debating specific power outputs is pointless as it's just a factor of the state of tune of the motor.
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debating specific power outputs is pointless as it's just a factor of the state of tune of the motor.
Anyway...... this is meant to be an 8 cylinder engine thread. So Honda doesn't win! It's short of 4 cylinders and is therefore disqualified from this thread. :cool:Quote:
Originally Posted by marcus
Im a fan of old school v8s. In particular, the 426 HEMI.
i think the reason they only use 2 valves per cylinder is to save feul
i mean less air means less feul - the power of holden engineering
should try variable lift but then agen they still havent even got DOHC
this would probably be to complex for them
however i was surprised to learn about some of the high comperssions the old hemi ran back when we had leaded feuls like 12 or 13 was it???
yea its nice to drive a car where u put ur foot down and of u go, no downshifts,no screaming, no controll of what gear ur in and ultimately very little controll in a long drift situation or even a sharp turn, causeing the thing to downshift and loose controll
thats the one i driven anyhow
lolz i seriously doubt that the ls2 would have a chance, even if the honda was making half the power of the ls2 it would still have no trouble to pull away even at 180
iv witnessed a race with a 5.7 V-whatever(something like 2004 with the triangle tail lights)
racing a DC2R(modded) suprising results hehe
having two valves as opposed two four is only going to impede the flow of air, not reduce the amount thats going in. you can reduce the inflow of air by having a restrictive intake, theres no need to go ditching valves.Quote:
Originally Posted by crx_boy7
having 4 valves per cylinder would make the engine more efficient, meaning it could make similar power with lower fuel consumption, and besides, youd have to take into account the size of the valves before you started saying that two means less air, for all you know they could be twice the size
I don't know if you've noticed but holden haven't made their own v8 since VT series 1. I actually heard they were developing a sohc 5.0 but gm came along and told them to just use the gen 3. And what the hell are you doing trying to drift an early 70's V8 for? Different cars are made for different reasons. Those old dodges, straight line performance. Little civics, excels, corrollas etc, economy. Even F1 cars can only be raced. Take them on the road and there stuffed. Don't go bagging cars just cause they can't do everything.Quote:
Originally Posted by crx_boy7
Yeah but the reason why they put lead in fuel was to increase the octane rating and reduce chance of detonation.Quote:
Originally Posted by crx_boy7
um -hmm.. less air getting in means less feul needs to be added to make the same feul ratio, the only other large factor is friction and inertiaQuote:
Originally Posted by Mr_will
y dont they use a quad cam and make the intake smaller?? i dont know ring holden and ask... mabe the want reduced costs,mebe they want lighter drivetrain, or mebe their just too stupid
and how is a 4 valve going to be more eficient on feul????? hahahahahaha
how the *** can u get more air in with a 2valve engine as opposed to a 4 valve using the same lift and duration ??? r u F***d in the head ??? its obvious that u can make more room for air to travel through using more of the heads surface area.. considering the head in most cases is a flat circle and the valves have to be circles too more of the head can be open to flow air in
if there is more valves. FFS y do u think the toyota 20valve was so popular??
and y dose anything anyone say have to have a comeback on these v8 related discusions??
Totally agree with you there squire. If you are a car fan you'll appreciate what this engine is all about, supercar for the masses, just like the old Hemi's in the 60-70'sQuote:
Originally Posted by Hadean
i love my Honda's, always have, but the sound of a V8 tuned and snorting... pffft vtec sounds like a starter motor in comparison.
I drive all manner of cars from lowly Kia's all the way upto the finest offerings on our roads, and nothing beats the bang for your buck like a big boofy Holden Monaro sideways up Princes Highway! If i had the cash, I'd have one just for the noise alone.
Actually, LS1's valve placement is almost flat, and not at an angle like a 4-valve per cylinder engine. I think it's because of the way the pushrods work that the valve has to be flattish. If you look at this pic of the LS1, I'd say having 3 or 4 valves would drive up the cost and complexity.
http://memimage.cardomain.net/member...22_29_full.jpg
BTW, having 2 large valves means that air can enter without much restriction at low RPM. But at high RPM, the additional surface area of the 4 (And 5) valve engine gives it a bigger advantage. Since the ORIGINAL design of the pushrod V8 was for a muscle car and emphasised on instant push at normal driving RPM, 2 valves was adequate and in fact a good design to balance between price and performance.
Of course, nowadays with VTEC valve control, having 4 valves at low RPM is better than 2 valves because VTEC allows 1 intake valve to be shut at low RPM so that there is a swirling effect and thus better mixing for low end torque (12 valve operation of the K series engine for the Thai Accord). In fact, when you look at the LS1's 1 intake valve on the side, that too provides better mixing with just a simple cylinder head design!
yea there is a lil more room arond the valve for the air to get in but with the slight angle on 4valve engines there is more room for air to get around anyhow, and a 2valve has to have less flow through the runners compared to a 4 valve, unless the 4valve has unnesaserally small runners
i think the reason is that at lower rpm there isnt as much need for more efficient breathing, like think about ur car at 1500rpm there is no need for full throttle as it will not make worthwile gains after about 1/2 open throttle. its probably the same with the holden and its the cause of its lack of power in the higher rev range
the way the air gets in is by the piston sucking it in so the smaller the runners or the less the valves the more the vacum even at lowwer revs. but at higher revs there is less time for the air to get in so u need a better flowing head