LS fucking 1
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is their any measurable flaw with this engine?
>>15183154
the fanbase
>>15183154
Yes the car around it. Gm a shit
the gm fangirls that shill for it.
>>15183154
There are many.
>>15183224
>power
>torque
>will last for fucking ever
>vast aftermarket
>takes boost like it was made for it
>Compact
>light being made of high strength aluminum
>>15183154
<4" bore
overpriced
overrated
sounds awful
horrible power for the money and size
cancerous fanbase
its a meme engine
>>15183236
LS1 is not those things
its garbage for boost and a pretty fucking weak engine
>>15183154
Airflow is down compared to their Mopar counterpart - the third gen Hemi. If there ever is a fourth gen Hemi, made with aluminium instead of iron, it could objectively outclass the LS.
>>15183236
>>takes boost like it was made for it
No it doesn't. The bog standard LS1, with it's relatively big (in diameter), thin and weak pistons, doesn't hold up to boost very well. None of the LS family engines do, unless you rebuild the entire bottom end to handle those high cilinder pressures. Exception are the smallbore 4.8 and 5.3 engines, which can support masses of horsepower. Problem with those two is that only the 5.3 is available with an aluminium block, and even those are outnumbered 10 to 1 by their iron counterparts.
>>15183262
Also, this. Needing to use siamese bores for the LS7's 427 cui. displacement really showed a weakness in the base engine design, although the base LS design is still reasonably big by smallblock standards.
>>15183288
>overpriced
Nope. Cheapest aluminium V8's you can get, except maybe smog-tier Buick/Rover 215's.
>overrated
Definitely.
>sounds awful
Sound can be fixed with exhaust and cam.
>horrible power for the money and size
Money, see above. Horrible power for it's displacement? Definitely not cutting edge, but still fair considering the engine's technology. The power output is actually pretty good considering it's exterior dimensions and ease of packaging.
>cancerous fanbase
100% agreed.
>>15183154
yes
>>15183290
there were some 6.0 aluminum truck blocks
LS9 handles boost pretty well too :)
>>15183299
it just sounds like every other sbc with a cam and exhaust.
which is cool in certain cars, but really out of place in anything else.
>>15183290
>base LS design is still reasonably big by smallblock standards.
No it's not, it has the same 4.4" bore centers as an SBC.
>>15183290
I run 10 lbs of boost and have for the last 10k. Stock bottom end. Git gud.
>>15183311
I know there were several 6.0 aluminium truck blocks, which puts them in line with the 4.8 and 5.3, but the thing is that those truck blocks had bigger bores (4'' instead of 3.78'') and therefore tend to have weaker pistons. Not really great for handling boost.
>LS9 handles boost pretty well too :)
>unless you rebuild the entire bottom end to handle those high cilinder pressures
LS9's and LSA's of course handle boost better, with their lowered compression ratio's and different lower end internals.
>>15183332
Size isn't just bore spacing. SBC's can't be stroked as easily as an LS.
>>15183369
How much horsepower? What's making those 10 psi (turbo, centrifugal or positivie displacement)? What engine?
10psi is less than 0.7 ATM. Why go through the hassle of boosting if you're not even doubling the amount of air shoves into your motor?
>>15183154
Missing 4 cylinders
>>15183299
>Cheapest aluminium V8's you can get
wat
>>15183369
>I run 10 lbs of boost
you also run the quarter mile in 17 seconds
I have some dumb questions.
>What's so special about LS 1&2 engines?
>What are the prices on it?
>Are they economical in an acceptable way?
>>15183684
Fuck off tripfag
>>15183685
>>What's so special about LS 1&2 engines?
aftermarket
>>What are the prices on it?
cheap for the truck iron ones, which happen to make no power and are pigfat
>>Are they economical in an acceptable way?
well, no, a swap is easy 10k if done right
>>15183701
IT'S A PRANK BRO
>>15183673
LS engines are cheap, light, V8's. The cheapest, pretty much lightest V8's that make any decent power.
>>15183702
>which happen to make no power and are pigfat
Although they take boost like champs.
>>15183712
the cheap LS engines are the iron truck ones, which aren't light
>>15183154
Buying new crate engine?
LS1
>GM
>about $6,000 for a good 410 horsies
>Rev limit at 6,000
>aluminum block
>bad on gas
Coyote 5.0
>Ford
>about $6,000 for a good 435 horsies
>Rev limit at 7,000
>Aluminum block
>decent on gas
Dollar for dollar, the 5.0 is the motor you want.
>>15183723
Fuck off tripfag
>>15183723
They still have aluminum heads and a plastic intake, which make them light for what you get.
>>15183736
>the 5.0 is the motor you want.
unless you have a Ford from the 60's and don't want to hack-up the body
>>15183742
BRO IT'S A PRANK
>>15183754
They dropped 427's into old Fords with no issues. Why wouldn't a 302 fit? Unless your trying to fuckrig a Pinto.
>>15183764
they're talking about coyote 5.0 not sbf 302
>>15183154
its not ran by pumping seaman up its exhaust port thats all i want and manufactures refuse to build it
>>15183723
You show me a lighter Ford or Mopar engine then, for the same amount of money.
You can't. Mopar uses iron blocks, Ford's Modulars are heavier despite the use of aluminium, and Chevy crate engines are, generally speaking, the cheapest.
>>15183736
LS3:
>5900$ for 430 hp
http://www.summitracing.com/int/parts/nal-19301326/overview/make/chevrolet
Coyote 5.0:
>7000$ for 435hp
http://www.summitracing.com/int/parts/fms-m-6007-m50ak/overview/make/ford
Both are good on gas. LS Corvettes get great gas mileage. Nobody cares about the rev limit as long as power production is sufficient (you could even argue the higher powerband would decrease mpg with pumping losses and internal friction). Also, the Modular 5.0 is physically bigger, to the point where it's about as big as a BBF.
>>15183764
>They dropped 427's into old Fords with no issues.
The Mustang had to grow from it's '64 inception to it's '69 version before a BBF would fit comfortably - and even then it was with chassis compromise. 5.0 Modulars are about as big.
The older 302 small blocks, however, are pretty damn small and light. Smaller than the LS, and damn near close in weight (if you use aluminium heads), despite the use of aluminium in the LS block.
>>15183816
>ford or mopar
wat
a toyota UZ or a Nissan VH can be had for $500 and are lighter than iron truck LS, they both weight less than 500 lbs
a jaguar aj v8 is probably lighter aswell
>>15183787
have you written to manufacturers? what did they say?
>>15183836
I thought we were talking about crate engines, which offer a more fair comparison. Anyone can get lucky at a junkyard.
>>15183154
Not being an LS3 is about all I can think of.
>>15183816
Stop shopping summit. You'll save a lot of money.
>>15183889
>LS3
>not LS7, LS9 or LSX
Close.
>>15183906
Show us some cheaper prices on that Mod motor then. At least I include some sources.
>>15183922
desu its a much better idea to buy remanufactured engines directly from ford or chevy, they include warranties aswell
i almost bought a coyote some years that way
PUSHRODS
U
S
H
R
O
D
S
>>15183154
No
Besides the LS3 serge's at part throttle and the after market like on small block Chevy's,, STILL hasn't opened up to making the front dress fit all together without some help.
>>15183154
>their
>>15183939
do you forget about filters every time you post? or are you so new you haven't figured that part out yet?
>>15183387
10 PSI on a built LS3 is enough to make 700hp on pump gas and still get 20/25mpg city/highway
>>15183736
>LS1
>bad on gas
i get 24 mpg in a 3500lb car. muh V8
>rev at 6k
with a cam/tune its 7000 rpm
>>15184138
>pushrods
>not just a meme
whats wrong with pushrods?
hardened pushrods are like $100 for a set
my LS1's valve train is very quiet when its warmed up.
not like my honda d15b that sounds like a tractor
>>15187243
what did he mean by this?
>>15187342
most people can't see you or your grade A posting
>>15187342
desu desu desu
>>15183154
pushrods and thus being SOHC
shit HP/liter
port injection
>>15188002
>SOHC
mfw
>>15188002
>>15188076
>sohc push rod
>tfw
>>15188076
>>15188111
i meant 2 valves/cyl
>>15188143
guess ill have to wait on the ohc side valve ;L
>>15188143
Suzuki do a 16v SOHC
>>15183204
This.
The LS is like an athletes heart. Small strong, effective.... built into an obese smoker body.
>>15187296
10PSI with a turbo maybe, but you're running out of bottom end at that point. 10PSI worth of non-intercooled positive displacement boost will produce enough heat to break bottom end stuff.
>>15188151
Fiat also offers SOHC 16v's with fully variable intake and exhaust timing and lift.
It's american
>>15183154
>pushrods
>low redline
>too much torque, must be paired up with tall gearing which is shit for performance and severely beefed up drivetrain components which just adds excessive weight
anyone who knows shit about engines knows that better overall performance can be seen by sacrificing torque for shorter gearing and a higher redline.
it's a god damn truck engine and I'm sick of murifats glorying a shitty poorly built engine
>>15189271
You don't know your ass from a hole in the ground apparently.
>>15188111
Why does this abomination exist?
>>15189271
>tall gears are bad for performance
That's like the cheapest easiest way to BOOST performance on your car, it just makes it shitty to drive in the city
>>15189313
Is the hole in the ground the one where the dicks go?
>>15188147
>guess ill have to wait on the ohc side valve ;L
Pic fucking related. Can somebody make a non-Paint version of this?
>>15190019
Wat
>>15190019
Non paint version?
Maybe, would take lots of rockers and pushrods.
Yay for heavy valvetrains!
Pic semi-related, flathead I'm working on.
>>15190019
Put both valves on the same side. Will cut chamber volume for dat compression ratio.
>>15190723
But then going DOHC would be impossible. T-head sidevalve engine still got some decent compression, and I suspect the chamber volume should be pretty similar.
>>15190019
flatheads are fucking awful and only belong in tractors and lawn equipment.
>>15183712
I ma be wrong but isn't the 4.7 dodge lighter and makes comparable hp? 310 hp for 08 and up
>>15190734
Oh I didn't know dohc was part of the design requirement.
Back to the drawing board.
Want stroke? Need an aftermarket block with long skirts. Want good heads? Need taller straight port heads. Engine is no longer small.
Not fuel efficient, relies on auxiliary bullshit to kill emissions.
>>15190741
>flatheads are pretty decent, shit at making power, and only belong in tractors, lawn equipment and pre-war cars
ftfy
>>15190751
Not a requirement, but it damn sure add to the useless complexity. Also, fully variable intake/exhaust valve timing. Because you need that on a flatty.
>>15190748
No, those 5.7's are heavier because they use iron blocks.
>>15183387
>How much horsepower?
780whp
>What's making those 10 psi (turbo, centrifugal or positivie displacement)?
Centri and boltons
>What engine?
LS3
>Why go through the hassle of boosting if you're not even doubling the amount of air shoves into your motor?
Because pic related.
I'm not the only guy making decent power on stock bottom ends. Theres a dude on camaro5 that's making something like 1100 whp on a stock bottom end. I understand the LS1 isn't quite as stout as an LS3 but an LS1 will take some boost just fine. You'll need hardened pushrods and better springs but it's not like its pushing it to run any boost at all.
>>15183684
>He's so new he thinks he's the first autist to post that in every thread
>He's so new he doesn't even know the original meme/slip was 15 seconds until I started implying it was actually 16 or 17
>He thinks he's making me so mad
>He thinks a reply means I'm so mad
>He just realized his ebic tr00ling is facebook-tier
Post your slip, bb.
>>15189647
how do you expect taller gears to make you faster? Maybe topspeed if you are gear limited but thats a rare occasion
>>15188143
>2 valves/cyl
yeah that doesn't mean a goddamn thing when the intake valves are 2.0" diameter like a stock LS1
number of valves means fucking nothing. look at the flow of the heads and the power the engine produces
>>15188151
so does every honda D series except an HF engine you fucking idiot
>>15190794
Seems nice, but the amount of bottom end strength per dollar (if you understand what I'm saying) is still lower than a truck engine. Still, that output just puts any arguments aside.
>Boltons
Boltons make boost now?
All kdding aside, I'm jelly as fuck.
>>15190794
>he thinks he isn't a faglord
my stock ford fusion runs the quarter in 15 seconds desu
>>15189271
>low redline
>HAS NEVER BEEN AT 6000 RPM IN AN LS1 CAR
>too much torque
WHAT. this isn't even a thing
>has to be paired with tall gearing
0-60 in 5 seconds stock. flat.
>has never been in a car with tall gears and a powerful V8.
its fucking heaven. it pulls FOREVER. the power feels literally endless
>god damn truck engine
no its not you mongoloid. its fully aluminum unlike the actual truck LS family "Vortec" engines.
>poorly built engine
>forged bottom end capable of 600whp stock
kill yourself
>>15190759
>Not fuel efficient, relies on auxiliary bullshit to kill emissions.
20+ mpg is very good for a 300hp heavily restricted stock V8.
>relies on auxiliary bullshit to kill emissions.
what, EGR, AIR, cats?
fucking delete them you pussy
>>15190856
This. People who don't have torque make excuses as to why they don't need it. As long as your car is making power it doesn't need to rev. Look at cvts
>>15190794
>runs 15's in a 700whp car
i ran a timed 14 sec 1/4 ON THE STREET in a 300whp car on the first pass. you can't drive for fucking shit
>>15190868
> delete them you pussy
It's California
Also my 4.0 dohc vvt v8 barely gets 23 Highway. I couldn't survive with 17.
>>15190826
>number of valves means nothing
lol, gm fags are delusional
>>15190876
>tfw your honda d15b 8V redlines at 4800-5000 RPM, making peak torque at 2200
60 fucking horsepower bitch
my LS1 can't make that little power and be running. it has more hp at idle.
torque is EVERYTHING
>>15190908
>engine 3 times as big makes more power
someone give this man a nobel
>>15190833
>the amount of bottom end strength per dollar is still lower than a truck engine
Yes but that has more to do with it being an ironblock. The crank in these engines is stout as fuck, so really its pistons and tuning that ultimately determine what sort of boost it can take. Theres an LS1 C5 where I work that just got back from the texas mile. It's running a YSI (big centri) with a stock bottom end and the only thing that got borked was the pushrods since the last shop didn't swap the stock ones out. Still if I was doing a project vehicle I'd just do an iron 5.3 and stud it (or a 4.8 to troll benchracers with). That iron definetly makes a difference in strength like you said, but the 100lbs of weight savings with the aluminum LS1 5.3 isn't a piece of your grandmother's fine china either. I wouldn't be afraid to dd one running 8 lbs of boost so long as I had a decent tuner.
>>15190883
>ON THE STREET
>Inb4 with your OBDII timer
The pass after that 15 second one was a 12.3, so calm your tits.
>>15190914
>hp/l
Take your insecure/incorrect cop out and blow it out your ass. Adults are talking.
>>15190884
>I couldn't survive with 17.
dudebro i get at least 24mpg on the highway.
my car has likely much better aero however.
>4.0 dohc vvt
yeah you get shit mileage because its in grannys lexus
>>15190894
Post a fourvalve head that outflows a nicely ported aftermarket 2nd Gen Hemi head then. Those are two valve.
How about the lsx 454 :^) 650 hp 9,000$ or less for that engine :^) (opinions br/o/s)
>>15184156
There's your answer, that thread sure worked out well!
>>15190914
Just out of curiosity, are you some kind of cuck who gains satisfaction from being humiliated in every thread?
>>15190914
>3 times as big
almost 4x.
the LS1 still makes more hp:L
my honda gets 45mpg and the LS1 gets 24 mpg.
if im driving on the highway, i'd rather have 300+ hp available. not fucking 60
my civic can't even pass someone.
>ricers think they don't need torque
because you've never had it
>>15190918
No, the difference with the truck engine is that they're smaller bore. Given how thin and relatively weak (not saying they're weak outright by the way) the 4" units in the LS'es are, they're easier to break. It's got nothing to do with block strength, it's all about bottom end strength - which the truck engines have boatloads of, because they got sturdier, smaller pistons. You can have an aluminium 5.3, and it'll hold just as much power as it's iron counterpart - well over 4 figures if you do it right.
>>15190934
Uses the shitty LS7 heads. Would rather have a LSX 376-B15 and some boost if I had to have an LSX. Or better yet, just get a junkyard 5.3, get it built, and slap a bigass single turbo on it.
>>15190936
nice projectin familia
>>15190918
>thinks you can't use a 1/4 mile section of road and a stop watch
MUH 15's BRO
>the pass after that was almost 3 fucking seconds faster
was it the same CAR?
absolutely fucking pathetic drag racing there bro. i wouldn't be telling people thattt
also
>12.3
>700 fucking WHP
thats like heads/cam/exhaust N/A LS1 territory. you SUCK
>>15183154
MPG
>>15190983
>the pass after that was almost 3 fucking seconds faster
It's amazing what difference first pass ever with an additional 300whp and the second one can be huh?
>>15190918
To expand on >>15190964:
>8 lbs of boost
http://www.hotrod.com/how-to/engine/hrdp-1109-stock-gm-ls-engine-big-bang-theory/
>Stock bottom end
>26.8 PSI on race gas
>Ignition failure
There's no reason whatsoever that says you couldn't do this with a 5.3, alum or iron, doesn't matter. Crank holds up, pistons hold up, rods will too (probably). If not, slap 4.8 internals into a 5.3 aluminium block. Have your cake and eat it, baby.
>>15191007
>additional 300whp
>make car slower
bro. its amazing you think this is an reasonable excuse
>>15191024
I'm not him, and I know you're trolling, but adding 300hp without 300hp worth if traction (or 300hp worth of throttle management) is going to slow you down.
>>15190983
>thinks you can't use a 1/4 mile section of road and a stop watch
I'm sure there was nothing generous about that 14 seconds you're claiming. I dare you to go to any actual drag strip and spew that newfag science.
>>15191024
>What is wheelspin
What's wrong with it? Nothing really. It's a great engine.
But it isn't a sexy inline 6 or a FPC V8. That's.....really it.
Nelson Racing Engines have done GLORIOUS things with LS motors. Those things make me hard.
>>15190969
Mmm im considering to buy a lsx (n/a) but i dont know which one, that thing need to make easily 500 or 600hp or more with a little upgrades obviously
>>15191095
Inline sixes are only sexy in their internal balance and sound. As far as packaging and weight distribution is concerned, they're a mess (sadly).
I'm amazed there hasn't been a single aftermarket company coming up with a flat plane crank for the LS engine. Seems like there'd be demand for that. I'd love to see what an LS7 could do with a flatplane crank - it'd probably outdo the Voodoo. Also, something like a short-stroke 302 screamer would be nice.
>>15191048
my car should easily pass under 14's on a real strip. especially on the 1000ft. i'll be going there soon with my cousins V8 S10. (gateway international in Illinois)
it can run 13's stock.
>>15191082
>add power
>lose acceleration
what is THROTTLE CONTROL
>>15191151
https://www.youtube.com/watch?v=HIxngbwE8jg
orlly
>>15191287
Yah really. Lingenfelter isn't selling any of those.
>>15191352
>demand
>flat-plane crank OHV racing engine
i'm sure they'd build you one, if you could fucking afford it. shits getting stripped every race
>>15183154
oil pump sucks
too computer dependent
>>15189313
>>15189647
>>15190856
wow sure is alot of fucking stupid up in this thread.
http://www.onpointdyno.com/?p=3857
>>15191151
>a short-stroke 302 screamer would be nice.
But the longer stroke was found to make more power, better torque curve, and cheaper.
>>15192307
so what? if someone wants 2500hp in a street car they can have it now.
no need to bring up the hp pissing contest as there's always something better if you want it.
>>15192294
>this post
the fuck you on about?
If my LS1 made the same HP as it does now, while making the same ft-lb my honda d15b does (70 ft-lb) it would have to rev to 24,000 RPM just to make it.
>TWENTY FOUR THOUSAND FUCKING RPM
there's a reason that TORQUE is a thing. RPM is cool as shit but we can't all be driving F1 engine powered cars that idle at 12000
>muh RPM bro
HP is really the only one that matters.
>>15183154
Yes, provided you're referring to the LS1 exclusively.
-Bad at handling 1g+ cornering due to not having a true priority main oiling system. (Applies to all LS motors even dry-sump ones which once again are not true dry-sump set ups.
-Bad head design (cathedral ports) compared to any other modern v8 design. This was fixed with the LS3/L92.
-Small bore spacing (this only applies in racing situations). LSx engines aren't that cheap to build in racing situations and you'd be better off going with a BBC with an aluminium block.
Look, for street engines they're great due to their compactness and good power/engine weight ratio. My primary issue with them is in racing applications. When it comes down to it, its more expensive to build to high boost/hp levels than an aluminium blocked BBC which will have much higher hp potential and be more reliable.
>>15183154
The bore is too small and the stroke is too long.
Make it 5.7 but make it really Oversquare as fuck
>>15192372
>HP is really the only one that matters.
HP and Torque.
Torque tells you how efficient your engine is working.
people who think the LS series are a bunch of meme engines don't know anything but what they've been fed through their VTEChochamber
>>15190933
You do realise a gen.2 Hemi has e bore size of 107.95mm. If you were to build a 4v head with that size bore it would absolutely destroy the hemi in flow. Additionally it would be able to match the hemi's flow at much lower valve lifts resulting in a much more reliable valve train which wouldn't need to have the valve springs replaced every few runs.
Also gen 2 hemis have terrible combustion chambers. You need stupid large domed cylinders to get any sort of decent compression and you end up getting a crescent shaped combustion chamber that burns extremely slowly making the engine extremely prone to detonation.
>>15190933
>falling for the flow meme
jej
>>15190918
>slower than a 03 cobra with a pulley
You should really be ashamed of yourself. Do yourself a favor and find another tuner ASAP. There is zero fucking reason for you to be running anything higher than a 10 and you should be real close to 13s in the trap.
>>15192333
Manufacturers make more money if they follow sound engineering. Making obscure parts for rare eccentric billionaires is a tough business.
>>15190933
>2 valve flow meme
You'll have better flow with two intake valves than one.
You'll cover more cylinder area, your valve area would be equal or more with less cam lift/rockerarm ratio.
Where did this meme come from? You could've atleast used something like an R5 or P8 engine by Mopar, but they need really high lift with 2:1 rockerarm ratios
Im not reading through this whole thread but from what i skimmed no one mentioned this
Throttle body causing reduced engine power. Super common on these engines, we have an Isuzu box truck at my work with a 6.0 and it had really low power at the most random times. It's fixed now though
>>15192482
did you reply to the wrong post?
>>15192488
he didn't understand that you were talking about the cheap LS aftermarket and thought you were talking about a boutique engine
>>15192486
Blame emissions and MPG laws for that.
Can't make a 6L V8 that makes lots of power on top and beats emissions and MPG laws for under 8 grand.
A bit off topic but why doesn't GM use the Ecotec/Vortec V6 in their V6 offerings instead of the dumb High Feature engine?
They should start turbocharging it, lots of potential there since it's just an LS/Vortec with two cylinders cut off.
>>15183288
>>15183290
http://www.superchevy.com/how-to/project-cars/1404-how-to-boost-a-5-3l-ls-engine-611-horsepower-alternative-fuel/
>>15192307
Wouldn't a long stroke increase the harmonics issues of that flat plane crank though?
>>15192423
If you made it oversquare it would move the power band up, and the valvetrain wouldn't work as reliably up there. Best keep it undersquare, produce more torque, and gear it down. That's also good for the LS' other applications, like trucks and SUV's.
>>15192447
>>15192465
Alright then, third gen Hemi. 370cfm (intake, 28") is the highest I've seen on ported 6.4 stock units, with something like .650" lift. Try and beat that - you can't.
>>15191151
>As far as packaging and weight distribution is concerned, they're a mess
yup, IIRC the 2JZ weighs almost the same as a LS
Prob wrong but w/e this is /o/
>>15192485
Valve area is a lie. Head airflow is related to valve curtain, and ultimately limited by it, but the usual limit is the ports, not the valves. There are no 4v heads that flow as much air as a good 2v, simply because they can have extremely well designed heads. Probably got something to do with the head being less crowded. Even despite the added valve area, 4v engines rarely outflow similar 2v pushrod ones. The trick is that 4v heads are easier to make a wide torque curve on, because they don't use massively sized ports for raw airflow, they cab use two smaller ports - which means you can close one port, and tune it via intake resonance, optimising it for almost the entire revrange. Can't easily do that on a 2v (unless you go with a variable length trumpet on an ITB, which you should)
>>15194270
It's even a bit heavier iirc but the JZ is an iron block. Supras and SC's aren't particularly light and nimble chassis' anyways, so it doesn't really matter. Inline six are stil a sexy engine, just not that practical.
>>15194268
http://www.jpcracing.com/rgr-jpc-cnc-stage-3-coyote-5-0-cylinder-heads/
Falling for the flow meme, but here you go anyway. This from a cylinder head with a bore of 92mm versus 103.9mm. Also the coyote head will have much better low/mid lift flow, have less valve-train mass allowing a higher redline with lower spring pressures.
Additionally I bet that hemi head has a much larger intake runner resulting in lower air velocity, once again messing with low/mid rpm performance.
>>15194287
The larger valve area of 4v heads does increase valve curtain area even after accounting for shrouding. The reason why there are no 4v heads that flow as well as 2v heads is that there are no 4v engines with large bore sizes on the market currently. Ford modular engines have bore sizes of 90-92mm whereas many of those high flowing 2v heads are designed around engines with bore sizes of 110+mm.
>>15194313
Bore is irrelevant when considering head efficiency. Airflow compared to valve area is. given the same valve lift, valve area is determined by valve circumference. Let's look at the numbers:
Hemi:
>Intake valve size: 2.135''
>Intake valve circumference: 13.414''
Intake cfm is 371 @ .650''.
http://www.hotrod.com/how-to/engine/1601-top-ten-tricks-to-optimize-the-chrysler-6-4l-hemi-cylinder-head/
Coyote:
>Intake valve size: 1.5''
>Intake valve circumference: 9.424''
>Total valve circumference: 18.848''
Intake cfm is 342 @ .650''.
http://www.jpcracing.com/rgr-jpc-cnc-stage-3-coyote-5-0-cylinder-heads/
If you do that maths (both heads on .650''), the Hemi is way more efficient with it's head, producing 26.6cfm per inch of valve circumference. The Coyote manages 18.1cfm per inch of valve circumference.
Now, let's start talking some other numbers. Those Coyote heads are almost 4 grand. The Hemi ones are factory castings. Despite this, the Hemi ones outflow the Coyote ones, especially when you take into account the added valve area of the Coyote. Flow is what makes power: cfm of air combining with cc's of fuel to make horsepower.
>the coyote head will have much better low/mid lift flow
True (the Coyote outflows the Hemi up to .300'' of valve lift), but unless you've got a VVL system, both of those engines will be spending less than 20% of their time at those low valve lifts. That's how cams work.
>have less valve-train mass allowing a higher redline with lower spring pressures
True. But if you don't have the airflow or high-RPM bottom end (neither of which a Coyote has) to take advantage of the higher redline, that's useless.
>that hemi head has a much larger intake runner resulting in lower air velocity
True, hence the lower performance at low valve lift. As said in >>15194287, 4v head can be optimise for a wider power range, but 2v heads can make more raw power.
>>15194358
See >>15194399
Despite the added valve area, the Ford cannot make generate more airflow than the Hemi.
>>15194399
>>15194399
>If you do that maths (both heads on .650''), the Hemi is way more efficient with it's head, producing 26.6cfm per inch of valve circumference. The Coyote manages 18.1cfm per inch of valve circumference.
Bore is very relevant as you are most often limited to a certain bore based on what architecture you are using(Assuming you use a factory casting). Sure the Hemi may flow more CFM when adjusted for intake valve size but thats to be expected due to the increased shrouding encountered by a pent-roof 4v layout. But the the main advantage of 4v is the ability to fit much more valve area in a given bore size and hence within a given engine architecture where you are limited by bore-spacing. The hemi is more efficient with its valve area, but the coyote is more efficient with its head.
>Those Coyote heads are almost 4 grand. The Hemi ones are factory castings.
I don't get the point about the coyote heads costing $4k. They are factory castings too. Most of the cost is in paying for the port work. The cost would be similar were you to pay for the port work done on the hemi in the article.
>both of those engines will be spending less than 20% of their time at those low valve lifts
4v heads still gain that flow without compromising high-lift flow and overall your able to get a flatter torque curve, which may not be important in all out race applications but nonetheless are still a benefit of 4v heads.
>if you don't have the airflow or high-RPM bottom end (neither of which a Coyote has) to take advantage of the higher redline, that's useless
I'm not focusing specifically on the coyote but the fact that a 4v head with similar flow to 2v head will put less stress on the valvetrain, increasing reliability and reducing the investment needed in expensive valvetrain components.
>>15194358
>Ford modular engines have bore sizes of 90-92mm whereas many of those high flowing 2v heads are designed around engines with bore sizes of 110+mm.
Sounds like a design flaw to me - then again, stock bore spcaing Modulars are already pretty huge, I can't imagine there being any demand for ones with even bigger bore spacing.
>>15194489
First off, let me say I'm happy to have an educated, properly argumented and civil discussion about engine design on /o/.
>4v heads still gain that flow without compromising high-lift flow and overall your able to get a flatter torque curve
You're confusing engine rpm and valve timing there. Per cam cycle, a valve is at 80-90% of full valve lift for about 80-90% of the time it gets lifted off the base circle. Therefore, low valve lift numbers aren't as important as high lift flow numbers. 90% of the air flowed in a cycle is generated during that high valve lift. The only situation where low lift is useful, is when you don't use a camshaft eith a high lift number (or low rocker arm multiplication).
Did the maths on the airflow per bore size, and the Coyote came out on top indeed. Then again, I'd suspect it would get decreasing results from just going bigger, and a Coyote is really limited with it's bottom end architecture.
>reducing the investment needed in expensive valvetrain components.
While I agree that in a similar situation, a 4v unit puts less strain on the valvehead, it does have more components, so it's a few expensive parts vs. more parts that are less expensive. Not as important for a manufacturer maybe, but when you're DIY rebuilding an engine, those small numbers add up quickly.
>>15194533
Decreasing results should be diminishing returns.
Valvehead should be valvetrain.
My enrish is pretty weak.
>>15194287
Get a load of this guy. 2v engines suck dick. The LS isn't even good. It's a 300hp 5.7 liter engine.
It's common knowledge 2v is trash, get over it.
>>15194423
dam son, you are missing one big fact, even if the coyore has a bigger valve area, the smaller bore affect the total cfm, because with a bigger bore, the total valve area would be even bigger
>>15190794
wheres your build thread, is the maro your daily?
>>15183159
>>15183204
Nicce
It's not a LS7.
>>15194260
Only up to 8000 which the LS can pull off with decent springs and rocker arms
http://www.hotrod.com/how-to/4-8l-crank-ls3-block-how-to-build-an-8000-rpm-ls-stroker/
http://www.superchevy.com/how-to/vemp-1203-de-stroked-ls7-short-stroke-of-genius/
https://www.youtube.com/watch?v=fdv4qgKjtwk
>>15194399
>comparing 4.060 Bore to 3.700 Bore
come on don't do this
>>15198592
fuck i want an LQ4 destroked to 334 in my trans am.
>those RPMS
>>15199831
>tfw no custom crank LS 302
>>15189271
How would short gearing help? Doesn't that mean you have to shift more?
Also look at the viper...
