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Need Crankshaft!

Posted: March 20th, 2014, 6:25 am
by Jr. Mechanic
Our build is off to a rocky start... With everything dropped off at the machine shop, I received a call saying that my 1989 3727 crank has 3 cracked journals :brickwall:

I can't seem to locate a used one locally (or an entire 4.2 for that matter), plus I'm paranoid about a used crank now. I personally bought and tore down the 4.2 this crank came from and the engine was in excellent condition with no signs of abuse, so I'm worried about getting the same thing with another crank, or worse.

The $500 dollar Scat/Hesco crank is pretty much out of the question right now, plus, isn't it just a stock replacement? Seems like a big chunk of change for no strength upgrade with no bearings included.

Advance, Oreilly's, and Autozone all list a remanufactured crank kit for around $170 with bearings, part number 25300 from Crankshaft Rebuilders. Frustratingly enough, it is unavailable to order and after contacting Crankshaft Rebuilders I was told they don't sell directly, only through authorized dealers. I tried looking up an older 4.2 crank and of course it isn't available either.

I found a crank kit online from Northern Auto Parts, but at $306 dollars plus a ridiculous core charge and shipping, it doesn't seem very appealing.

Help! My machinist needs a crank ASAP

Re: Need Crankshaft!

Posted: March 20th, 2014, 9:19 pm
by beiwulf
what do you find a reasonable cost to replace a crankshaft? A billet or forge will run well over 2 grand. And you have the pricing from scat for there's and a reman'ed one. for 300+ a core charge which you have the core.

Car-part.com would be my only suggestion. You might find one there without bearings and out of a scrapper for $100-200 and not necessarily a garauntee on quality. So now that is a chance you take as well.

good luck and hope you find the deal that works for you.

Re: Need Crankshaft!

Posted: March 20th, 2014, 9:34 pm
by jsawduste
What part of the country are you in ?

Re: Need Crankshaft!

Posted: March 21st, 2014, 8:31 am
by 6TIME
I have 2 4cw cranks laying around if you're interested. One is polished and ready to go.

Re: Need Crankshaft!

Posted: March 21st, 2014, 3:55 pm
by RenoF250
Did the crank with the cracks ring if you tapped it? Mine rang like a bell for a long time and I understand that is a pretty solid indication it is not cracked. The 4.0 crank I took out is pretty dull even though it looks great. Anyhow, that is a simple test if you are buying used.

Can't you use the cracked journal crank for a core?

Re: Need Crankshaft!

Posted: March 21st, 2014, 4:15 pm
by Jr. Mechanic
I talked to RPM machine and they have the Scat crank in stock for $425 so we bit the bullet and have it en-route to the machine shop along with a set of stainless exhaust valves :|

You can't send a crank with cracked journals in for a core. When they mag it and find the cracks, they will not refund the core charge and they won't ship the crank back to you either, at least that's what the 3 manufacturers I spoke to said.

RPM machine does have a remanufactured 12 counter weight crank and a 4 counter weight crank with the long snout in stock, they were the only remanufactured cranks I was able to find anywhere, and he said they probably won't last long. At $424 dollars (including the core charge), it didn't make sense to buy a reman over the Scat when bearings will only be another $85 or so.

As for the cost, I do find the $500 + shipping Hesco is asking to be outrageous. It's a stock replacement cast crank, people. $425 is a little better, but I feel it should be priced at $400 MAX, or include bearings at it's current price. Being an inline 6 and not the most common application, I generally feel that double the cost of your typical small block parts is reasonable. To give you an idea, Summit sells the same Scat crank but for a SBC application for $195 shipped.

Don't think I'm comparing a Jeep stroker to a small block chevy, but $500 for any aftermarket cast crank seems ridiculous to me.

Re: Need Crankshaft!

Posted: March 21st, 2014, 5:36 pm
by SilverXJ
Jr. Mechanic wrote:Don't think I'm comparing a Jeep stroker to a small block chevy, but $500 for any aftermarket cast crank seems ridiculous to me.
We are very small market so the prices will be very much higher than other engines. I hate it too. $2000+ for an aluminum head from the only manufacture really sucks. $700 for a Doug Thorley header. Roller rockers aren't much better either.

Make sure your machinist checks the crank clearances thoroughly. Many people have said that the cranks are ground on the small size which leads to larger clearances than needed. Some have tried to find slightly oversized bearings and others have just ground the crank .010"/.010" to get it to a good clearance.

Re: Need Crankshaft!

Posted: March 21st, 2014, 6:21 pm
by Jr. Mechanic
SilverXJ wrote:
Jr. Mechanic wrote:Don't think I'm comparing a Jeep stroker to a small block chevy, but $500 for any aftermarket cast crank seems ridiculous to me.
We are very small market so the prices will be very much higher than other engines. I hate it too. $2000+ for an aluminum head from the only manufacture really sucks. $700 for a Doug Thorley header. Roller rockers aren't much better either.

Make sure your machinist checks the crank clearances thoroughly. Many people have said that the cranks are ground on the small size which leads to larger clearances than needed. Some have tried to find slightly oversized bearings and others have just ground the crank .010"/.010" to get it to a good clearance.
Oh absolutely. I may just be a little bitter because we didn't anticipate wrapping an additional $500 or so in a crankshaft.

I'm sure my machinist will check it out; he's assembling the short block for me and I asked him to record the individual clearances so I know. I do know I won't be happy if we have to pay to have a new crank ground however!

Re: Need Crankshaft!

Posted: March 21st, 2014, 7:56 pm
by RenoF250
Jr. Mechanic wrote:I talked to RPM machine and they have the Scat crank in stock for $425 so we bit the bullet and have it en-route to the machine shop along with a set of stainless exhaust valves :|

You can't send a crank with cracked journals in for a core. When they mag it and find the cracks, they will not refund the core charge and they won't ship the crank back to you either, at least that's what the 3 manufacturers I spoke to said.

RPM machine does have a remanufactured 12 counter weight crank and a 4 counter weight crank with the long snout in stock, they were the only remanufactured cranks I was able to find anywhere, and he said they probably won't last long. At $424 dollars (including the core charge), it didn't make sense to buy a reman over the Scat when bearings will only be another $85 or so.

As for the cost, I do find the $500 + shipping Hesco is asking to be outrageous. It's a stock replacement cast crank, people. $425 is a little better, but I feel it should be priced at $400 MAX, or include bearings at it's current price. Being an inline 6 and not the most common application, I generally feel that double the cost of your typical small block parts is reasonable. To give you an idea, Summit sells the same Scat crank but for a SBC application for $195 shipped.

Don't think I'm comparing a Jeep stroker to a small block chevy, but $500 for any aftermarket cast crank seems ridiculous to me.
I had read Autozone etc had cranks and those guys never check cores.

Yeah, I looked around and $120 was the best I could find on crank grinding, I would not want to add that to the cost of a new crank.

This just came up here:
http://sacramento.craigslist.org/pts/4376517867.html

Why $85 for bearings? I was quoted $40 for a full set of King are you going for Clevite?

Re: Need Crankshaft!

Posted: March 22nd, 2014, 10:40 am
by IH 392
Personally I don't think guys put to much effort into finding a crank??, a while back one of the guys was whining that he couldn't find a crank?, after telling us where he was I found him one on Craigs List, he got the whole engine for $75!

I got my 12cw crank for free!, in fact the guys loaded the whole engine in the back of my truck when I wasn't looking!

When I worked for the machine shop they had two suppliers!!??, if they didn't have it it didn't exist!?? :bs: you NEED to ask around beyond the "obvious" suppliers!, I'd be hitting EVERY! wrecking yard I could find!, every swap meet I could find!, you need to look at Craigs List twice every day!, if you're only looking for the crank from a Jeep you're missing about a third of the availability!, of course you need to look for them in AMC applications, but also in INTERNATIONAL applications!, mine came out of a '75 IH 1200 pick up!

Re: Need Crankshaft!

Posted: March 22nd, 2014, 12:12 pm
by beiwulf
IH 392 wrote:Personally I don't think guys put to much effort into finding a crank??, a while back one of the guys was whining that he couldn't find a crank?, after telling us where he was I found him one on Craigs List, he got the whole engine for $75!

I do recall seeing that thread also. I've scored a few engines off cL but not for that good of a deal (usually 125-150). It was a 232 I did find for $80. I have a 232 crankshaft I would part for that price (not including shipping). It's a nice 12cw 3.5" stroke.


Brian

Re: Need Crankshaft!

Posted: March 22nd, 2014, 5:16 pm
by woodjeep
I bought a reman crank from Advance auto for 140 and change with a discount coupon found on line..it came with main and rod bearings, but the mains are for the year of the crank...not what its going in but I will just return them and exchange for whatever year I need..shipping was free since it was over 75. They list the 12 cw and 4 cw as the same part number so its a crap shoot but you will prob get the 4 cw. I contacted the rebuilders directly but they said since they are ""interchangeable"" they don't mark the boxes externally to specify 12 cw or 4 cw. Base price on line is 175 and they charge 35 core charge but they will take either a 4.2 or 4.0 crank as the replacement core. I kind of wanted the 12 cw but for 150 shipped with bearings and fully machined...I figured I cant go wrong for that price

Re: Need Crankshaft!

Posted: March 22nd, 2014, 9:29 pm
by beiwulf
That's a sweet exchange program. I have a 4.0L crank i would love to exchange (or 2). After I get done with my timely build my brothers jeep is next.

Re: Need Crankshaft!

Posted: March 23rd, 2014, 9:26 am
by SilverXJ
I'd be concerned about how much the had to remove from the journals to clean them up. Last time I got one from Advance there was more than I wanted removed. IIRC is was .040"

Re: Need Crankshaft!

Posted: March 23rd, 2014, 9:50 am
by woodjeep
Mine was ground to .010 . I have not yet verifies the dimensions but thats what the bearings said on them