32 valve LS2/7 anyone?

[ossme]

Hi All,

LS2 and LS7 engines became the new trend for Ultima builders. I wonder what can you guys do with these new 32v heads? 1000hp N/A? High revving engine?


http://www.araoengineering.com/LSX.htm

[Daston]

Sweet! I am no mechanic but 32v has to be a good thing

[chuntington101]

these heads look amazing! its a shame the company isn't quiet as good. there have been many cases of it taking over a year for people to get their heads from these guys. i think its cos they dont actually sell that many as all the reacers have to stick to 2 vavles. this leads to more developemnt of the 2 valvers and people going with the "treid and tested" route.

it would be really nice to see these on a built LS7 or new warhawk block.

Chris.

[SplatSpeed]

sweep stake on when wayne puts in an order for the GTW

[Daston]

just had a flick through their site they also do it for the Chevy small block as well. Might be an idea when I build mine being able to put the rev range to 9000rpm would also sound pretty good

[P15TON]

Throw them in the nearest skip.

The qualified version.

People have produced 4 valve heads for small & big block chevy's for over 30 years. They have never caught on.

Why? Not necessary. A load of complication for very little gain.

GM had more money to spend developing this LS series of engines that anyone here can imagine. Believe me, if this was the way to go, THEY would have done it.

You'll do well to beat a set of factory LS7 heads or C5R heads for ultimate output.

I'll wager these gimmicky heads will fall by the wayside like all the others.

Edited by P15TON on Friday 15th June 13:31

[dilley]

but don't they look pretty!!! real head porn!!

[peterpsg]

PK, can you settle this one for us?

Is the rev limit lower on the Chevy (& other push rod engines) due mainly to ...

1. valve train mass & spring damping limits
2. port flow volumes reaching sonic speeds and the airflow choking in the intake system
3. mean piston velocity and the stroke length, hence con rod loads...?
4. GM's miserly accountants demanding 100K+ mile endurance...

Thus a 377 shortened stroke block can out rev a normal or stroker engine mainly due to mean piston velocities (i.e distance traveled /time) ???

Or all of the above???

[SplatSpeed]

i think its a combo of 2 and 3

[CarMad426]

I would say 1 and 3, also i was going to say theres a video of one of those earlier 32v heads on nelsons racing engines site although i cant seem to find it at the moment. It was supercharged and sounded real nice.

[P15TON]

[quote=peterpsg]PK, can you settle this one for us?

Is the rev limit lower on the Chevy (& other push rod engines) due mainly to ...

1. valve train mass & spring damping limits
2. port flow volumes reaching sonic speeds and the airflow choking in the intake system
3. mean piston velocity and the stroke length, hence con rod loads...?
4. GM's miserly accountants demanding 100K+ mile endurance...

Thus a 377 shortened stroke block can out rev a normal or stroker engine mainly due to mean piston velocities (i.e distance traveled /time) ???

OK, there's a lot going on here, so the answer is ....

IT DEPENDS!

The main reason is reason 1, but this can be got around by using light weight components. With the right parts, 9000 rpm plus can be done (ie Winston Cup cars) & 12000 rpm plus (drag racing eg Comp eliminator, Pro-stock, Top Alcohol)

Reason two Can be got around

Reason three can be got around

Reason four is one of the most relevant , as the 'IT DEPENDS' bit depends on what stops the individual combination you're dealing with. ie, you might have nice high flowing big cross sectional area ports, but you have heavy valves that are the 'bottleneck' in the combination.

The fifth one, not mentioned, is oiling it all effectively at high rpm.

Generally speaking then, as you fix one problem, you find another, and until you've solved them all, you can't get the RPM right up there reliably.

For example, we have an engine that never runs below 6000 rpm, and makes max power at 7800. We use pankl light weight rods & crank, honda 1.888" rod journals, all titanium valve gear etc to get that working. Getting it to survive hour long races was not in the valvetrain, but was in the oiling. We had to cut off the oil to the cam bearings ( needle roller bearings installed) put oil into the block at both the front & rear of the main oil gallery, use the small Honda size journals, tighten the bearing clearances & use 5W / 20 Oil, at a certain temperature range.

That's why saying 'I want a high revving engine' fall's into the talk is cheap department when you know what work it takes to make a high revving engine really work.