[99v6stang]

okey so ive pretty much forgot about my car for a long time, but now it is time to put it back together. It appears as if i spun three connecting rod bearings, caused by a shredded cps gear clogging up the oil pickup tube. I am going to see how much it costs to take my crank in and get it checked out, but will probaly buy a new one regardless seeing as i spun multiple bearings. My question is do i need to replace the connecting rods as well? They dont seem perfectly smooth on the surface where the bearings go, but its not rough or anything just like a little scratch or two, does this matter?

And where the hell can you find a forged crank or is it not neccasary? I figured i mid as well buy a forged one if im replacing it anyways. And with a new crank i dont have to maching or do any work to anything do i? just drop it in with new bearings?

Also my k member appears to be bent as i slightly crushed my long tube header on one side and i had to cut the header to get it out. Can i get this bent back out or should i replace the kmember?

[stephen]

The big end of the rods (the surface where the bearings go) can be resized by +0.002 in
and aftermarket bearings are available to fit. The crankshaft can be ground to clean up the journals, probably 0.010 undersize will be adequate. Definitely replace all the bearings, main and rod.

I believe forged internals refers to the rods and pistons. The stock crankshaft is strong enough as is.

[99v6stang]

well i took the crank in to be inspected and they told me i would need to get it replaced as it was too damaged. The connecting rods also look like they need replacing. So screw the 4.2, im putting together my 3.8 and making a 3.8 m112

[turp]

Originally Posted by 99v6stang well i took the crank in to be inspected and they told me i would need to get it replaced as it was too damaged. The connecting rods also look like they need replacing. So screw the 4.2, im putting together my 3.8 and making a 3.8 m112

A very ambitious project... Keep us posted!

[itschristorres8]

a 4.2L crank is all but $150
you can get eagle forged rods very cheap too
Redlined Performance is selling a set of 8 for $250!
you would need a different piston though do to the longer stroke

which forged pistons you could grab for about $700. pricey but you wont have to touch your bottom end again

either way you look at it if your 3.8 crank has been sitting. hopefully standing up if not trash it...it has to be polished
you old rods will need new bolts
your old pistons cleaned good, and new piston rings, bearing set, main bolts as well.
and if your car ran low on oil i would check out your cylinder walls as well.

[stephen]

+1 on Chris's comments.

I know the rod bolts are supposed to be replaced but thought you could reuse the main bolts. Probably a good idea to replace all of them.

Also be sure to get all the oil passageways on the block, front cover etc cleaned out. I would check the oil pump for damage and clean out the pressure relief valve in the front cover.

[itschristorres8]

Originally Posted by stephen +1 on Chris's comments. I know the rod bolts are supposed to be replaced but thought you could reuse the main bolts. Probably a good idea to replace all of them. Also be sure to get all the oil passageways on the block, front cover etc cleaned out. I would check the oil pump for damage and clean out the pressure relief valve in the front cover.

any torque to yield bolts should be replaced at minimum check for thread damage.
I personally wouldnt risk it especially with a s/c setup or any power adder setup

[99v6stang]

Im dropping in a 3.8 that i purchased for the heads and intakes awhile back. It has 68,000 miles. But of course everything leads to a problem and now i have a stripped head bolt on the 4.2 so i cant get my damn heads off.

[stephen]

Originally Posted by 99v6stang Im dropping in a 3.8 that i purchased for the heads and intakes awhile back. It has 68,000 miles. But of course everything leads to a problem and now i have a stripped head bolt on the 4.2 so i cant get my damn heads off.

Do you mean you rounded the flats on the head of the bolt? You might try a 6-point socket and possibly hammer it on.

I think the design of the head bolts is such that you can chisel the head off the bolt and get the head off that way.

[itschristorres8]

lol that sucks
those head bolts are a bitch and a half to get off with a breaker bar

[99v6stang]

yea i was using a six point and the corners are very rounded, this is going to suck

[stephen]

Originally Posted by 99v6stang yea i was using a six point and the corners are very rounded, this is going to suck

One option is to try the next smaller socket. I think it is 15 mm and the next smaller is 9/16 = 14.3 mm. You might be able to hammer it on the bolt head and use that to turn the bolt.

[99v6stang]

i tried both the 9/16 and 14mm neither worked for me im not sure what to do

[stephen]

Did the smaller sockets not work because you couldn't get them on the bolt head or because they wouldn't hold?

How many bolts are stuck?

You might take the engine to a mechanic or machine shop that has impact sockets and a powerful air wrench.

If all else fails it might be possible to chisel or drill the heads off the stuck bolts but that may be difficult since the bolts are hardened steel. Again a shop with air tools could probably do this a lot easier than you can.