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what would you do? rebuild block or no?

  • fully rebuild engine block, new rings, new bearings, in debt

    Votes: 2 50.0%
  • use engine block as is, have head rebuilt, replace everything non-internal

    Votes: 2 50.0%
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Discussion Starter · #1 · (Edited)
Well ive probably got either bad rings or a cracked piston(or two, three, maybe 4) in my mx6, it smokes horridly... Ive already went out and bought a salvage 120,000 mile F2t from a hard-wrecked 91 mx6 GT.

The cylinder head on this 120k mile motor has been midas'd, the exhaust manifold stud wells are all stripped out, and theres also a broken spark plug in cyl no. 3.

Ive got the motor on an engine stand, and im not sure what i want to do next... I have the cyl head from my original engine that was milled 2 years ago and tanked, i know it'll need to be milled again, but the car hasnt ever boiled over, the valve seals were so-so, but the exhaust mani studs are PERFECT. I also have a cyl head from one of my parts cars that is 2-3 years old, that has PERFECT stud wells, and is in similar shape as my original head.

I planned on changing the head, however i dont know if i want to
A. rebuild the block as well, new rings, new bearings, hone the cylinders. Two bad things about this are it costs alot of money... which i dont have a whole lot right now, and ive heard of rings not seating well, and i dont want to do something twice...kind of like "if it aint broke, dont fix it"
B. use the block as is, have one of the two good heads ive got milled, new valve seals, clean up the block and replace everything not-internal...i wouldnt have to worry about breaking it in. with 120k the engine should be OK, it was from an automatic, that was pretty clean except for the insane damage, it had to be driving to wreck, thats for sure. oil was clean and it wasnt overly dirty under the hood.

i guess cash is the determining feature... as it is for most of us when it comes to everything. I just dont want the car to be down too long, put it back on the road and find out that my fuel pump died, mice ate my wiring harness, and brake pads rusted to the rotors.

I was planning on getting this used motor up to par, buying a new clutch, using my rebuilt transmission that is on my porch, installing my larger injectors, my Tbird turbo, making it so that i pull one driveline out, and put the other one in, so the car isnt sitting on my drive way looking like its ready to take flight with the front of the car 2 ft off the ground and all the spare parts in the trunk weighing down the back...

what would you do?

-Eric
 

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Well, considering I havent had luck with any of my 3 engine situtations, and opted to rebuild each time, I say put the shortblock in as-is. Before you tear off the head I would make sure to do a compression test though.

My next motor will be a longblock, unknown condition or mileage. From a few things I've noticed, I've come to the conclusion that it probably has well over 100k miles. came from a car that was not wrecked either. Hopefully the engine is good. I'm doing a leakdown test before putting it in though.
 

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Well, I'd have to go with doing things the right way. I'd rebuild the whole block. Rings, bearings, seals, valve seals, etc. Hone the block, check the pistons, if ok then re-use if not buy some new ones. I'd just do it all the way. I am in the process of rebuilding my FE DOHC and I'm replacing bearings, oil pump, water pump is almost new (less than 3K mi on it), t-belt (same as water pump), valve seals, blah blah blah.

However, if money is an issue and you need your car then do what you have to do. I have a second vehicle to drive so it doesn't matter how long the car takes.
 
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