Intake Manifold

[Harry]

Just confirming- there is no bracing for the intake manifold, I.e. it is simply mounted o the head, no brace also from the block?  The 190SLs with the big carbs hanging out there were braced to the block.

[johnk]

You are correct. No bracing.

[Harry]

Thanks John

[MikeSimon]

I always find it extremely difficult to re-install the cylinder head and the manifolds while engine is in the car. I cannot manage to put the head on the block and then install the exhaust manifolds. There is just no room to get the manifold on the studs on the head and at the same time on the two downpipes. I always have to fiddle the manifold in position while the head is hovering above its final position. Does anybody have a secret here?

[Aaron h]

I always find it extremely difficult to re-install the cylinder head and the manifolds while engine is in the car. I cannot manage to put the head on the block and then install the exhaust manifolds. There is just no room to get the manifold on the studs on the head and at the same time on the two downpipes. I always have to fiddle the manifold in position while the head is hovering above its final position. Does anybody have a secret here?

Take loose the right side engine mount, raise the engine from underneath, install the head with or without the manifolds, and then lower the engine back down while simultaneously aligning the manifold to the header pipes and/or the cylinder head studs.  Alternatively, one can also remove the studs in the cylinder head and reinstall them after the head has been installed.  Sometimes you can also raise the exhaust manifold from below high enough so you can slide the studs from the head into the manifolds, and then lower the exhaust down to seat the head. 

My usual method is to remove the intake manifold, take loose the header pipes from the exhaust manifolds, remove cylinder head bolts, and then remove the head together with the exhaust manifolds.  It's takes a bit of finessing, but this method has served me well for many many years. 

[MikeSimon]

Thanks, Aaron.
So, in reverse, when installing, do you mount the exhaust manifolds to the head and then lower everything down?

[Harry]

Aaron - you're in Knoxville?  (I think I've been trying to reach you for a long while.

Harry

[Aaron h]

Thanks, Aaron.
So, in reverse, when installing, do you mount the exhaust manifolds to the head and then lower everything down?

Mike, it largely depends on which model I'm working with.  (230/250/280), but more importantly has the exhaust system been touched/worked on by people that have no business touching a Pagoda.  I see that you have a 280.  When I do a 280, and due to the little room there is, I like to remove and install the head with the manifolds hanging onto the studs loosely.  That is, after the intake manifold has been removed put a few nuts back on the studs to keep the exhaust manifold from falling completely off when removing them with the head.  When I reinstall, I like to raise the exhaust system a little bit and then install the head with the manifolds loosely attached just like they were in removal.  At this point the head will not seat square on the block, so be very gentle until the exhaust system has been lowered back down.  If you're concerned about damaging the head gasket then put something in between the head and head gasket (that's resting on the block) that is clean and won't puncture the gasket.  The book tells us to use a piece of wood, so maybe a few small pieces of 1/4" ply wood?  After the exhaust system has been lowered back down simply lift the front and rear of the head up separately and remove the pieces of wood. 

There are several ways to do it, and it seems that each car has a preference.  haha 

Harry, yes, I'm in Knoxville.  I go through periods in which I won't turn my phone on for long period of time, but right now, and for the last several months, my phone has had a non lighted screen, so I can't see anything.  Having enjoyed not being tied down to a phone I've let repairing it slide for a long time.  However, I'm on this forum often.  Please reach out if you need to.  I often get calls from the dealership asking my permissions to pass my number on to someone with an older Mercedes.  Recently, one of the parts guys told me that someone was asking if I was back in Knoxville........I don't know what that means because I never left Knoxville.  Though, I do travel every other week for work.  Was that maybe you that asked? 

[Harry]

I am in the process of reinstalling the intake and exhaust manifolds on my 230 SL.  I had purchased new down pipes through Bud's because the older ones were pretty much a kluge and the exhaust system didn't align well with the channel under the car.  I had a local Midas shop (used by MB Knoxville) to install the new down pipes and to align the system under the car.  I brought it home with the exhaust loosely assembled.
On looking at the Intake and Exhaust Manifold install afterwards (at home), it seemed apparent to me that I would want to bolt up the exhaust manifold first so that I had unhindered access to those connections at the two headers.  Doing those with the intake manifold in place looked ominous.
But to install the exhaust manifold and make it align properly, I had to lower the exhaust at the rear of the car.  I did that and it worked well, but still a job.  I was now going to bolts up the intake/exhaust manifolds to the head (access to the studs is another bear), then lift the exhaust to the correct position - being careful as I can that I am not putting the exhaust manifolds in a bind/overloaded position.

Thoughts?
Harry

[ja17]

You can install the exhaust manifolds first by themselves temporarily without the intake manifold. Snug-up the manifolds so they are rigidly bolted to the head but do not fully tighten them. Now you can make  your front pipe/manifold connection and finish hanging your exhaust with the intake manifold still off. When the exhaust is hung and the front pipes are tightened to the headers, you can now remove the manifold/to head nuts, move the exhaust manifold from the head (1/2" or so) and install the intake manifold. Now finish installing the intake and exhaust manifolds together. I use some grease on the front pipe to manifold connection so the pipes and the manifold slide nicely together without any binding to prevent breaking the rigid cast exhaust manifolds. Don't forget the two metal crush rings at this connection also. The grease will quickly burn off in the first few minutes of engine operation.

[Harry]

Thanks Joe.  Right now, I have the down pipes securely installed into the headers, although the grease would have been a great idea.  Both manifolds are over the studs and in position, ready for the nuts/lock washers to be installed.  That access looks terrible and I’ll probably try this morning to see if access isn’t improved from below.

[ja17]

Harry, access to the head studs is not that bad. I use a 3/8" drive, 14mm swivel socket (14mm with built-in universal joint) on a long extension for most.

[Harry]

Joe - my bad.  I had already installed the heat shield and that was really limiting my access.  I removed it and it was clear sailing.

Thanks,
Harry