can a engine GO from cam install
08-20-2003, 11:46 AM
#1
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Join Date: Feb 2003
Location: NE philadelphia pa, FOX CHASE
Posts: 236
can a engine GO from cam install
can a engine GO from cam install cause i installed cam in sig and the shop said the the car is loseing oil pres. and a bearing or or something is bad im not sure but its a turd and they said it from having 77000 miles???
08-20-2003, 11:51 AM
#4
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Join Date: Dec 1969
Location: Webberville, MI USA
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1. Dirt from a sloppy install.
2. Overtorqing/Mistorqing the intake manifold (distorts the block and destroys the main bearings)
Engines rarely fail from cam changes unless someone gets dirt in them or is sloppy on the install. Of course, if the engine was in poor shape putting a cam in it can kill it. An example would be a car that had 77,000 miles on it and didn't get regular oil changes.
2. Overtorqing/Mistorqing the intake manifold (distorts the block and destroys the main bearings)
Engines rarely fail from cam changes unless someone gets dirt in them or is sloppy on the install. Of course, if the engine was in poor shape putting a cam in it can kill it. An example would be a car that had 77,000 miles on it and didn't get regular oil changes.
08-20-2003, 01:00 PM
#10
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Location: Webberville, MI USA
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I never heard of over torquing an aluminum intake manifold on a iron block distorting the main bearings.
08-20-2003, 04:04 PM
#12
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Location: West Palm Beach, FL
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Originally posted by dave1w41
Very common on 4.3 V6 and Small block engines. - Not the most common cause for post-repair failure but probably #2. Just looking at the block it does not look possible but just because it is made of iron does not make it impossible. If you study some finite element analysis and some basic cylinder case engineering it becomes obvious why it happens. You would be shocked at the amount of bore distortion that occurs when you tighten down a cylinder head or even an adjacent main bearing cap. That is why a block is machined and honed with a deck plate and the main bearing caps in place. It would help if you could machine it with the intake manifold in place as well but you can't.
Very common on 4.3 V6 and Small block engines. - Not the most common cause for post-repair failure but probably #2. Just looking at the block it does not look possible but just because it is made of iron does not make it impossible. If you study some finite element analysis and some basic cylinder case engineering it becomes obvious why it happens. You would be shocked at the amount of bore distortion that occurs when you tighten down a cylinder head or even an adjacent main bearing cap. That is why a block is machined and honed with a deck plate and the main bearing caps in place. It would help if you could machine it with the intake manifold in place as well but you can't.
08-20-2003, 04:44 PM
#14
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Join Date: Dec 1969
Location: PORTLAND, OR, MULTNOMAH
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My engine went after head and header install.
Only 8 grand on the clock.
Had cam installed with around 2 g on clock, but spun bearing with less than 500 after head installon.
Haven't a clue why it went, but I supposed that putting even 400 Hp at the crank could be too much on some engines, although there are engines with much more HP on the 2-bolts that have survived.
Glad that I have a 4-bolt now anyway. Just a bit more comfortable.
Only 8 grand on the clock.
Had cam installed with around 2 g on clock, but spun bearing with less than 500 after head installon.
Haven't a clue why it went, but I supposed that putting even 400 Hp at the crank could be too much on some engines, although there are engines with much more HP on the 2-bolts that have survived.
Glad that I have a 4-bolt now anyway. Just a bit more comfortable.
08-20-2003, 05:00 PM
#15
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Join Date: Jun 2003
Location: South Cali.
Posts: 233
Im gonna have to say the same thing on disagreeing on how the intake is put on. Yes there is a torque sequence but it is mainly for proper sealing of the intake to the gasket. In no way will it cause a Iron block to distort even a little with the heads fully torqued to spec.
The only thing is on Mustang 4.6s you have a detorque sequence because of the aluminum block and you have torqu to yield bolts that have to be throwen away each time of use.
The only thing is on Mustang 4.6s you have a detorque sequence because of the aluminum block and you have torqu to yield bolts that have to be throwen away each time of use.