M110 EFI cams in M110 carb motor? - PeachParts Mercedes-Benz Forum

Hit Man X · #1 05-18-2010, 08:42 PM

Gentlemen:

There is a 280SE here in the parts yard, '85 I do believe. Anyway, since this is a CIS motor it is of the 9:1 compression variety and should have bigger cams than the ones in my 8:1 carburetor motor, right? I would just take the entire motor, but since my M110 has been reringed it does not make sense to replace it.

Any issues installing those cams into my cam box? Or would I be better off grabbing the entire head from the 280SE?

Car is going MegaSquirt so no worries about it being able to run/idle with the slightly larger cams.

Thanks for any input

wolf_walker · #2 05-18-2010, 11:11 PM

I can't imagine any really noticeable issue, especially with the tuning ability of MS.
If it's cheap it might be worth getting the head and all the K-Jet stuff. I might be interested in some of that if you did.

Hit Man X · #3 05-19-2010, 12:44 AM

Do you think there is enough power to be gained to warrant the swap? I think the power differences are around 25hp.

No prob on the CIS stuff, just PM me.

Any idea on the difficulty to remove the head on the M110?

t walgamuth · #4 05-19-2010, 06:25 AM

R and Ring the head on a 280e is a triple b#tch according to my favorite machinist. The way the head is constructed does not really lend itself to easy removal. Just removing the cams is tough too. Unless I KNEW there was a significant difference in lift and or duration I would probably not fool with the cams.

It would be easier to r and r the entire motor (if it were the same).

I might pull the motor though just to have it.

JMURiz · #5 05-19-2010, 09:52 AM

I would think an all or nothing swap would be the best way to go, the FI motors have different pistons, heads and cams, right?
And the FI intake would make it way easier to do a MS EFI system.
With the carb'd car, I would probably just do a TBI or make your own EFI intake manifold.

daw_two · #6 05-19-2010, 10:14 AM

Just pull the entrie motor. You know you are going "need" it for some future project car/body that you stumble upon. Make sure you get the motor mounts, transmission, transmission cross frame, etc.

m4ff3w · #7 05-19-2010, 12:38 PM

Quote:

Originally Posted by JMURiz

I would think an all or nothing swap would be the best way to go, the FI motors have different pistons, heads and cams, right?
And the FI intake would make it way easier to do a MS EFI system.
With the carb'd car, I would probably just do a TBI or make your own EFI intake manifold.

KJet/CIS intake wouldn't really make it any easier to EFI than the carb intake.

The injector ports are in the head of a KJet engine.

JMURiz · #8 05-19-2010, 01:41 PM

I think you can use adaptors, like the ones in the link below:

http://cgi.ebay.com/ebaymotors/EFI-injector-adapters-Mercedes-201-190-_W0QQcmdZViewItemQQhashZitem4a8ca16b39QQitemZ320186968889QQptZRaceQ5fCarQ5fParts
With those you can make a fuel rail to link them all up, get a trigger wheel setup, and throttle body adapter and you're golden.
I did some research while I had a euro-spec motor I was going to swap into my 280C, but I sold off the motor as I had too many other projects to take care of.

wolf_walker · #9 05-19-2010, 06:51 PM

Top end work does look like a pain in the manual, lot of parts up there, cam box, head, timing, etc. Are your cams bad or just looking for performance?

Hit Man X · #10 05-20-2010, 03:47 AM

As pointed out, converting the 4A1 car to TBI is much easier than converting a CIS car over. The CIS is crap, plain and simple. TBI is not perfect, but far better than CIS. I am going to use TBI WITH MegaSquirt.

Head cast is different with the CIS bosses only. Static compression is about one point higher, that is about 2.5% total power increase. Not much with that variable alone.

I guess I could just pull the entire motor, but the place that has it is one of those large self serve yards and always want a core. If I could find a junk motor to give them I may just pull the entire thing. I need the Sanden compressor and bracket it has on there too.

Yes, main reason is for more power. With the larger cams and MS, the car should run quite nicely for what it is... all things considered.

t walgamuth · #11 05-20-2010, 06:03 AM

Does my 84 280e have cis? (I think it does). Why do you say it is crap? I have found it pretty bulletproof.

JMURiz · #12 05-20-2010, 10:08 AM

I don't think CIS is crap, seemed to work fine on the 190E 2.3 16v and the Porsche 930 turbos all those years. It's all in the setup.

Having said that, since I have a 280C with a Solex 4A1, I'd love if someone did a comprehensive TBI conversion kit....along with a York to Sanden A/C kit and electric radiator fan kit.

wolf_walker · #13 05-20-2010, 11:00 AM

CIS is a stone ***** if it's dirty, screwed up and/or you don't have diag tools and info. You just about can't wing it. But when it's right and the fuel is clean, it's golden for a long, long time. They only reason Mercedes grudgingly quit using it was cold start emissions couldn't be controlled well enough. There was little if any power increase going from CIS to the early Bosch LH injection.

Also, if you get into needing pumps and accumulators and fuel distributors and warm up regulators, you can spend a small fortune. Best running cars I've ever had have all been CIS, after a lot of money and effort.

thorsen · #14 05-20-2010, 11:50 AM

Quote:

Originally Posted by JMURiz

I'd love if someone did a comprehensive TBI conversion kit....along with a York to Sanden A/C kit and electric radiator fan kit.

You can buy the York->Sanden brackets for about $40. The last new Sanden I bought cost $50. Buying AC parts in January is the best way to do it.

Hit Man X · #15 05-21-2010, 04:23 AM

Yes, when CIS works it does so okay... I have a few CIS vehicles. It leaves quite a bit left on the table to say the least in terms of performance and overall drivability.

Face it, it is just more than old technology... it is archaic by today's standards and not really worth repairing when you have a total meltdown.

TBI is easy, just look at what 'MikeD' did (I believe that is his name). GM used it forever and it is very simple to diagnose and to squeeze more power from. Huge power? No. But enough to warrant the swap from even a CIS car over to it, let alone a carb car. I saw another M110 car in the yards with a 4A1 on it (W114)... be sitting over ten years. Geen I wonder why.

CIS, as pointed out again, is very costly when it starts to fail... not to mention is very susceptible to vacuum leaks and on the V8 cars makes you want to punch a baby when you get to reseal it.

Granted the early port EFI BMW used is not great here for the US cars, the ECE cars actually had pretty decent performance as they had more aggressive timing tables and fuel maps (yes slightly larger cam and a tad more compression helped some)... around '88 when BMW updated the electronics once again on the I6 cars, response and power improved drastically. I compare their I6 cars as it was their main offering in the early to mid 80s, so they are most similar. V12 cars are much more advanced and not really withing this realm as their electronics are not too bad, contrary to popular belief.

THAT my friends is the beauty of MS over CIS. Hell, most CIS cars (at least US W126s) drive fine on 87 octane fuel. Just more aggressive timing will yield more power and not just at WOT, let alone some extra fuel at WOT (power enrichment).

I do not see 15-25hp being out of the question for a modern EFI conversion once all dialed in, including massive upgrade throttle response and some fuel economy too. You can lean cruise the vehicle in question, add gobs of timing, the aforementioned PE, etc.