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Small Cam Cummins questions.


Outbehindthebarn

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Does anyone on here know much about a small cam 400 magnum?  Small cams were only sold up to 350h.p. in road equipment, correct?

If I was re-powering an old truck that had a bad 335, would going big cam be a no-brainer? I kind of like the nostalgia of period correct power plants.

Fun is what they fine you for!

My name is Bob Buckman sir,. . . and I hate truckers.

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how much do you use the engine brake? as I understood it cummins main reason for the big cam was to better take the abuse of the engine brake( too many people figured out that a loose set slave cylinder would greatly increase the jakes strength) this puts more pressure on the exhaust lobes of the cam, thus causing cam falure.   

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16 minutes ago, gearhead204 said:

how much do you use the engine brake? as I understood it cummins main reason for the big cam was to better take the abuse of the engine brake( too many people figured out that a loose set slave cylinder would greatly increase the jakes strength) this puts more pressure on the exhaust lobes of the cam, thus causing cam falure.   

Yeah, I've heard they'd bend pushrods and generally hammered the top-ends, but the 400 magnum??? The one I'm looking at has chrome valve covers, after cooler.... factory according to the owner.

Fun is what they fine you for!

My name is Bob Buckman sir,. . . and I hate truckers.

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So your looking at a truck which originally had a 335 but has been repowered with a magnum 400?

I wouldn't stress too much about it if that were the case. Sounds like it was something Cummins offered. Back when it was a working truck it would be a big plus!

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12 hours ago, Timmyb said:

So your looking at a truck which originally had a 335 but has been repowered with a magnum 400?

I wouldn't stress too much about it if that were the case. Sounds like it was something Cummins offered. Back when it was a working truck it would be a big plus!

No the truck I'm looking at has a 335 that's bad, and I found this 400 magnum for a good price. Plus, it has jakes, which the 335 did not.

 

Fun is what they fine you for!

My name is Bob Buckman sir,. . . and I hate truckers.

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1 hour ago, Outbehindthebarn said:

Glen, what are they talking about when you hear people say off-set key?

IMG_8156.jpg

There was nothing wrong with the 400 Mag, had two in two Stars. Ran right down the road with the BC's. Plus that engine in the photo has a plus, the Bendix air compressor.

The offset keys were nothing more than to advance or retard the cam timing.

Truck Shop

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3 minutes ago, Truck Shop said:

There was nothing wrong with the 400 Mag, had two in two Stars. Ran right down the road with the BC's. Plus that engine in the photo has a plus, the Bendix air compressor.

The offset keys were nothing more than to advance or retard the cam timing.

Truck Shop

What compressor is standard? And this does have the CPL 695.

Edited by Outbehindthebarn

Fun is what they fine you for!

My name is Bob Buckman sir,. . . and I hate truckers.

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That engine in the photo does not look like a magnum engine to me.A photo of the other side and numbers off the data plate who help but all magnum engine i was around had the steel oil pan with oil pump pickup tube at the front.And the oil pump will have a small oil line about six inches long connected to the oil pump to the oil galley of the engine behind the pump.

Like been stated the off set key was for timing the cam to the gear.Small cams as well as Big cams could use it.

glenn akers

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5 hours ago, Outbehindthebarn said:

Glen, what are they talking about when you hear people say off-set key?

IMG_8156.jpg

There was nothing wrong with the 400 Mag, had two in two Stars. Ran right down the road with the BC's. Plus that engine in the photo has a plus, the Bendix air compressor.

The offset keys were nothing more than to advance or retard the cam timing.   Like said above it should have a steel pan for sure and BCIII oil pump.  That Data plate on the

accessory drive should say CPL 695 and the cam timing spec should say 56*. Plus the turbo should be the later Holset and it should have a pulse exhaust manifold on it.

The injectors on those engines flowed allot of fuel and if I remember right the pump rail pressure ran higher than BC's 

Truck Shop

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1 hour ago, Truck Shop said:

There was nothing wrong with the 400 Mag, had two in two Stars. Ran right down the road with the BC's. Plus that engine in the photo has a plus, the Bendix air compressor.

The offset keys were nothing more than to advance or retard the cam timing.   Like said above it should have a steel pan for sure and BCIII oil pump.  That Data plate on the

accessory drive should say CPL 695 and the cam timing spec should say 56*. Plus the turbo should be the later Holset and it should have a pulse exhaust manifold on it.

The injectors on those engines flowed allot of fuel and if I remember right the pump rail pressure ran higher than BC's 

Truck Shop

It does say 695.

Fun is what they fine you for!

My name is Bob Buckman sir,. . . and I hate truckers.

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2 hours ago, theakerstwo said:

That engine in the photo does not look like a magnum engine to me.A photo of the other side and numbers off the data plate who help but all magnum engine i was around had the steel oil pan with oil pump pickup tube at the front.And the oil pump will have a small oil line about six inches long connected to the oil pump to the oil galley of the engine behind the pump.

Like been stated the off set key was for timing the cam to the gear.Small cams as well as Big cams could use it.

 

IMG_4547.jpg

IMG_0116.jpg

Fun is what they fine you for!

My name is Bob Buckman sir,. . . and I hate truckers.

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                                         One thing I learned about Cummins years ago was that they put together many strange items to make engines. Just because it doesn't have or look to

                                         me that it has a stamped steel pan doesn't mean Cummins didn't build some with cast aluminum. If it has a data plate saying it is a 695 then it 

                                         probably is. There really weren't that many sold so the plate is kind of rare it's self. Does the engine bar over 360*?

 

                                         Truck Shop

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2 hours ago, david wild said:

I think someone has been eating to much CAT food, lota bad talk about perfectly good engines made by Cummins, and yes Cummins  made plenty of cast pans. 

                                       Who has been eating to much Cat food? I haven't said one bad thing about Cummins, I ran four of them.

 

                                       Truck Shop

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So what era is the truck and 335 Cummins?

Im guessing the big cam and magnum 400 was early/mid 80's?

I bet there was lots of 335's changed out for either new engine through Cummins dealers. I wouldn't be too worried about doing that swap. But that's just me. I'd like to see the rig when the deal is done. 

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9 minutes ago, theakerstwo said:

And the fuel pump has been changed because a magnum engine came with a AFC fuel pump.some one has stole the pulse manifold and Holset turbo.And also i have never seen them come from cummins with the chrome.

Were there certain models that had factory chrome covers?

And yes, he said that the manifold/turbo were robbed.

 

Edited by Outbehindthebarn

Fun is what they fine you for!

My name is Bob Buckman sir,. . . and I hate truckers.

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