Do timing chain engines have cam and crank seals?

Crank seal only. It's the only thing that projects from the timing cover (for a normal push rod engine). Over head cams have a camshaft seal.
 
Thanks, that's kind of what I was thinking, so a modern overhead Cam (chain) 4cyl engine would have both cam and crank seals, if I'm visualizing correctly, the crank seal could in theory be part of the timing chain cover since its only purpose is to keep oil from dripping out of the chain cover, also... In theory could the crank pulley be eliminated if there were no belt driven accessories?
 
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The near-modern 4cyl engines with overhead cams usually feature half-moon cut outs in the cylinder head casting / valve cover gasket seal to allow camshaft removal
and timing chain replacement. There's usually a chain 'tunnel' in the interior of the engine front for the tensioner & guides. Only one vertical circular seal at the crankshaft seal.
 
Originally Posted by vw7674
The near-modern 4cyl engines with overhead cams usually feature half-moon cut outs in the cylinder head casting / valve cover gasket seal to allow camshaft removal


The half moon cutouts are there for/from line boring the cam journals
 
Originally Posted by clinebarger
Originally Posted by vw7674
The near-modern 4cyl engines with overhead cams usually feature half-moon cut outs in the cylinder head casting / valve cover gasket seal to allow camshaft removal


The half moon cutouts are there for/from line boring the cam journals


No. They are there for ready access with a socket & torque wrench to torque the camshaft sprockets to the shafts.
The builders could easily of blanked the boring holes off with affordable plugs otherwise, just like the backside of 20th century american V-8s.
But they thought of repair service while they engineered their DOHC wonders.
You say potahtoe, I utter potato..........
 
What? Of course they are there for line boring, how else are they getting the boring bar in there without through access. It would be a good idea if you knew what you were talking about before calling one of the best mechanics on the board out.
 
Originally Posted by ka9mnx
Over head cams have a camshaft seal.


Not if they are chain driven cams.
 
Originally Posted by ZeeOSix
Originally Posted by ka9mnx
Over head cams have a camshaft seal.


Not if they are chain driven cams.

Not at the rear of the head opposite of the chain?
 
Originally Posted by ka9mnx
Originally Posted by ZeeOSix
Originally Posted by ka9mnx
Over head cams have a camshaft seal.
Not if they are chain driven cams.
Not at the rear of the head opposite of the chain?
My SOHC Mazda had the distributor there in-line with the camshaft, but no camshaft seal as such. At the other end, a semi-circular cut-out in the timing-chain cover for access to the sprocket nut.
 
Probably engine family dependent? I mean, I think my engine has a seal for the distributor that it used to have--over the years it was designed out, but there's still a hole on the end of the head for it. Probably used for line boring for one of the camshafts, but I think the seal is still considered "for the distributor". Now that I think about it, it probably depends on if the cam bearings are above or below the valve cover mating surface--below and they probably need seals, above and no need need.
 
The 2005 Ford Escape Duratech V-6 has a timing seal for an external pulley riding off the cam. Can't remember if it is intake cam, or exhaust? Anywho, it runs a belt for the water pump. So there are some funky set ups as well.
 
Originally Posted by Jeff8820
...since a timing chain cover is bathed in oil..


Does timing change get inside the oil pan?
 
Originally Posted by oilboy123
The 2005 Ford Escape Duratech V-6 has a timing seal for an external pulley riding off the cam. Can't remember if it is intake cam, or exhaust? Anywho, it runs a belt for the water pump. So there are some funky set ups as well.



It sure does... and it also has an additional flat seal underneath that extended part of the valve cover as well. You can't see it from the top down, but it's there... and when it leaks it drips right on to the front catalytic converter's heat shield. It smells wonderful at a stop light. Ask me how I know....
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The duratec v6 is DOHC with a timing chain... it has both a cam seal and a crank seal. I had to have the timing cover gasket replaced on my Fusion... so they went ahead and did the crank seal at the same time since they were already there. Then they did the cam seal and that flat gasket as well. Good news - no leaks! Bad news - $2k lighter wallet.
 
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