably be.

[TERRAFIRMA]

Originally Posted by MYT05

You want a cruiser, just stay with your trusty Holden 8 and take her out to 355 IMHO. Its going to be more reliable that an LS1 conversion and half the price to achieve a similar result. Remember that the 5L are a lot more punchy down low, and that's where a lot of your 'cruising' will probably be.

as above, 355 for a cruiser, will be as quick as a stock ls1 but its already in the car,

making your current motor a 355 is going to be much cheaper and in the end will put a smile on your face every time you hit the loud pedal, LS1 conversions seem like a mad idea at the time......there really not lol

[PREDATR]

As above^^^ 355 for a cruiser... pretty sure if you put your foot down in an LS1 and put your foot down in a 355 i know which one will turn heads more.

[PFI82]

OP's original question
yes the factory manifold on the Holden is going to be your main problem. I think you'd be seriously struggling to get 225rwkw with the factory manifold. They run out of breath at about 5200-5500rpm on a 304, no doubt worse on a 355. However there are plenty of good aftermarket manifolds about that will open up the breathing and easily achieve 225+rwkw.

My mild 304 with aftermarket intake is making a consistant 206rwkw (2 different dynos were within 3rwkw). So a 355 is easily going to make an additional 20+rwkw. Judging from other 355's I've seen, 250-260rwkw is easily achievable with à good intake.

[Soopy]

Which is basically on par with an LS1 that has similar mods.

[JBA05]

Sounds good that is what I was wanting to know and 250/260 rwkw sounds good to me..

[220isenator]

Originally Posted by PFI82

OP's original question
yes the factory manifold on the Holden is going to be your main problem. I think you'd be seriously struggling to get 225rwkw with the factory manifold. They run out of breath at about 5200-5500rpm on a 304, no doubt worse on a 355. However there are plenty of good aftermarket manifolds about that will open up the breathing and easily achieve 225+rwkw.

My mild 304 with aftermarket intake is making a consistant 206rwkw (2 different dynos were within 3rwkw). So a 355 is easily going to make an additional 20+rwkw. Judging from other 355's I've seen, 250-260rwkw is easily achievable with à good intake.

Which intake are you using?

[aZ`]

I think your original post was a little too simplistic for a genuine comparision, head flow figures and compression ratio will only get you so far. Now i'm still on the 5.0 bandwagon because that's where i choose to be. However i am not nieve, the ls engine is superior to the holden v8 not only because it comes with better heads and more comp but a myraid of other improvements to every other OHV V8:
-The fact is is all alloy (or at least alloy heads) means the comp can be bumped up without risk of detonation or need for higher octane fuel.
-The chamber design in the head does the same as above with the same results.
-The beehive springs both reduce valvetrain weight along with harmonics keeping them far more stable at high rpm, meaning you can rev it without adding additional spring pressure, that's free hp right there.
-The rotating assy is lgihter than a 355 holden (excluding specific custom racing applcations) more free power.
The valvestems are thinner making the valve lighter resulting in (again) lighter springs and less valvetrain loss.

This is not a list of reasons why i love LS engines over holdens, this is a list of reasons why your proposed 355 will never quite compare to an ls1

You'll also want to add a roller cam conversion to the 355 to even up the playing field.

[keith reed]

My vt with orcai, extractors, twin 2/12 exhaust make 230 rwkw. My 355 vb with Ported heads, bigger injectors, 10-1 compression, cam, extractors and 3" exhaust makes 200 rwkw. I suspect with a better tune it could have done better. With the same modifications the 355 would be nowhere close.

[Flanker]

short answer: If you get the holden stroker up to same standards of power AND reliability as the LS motor you'll probably be spending double. Even if you get more power your still losing since the holden motor weighs more.... just face it the choice is obvious

5oh VS Ls is that people with 5oh commodores toss up whether its more economical spending the money on the old 5oh or doing the whole LS conversion, which is always the big debate

[SIG-054]

Originally Posted by Soopy

But VT LS1's aren't all that flash. They have a crappy intake manifold, poor heads and small injectors. The cam is also not all that crash. Basically its no better if not worse then the series 1.

All of which can be found for a few hundred $$.. Nothing wrong with a VT LS1 at all, tune and 3g convertor mine ran 12's.

[JBA05]

Some very good points been raised by az I had not thought about all them and they make a good debate... Keep it coming guys I'm enjoying it I don't have any set.plans yet..... I have a ls1 in the garage and the 5oh in the vt so plenty options....

[cava454]

Blah blah blah. Who cares which is better...

Without a budget or desire you wish to achieve we are all pissing in the wind telling u which is better.

You can't just compare the 2 motors with the same comp and cam. The playing field isn't even.

If ur gunna just drop in a stock ls1 and leave it at that, then yor better of spending what u would spend on the conversion, on the 5oh and it will spank the ls1 any day of the week.

If u got 5k to spend on either motor aside from conversion costs then you would go ls1. But u got to weigh up what it's goin to cost to drop it in etc and then count that into you budget.

[slideways]

Holden motor in the daily would be my pick. Even if it does cross the line after the LS powered equivalent, it will still sound better leaving the pub which is what really counts.

Im putting together an LS converion at the minute instead of the 5lt as I intended to go big and boosted from the start which meant bulletproof 355 bottom end and heads to match= big $$$ and T56 conversion to compensate for definite 5spd failure.

The 6 bolt mains, alloy heads and off the shelf proven go fast bits was what sealed the deal for me as well as the newer computer/tuning and T56 factor aswell.

Really depends on what you want to do in the car and what you want out of the car while your doing it, balanced against what your willing to spend on said car for said purpose.

Good fun, ear pleasing, lower costing - 304, reasonable cam,manifold and exhaust.

Scary, limiter bashing, tyre melting - L76 speedway motor at 9000rpm all day.

Seems legit? - Opinions;

[savage1987]

Originally Posted by Soopy

It would be interesting to find out what his mates 355 combo was. I've driven Holden motors that would obliterate a bolt on LS1.

Where do you go for power with a 355?
Umm... Same place as an LS1? They both work in exactly the same way, on exactly the same principles. Stick a big cam in a 355 and it will do exactly the same job for exactly the same reasons. The benefit to building a motor is you can tailor the compression ratio and piston design to suit what ever application you choose.
He will also have a brand new motor, as opposed to something touching 200,000km (going to be the case with another VT or a replacement motor.)

What do you think the LS1 has over a Holden 355 to allow it such drastic gains?

SUSPECTSS on here, go check out his thread. Hopefully he might pop in here and have a chat. I remember his initial reaction being pretty positive when I took him for a highway run in the LS1 one night.

Here's his specs listed in post 1 of the thread...
engine mods
*fully rebuilt vs 215i stroker
*c.o.m.e racing twin throttle body manifold
*custom fuel rails/pro flow fittings
*high volume oil pump
*double row timing chain
*custom formula tech cam [284]
*bored block to 355.
*blue top injectors
*bosch 044 fuel pump
*pacemaker tri-y extractors
*exhaust-diflippio twin 2-1/2 inch into 3'',twin chrome dumpers
*au twin thermo fans
power:
*350rwhp

Originally Posted by MYT05

Since it has turned into a 5L vs LS1 debate (like always) I'll throw in my 2cents (as always).

MOTOR vs MOTOR - LS1 wins hands down always $ for $ investment. Your already starting with a 5.7L that is lighter, more economic and parts are cheaper believe it or not.

STROKE HOLDEN V8 to 355 vs LS1 CONVERSION - Stroke your Holden V8. It is going to be well under HALF PRICE of the full cost of conversion I promise you. With that money left over you could throw in a supercharger on top of the 355 and piss all over your converted LS1 anyway...

You want a cruiser, just stay with your trusty Holden 8 and take her out to 355 IMHO. Its going to be more reliable that an LS1 conversion and half the price to achieve a similar result. Remember that the 5L are a lot more punchy down low, and that's where a lot of your 'cruising' will probably be.

I know you have owned a H&C LS1 VP, so I'm honestly surprised at a couple of things you've said My LS1 VN certainly has more punch down low than my 5.0 VN. I've touched on this before elsewhere - perhaps it's to do with IRS vs live axle to some extent. I certainly get a lot of power out of it down low, it's never left me wanting even before the 3.9s went in.

Originally Posted by TERRAFIRMA

as above, 355 for a cruiser, will be as quick as a stock ls1 but its already in the car,

making your current motor a 355 is going to be much cheaper and in the end will put a smile on your face every time you hit the loud pedal, LS1 conversions seem like a mad idea at the time......there really not lol

Pipe down you are just upset you didn't get yours done because you spent too much time buying top shelf parts and not enough time actually doing things

Originally Posted by SIG-054

All of which can be found for a few hundred $$.. Nothing wrong with a VT LS1 at all, tune and 3g convertor mine ran 12's.

It's worth mentioning (and I think a lot of people forget) that HSV fixed a lot of the early ones with recalls and warranty claims, so while they may have a bad reputation overall it's certainly worth looking at them on a case-by-case basis.


Also, to whoever keeps saying LS1 will be less reliable than the Holden stroker - I drove my fresh conversion across the country and had no problems whatsoever. The only trouble I have had with it is snapping an axle (directly my own fault). It's never overheated or anything basic/stupid like that, something that cannot be said for a lot of 355s I think you will find

Sam

[Soopy]

Reliability is a funny thing.

You could convert to an LS1 and use a 250k+ old engine and have it grenade the week after while you're having fun with your new toy.

Or you could have a 355 Holden that goes for 10 years because its fresh built by someone who took great care during the build.

Unfortunately we usually only get half a story on forums.

With regards to the VT LS1's.
Reliability issues pertaining to the C4B motors and LS1's in general are kind of moot. I doubt that any early LS1's that are still around will have any of the major issues such as piston slap, as they would either be dead or fixed.
I believe also that the C4B's only real issue was poxy valve springs. If you're going to do a conversion using this engine, then a few hundred dollars for some new valves springs, seals and locks is cheap insurance. Heck even if you used a late model motor it wouldn't silly money IMO.

At the end of the day, for a street driven car. Who cares?
The 355 has an unmistakable coolness about it. They do go well, and will be as fast as you'll ever need to go.
The LS1 has some seriously decent parts available to it. Is quite stout as standard and if looked after will last. But like anything, being second hand its already lived a life.

Over all, if money were no object. I'd be using a Gen3 4" bore block and slutting it up with some fancy insides.
Best of both worlds then.

[Build_305]

Originally Posted by JBA05

Yes I know the ls1 is better and will be cheaper... But what I want to know is will a tp manifold remove the restriction and say make 300 hp with a stock cam??? And 10.1 comp....

My GTS runs

Factory Stroker (~350ci)
Starr Manifold, 90mm tb
Pacemaker headers
Full stainless twin 2.5" exhaust
Dyno Tune
Stock everything else.

Made 304rwhp on stock 8.5:1 comp. Dyno tune was done before this exhaust went on and in the coming months i'm getting it retuned & expect to see a little more outa it. Effectively i've spent roughly the same $ as you would on Exhaust, OTR & Mafless on an LS1 for roughly the same results. Give or take a few $ and hp

Hope that helps you out??

Ditching the stock manifold is the key. People underestimate just how restrictive they really are. LS1 is still a much mor refined & cost effective motor, and most likely superior in everyway, but i love the 5oh.

[Soopy]

8.5:1 compression does it NO favors either. It would be very interesting to see what sort of power it could make with 10.5:1.

[Build_305]

No shit. Im dying to put some $ into it & up the comp & throw a cam in. Unfortunately other things are far more important at this stage
Would love to see what a setup like mine wit higher compression & a nice cam could actually do. Especially in a 2nd gen against a ~200kg heavier 3rd gen.

[Soopy]

It would be very interesting.

[aZ`]

All factory 5.7L vr-vs engines were actually 8.9:1

[savage1987]

Originally Posted by Soopy

Reliability is a funny thing.

You could convert to an LS1 and use a 250k+ old engine and have it grenade the week after while you're having fun with your new toy.

Or you could have a 355 Holden that goes for 10 years because its fresh built by someone who took great care during the build.

Unfortunately we usually only get half a story on forums.

With regards to the VT LS1's.
Reliability issues pertaining to the C4B motors and LS1's in general are kind of moot. I doubt that any early LS1's that are still around will have any of the major issues such as piston slap, as they would either be dead or fixed.
I believe also that the C4B's only real issue was poxy valve springs. If you're going to do a conversion using this engine, then a few hundred dollars for some new valves springs, seals and locks is cheap insurance. Heck even if you used a late model motor it wouldn't silly money IMO.

New strokers can fail too. Go have a read of ORIGINL's threads over on squaredarches forum. He had a crate motor from Pavtek (IIRC) that blew up on the dyno even though all run-in procedures were followed. You can pull up 'ifs' and 'maybes' all you like, it's worthless discussion.

Also, the C4Bs had trouble with the camshaft being built from cheese. I have never heard of one lasting over 200,000km without eating a lobe. I've seen this first hand in two SV300s.

Originally Posted by tire_me

My GTS runs

Factory Stroker (~350ci)
Starr Manifold, 90mm tb
Pacemaker headers
Full stainless twin 2.5" exhaust
Dyno Tune
Stock everything else.

Made 304rwhp on stock 8.5:1 comp. Dyno tune was done before this exhaust went on and in the coming months i'm getting it retuned & expect to see a little more outa it. Effectively i've spent roughly the same $ as you would on Exhaust, OTR & Mafless on an LS1 for roughly the same results. Give or take a few $ and hp

Hope that helps you out??

Ditching the stock manifold is the key. People underestimate just how restrictive they really are. LS1 is still a much mor refined & cost effective motor, and most likely superior in everyway, but i love the 5oh.

Nice figure there John, must be a healthy motor. I hope you're not dumb enough to ever sell that car I have always loved it.

[Soopy]

Oh I know new motors can fail. Which is why I added in the bit about being built with care.
I know if my life depended on it, I'd back the new motor over an old one for longevity.