Crankshaft journals machined incorrect
 

I have a forged 4340 crank with 4” stroke, 3” mains and supposedly 2.25” journals. I bought this 3 months ago and left in the box. I bought 428 Icon pistons at 1.595 compression height and 5140 I beam rods with 6.625 and 2.25. After bringing to machinist the journals are cut from the factory at 2.20. All literature and documents from the company say 2.25 journals. I believe when they changed over the cranks it accidentally was cut for the Chevy journals.

What is the best way to correct it? It’s a pain to return the crank and everything else on the crank checks out. But if I keep the crank I need new rods and maybe a custom piston? Do they make a thicker bearing shell so I can use my rods?

Your FIRST action should be to contact the folks you bought the crank from.

Yup, I did, no response yet, been a week. If they make good no problems. Looking for options.

I bought one that was supposed to be Pontiac Js and when I got it I checked and it was BBC

Is this one of the Speedmaster cranks?

Murf


Sent from my iPhone using Tapatalk Pro

Another option. Sell your rods. Keep the pistons and the crank. Buy BBC 6.635 length rods. Only .010 taller, will put the pistons closer to zero deck height.
Make sure to get BBC rods which have a small end bushing because you'll need to re-bush them for the .010 smaller size Pontiac pin. You'll need to buy smaller bushings.

Yes, speedmaster for me, it’s too bad because the rest of the crankshaft checks out fine.

Only Ohio Crankshaft ever had a 3” main 4.00 stroke crank for Pontiacs but they discontinued it some time ago. I have to agree with the suggestion of selling your 6.625 inch rods and acquiring 6.635 BBC rods.

Can the BBC rods be sized down .010 from .990 to .980? Is there enough “meat” left in the bushing, or do I need new bushings? It about a 500hp build.

Youl'd need new bushings with a smaller ID.

Was your new pistons made for press or floating wrist pins?

Clay

Pistons are forged Icon for floating pins.

All your machine shop would have to do is order the correct bushings and hone them to the correct pin size.

Back in 2009 on a trip to the states I bought a 428 crank kit from star galaxy. It sat on the shelf till quite recently. I decided to assemble an engine a while ago and found I have the standard 428 pin height pistons with 6.7 rods and a 2.20 crank. As luck would have it I picked up a 428 block and crank for a good price . So now I need to buy a set of pistons to suit the 6.7 rods and crank and a set of 6.625 bushed rods. It would seem we need check our parts as soon as we get them. In my case due to the currant exchange rate it’s quite an expensive exercise

I picked up a forging over here in NZ recently, was stamped 4.250", but had 2.250 journals. Got the stroke checked, yep 4.250".
Waiting to do a mock assembly in the block. With an SRP flat top my last assemby ended up about 30thou in the hole and required a cut for zero deck.
Might get away with 4.25" and std 6.625 rod in this one (hopefully 🙄)

I will need to find those bbc bushings. Is the OD the common 1.017?

Jeggs have got advertised 3” main 2.25 “ journal 4.210 stroke cranks by speed master(cast) does anyone know if the 2.25 journal size is correct? I was about To order a couple but this thread has got me wondering as no other company will do the cast 455 crank with 3” mains and 2.25 journals. It would be good as I have a few parts to use up.

Mine was also a speedmaster. Based upon what is said so far in this thread seems hey are all BBC journals. Good lyck with speedmaster answer a email or phone call, no luck so far.
It’s ok for me with a bbc rods if I would have known ahead of time.

My 4340 Star Galexy Ohio 455 Crank from 2009 had BBC Rod Journals, and was out of Spec. They remachined it. So i got a "bargain". I had it trued-up in AL, and meets PMD Main Specs, and BBC rod Specs (-020).

Confident in it, but need a 6.625" AL rod, or...a a set of >\= 455+030 slugs for 6.8" rods.

Sorry to hear you are going through this issue. I bought one of their 4" stroke cranks during Black Friday sale too. After reading the thread reviewing the cranks I measured mine and found the same problem - glad I did. Speedmaster was easy to deal with on return - paid for shipping and full refund. See the thread here: http://forums.maxperformanceinc.com/...d.php?t=836084

You can buy the bushings here, they are about $10 ea., page 9 in the online catalog.

http://www.pppcenter.com

Not sure what size you'll need, for aftermarket rods it's hard to say. I just got done doing this for a current project.

https://live.staticflickr.com/65535/...1c0ecb70_c.jpg

Until you get one of the bushings removed from the rod, it can be very hard to measure for the new bushing OD. Due to the very thin wall, the only way I know of to get the bushing out of the rod is to bore it out on a milling machine, which is how I did it. The bushings are pressed in with a minimum .003" interference and this is very tight.

There is likely some more machining to do to get the new bushings to fit properly in the rod end. The rods will have to be heated and the new bushings pressed into the rod end when the sizes are correct. The .003" interference is very important to keep the bushing from spinning.


https://live.staticflickr.com/65535/...df257a07_c.jpg

Next you will need to drill the oil hole from the rod end through the bushing, and be sure the new bushing length is exactly the same width as the rod end (which it won't be) - more machining.

Then you can final hone the bushing ID to fit the pins.

Probably cheaper to buy new rods.

Those pistons will run as pressed pin even though they have the options to be full floating.

I would NOT recommend bushing rods for another pin size as it's a special operation (talked about some above) and will be time consuming and pricey.

Better to either keep the crank and buy the correct rods/pistons, or get the correct crank and keep what you have for rods/pistons.

I don't think you'd have any trouble selling anything that's left over no matter what direction you decide to go.........

Thanks for replies. Got the pistons through KRE and Jeff said no problem to return whatever I decide.

Yeah, it's a real surprise when you buy bargain-basement, bottom-feeder Chinese parts, and they aren't as advertised and/or don't meet specs.

It's not like the Chinese are known all over the world for lying or shipping defective product.

And the Communist Collaborators in this country are sure to catch all the defects their Chinese suppliers miss.

I'm not surprised, I bought some 5140 rods off them 2 years ago, and he was great to deal with. I'd buy off again in a heartbeat.

I think I saw that crank on summit, listed for 2.25" rod journals and got me real intrested in it since I had just got the 5140 rods, but I have never read or heard of anyone using a aftermarket 4" stroke 3" main crank for use with stock pontiac dimension rods so I thought it kind of odd.

I did this exact build about 10 years ago using a Ohio crankshaft. That one did have the 3”M and 2.25RJ. So was thinking this probably a common offering. Used crower rods on that one.

Oh ok, I never built a stroker, I spend alot of time on here reading, and most use the 4" and 4.25" stroker with the longer BBC rods, and butler's kits use the longer rods too.

I love the 4" stroker idea. Mid range between 3.75 and 4.21 strokes.

FYI. The make a Icon forged piston at 4.155 with a bbc .990 pin at 1.425 compression height. You can use the bbc 6.800 rod with this combo for the 4” stroke.

Pontiac pin is .980
BBC is .990- it's already .010 too large. You need to go the other direction to make the sizes match up.

X2 ! I have victimized myself so many times trying to get parts together ahead of time and things happen that change the plan.

And then there was the time I had a chance to buy some RPM rods and didn't do it, so it's a double edged sword.

Butler uses a 4" stroke with a 6.7" rod, and I'm fairly sure it's a 2.2" rod journal so they likely can get you some pistons that they are using in their custom production stroker kits.
https://butlerperformance.com/i-2445...tegory:1459547

Did you mean pistons to work with the 6.7" rods OR a set of stock sized rods to work with your stock pin height pistons ? You can get a set of stock sized Eagle rods for $370. https://butlerperformance.com/i-3164...tegory:1234812

Thanks JC.

Contact your credit card company, you'll be surprised at how long the limit is to file a claim.

Thanks for that.

Can you imagine the looks on the faces of the people importing this crap, when the credit-card claw-backs start piling up?

They might have to start caring about the product they ship, and how they advertise it.