347 lifespan?

nick6690

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Mar 2, 2008

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Mar 16, 2008

#1

• Mar 16, 2008

• #1

How many miles can you expect to get out of a 347?

 

5.0Droptop

...all those nights we shared, and you're a dude??

Special Agent Mukity-Muck Whats in Charge Round Here

May 15, 2002

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Mar 16, 2008

#2

• Mar 16, 2008

• #2

Honestly alot of that is determined by how much you put into it when you build it. If it is built right and maintained properly and not ragged on all the time it should last as long as any other engine.

My experience has been the rings wear out faster then normal. Put the best rings in it you can get.

 

mrmustangman357

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Feb 11, 2007

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#3

• Mar 16, 2008

• #3

8927397 miles

 

JH96GT

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Mar 17, 2008

#4

• Mar 17, 2008

• #4

mrmustangman357 said:

8927397 miles

Click to expand...

+/- .2356897

 

1991vert

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#5

• Mar 17, 2008

• #5

depends on how well the machinist did putting it together

 

85_SS_302_Coupe

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#6

• Mar 17, 2008

• #6

Imagine that you have just bought a brand new 5.0 Mustang. Take it out and beat the balls off of it like you know you're gonna do with a 347...how long would you expect a new engine to last under race conditions? Most of the high mileage 302s you hear about are the ones that are driven and not raced. I would expect to do a rebuild at least by 50k miles even with the best rings and bearings, and especially new valve springs if you have a radical cam and wind out the RPMs a lot.

 

nick6690

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Mar 17, 2008

#7

• Mar 17, 2008

• #7

is that a lot less than just a 302?

 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

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#8

• Mar 17, 2008

• #8

nick6690 said:

is that a lot less than just a 302?

Click to expand...

Well my stock '85 short block has over 250k on it and it doesn't even smoke, and every time it gets driven it seens wide open throttle and at least 5k RPM more than a few times.

 

nick6690

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Mar 2, 2008

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Mar 17, 2008

#9

• Mar 17, 2008

• #9

would a 331 be any better?

 

5spd GT

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#10

• Mar 17, 2008

• #10

All depends on the builder.

Rings take the brunt of the wear anyways.

Technically a 302 would lost longer than a 331, and a 331 would last longer than a 347. But the reality is, it is not going to be noticeable with a good builder.

Take a gander at the Stroker Information link in my signature.

I propose a 1.175" piston/5.315" rod/3.4" stroke for most N/A situations.

The builder is everything...

Good Luck

 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

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#11

• Mar 17, 2008

• #11

nick6690 said:

would a 331 be any better?

Click to expand...

Well, compared to the extreme piston to rod angles that a 347 sees, yeah a little, but in the end it's still gonna come down to how hard you drive it. You could build a 347 and use it as a law abiding never raced never rev limiter bounced daily driver and probably get well over 100k out of it. It's the abuse that shortens their lifespan more than anything.

 

just4bob50

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Apr 2, 2005

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Mar 17, 2008

#12

• Mar 17, 2008

• #12

My 347 has been waiting to be installed since December, so at the rate Im going my 347 will last forever!!!!!!

 

nick6690

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Mar 2, 2008

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Mar 17, 2008

#13

• Mar 17, 2008

• #13

alright thank yall a lot for your help