'85 cam on my '79 300SD head?

In the midst of installing the > $600 worth of stuff I bought off the site :-) and am curious about your take on cam. The '79 300SD had the lowest HP of the 617 turbo run and 85's the highest. Folks on some of the chat boards are suggesting I put an 85 cam and cam tower on the head once I get it back from the shop. Thoughts? that and know where a guy might get a good '85 cam/towers?

Thanks!

Ben near Detroit

Forums

Diesel Engine Specific Aid

Chassis Model Number

W116

There may be other things more important

I have driven hundreds of older Mercedes diesels over the years and power output has more to do with engine tuning than it does with the mechanical makeup of the engine (except in cases of severely worn camshafts, piston rings / cylinder walls). I have driven some tuned non-turbo 300D's that will outrun an average neglected 300D turbo. My own personal 79 300SD will blow by most 85 models I have driven.

If your engine is mechanically healthy ( ie good compression, good camshaft, good chain, etc) I would recommend you put your time and money into your fuel injection system and turbo charger. That would include making sure your ALDA system is clean and working properly, your fuel injectors are releasing at the right time - both pump timing and release pressure), injector spray pattern is correct - install Monark nozzles, your turbo charger is clean and not excessively worn, turbo boost pressure is correct,and finally, your transmission shift points are adjusted properly.

IMPORTANT: You will read a lot about adjusting the ALDA mixture at the fuel injection pump. It can give results but often it is done to mask another problem (like bad fuel injectors or poorly performing turbo charger. The turbo on these engines is often neglected and only serviced if it fails. Experience has shown it should be opened up, cleaned, rebushed and resealed about every 100,000 miles. I recently rebuilt the turbo on my daughters 300TD wagon. The results were remarkable. She particularly notices the difference between 40 to 60 mph when she accelerates in passing gear. Not reluctant to pull out or pass anymore! She says it is like driving a totally different car! After redoing the turbo I had to lean out the fuel mixture ( it had been blowing some black smoke under heavy acceleration). Now it does not smoke and fuel economy has improved 2 to 3 mpg.

I see from your order you are already on the right track... :-)

Just going to say I picked

Just going to say I picked up the new turbo rebuild kit along with the head goodies I got from the girls last week. I'll have my hands full this weekend rebuilding the turbo!

I agree with you completely and will stay focused on the task at hand although I'm putting the head (and cam) from my '80 SD on the '79. Word has it that cam is a little better than its predecessor. Since I already have it and it's paid for...why not?

Related question on the head gasket. The FSM says to not open it until the last possible second so it doesn't get exposed to light and ozone. The Haynes book makes no such mention and in fact has you taking it out of the wrapper to trace on cardboard to reinstall the head bolts in the same place.

Would love your take on that and the wisdom of new head bolts while I'm at it.

One other thing I forgot to

One other thing I forgot to mention...

On the head bolts that I pulled from the '80SD donor, a couple were "wet" but rest dry (and rusty). Help a noob out and tell me what that means?

Thanks Kent!

Yea I know what you mean

I once pulled a head gasket out of the wrapper the day before and when I came back the next day to install it, it had already turned to ash.... just kidding. I would not worry about it unless you were going to stick it outside in direct sun for a few days... :-). I have reused head bolts many times in the past without problems - as long as head bolts are not rusty and have not come from an engine experiencing catastrophic failure. Some may argue to be safe always use new head bolts. Your call.

It's been inside the house

It's been inside the house in my office and being winter in Michigan we haven'e seen the sun in months! So room temp and dry heat. Thanks (but that cost you a guilt sale of $42.50!). I do think I'll opt for new head bolts though - peace of mind for under $100. Any brand to avoid? Once again, thanks!

Bolt recommendation

I recommend you purchase the Reinz bolts that I sell here.

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