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#1
bmarshall1

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If you read my other thread you see that the motor let go, I have a 74k used motor from a 99 and will be installing it.  Prior to install I want to make sure it's ready to go, my question is short of tearing it down, what should I check and what do I need for install? It's a complete long block so I'll be reusing intake and exh mani, MAF, Alt, coil packs etc...

 

 

 

Here's the list... tell me what I am missing or what else I need to do before I place my order.

 

 

 

Gaskets - intake, exhaust mani, H2O pump, MAF, Manifold to "A" pipe, "A" pipe to "B" pipe,

 

Hoses - Upper and Lower radiator, (2) heater hoses,

 

Clutch M/C

 

Timing Belt

 

Motor Mounts (broken)

 

Used Clutch and resurfaced Flywheel

 

Pressure Plate?? (Can these be resurfaced)  (my car had a shudder on takeoff)

 

Should I replace front and rear main seals and/or cam seals

 

Throw-out Bearing

 

Cleaned Injectors

 

 

 

Radiator cap

Air Filter

Shift Bushings and Boots

Plugs

RTV Sealant

Thermostat

Belts

PVC

Fluids

 

 

 



#2
Ron Alan

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What you reuse and what you replace often comes down to budget and what you are comfortable with. If your personality is such that new is better and or you are OCD about anything thinking everything will fail...change it all! What you know about both motors and the parts on both motor also will determine reuse. 

 

Do you know anything about your junkyard motor? Did you see it running before it came out? If you did and are confident it will fire up and run decent go for it. But at a minimum do a leak down test.

 

BUT...if you really have no idea...at a minimum have the head worked on(after a leak down test determines the current state). If you go to a random machine shop...go in with the knowledge of exactly what you want! Research what that is...before you start another thread :duck: The easy button is to choose a SM shop local or anyone of the half dozen shops here that you can ship too!

 

When the head comes off...you will get a good look at the cylinders. If there is no obvious signs of damage and you determine there are no rod knocks, I personally wouldn't be afraid to bolt back on a fresh head and go! Did this with our first motor and it lasted 4 more years! Was the original motor and had 60k when we started...ran it out of oil at 64k(user error :( )...but for where we were at at the time in racing it worked for our budget and actually was really strong!

 

For me...I look at parts replacement this way. If something were to fail the 1st or 2nd weekend after I install...how difficult would it be to fix? A new throw out bearing is cheap compared to changing a month later. Look at as insurance! 

 

With regard to your old motor and the metal that is now in the intake side...certainly can be used but making sure it all gets cleaned out is imperative. Sucking in a metal flake later on into the combustion chamber would suck. If other SM shops are anything like me...intake manifolds and TB are piled on the shelves...pretty cheap! BTW...I'm not a shop just a hoarder who doesn't throw away any Miata stuff...sadly :panic:


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#3
bmarshall1

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I saw the motor run prior to purchase and will do a leak down test just the same.  I'm not all that OCD so I'll be transferring old parts to the 'new' motor.  I will be replacing normal wear parts like throw out bearings and such, but will likely re-use the intake and MAF, unless someone wants to send one my way for a "Man w/ 3 kids on a budget after Christmas" price  :wave2:

 

I have a borescope and the cylinders looked good to me  :nerd: , maybe just the smallest bit of scoring, but I don't know how much would be normal...some...none?  I also have a leak down tester (Thanks Harbor Freight) and will do that as well.

 

I'll likely reuse the alt and leave the H2O pump alone (if it's not broke...), replace the timing belt and look for signs of seals leaking.  I'll get the injectors cleaned as well.

 

I want to get back on the track and the next time there is a long break btw event, if needed, send the heads out for a refresh.

 

Ron - thanks for the tips.



#4
Icedawg

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The leak down test will tell you a lot about any need to take the head off.  Most likely the exhaust valves will have some leakage on any used engine.  You have to decide how much is too much, and what to do about it.

 

I have dropped in a good number of junkyard engines over the years.  I found it is good to replace a lot of the reusable parts the first time, or have them serviced (alternator), and then you know you have a good set of those to reuse on the next several engines that blow up.

New water pump, timing belt pulleys, timing belt, and alternator belt, then you more or less never have to replace them again, within reason.

 

Replace front and rear crank seals if you have the skill to get them out without doing any damage, which is not as easy as it might sound.  Going back in is straight forward.  Visual inspection is never really sufficient, unless they are screaming "I am done".

Cam seals seem to last forever.

Replace the throw out bearing once, and the pilot bearing once and you probably never have to do it again.

Replace the o-ring on the water recirculating line that fits into the water pump fitting under the exhaust manifold.

 

Look for oil pan leaks and valve cover leaks, and redo those only if needed. 

Inspect intake and exhaust gaskets, replace if flaky and rusty, other wise they seem to survive multiple re-uses.  Although buy new now and they will see you through several more engine swaps.



#5
Alberto

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the intake and exhaust manifold gaskets are metal and can be re-used iirc


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#6
bmarshall1

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the intake and exhaust manifold gaskets are metal and can be re-used iirc

True, but if I recall don't they have a raised 'bead' that helps seal? I may be incorrect on this, or maybe a bead of RTV will do the trick and save a buck or $50



#7
FTodaro

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I sold someone a used motor that we had sitting around for quite some time, It ran perfect before we stored it. The put it in a car and the water pump failed. I am told because the sitting around without water in it can impact the water pump. So change that.


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#8
Ron Alan

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True, but if I recall don't they have a raised 'bead' that helps seal? I may be incorrect on this, or maybe a bead of RTV will do the trick and save a buck or $50

No RTV! Budget...reuse no worries! If you actually were to get a vacuum or exhaust leak with these...you probably have bigger issues...or you forgot to tighten!


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#9
bmarshall1

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Thanks for the tips, no RTV and replace H2o pump.






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