Dan9687

I thought a straight 6 was the engines that were V6 but were straight....shaped like an "I"

Ok neways this stuff is way off topic but its ok I dont mind...my question now since we got all that figured out is how does a "Push Rod" engine work? And not the whole thing thats too much, I just mean the push rod part??? Thanks.

ShadowDrake

Here's my TOTAL GUESS... this is just what makes sense to me:

A rod goes from the cam which usually sits in the valley from the V-shape of the motor and pushes against the rocker arm which opens up the valve... Thus the name Pushrod, because the cam pushes a rod. Works just as well as SOHC or DOHC.

Am I right about this?

Edit: I tried to draw a picture in photoshop, failed, went to paint, and failed there too... If you really need one I'll try to make one up again.

Dan9687

Thanks for the input but I think you have it backwards....I too am not 100% sure but I think it goes in this order...

STEPS:
1.)Piston hits valve
2.)Valve pushes up on springs pushing the rocker arm up
3.)Other end of rocker arm (pushrod end) pushes down on pushrod pushing the cam lobes

I am not sure, maybe the other guy is right I dont know?!?! But thats the part I dont get is what happens after step 3???

redass02gt

I think you are saying that the valve drives the pushrod???? the cam is what causes the valves to open (through the use of other parts), the valves don't "drive" the cam. i think I must be misunderstanding what you are saying, dan9687, or you are really missing the basics. very very basically, the cam(s) drive the valvetrain and determine the timing for the valves to open and close.
the pushrod is what cause the valves to move when the cam moves the pushrod. and the piston doesn't move a valve. try searching google for pushrod motors or something. maybe ls1tech has something. a cutaway diagram would really help.

JD1969

Here read this it might help. Please note that this is an SOHC engine, a pushrod engine works the same only the cam is in the block and uses a pushrod to press against the lifters which in turn open the valves.
http://auto.howstuffworks.com/engine1.htm
Ah yes here you go a pushrod engine read all this, it explains things pretty well.
http://auto.howstuffworks.com/camshaft5.htm

Fallstar01

A V6 has two heads to cover three combustion chambers each. It's shaped like A V with the camshaft at the middle above the crankshaft. A straight 6 is one head that covers all six chambers which are all in a row. There is something called an inline six that, I believe is similar to a straight six but has a different firing pattern (correct me if I'm wrong). There are also 6 cylinders where the heads point out horizontally (not like a V but actually straight at the fenders), I've seen one on a Volkswagon. Maybe it's an H six?

SOHC is Single overhead cam. Overhead, means it's in head, and SOHC means there is only one in the head. In motors with more than one head, there is more than one cam. DOHC motors have two cams in the heads. They usually have 4 valves for each chamber and require the extra cam to move all of those valves. There are MANY 4 cylinder engines with 2 cams in their one head(DOHC). Likewise, there are a number of DOHC V8s (mach1, Cobra) that have 4 cams total, 2 in each head. OHV or pusrod motors are interchangable terms for the same concept where a cam sits below the head and uses long rods to move the lifters. In OHV V-style engines, there is only one single cam in the whole engine that sits near the crank in the bottom of the V and pushes up on the pushrods which go up into the 2 heads. Late model Camaros, Trans-Ams, Corvettes, and those Caddilacs with the Vette engines, all have LS1, LS2, LS6, or LS7 motors which are quite powerful, despite being older technology. Those engines also tend to get better gas milage despite having more displacement, less valves, and only 1 cam in an older style engine. Even the Saleen S7, one of the most exotic cars in the world, uses a single cam OHV engine. There are plenty of exotics that use OHC engines as well. Ferrari has a 6.0L V12 DOHC engine with Variable Timing (Think V-Tec) that puts out some major horsepower naturally aspirated.

Just to recap, SOHC refers to single cam per head, DOHC refers to 2 cams per head, OHV refers to single cam in the whole engine and it's not in the head but near the crank.
The cams in the OHC engines are turned by a timing chain or a timing belt that runs all the way up from the crank (at the bottom) to the head.

As stated, while it's older technology, OHV cars are still in production and still put out good numbers.

Dan9687

JD I actually found that exact site about how a Pushrod engine works with the animation. It helped me alot, see I was all backwards...I thought the pistons hit the valves to close them etc. but as I saw in some pics when the pistons hit the valves it majorly f*cks them up. But thanks for all the help fellas.

Also, isnt the camshaft connected to the timing chain which is also connected to the crankshaft which spins both? (still talking about pushrod engines here)

ghoste

Inline (straight) 6 = |

6 cylinders in one straight bank.

V6 = V

6 cylinders, divided by 2 sides = 3 cylinders per bank