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Offset grindin SB crank? #231507
02/21/09 05:16 PM
02/21/09 05:16 PM
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Kalispell Mt.
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HotRodDave Offline OP
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How much can a good std journal 273 crank be offset ground? Can it be ground down engough to use the honda rods? There are no holes in the throw so it should be OK right?


I am not causing global warming, I am just trying to hold off a impending Ice Age!



Re: Offset grindin SB crank? [Re: HotRodDave] #231508
02/21/09 07:03 PM
02/21/09 07:03 PM
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Oakland, MI
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dizuster Offline
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I can't answer, but I can't help but wonder why you would want to do it?

Why not just turn the mains down on a 360 crank and be done with it?...

Re: Offset grindin SB crank? [Re: dizuster] #231509
02/21/09 07:15 PM
02/21/09 07:15 PM
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Kalispell Mt.
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HotRodDave Offline OP
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I figured 1. I have it, 2. it is forged 360 is cast, 3. with the small journals it would be pretty light and lots of dirt cheap NASCAR rods on e-bay with that journal size in pretty long lengths so I could run a light weight piston also.

According to my calculations it could go to 3.55 stroke, is this remotely close? With a long rod in my 340 block .020 over it would be a rev happy 360 ish Also this crank is for a 4spd and a 360 4spd crank aint easy to find. It is just a though since I already have it.


I am not causing global warming, I am just trying to hold off a impending Ice Age!



Re: Offset grindin SB crank? [Re: HotRodDave] #231510
02/21/09 09:06 PM
02/21/09 09:06 PM
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Menomonee Falls
DemonDust Offline
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Your gonna be taking off about .245. Not sure what That will do to your oiling holes in the rod journals. Good idea, not sure if it will work though. Your oiling holes may end up close to the radius.


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Re: Offset grindin SB crank? [Re: HotRodDave] #231511
02/22/09 12:09 AM
02/22/09 12:09 AM
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So Cal
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Quote:

How much can a good std journal 273 crank be offset ground? Can it be ground down engough to use the honda rods? There are no holes in the throw so it should be OK right?




Good question. I wonder if you could adapt Chevy SB honda sized rods. Could would you have any room to ALSO offset grind the journal, if so how much?

The circle track guys use some super lightwieght ones that I think would live in a Sub 400 HP street motor.

Re: Offset grindin SB crank? [Re: HotRodDave] #231512
02/22/09 01:48 AM
02/22/09 01:48 AM

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you'll effectively destroy an otherwise good crankshaft if you take it to 1.88 journal size on an offset grind for the aforementioned reasons. the oiling holes will be right at the cheek of the fillet.

Re: Offset grindin SB crank? #231513
02/22/09 04:44 AM
02/22/09 04:44 AM
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So Cal
autoxcuda Offline
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Quote:

you'll effectively destroy an otherwise good crankshaft if you take it to 1.88 journal size on an offset grind for the aforementioned reasons. the oiling holes will be right at the cheek of the fillet.




So an offset grind with honda journals is a no-go. But just grinding down to a honda journal is ok on the oiling hole placement??

Re: Offset grindin SB crank? [Re: autoxcuda] #231514
02/22/09 07:39 AM
02/22/09 07:39 AM

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Quote:

Quote:

you'll effectively destroy an otherwise good crankshaft if you take it to 1.88 journal size on an offset grind for the aforementioned reasons. the oiling holes will be right at the cheek of the fillet.




So an offset grind with honda journals is a no-go. But just grinding down to a honda journal is ok on the oiling hole placement??




no, either way will be a problem.

Re: Offset grindin SB crank? [Re: dizuster] #231515
02/22/09 02:17 PM
02/22/09 02:17 PM
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Kalispell Mt.
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HotRodDave Offline OP
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Are 2 inch chevy rods ok?


I am not causing global warming, I am just trying to hold off a impending Ice Age!



Re: Offset grindin SB crank? [Re: autoxcuda] #231516
02/22/09 06:14 PM
02/22/09 06:14 PM
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So Cal
autoxcuda Offline
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Quote:

Quote:

you'll effectively destroy an otherwise good crankshaft if you take it to 1.88 journal size on an offset grind for the aforementioned reasons. the oiling holes will be right at the cheek of the fillet.




So an offset grind with honda journals is a no-go. But just grinding down to a honda journal is ok on the oiling hole placement??




Thanks.

Now the stock big block cranks don't have a problem going to honda journals? Is that correct?

Re: Offset grindin SB crank? [Re: autoxcuda] #231517
02/22/09 06:24 PM
02/22/09 06:24 PM

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Quote:

Quote:

Quote:

you'll effectively destroy an otherwise good crankshaft if you take it to 1.88 journal size on an offset grind for the aforementioned reasons. the oiling holes will be right at the cheek of the fillet.




So an offset grind with honda journals is a no-go. But just grinding down to a honda journal is ok on the oiling hole placement??





Thanks.

Now the stock big block cranks don't have a problem going to honda journals? Is that correct?




no, that's not correct. if the manufacturer plans from the beginning to go to 1.88 rod journals, the drill the oiling holes in the proper place to start with. to do it after the fact by reducing a 2.375 journal down to a 1.88 you'd be removing .495". the oiling hole would be coming out the side of the radius on the crank.

for the crank in question, yes, IMO a 2.00 rod journal is doable.

Re: Offset grindin SB crank? #231518
02/22/09 06:48 PM
02/22/09 06:48 PM
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Pa
Hot 340 Offline
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Quote:

Quote:

Quote:

Quote:

you'll effectively destroy an otherwise good crankshaft if you take it to 1.88 journal size on an offset grind for the aforementioned reasons. the oiling holes will be right at the cheek of the fillet.




So an offset grind with honda journals is a no-go. But just grinding down to a honda journal is ok on the oiling hole placement??





Thanks.

Now the stock big block cranks don't have a problem going to honda journals? Is that correct?




no, that's not correct. if the manufacturer plans from the beginning to go to 1.88 rod journals, the drill the oiling holes in the proper place to start with. to do it after the fact by reducing a 2.375 journal down to a 1.88 you'd be removing .495". the oiling hole would be coming out the side of the radius on the crank.

for the crank in question, yes, IMO a 2.00 rod journal is doable.


You sure Dan? I was just downstairs looking at my steel sb crank and if you removed .250 off the face of the journal by the oil hole(.495 total dia) it wouldnt bring the hole near the fillet..

Re: Offset grindin SB crank? [Re: Hot 340] #231519
02/22/09 07:51 PM
02/22/09 07:51 PM

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Quote:

Quote:

Quote:

Quote:

Quote:

you'll effectively destroy an otherwise good crankshaft if you take it to 1.88 journal size on an offset grind for the aforementioned reasons. the oiling holes will be right at the cheek of the fillet.




So an offset grind with honda journals is a no-go. But just grinding down to a honda journal is ok on the oiling hole placement??





Thanks.

Now the stock big block cranks don't have a problem going to honda journals? Is that correct?




no, that's not correct. if the manufacturer plans from the beginning to go to 1.88 rod journals, the drill the oiling holes in the proper place to start with. to do it after the fact by reducing a 2.375 journal down to a 1.88 you'd be removing .495". the oiling hole would be coming out the side of the radius on the crank.

for the crank in question, yes, IMO a 2.00 rod journal is doable.


You sure Dan? I was just downstairs looking at my steel sb crank and if you removed .250 off the face of the journal by the oil hole(.495 total dia) it wouldnt bring the hole near the fillet..




your talking about a smallblock crank and someone else mentioned a BB crank. for the sb crank you'd remove .245 total. if you offset grind it then more will come off the bottm half than the top. either way, i wouldn't do it. i'm just relaying what i've personally seen, your results may vary.

Re: Offset grindin SB crank? #231520
02/22/09 08:44 PM
02/22/09 08:44 PM
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MARYLAND
69Cuda340S Offline
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An off the shelf 3.79" stroke crank is available with 318/340 mains. I believe Mopar Performance sells it.

Re: Offset grindin SB crank? [Re: 69Cuda340S] #231521
02/23/09 09:41 AM
02/23/09 09:41 AM
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State College, PA
RyanJ Offline
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Quote:

An off the shelf 3.79" stroke crank is available with 318/340 mains. I believe Mopar Performance sells it.




MP does'nt offer it anymore, but Callies & K1 both make a 3.79, but both have a 2.10" GM rod journal.

We do about 10 offset ground stroker cranks a year going to 2.0" Journal, most stuff can not go further unless the forging was intended for it.

We just DE-stroked a Callies 3.58" down to 3.48" a few weeks ago.

Stock 3.31" crank should have no problem going to 2.0"

Re: Offset grindin SB crank? [Re: RyanJ] #231522
02/23/09 11:38 AM
02/23/09 11:38 AM
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Winnipeg, Canada
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StrokerDart Offline
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sorry ... off topic .... but, RyanJ your PM box is full ....

Re: Offset grindin SB crank? [Re: StrokerDart] #231523
02/23/09 12:02 PM
02/23/09 12:02 PM
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State College, PA
RyanJ Offline
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Quote:

sorry ... off topic .... but, RyanJ your PM box is full ....




fixed

Re: Offset grindin SB crank? [Re: HotRodDave] #231524
02/23/09 01:11 PM
02/23/09 01:11 PM
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Finally a HUSKER again
Moparnut426 Offline
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Also this crank is for a 4spd and a 360 4spd crank aint easy to find. It is just a though since I already have it.




As far as a 360 crank being specific to a 4 speed, its only the flywheel. All you have to do is take a 318 or 340 flywheel inn, and a 360 torque converter in, and any machine shop will balence it for you. My 360 didnt even need the pilot bearing drilled to fit the bushing. Every 360 I have ever owned has had a 4 speed put behind it with no problem. I have had probably half dozen of them without problem.

Kasey

Re: Offset grindin SB crank? [Re: HotRodDave] #231525
02/23/09 06:38 PM
02/23/09 06:38 PM
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North Dakota
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Jesse_Lackman Offline
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Quote:

How much can a good std journal 273 crank be offset ground? Can it be ground down engough to use the honda rods? There are no holes in the throw so it should be OK right?




Yes. If ground to HRJ with max offset the rod oil holes will be in the same place as if you ground the rod journals to a normal undersize. I'll have to check what the stroke increase is.

Re: Offset grindin SB crank? [Re: HotRodDave] #231526
02/27/09 01:44 PM
02/27/09 01:44 PM
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North Dakota
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Stroke went from 3.310 to 3.541 using standard Clevite 77CB-1663 H rod bearings. Don't know if those are available undersize, if they are you could get a bit more stroke.

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