New Performance Camshaft from Midwest-Bayless

Matt Brannon - Midwest Bayless

Matt Brannon - Midwest Bayless

Mad.Matt
Hey folks,

Thought we'd share that we have a new performance camshaft grind available:

http://www.midwest-bayless.com/storefrontprofiles/DeluxeSFItemDetail.aspx?sid=1&sfid=208227&c=193015&i=294607099

This camshaft is comparable to stock European specs, but with higher lift.

We measure the duration of our cams at .050 lift, as opposed to inflated "Seat-to-Seat" specs.

A stock North American cam comes in around 212 degrees at .050, with 9.2mm of lift.

These cams are 223 degrees at .050, with 10.2mm of lift, and fully nitrided.

SOHC-223-perf-cam.jpg


These units are good for any carb application, and GREAT for installing in factory Bosch L-Jet Fuel Injection applications, providing more torque and horsepower than stock with minimal disruption to cold-start idling.

In addition to this 223 degree unit, which is now our lowest duration performance cam, we offer three longer duration cams as well.


As a note, these are regrind cams, not billet, so you will need thicker-than-stock shims, or a milled cambox.

We use this maker's high duration cobalt-welded regrind cams in all of our race cars.
 
Matt,
Can you explain the difference in performance (HP and torque) between your 223 and 231 cam shafts. Also, which would be best for highway use, especially on long steep grades at altitude?
 
An explaination could be pretty long... lol

There are many aspects of camshaft specifications which dictate what it will do in the engine. Duration, lobe separation, maximum lift, lift * .050, lift profile per degree, etc... However, in most simplistic terms, duration is typically the most obvious and important.

A longer duration camshaft allows more air and fuel to be drawn into the cylinders because the intake opens earlier and closes later than stock.

The downside is that above a certain point of extended duration, the intake and exhaust valves tend to have longer durations of "split overlap", where they are both open as the events change from the first half of the cycle to the second set of the cycle.

What this manifests itself as is a lumpy idle, where at low engine speeds some of the intake charge is actually being spit right back out of the exhaust during the compression stroke.

Because of this, longer duration camshafts make their additional power at higher RPMs than stock, where piston speed can "outrun" this pumping loss. The pumping loss issue is part of the term "volumetric efficiency", meaning how quickly and completely can the cylinder be filled with a full charge of air/fuel mixture.

So, after all of this explaination, the new 223 degree cam will have minimal pumping loss at idle, but extended duration and lift for better flow. For a factory FI car, this is optimal, providing additional power with minimal disruption to the "preset" idle controls in the system.

The 231 degree cam, next up on the list, is the only other alternative camshaft we recommend for a stock FI system. Because of its additional duration, the power is increased a bit but the power band is moved slightly upward by about 500 RPM. It works extremely well in an FI system, with one downside; - at cold-start, the idle can be low and rough. After the system is fully up to temp, the idle smooths out nicely, but is a tick high (1100 -1200 RPM). Aside from completely changing the cold start enrichment mechanisms, there isn't much that can be done to work around this.

The other two cams, the 236 and 240, continue to produce additional horsepower due to their extended duration, but the power band continues to move upward in approx. 500 RPM increments. Consequently, these grinds are simply too long in duration for any form of reliable idle with a factory FI system and are not recommended for this set-up; - they are carb, or programmable EFI application only.

The 240 is the longest duration camshaft that we recommend for the street because it is noticably "on-cam" between 3,000 - 6,000 RPM and that can get tiring for stop-and-go street driving.

As a final point regarding duration to power band, our race cars use 270 degree and higher camshafts. The power band is typically between 7,000 and 9,000 RPM. Below 3,000 RPM, the pumping losses are so severe that on a dyno, the race motors show less horsepower at that speed than a stock engine...

Hope this helps,
 
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