603 Never needs a VAlve Adjust Could this BE?? - PeachParts Mercedes-Benz Forum

777funk · #1 02-26-2007, 09:47 AM

Hi guys,
I recently saw somewhere that the 603 six cylinder MB doesn't ever need a valve adjustment... How could this be?

Is it safe?

Also, I can't find the spark plugs on this thing. Where are they at?
Just kidding. But I'm serious about the first question with the valves.

Thanks,
Nick

cgunderm · #2 02-26-2007, 09:53 AM

Correct and safe. The 601, 602, 603 engines have hydraulic lifters and don't require manual adjusting.

rg2098 · #3 02-26-2007, 09:54 AM

They use hydraulic valve lifters.

wikipedia - hydraulic lifters.

Quote:

A hydraulic lifter, also known as a hydraulic tappet or a hydraulic lash adjuster, is a device for maintaining zero valve clearance in an internal combustion engine. Conventional means of adjusting valve actuation always require a small clearance to be left between the valve and its rocker or cam follower to allow for thermal expansion and wear, as it is vital that a valve must never be prevented from closing completely; this rapidly burns it away, especially in the case of the exhaust valve. The hydraulic lifter was designed to ensure that the valvetrain always operates with zero clearance, leading to quieter operation and eliminating the need for periodic adjustment of valve clearance.

The hydraulic lifter consists of a hollow expanding piston situated between the camshaft and valve, either operated by a rocker mechanism or, in the case of double overhead camshafts, directly by the camshaft. It is filled with engine oil intermittently from an oil gallery through a small drilling. When the engine valve is closed, the lifter is free to fill with oil, but when the valve is opening and the lifter is being operated on by the camshaft, the oil feed is blocked and the lifter acts just as a solid one would, oil being nearly incompressible.

Hydraulic lifters were popular on automobiles designed in the 1980s, but most newer cars have reverted to bucket-and-shim mechanical lifters. Although these do not run as quietly and are not maintenance-free, they are cheaper and rarely need adjustment because the wear caused by operation is spread over a large area.

There are a number of potential problems with hydraulic lifters. Frequently, the valvetrain rattles loudly on startup due to oil draining from the lifters when the vehicle is parked. This is not considered significant provided the noise disappears within a couple of minutes, although typically it usually only lasts a second or two. A rattle that does not go away can indicate a blocked oil feed or that one or more of the lifters has "collapsed" due to wear and is no longer opening its valve fully. The affected lifter should be replaced in the latter circumstances. In extremely rare circumstances, a lifter can "pump up" and create negative valve clearance so that its valve cannot close. This is more serious as burned valves will result. In all cases it is important to follow the manufacturer's recommendations for oil viscosity and quality.

Cars with hydraulic lifters include the first generation Mazda MX-5 and most General Motors models produced in the 1980s.

777funk · #4 02-26-2007, 10:00 AM

Cool thanks guys!

Now I'll never Adjust my valves again. Period!

But I will change my oil.

cgunderm · #5 02-26-2007, 10:06 AM

Quote:

Originally Posted by 777funk

Cool thanks guys!

Now I'll never Adjust my valves again. Period!

But I will change my oil.

Yup. Don't even attempt to, not matter how much satisfaction you may have derived from adjusting them on your old 617

Period!
(I hate doing the adjustment)

justinperkins · #6 02-26-2007, 11:24 AM

Quote:

Originally Posted by 777funk

Cool thanks guys!

Now I'll never Adjust my valves again. Period!

But I will change my oil.

I thought you were convinced the 603 was crap, thinking otherwise I take it?

777funk · #7 02-26-2007, 11:33 AM

This forum actually convinced me that they were not a good engine. I've owned the 617 and this and I'm still debating which I like better. So far it's a nice thing to see that I won't have to touch the valves. That's something I hated off the bat when I bought the car was looking at the intake and thinking, now I have to tear that apart every 30k. This stinks. But now that I don't have to mess with valves, that paints a completely different picture. I'm still a little worried about things other people have said about it. But... I can't believe everything I see on the internet can I.

I paid $500 for the car plus about $700 of parts (including a new/safer vac pump) are going into it.

So for that cost, I'll drive it hopefully til it drops

We'll see. I take car of my cars, so hopefully alls well.

justinperkins · #8 02-26-2007, 11:37 AM

Quote:

Originally Posted by 777funk

This forum actually convinced me that they were not a good engine. I've owned the 617 and this and I'm still debating which I like better. So far it's a nice thing to see that I won't have to touch the valves. That's something I hated off the bat when I bought the car was looking at the intake and thinking, now I have to tear that apart every 30k. This stinks. But now that I don't have to mess with valves, that paints a completely different picture. I'm still a little worried about things other people have said about it. But... I can't believe everything I see on the internet can I.

I paid $500 for the car plus about $700 of parts (including a new/safer vac pump) are going into it.

So for that cost, I'll drive it hopefully til it drops

We'll see. I take car of my cars, so hopefully alls well.

I don't really understand how having to adjust the valves or not makes the engine any better, but you're entitled to your own opinion.

I'm actually surprised that the 617 didn't have hydraulic lifters, VW started putting them on their engines in the mid-70s I believe.

777funk · #9 02-26-2007, 06:32 PM

Doesn't make it any better but definitely easier to work on.

pawoSD · #10 02-26-2007, 06:39 PM

I like adjusting the valves on a 617, its interesting to see which valves are tight and such...and I just like to see the cool looking valve train.

vstech · #11 02-26-2007, 07:20 PM

I was thrilled to learn my MB had "solid" for lack of a better term lifters.
I loved adjusting the rockers on my old chevy, and and on my high performance race cars. I missed it in the newer motors. Glad I don't have to remove the intake to do it though!
John

justinperkins · #12 02-26-2007, 07:25 PM

I bet you guys that love adjusting your valves so much would make your diesel carburated too if you could, eh?

Personally I like not having to adjust the valves. Leaves time for other, more important tasks.

babymog · #13 02-26-2007, 07:49 PM

I'm trying to remember Justin, the memory's foggy, but my '77 Audi Fox and '78 VW Dasher had solid lifters, my '85 Audi quattro and '85 Jetta had hydraulic, changed somewhere in-between but I'm not remembering when. The I-6 Gas 3.0 Mercedes I believe started out with hydraulic lifters, which probably puts Mercedes' gas cars before the diesels for hydraulic lifters, if the 601 came with hydraulic, the 190D started in '83? in Europe and had a 601? Not sure.
Basically the new engines came with the new stuff, VW with the 1.8L I-4 and 2.2L I-5, Mercedes with their new engines. The 617 just wasn't re-tooled at the end of its life, ran out in '85 with solid lifters.

justinperkins · #14 02-26-2007, 08:05 PM

Quote:

Originally Posted by babymog

I'm trying to remember Justin, the memory's foggy, but my '77 Audi Fox and '78 VW Dasher had solid lifters, my '85 Audi quattro and '85 Jetta had hydraulic, changed somewhere in-between but I'm not remembering when. The I-6 Gas 3.0 Mercedes I believe started out with hydraulic lifters, which probably puts Mercedes' gas cars before the diesels for hydraulic lifters, if the 601 came with hydraulic, the 190D started in '83? in Europe and had a 601? Not sure.
Basically the new engines came with the new stuff, VW with the 1.8L I-4 and 2.2L I-5, Mercedes with their new engines. The 617 just wasn't re-tooled at the end of its life, ran out in '85 with solid lifters.

My 78 and 79 VW buses had hydraulic lifters (air cooled), as did my 86 diesel Golf and my 87 Syncro.

When I bought that 79 and I realized I didn't have to adjust the valves anymore, I was a happy man (I had a couple 60's buses, which need valve adjustments with every oil change).

babymog · #15 02-26-2007, 08:30 PM

In boxers I'll have to bow to your knowledge, I had a '72 Westy with solid, and the next one was the '86 Wasserboxer at which time everyone had hydraulic lifters. Why VW didn't put hydraulic lifters in the 1.6L I-4 I don't know, I believe that '85 was the first year (and both of my '85 cars had to have them replaced in the first 2 years, thank you VW).