M110 Exhaust manifold swap - PeachParts Mercedes-Benz Forum

lunchbox · #1 05-08-2009, 04:25 PM

I thought that I should post my progress on the project I started a month ago. I replaced the middle muffler on my 1975 W114 280c and I plan on replacing the horrible stock exhaust manifold with a much more standard setup that was from a fuel injected model. The stock manifold for 1975 included a Thermal Reactor setup for those of you who don't know. They were problematic and costly, so the previous owner instead replaced it with an aftermarket cat that is mounted inside the engine compartment. Needless to say, the engine compartment gets so heated on the exhaust side that the paint on the hood has started flaking of (granted the hood pad was taken off long before I got my hands on the car).

So yesterday I received the newer style exhaust manifolds that came off of a fuel injected M110 engine. It has a built in EGR setup, but I plan on putting a block plate on. The manifolds were solid, but needed some paint so I quickly picked up some header paint that is good for up to 2000 degrees F.

My hope in this project is to benefit all across the board: Better fuel economy, more top end power, less noise (the old manifold had a leak), and more room in the engine compartment/less heat! The manifolds that I am removing are very strange and if you can see in the pictures they are a log style manifold........that points to the front of the car! The flow of the exhaust should be substantially better even just using these stock manifolds.

I'll post pictures when I finally install both manifolds (there are two separate manifolds, one manifold for the first and last set of 3 exhaust ports) and hopefully I will be able to report some improvement in the "Butt Dyno"

For those who are interested in the swap, it is not smog legal to remove the smog equipment that was put in place by the manufacturer on ANY CAR in California, regardless of age. Cars built like mine (model year 1975 and prior) are exempt from biannual smog tests, but are still required to use all smog equipment that it came with from the factory. If you remove the thermal reactor from your 1976 car and attempt to smog it, you will get an automatic fail based on the visual inspection (unless the smog attendant does not know what he's looking at) and your smog readings would be significantly altered as well.

Nate Stanley · #2 05-08-2009, 06:30 PM

Just a quick question- are you saying that a 1974 model, since it is exempt, will never be inspected again?
My MIL has a 1974 280 with the original thermal reactors, and I was wondering about how such a swap would work. Please keep us posted.

280EZRider · #3 05-09-2009, 08:55 PM

Nice paint job! A blocking plate may be noticable where as a plugged vacuum line to the EGR would not. But I'm not advising. A front exhaust manifold from a Euro M110 does not have a port for mounting an EGR. But I'm not advising.

I'm originally from the East Bay too. Where are you?

lunchbox · #4 05-09-2009, 09:16 PM

Nate, if your car were in California and you were referring to a model year 1974, then your car is exempt from biannual testing. You are still subject to being tested if an officer sees reason to suspect you've been tampering with the smog equipment. In that regard, no auto in california is completely exempt from smog checks.

thanks for the compliment 280EZrider, I know there were other routes I could have taken, but this was definitely the most cost effective for me and retains a nice presentable look. You may be right about the block plate sticking out though. Also, I still live in the East Bay, I'm in the Danville/San Ramon area and I've been here most of my life! The weather couldn't be any better and I keep the windows rolled down from here on out till november!

lunchbox · #5 05-09-2009, 09:19 PM

While this thread is still hot, I thought I should ask a few other questions that I've been thinking about while working on the 280C:

1. What product does everyone use when lubricating the throttle linkages? I used a standard off the shelf spray lubricant.

2. I have jumpy gauges so I was going to pull the cluster and make sure the ground connections were solid. Is the oil pressure gauge the same style as my W108 280SEL in that it has an oil feed line to the gauge itself??

280EZRider · #6 05-09-2009, 11:39 PM

Quote:

Originally Posted by lunchbox

While this thread is still hot, I thought I should ask a few other questions that I've been thinking about while working on the 280C:

1. What product does everyone use when lubricating the throttle linkages? I used a standard off the shelf spray lubricant.

2. I have jumpy gauges so I was going to pull the cluster and make sure the ground connections were solid. Is the oil pressure gauge the same style as my W108 280SEL in that it has an oil feed line to the gauge itself??

#1 Sylicone spray works well; it resists moisture & crud.
#2 Yes.
For 3 years, I lived just around the corner from you if Walnut Creek - small world.

panZZer · #7 05-17-2009, 04:02 PM

Quote:

Originally Posted by 280EZRider

Nice paint job! A blocking plate may be noticable where as a plugged vacuum line to the EGR would not. But I'm not advising. A front exhaust manifold from a Euro M110 does not have a port for mounting an EGR. But I'm not advising.

I'm originally from the East Bay too. Where are you?

These are from a euro m110, I still have the complete 185 hp k-jetronic FI setup from the car these manifolds came off of. panZZer