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small journal crank in large journal block

  
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small journal crank in large journal block

 
smokinz28lt1 smokinz28lt1
New User | Posts: 18 | Joined: 03/11
Posted: 03/09/11
11:50 PM

Well I have a small journal (2.30)main forged steel crank and its goin in a 400 block that has (2.65)main and I found journal spacers and adapters to go from the med 2.45 to the small 2.3 journal and the ones to go from large 2.65 to med 2.45..... my problem is i cant find any that go are thick enough to put my small journal 2.30 crank into a large 2.65
Anyone know who sells an adapter or spacer??? or know another way of making this work?  

zman123 zman123
Enthusiast | Posts: 531 | Joined: 06/08
Posted: 03/09/11
11:53 PM

yeah, put a large journal crank in it! Don't be a cheapskate!  

chevelle83 chevelle83
Addict | Posts: 2280 | Joined: 11/09
Posted: 03/10/11
06:57 AM

Ugh,,, why would you want to do that?????  

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 03/10/11
07:57 AM

Yes they do make them.,. However, there is only one brand that is worth using.
King bearing spacers are made in Israel and are the only quality option for a main bearing spacer. I looked at some brand names including Comp Cams, for a destroked 400 (352) and they all are simply soft babbit main bearings that still retain the bearing grooves in them and are machined to be used as spacers.
King uses hard steel inserts that are machined to fit between the main saddle and bearing and have no groove in them because you don't want a groove in the spacer anymore than you'd want a groove in the block main saddle.,. The groove is in the bearing where it belongs. 
Bearing clearances are the most critical part of engine assembly!!!
There are no worse rods than the 283 rods, very thin beam profile and small bolts.,.
These are not suitable for high RPM use.,. Do yourself a favor and buy a good set of aftermarket connecting rods with the best bolts you can get. If you can't do that then a set of the factory small journal 327 rods from 65-67 would be the best of the small journal rods. They have more meat on the big end than the 283 rods, which don't have much. They also have a beefier beam, but the bolts are still tiny.,.
You'll need ARP PRO-series wave loc bolts for these, not just the standard ARP wave locs. They still aren't the greatest, but they are the best of the small journal rods that GM produced.
Now we come to the balance issue.,. BUT, that's another  problem that very expensive mallory metal can "fix"
Is it worth all the effort???

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

Pontiacman2 Pontiacman2
Moderator | Posts: 8956 | Joined: 09/08
Posted: 03/10/11
09:30 AM

+1  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

zman123 zman123
Enthusiast | Posts: 531 | Joined: 06/08
Posted: 03/10/11
11:33 AM

Is the 400 crank any good? Why not make yourself a nice 400 if you have all the parts? Lots more torque than the de stroked (352) you are thinking of.  

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 03/10/11
12:05 PM

+1
I agree

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

skyeking skyeking
Addict | Posts: 2738 | Joined: 08/09
Posted: 03/10/11
05:08 PM

Hi there,
 With a dozen better combos why have you picked a costly nothing to gain project
 which should be left to the very highly skilled ENGINEERS who live in Canada..
 Buy a Nice Create motor of your choice and avoid unnecessary trauma..Skyeking  
skyeking

Pontiacman2 Pontiacman2
Moderator | Posts: 8956 | Joined: 09/08
Posted: 03/10/11
05:38 PM

+2 on building the 400.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 03/10/11
05:39 PM

Hi Skye.,. guess you're talking about me now, in a good way.
Yes.,. this mod is for those that thoroughly understand the anatomy of an engine.,. Much like a surgeon doing a delicate operation.,. and he has to turn around every few seconds for the next hint, like a game of charades.
For this build, most lack the experience level to appreciate the complexity and involvement, to pull this build off.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

smokinz28lt1 smokinz28lt1
New User | Posts: 18 | Joined: 03/11
Posted: 03/10/11
08:14 PM

I bought just the block all I have is the block and the main caps or i probably would... And the two cranks I have are the forged steel 3in crank from a 283 and a cast 3.25in crank from a 307 a I thought I would be better off with using the forged crank...  

smokinz28lt1 smokinz28lt1
New User | Posts: 18 | Joined: 03/11
Posted: 03/10/11
08:29 PM

what is so complex about it? i already have a couple different rod length and  compresion height piston combos figured out that i can use all i was woundering is if anyone knew if they made bearing spacers or adapters to got from large to small journal?  

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 03/10/11
08:32 PM

I believe you've completely overlooked the balance issue.,. The 400 crank has 3.75" stroke with beefy mains, larger throws, heavier rods and is externally balanced, front, back and center. In short, your 400 reciprocating mass is much heavier than either of your small cranks will support, unless you go the distance with mallory metal @ $50 a pop.,. you might need a dozen or more, with no guarantees.,.
Still with me, good, now you still have the bearing spacers and flywheel/flexplate to balance, since you just did the crank.
Total cost for this experiment, bout $1000+
Not bad for a neutered once good 400, which by the way, if built with stock rods/pistons and crank would eat your one of a kind creation alive.
With a decent set of heads, which you'd need anyways with your destroked 400
The only substitute for cubic inches, is more cubic inches.,. which can also be achieved with nitrous or boost.
Think.,. spend your time and money wisely
Sell your 2 cranks and buy a 400 crank
nuff said.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 03/10/11
08:38 PM

Icon Quotesmokinz28lt1:
what is so complex about it? i already have a couple different rod length and  compresion height piston combos figured out that i can use all i was woundering is if anyone knew if they made bearing spacers or adapters to got from large to small journal?

Glad you think it's just a walk in the park.,.
Do it, show us how it's done.,. I answered your question.
Summit sells inserts and King Bearings does too.,.
Great that you have the rods, you're almost done.
Keep us posted, please, cuz we're eager to learn
"new tricks"

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 03/10/11
09:10 PM

Almost forgot, what stroker pistons are you planning on using for this build.,.
JE or Mahle may have what you need, but they are pricey and just under $1000 for a set.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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