[CraigG.]

Hey Everybody,

I want to re-use my eagle crank in the new block - Turning down the crank to "3 worth it and who can do it?

Thanks, Craig

[tom s]

How are you going to overcome the thrust diff?Weld up or do a spacer system?Tom

[CraigG.]

I haven't purchased the block - All Pontiac or Kauffman - so Don't know - what are some options?

[steve25]

The best way to go is to use a Oldsmobile thrust bearing to get to the needed bearing width.

[Gary H]

Because of the cost involved in turning the crank down properly, and the issue with the thrust bearing, I wouldn't do it. Me, I would sell that crank and then buy the proper 3" main crank and use it. I think you would be money ahead.

[tom s]

2X Gary.I think the Olds bearing requires a spacer? Tom

[slowbird]

Sell crank

[Jay S]

I have a couple cut down 455 cranks in 400 blocks. Shop in SE Nebraska cut mine down. I used a Olds main and made a shim. I made a spacer from an old thrust bearing on my lathe, bolted two mains together and clamped in the lathe. Was super easy. You also have to cut the main seal down. I cut it down in my lathe, the shop would have to change stones to grind the rear main down. I don’t have much money in the conversions I have done. Would definitely do that to save a $700 crank it that was the only option.

[tom s]

Thanks Jay,I was pretty sure it needed a ship spacer.Had to do the same putting a 400 crank into a 301T block.Tom

[tom s]

SHIM!Tom

[Dragncar]

No. I would not deal with cutting down or welding a crank. I have done it and have more in the crank than it is worth.
KRE still does the 3.25 main MR1 if you wanted it but I would not do that either.
Someone will give you 400$ for the crank you have. Kick in 400$ of your own and be done with it.
Many things can go wrong welding, grinding down, shimming a crank.
Buy one, not so much.

Besides, are Eagle 3.25 cranks cross drilled ? I believe so. "Straight Shot" Scat oiling, better.

[Jay S]

Midwest cylinder head out of Nevada, IA welds and grinds cranks, likely could repair it also.

Meant the stone needs to be changed to grind the rear main seal down in that other post. Not the rear main bearing.

[tom s]

I found it necessary on my 301 stroker build but I would only weld a forged crank.Tom

[Jay S]

FWIW…if the direction is a new block, my opinion is the same as the other guys that say sell the 3.25” crank. I would prefer to get a new 3” crank and a 3” aftermarket block. If it was working with used parts that you already had, then possibly consider some of these other options.

[Jim Moshier]

Just curious, what is the cost to cut the mains from 3.25 to 3.0? A couple hundred. It seems to be best to sell the 3.25 crank and purchase a 3.0 crank. JMO but I am wonderig.

[Jay S]

Everything is going up in price, so this is a FWIW. Last couple years we generally spent just under $190 to grind the mains down, and that includes grinding the rods as well. Normal crank grind usually runs $135. In my case it was roughly $65 extra over a typical crank grind to go from 3.25” to 3”. But I cut the main seal down in my shop. On more modified cranks where the mains were cut .25” and the rods were turned down .175” past stock ( like doing a sbc pin on a Pontiac, that was $250+. What adds up on a Pontiac isn’t really cutting down the mains, it is when they have to change the stone to grind the main seal journal down, it is extra set up time. Not all shops have the stone to do it either.

If I had a 3.25” forged or N crank sitting here I would have no issue grinding that down and putting it in a 3” PMD block and doing the shim and olds bearing. But for an aftermarket block, I would definitely sell the 3.25” crank that needs work and start fresh. If your making big power (and need an aftermarket block) my preference is to not want anyone welding on a crank, even on a forged crank. It is done sometimes but would never be not my first choice.

[CraigG.]

What is the down side of a 3.25 KRE MR1 block under 7,000?
Thanks, Craig

[tom s]

FYI,forged cranks are welded everyday at shops that do it.Spun bearings Js are EZ to fix.Tom

[padgett]

And the hardening (tuftriding ?) that is only .010" deep ?

[tom s]

mine was rehardened.No clue what they do for big DSL engines cranks.Tom