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Guest Anonymous

If I put on the Schrick 304 cam, what other things are neede

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Guest Anonymous

I know that some 40DCOE's are needed, would a 38/38 downdraft work? And what about other things, like heavier valve springs?

The head I have may already have upgraded valve springs, is there anyway I can tell?

Thinking about hitting Santa Claus up for the Schrick (he's German), so is there anything else I need?

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Guest Anonymous

You need at least 9.0:1 compression pistons for the cam to work in a positive manner. If you drop side drafts and that cam in without upgrading compression, you will make you car slower.

If you can't afford to go that route, and want some simple bolt-on performance, the best way to go is to get a pair of 40DCOEs. While they work better with a modified motor, they will give a stock motor some get-up-and-go.

You gotta remember performance upgrades work best as a package: carburation, cam, compression, upgraded spark. Going fast is easy; it's just a matter of money.

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Guest Anonymous

along with the stahl header and the ansa exhaust, lightened flywheel, centerforce1 clutch, 3.9lsd, I think that is it for now. But the engine isn't even installed in the car right now

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Guest Anonymous

There is so much overlap, that dynamic compression ratio falls down. Not to mention that it requires more compression to burn all that extra fuel...

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Guest Anonymous

9.5 will work and 10 or 11 will work better.... but what range do you plan on running the motor most?

You can choke and jet carbs accordingly and do lots of things with spark, so too much fuel wouldn't really be an issue.

I would be more concerned with where the power range is going to be in relation to how you plan to drive the car.

Yes you would need dual springs if you went that route.

MHO

Brian C

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Guest Anonymous

and with a 32/36 was dyno tuned out at 135 hp @ the rear wheels. You should open up the passages in the intake manifold & head of course to realize more of the potential of the components your installing. I'm considering that Schrick with sidedrafts so if you do go that way let us know what the results were once it's set up.

JH

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Guest Anonymous

I mainly concerned about the loss of power in the lower RPM ranges. It would certianly be nice for passing, and leaving behind some Civic from the line. But for the rest of the day that I spend in the 3kRPM range, would a 304 adversly effect my performance even with proper use of spark and choke on the carbs?

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Guest Anonymous

There was an article on an old roundel explaining

what contributes to higher or lower redline, If I

remember right it was a function of reducing

rotating mass, which will demand more gas more

air etc, so it is actually a bunch of things not only a

bigger duration cam.

Michael

72 tii

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Guest Anonymous

Camshaft dictates this for the most part, as well as intake manifold, ports, valves, pistons, exhaust system. Balance and rotating parts mainly limit maximum revs due to physics, ie they can only take so much stress before flying apart. More a factor of reliable rev limiting.

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Guest Anonymous

You just left the 292 in there.

As Michael said the redline is not necessarily raised by installing a lumpier cam, only the effective power range assuming you have other components working together properly.

Knife edging the crank, lightening the flywheel, lighter/stronger rods, and lighter pistons all weight matched will "allow" a higher redline.

Brian C

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Guest Anonymous

I know several people who have used 304 and 9.5, but Lee is right, you lose a lot of compression because of the overlap in that cam. A 292 will deliver close to the same horsepower, but is less peaky and much more streetable. The 304 is better for a parttime track car, I think. I have a 292 and 9.5s in my A4/tii and it is great.

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Guest Anonymous

A long duration cam will lower dynamic compression ratio.

The piston is already on it's way up before the valves shut.

So start of with a higher static CR.

Next, the duration of the cam is tied to the inertia of the air/

fuel mixture mass between the throttle valve and the inlet

valve. If cam duration is short, it will work in low revs, but

choke the car in higher revs. If cam durarion is long, it will

work in high revs but it will be inefficient in lower revs, hence

the lumpy idle.

Last but not least, the red line is determined by how fast your

engine can turn without shredding itself to bits. Fitting a cam

which performs above the red line won't raise the redline of

the other mechanical bits in the engine. Things like

balancing and heavier valve springs will, but not to infinity.

Think of the forces on conrods and their bearings: they make

a piston accellerate and stop again 100 times per second at

6000 rpm. Balanced or not, those are huge pulling and

pushing forces.

Good luck,

Hugo

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Guest Anonymous

a high- overlap will give low static compression, but the faster the motor spins, the more effective its pumping will become, raising the effective dynamic compression ratio back up to somewhere around the swept area of the cylinder.

In short, a high- overlap cam makes an engine an effective pump at high rpms- a low overlap cam is more efficient at lower rpms...

t

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