m117 startup questions
 

If the car gods agree I might be able to start the '72 280 4.5 this weekend and I have a few questions:
-Any tricks to filling to cooling system other than adding coolant until full?
-Old fashioned antifreeze will be fine? I assume so, as I use it in all my iron block/alu head cars.
-The manual says the ignition timing at idle should be 5 degrees AFTER TDC.
Reallly? How the heck can an engine run that way? Should I set it there?
What is max timing supposed to be (say at 4000 rpm).
My 'other' car runs waaaay better when advance 10 degrees from stock, as the stock spec was retarded to reduce NOx emissions.

BTW, I will spin the engine with the plugs out until the oil pressure comes up.
Thanks,

Csaba

Csaba

-Any tricks to filling to cooling system other than adding coolant until full?

Nope


-Old fashioned antifreeze will be fine? I assume so, as I use it in all my iron block/alu head cars.

I believe so, but others will insist on Zerex. Really it depends on how often you change your coolant.


-The manual says the ignition timing at idle should be 5 degrees AFTER TDC.
Reallly?

Really


With the vacuum on, I think it's something like 15-20 degrees at 1500rpm. The deal on the distributor is actually a vacuum retard, not an advance.

My 'other' car runs waaaay better when advance 10 degrees from stock, as the stock spec was retarded to reduce NOx emissions.

Set it up to spec first then mess with it. Do you have a CO meter?

Manuel says ... With vacuum 11-15* @1500 and 18-20* @3000 rpm

I set mine at TDC and I think its much better.

Perhaps raise front of car so that air escapes more easily as block is filled.

Much of the standard green AF states it is good for aluminum. I have used it for 20+ years on similar engine. But no harm in using Zerex G05.

The 5degATDC is the NA spec and is caused by the vacuum retard. But Euro specs are different. I would start at TDC or even 5 BTDC at idle with vacuum connected. Or about 7BTDC without vacuum. Then check at 3000rpm - it should advance to about 27deg BTDC if centrifugal advance is not stuck. I usually rotate the distributor fully CCW, then back off CW about 1/4" on clamping slot as a starting point.

BTW, Having the AC on stops the vacuum retard.

Make sure points are set - before worrying about dwell, set then to 0.014".

Al asked about a CO meter. Hardly anyone has one. But to adjust idle mixture (knob on ECU) and load mixture (MPS) you really need to have a way of measuring exhaust %CO or AFR. But most people are just shooting blind on these adjustments. Best not to touch MPS without a meter. But for ECU knob, set it in centre of range and then try moving it one click at a time either way with a little burst in-between until you get smooth idle. The ECU adjustment only affects idle (gas pedal not touched).

Have fun.

I used Peak green antifreeze in the MB as well as the Jeep. It's good quality and it was $10/gal @ Target for the full-strength formula so it was cheap compared to say G05 which I use in my 300M and Charger and is ~2x the cost. About 6 years later and it's still green in the Jeep with no discoloration (but I don't drive it much either).

I assume you need oil. You can use conventional... I always did... but synthetic would be better. The problem is unless you redid all of your engine seals, synthetic will clean everything so well it'll pour out of every crack. 10w30 is probably ideal. Some recommend thicker oil but... read Putting the Simple Back into Viscosity - Bob is the Oil Guy. Educate yourself and decide for yourself. I use synthetic 5w30 in my 196k 300M and my Jeep 178k now. 4-5k between changes (5k 300M, 4k Jeep); I use Pennzoil plat or ultra in the 300M and Valvoline or whatever syn is cheapest in the Jeep.

Set your points gap before timing and set both before touching mixture or idle settings. Make sure the ignition systems (Points, cap, rotor wires etc) are all good before bothering with doing any of it or you'll be doing it again.

I set my timing 5° ATDC on it but preferred more around TDC for feel of throttle (this is with vac) especially with the higher-compression 3.5 heads I put on. Plus it seemed to cut down on pinging.

I would suggest keeping the valve covers off at first, put a towel on the exhaust manifolds, and making sure oil pees out of the cam oiler holes before doing actual starting. Don't crank with the plugs out & D-Jet trigger points plugged in, you will get gas dilution in the oil. Unplug the D-Jet harness from the points so your injectors don't fire.

As you have rebuilt the engine, an Engine break in additive with zddp would probably be smart.

A lot of great suggestion, thanks!!

Is ZDDP additive available at regular auto parts stores? I'm sure the ppl who work there would have no idea what that is...

The engine supposedly ran fine before, so I will not mess with mixture at first. I plan on getting a wide band o2 sensor soon, then I can adjust the mixture.
I am also converting to Pertronix, so no points for the ignition, only for the D-jet.
Thanks!

Csaba

I get mine from worldpac and have a couple of bottles knocking around. If you can get to Carrollton in the next couple of hours, I can give you one. Or on Thursday when i get back from my travels.

https://fbcdn-sphotos-f-a.akamaihd.n...35895137_n.jpg

Al,

Thanks for the offer but just got home from a bday party my son was invited to and don't want to drive any more. Thanks anyways!!

Csaba

No sweat, if any retailer has it, I would expect that it would be NAPA. But you may need to ask as it would be behind the counter.

Hi Al,
Well, I've broken in dozens of new engines without it, so I think this one will be fine too.
I did crank the engine with no plugs and got oil pressure eventually. A right rear camlobe is very unhappy, so I need to recheck the clearances. Also found a fuel leak from a short section of rubber hose under the car. Guess it cracked just sitting there...
Still need to install the alternator, fan, PS pump and add coolant.
bye,

Csaba

Oh oh
 

OK, I checked all the valve clearances on the right side and they are all fine.
Hm, so what is that tapping noise?
I had my 5 yo crank the engine while I looked with the valve cover off and it turned out that it's not coming from the valve train (oil tubes squirt oil, BTW :-)
It's like a slight knock once a revolution. I listened with a long bar against the rear of the block and also the starter area, but I can't seem to determine where is it coming from. Grrr... so close yet so far away...

I may also have an injector that is leaking even when it's disconnected.
bye,

Csaba
72 280SEL 4.5

Odd. Around here G05 is about $10 a jug also, pre-mixed. Full strength is cheaper at $8. Bumper to Bumper. So thats why I use it, its better and does not cost much more at all.

If I could get it that cheaply I'd sure stock up on it. Only 1 place sells G05 that I know of (A&A); none of the mainstream places (Autozone, Advance, PepBoys) stocked it last I looked.

Vandor, is your knock possibly fan related? Been there before. If you're sure it is coming from the engine, did you check for bent rods due to the chain detonation the engine previously had? There could be a rod hitting the block or crank counterweight depending how it bent.

Here in Canada, at Walmart, premix is $17.88, concentrate $18.88 and MB premix about $23. Prestone allmakes premix is $15.47, which would likely make the G05 a good choice. Cheapest aluminum compatible housebrand AF is $11.99.

Not suggesting this, but my 1972 owners manual say car takes 15L or about 4 usgal. It says to fill with "treated water" with 2.5-5 cc "treating agent" per litre! (in another place it says add 10% anti-corrosion oil)

The knocking noise is a tough one and i am no expert. But some quick thought: Did you get enough oil pressure to tension chain? Double check cam timing?