|
|
Joined: Nov 2004
Posts: 329
CEG\'er
|
OP
CEG\'er
Joined: Nov 2004
Posts: 329 |
I took the crank from my 2.5 to the machine shop to see if it was still useable/salvageable. For those that don't know or recall I spun a bearing a while back and have been working on a 3.0L swap since. I know, its taking me forever. Anyway, the 2.5 crank was a bit roughed up but it will be fine after all. It just needs to be cut .25mm. But the machine shop also says that not only does it have to be cut but that in one particular spot it has to be welded back UP to meet the -.25 spec. This particular journal was in worse shape than the others and rather than take everything down to say -.50 they just want to shave everything down and then add material in the one spot and make it all .25 under standard size. Now I've been reading up a little on people that have had their cranks cut (ouch that sounded painful lol) but I haven't heard of adding girth  to one's crank before. Seriously though. Is this just what it means to having it balanced? Is this a common practice? Safe? According to the shop they do it all the time and I'll have nothing to worry about. Should I be worried if I may want to use this for another project? And one other thing. Does Clevite make bearings for the 2.5? I already have them for the 3.0L but I'm guessing it would be a different part# for the 2.5. Anyone got that #? Thanks
1998.5 SVT
I'm working on it.
WTB 2.0L Contique.
|
|
|
|
|
Joined: May 2000
Posts: 21,197
I have no life
|
|
I have no life
Joined: May 2000
Posts: 21,197 |
Originally posted by 04marauder:
And one other thing. Does Clevite make bearings for the 2.5? I already have them for the 3.0L but I'm guessing it would be a different part# for the 2.5. Anyone got that #?
Thanks
The 3L and 2.5 have the same cranks. 
-'96 SE MTX 3L
-'98 SVT 1,173 of 6,535
-'05 Mazda 6s, loaded, g/f's ride
-Need a 96-00 manual on CD? PM or email me
|
|
|
|
|
Joined: Sep 2000
Posts: 7,025
Hard-core CEG'er
|
|
Hard-core CEG'er
Joined: Sep 2000
Posts: 7,025 |
Originally posted by todras:
Originally posted by 04marauder:
And one other thing. Does Clevite make bearings for the 2.5? I already have them for the 3.0L but I'm guessing it would be a different part# for the 2.5. Anyone got that #?
Thanks
The 3L and 2.5 have the same cranks.
i dont think they are 'exactly' the same. I believe the counterbalances on the 3.0L are different due to the larger pistons.
Jim Hahn
1996 T-Red Contour SE Reborn 4/6/04
3.0L swap and Arizona Dyno Chip Turbo Kit
364 whp, 410 wtq @ 4,700 rpm
|
|
|
|
|
Joined: Sep 2000
Posts: 4,693
Hard-core CEG'er
|
|
Hard-core CEG'er
Joined: Sep 2000
Posts: 4,693 |
It was once a very common practice to turn cranks. Engines hold up better today so it is not as common.
In high school I worked for an auto parts store that included a machine shop and was involved with helping the machinist. He didn't have a crank grinder, but he delt with a shop that did when he needed that type of service. I've also been involved with hot rod stroker kits that were made from welded cranks.
Yes, it is practicle to build up a crank with welding and then grind it down to size. As with any welding, it must be done correctly, and when done correctly, it is just as good as a non welded crank. Also, there is plenty of strength in the crank to be taken down slightly to the first or even second undersize. You must use bearings that are made for the new diameter. If not ground correctly by leaving a radius at the edges, it can weaken the crank, but your crank grinder should know what is necessary.
Balancing is always nice. It is more critical on an engine that spends a lot of time in the upper rev range. It may not really be necessary if you stay with stock pistons and other recipricating parts. It is essential if you change piston weight and/or rod weight.
Jim Johnson
98 SVT
03 Escape Limited
|
|
|
|
|
Joined: Nov 2004
Posts: 329
CEG\'er
|
|
OP
CEG\'er
Joined: Nov 2004
Posts: 329 |
1998.5 SVT
I'm working on it.
WTB 2.0L Contique.
|
|
|
|
|
Joined: Sep 2000
Posts: 4,693
Hard-core CEG'er
|
|
Hard-core CEG'er
Joined: Sep 2000
Posts: 4,693 |
The 3.0 crank would be preferred because of the difference in the counter balance weights. I would go out of my way to find a 3.0 crank.
Jim Johnson
98 SVT
03 Escape Limited
|
|
|
|
|
Joined: Sep 2002
Posts: 6,106
Addicted CEG\'er
|
|
Addicted CEG\'er
Joined: Sep 2002
Posts: 6,106 |
What happened to your 3.0L crank that you're doing all of this extra work? My head is hurting from thinking about doing all of that!
Mark
2000 Black CSVT
3.0L Hybrid - 206fwhp & 195fwtq
|
|
|
|
|
Joined: Nov 2004
Posts: 329
CEG\'er
|
|
OP
CEG\'er
Joined: Nov 2004
Posts: 329 |
Originally posted by Y2KSVT:
What happened to your 3.0L crank that you're doing all of this extra work? My head is hurting from thinking about doing all of that!
Mark
My 3.0 crank is fine. And I'll be using it for the 3.0 rebuild. It just needed to be polished.
I just felt like looking into whether or not I might rebuild the 2.5 too.
It seems like a waste to me to have the 2.5 sitting there or junking it when all it needed was some minor touch ups. By turning the crank, honing the cylinders and getting new rings and bearings I'll have a good as new 2.5 engine and a second project. Nothing else is wrong with it so why not. Seems like its pretty easy to find something worthwhile and affordable to drop it into.
I did the exact same for the 3.0. New rings and bearings, honing, etc and as I did that it just got me to thinking I should do it on the 2.5 too.
Now I just need to get to work. 
1998.5 SVT
I'm working on it.
WTB 2.0L Contique.
|
|
|
|
|
Joined: Jun 2000
Posts: 2,621
Redneck Troll
|
|
Redneck Troll
Joined: Jun 2000
Posts: 2,621 |
Originally posted by beyondloadedSE:
Originally posted by todras:
Originally posted by 04marauder:
And one other thing. Does Clevite make bearings for the 2.5? I already have them for the 3.0L but I'm guessing it would be a different part# for the 2.5. Anyone got that #?
Thanks
The 3L and 2.5 have the same cranks.
i dont think they are 'exactly' the same. I believe the counterbalances on the 3.0L are different due to the larger pistons.
You are correct Jim. The crank and rod bearing surfaces are the same diameter (hence the same bearing part numbers), and the stroke is the same. The only difference is the larger/heavier counterbalances.
http://www.bnmotorsports.com
"And I will strike down upon thee with great vengeance and furious anger those who attempt to poison and destroy my CEG brothers. And you will know I am the Moderator when I lay my vengeance upon you."
|
|
|
|
|
