617 Non-Turbo Head on 617.951???

[Doktor Bert]

Dad needs a head for his 617.951 and we haven't found a good one around here as of yet. Today, we went to the local Pik-N-Pull in Visalia, California because they had a 50% off weekend...

Today, we pulled a head from a non-turbo 1976 123 chassis that looks to be in fantasic condition. Aside from obvious differences with its turbo counterpart, like the 'recessed' pockets in the intake valves (to reduce compression perhaps?) and the flat-on-the-bottom prechambers, we saw no other significant differences. I'm curious if we could use this on his 617.951, in the long-term, and wanted to ask the forum members for advice.

By the way, the head bears a '617' casting number.

Keep this in mind....

Years ago, when I was working for a Mercedes-Benz dealer in Visalia, California, a customer cracked a head on a 617.950 and they brought us a non-turbo head, just to 'patch it up' and get it running again. The service manager had them sign an 'As-Is' disclaimer before we started work and I do remember shimming up the pre-chambers to gain piston clearance, but it ran fine. I do not know if there could have been any long term complications, but the head bolted up and the car did run.

I would sincerely appreciate any advice you folks may have to offer. Thanks very much for your time and expertise...Robert

[jt20]

I would change out the exhaust valves and seat them.

the prechambers are different as well.


I would also be concerned about the cam timing, it would be optimal if you kept the turbo cam.

[Doktor Bert]

I use the '05' cma in everything and we have all new valves. IIRC, the heads are the same casting number, but the turbo prechambers are bigger by about 1.0mm...

P.S. I have used the '05' cam successfully in many non-turbo applications...Robert

[jt20]

I don't doubt that the non-turbo cam would work... but the scavenging is not maximized.

I was under the impression that the '05' had some changes in timing.

[Diesel911]

Does the Non-Turbo Cylinder Head also have the Sodium Filled Exhaust Valves?

[vstech]

no, but the sodium valves from a turbo head will slide right in.
of course, the glow plug holes are large thread for the loop plugs, so you'll have to buy the pencils with the large threads... pricey.
it's gotta be easier to find a turbo head. or at least an 80+ year that has pencil plugs...

[Dieselkraut23]

anyone get any info on if the euro non turbo heads had a different "high speed" as oi have heard more than once? this would be 82'-86' non turbo 300ds

[t walgamuth]

I doubt the euro heads are different. The only difference I am aware of is in the pump.

[Doktor Bert]

So, the early head, like this one in question being a 1977, has the early style 'big' glow plugs?????

[colincoon]

Originally Posted by vstech

no, but the sodium valves from a turbo head will slide right in.
of course, the glow plug holes are large thread for the loop plugs, so you'll have to buy the pencils with the large threads... pricey.
it's gotta be easier to find a turbo head. or at least an 80+ year that has pencil plugs...

Mine has threads for pencil style glow plugs and it's a NA.

[t walgamuth]

Originally Posted by Doktor Bert

So, the early head, like this one in question being a 1977, has the early style 'big' glow plugs?????

I don't know but I would say a good chance. Probably can look at parts here and cross reference it.

[vstech]

Originally Posted by colincoon

Mine has threads for pencil style glow plugs and it's a NA.

I didn't say it had to be a turbo head, I said it has to be a head from an 80 and up, or an SD. 79 and older N/A motors had the large glow plugs.

[Doktor Bert]

Ok....

The pre-chambers from the 617.951 Turbo slide right in. So did the Turbo valves. We are using the 'flat' intake valves and not the '300D' intakes with the 'cup' in them.

Dad picked up a set of 18mm glow plugs from ********e AZ that work with the late controller, used an '05' cam/follower/springs and the rest is history!!!