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help...motor question

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86chevyk10

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im going to look at a used 350 crate motor thats for sale. Its already out of the truck, the owner said it has 21000 miles. What should I look for? Can you do a compression test on a motor that is not in a truck (maybe by just turning it over by hand?) Any other suggestions would be greatly appreciated. Thanks
 
Compression test can be done but you will need to have the starter hooked up to turn it fast enough to do the test. The big question is why is he selling it if it only has 21K.

I personally would never buy an engine from someone that i don't know or that i couldn't see and hear run first.
 
You can do a leak down test with an air compressor and differential gauges. no starter required. Make friends with an airplane mechanic, this is how they check airplane engines for compression. You can buy the gauges from matco.
 
He says he's selling this one because he found a 383 for his c10. The motor came out of a show truck so i imagine it'll be clean. Im just in the need of a motor, but not ready to get ripped off. $$$ is tight so im trying to save where i can, but at the same time i dont want someones junk....i may go look out of curiosity, thanks for the help!
 
86chevyk10 said:
He says he's selling this one because he found a 383 for his c10. The motor came out of a show truck so i imagine it'll be clean. Im just in the need of a motor, but not ready to get ripped off. $$$ is tight so im trying to save where i can, but at the same time i dont want someones junk....i may go look out of curiosity, thanks for the help!
Click to expand...

Not to offend anyone but around these parts we call that a mexican rebuild (a can of paint goes a long way if you get my drift).

I can paint an engine and make it look new also. :D

How much is the guy asking for it? You can buy a brand new GM crate engine from Summit racing for 1795.00
 
4X4HIGH said:
Not to offend anyone but around these parts we call that a mexican rebuild (a can of paint goes a long way if you get my drift).

I can paint an engine and make it look new also. :D

How much is the guy asking for it? You can buy a brand new GM crate engine from Summit racing for 1795.00
Click to expand...

He's asking $600obo, im also lookin @ the 290 hp crate from summit, its $1400 more, but that 3 year warranty and being brand new sure is nice
 
Got to agree with Scott.

There are good people out there, offering honest deals, but A) they have no control if it happens to break right after you buy it and B) if you can't install it the day you bought it, chances are by the time you get around to it, the chance of getting hold of the seller, or them still having your money for a refund, are long gone.

To be honest, wrecking yards would be a better bet. Most offer at least a 30 day warranty, and all that I know of DO test them before they are pulled.

Crate or build your own would be my choice, but when money is tight the upfront cost might be prohibitive. BTDT, had good luck with the one wrecking yard motor I bought.
 
I agree with just about everyone here. you can find some good deals out there but buyer beware.

If you do decide to go with this motor lets at least arm you with some tools to help determine the engine condition.

It was mentioned before that you can do a leak down test without needing to spin the motor with the starter.

Here is a quick vid I found on a guy doing a leak down test on a boxer engine. Same principal for any engine.

http://www.youtube.com/watch?v=dB_bXXRagi4

you can get a cheep leak down tester at Harbor Freight.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94190

Listen for air leakage from various parts of the motor if one of the cylinders are leaking more than the others. Air out the exhaust=bad exhaust valve, air out intake=bad intake valve, air out oil filler cap=bad rings, air out adjacent cylinder or water jackets=bad head gasket or crack in block or head.

It does not check oil pressure or bearing condition but it is a good start to tell if something is horribly wrong with a used engine.

Hope that helps.

Cheers,

Rufus

On Edit: There will always be leakage on even a new engine. The key is there should not be excessive leakage or a large difference in leakage between cylinders.
 
I appreciate the info guys, but I think Ive decided to just try my hand at rebuilding mine. After running the numbers, $2000 for crate from summit, $600 for unknown condition motor, or approx. $1000 for machine work and parts to rebuild my current motor. Ive never rebuilt a motor before but Im not an idiot and I can read manuals, so we'll see. One more question, is it worth having the head surface machined flat on block and heads? Remember, its not a race motor, just a DD. The motor had a good seal before I took it apart, any opinions? Thanks
 
Good for you on the first rebuild. With help from the board and your machinist you will be fine.

With regards to surfacing the block and heads it is all about the numbers. Your machinist will take a measurement with a precision straight edge and that will tell the tail. If it is flat enough...no machining required.

repeat after me...Clean everything...clean it again...when you think it is clean...clean it again. You cant be too clean when assembling an engine. :-)

Cheers,

Rufus
 
very cool video, what is the official terminology for that? decking? ive heard it before but im not certain.
 
The block deck usually never needs to be machined, however i always like to machine the heads before installing them since they don't have the massive amounts of casting like the block does which keeps things straight.
 
the machine shop ill use is really respected around here, so i sure ill have a good start. my neighbor has some 305 HO heads he said people put on 350's. he willing to give them to me, said it raises compression, any input?
 
86chevyk10 said:
the machine shop ill use is really respected around here, so i sure ill have a good start. my neighbor has some 305 HO heads he said people put on 350's. he willing to give them to me, said it raises compression, any input?
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Sure they will raise compression to the point that it will be hard to find fuel to keep the engine from detonating itself. Also the 305 heads use a smaller intake valve and they are shrouded pretty good so i would stay away from using 305 heads on a 350.
 
DITTO.....I think you'll be surprised at how much rebuilding your own will cost...:eek1:

What is your motor now?
how many miles?
what are your goals for the engine?
 
76zimmer said:
DITTO.....I think you'll be surprised at how much rebuilding your own will cost...:eek1:
What is your motor now?
how many miles?
Click to expand...
the motor is a 350, with around 115k miles. im not intersested in a high hp motor, just a daily driver type. i have it figured around $1000-$1200 for parts and machine work, the crate motor i was interested in is $2000 from summit. they have one with 200 hp, but the guys ive spoke with says i will be highly disappointed in that motor even though i dont want anything special.
 
wow, its not often that a manufacturer/dealer will talk you out of a sale, unless they leading you into something more expensive! that salesman sux
 
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