#61571 - 11/16/10 08:57 AM
Re: GM 4 cylinders 151 153 181
[Re: Beater of the Pack]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Beater:
I'm assuming the Chevy-II 4-banger being the smaller brother to the 194/230/250 six, nearly everything is the same (only minus two cylinders). With that in mind ...
You're right that the big end width of the six rod is wider at about 1.030" where the SBC width is .940" (as I recall). For the six, the big end diameter is the same as the SBC "small journal" (265/283ci) at 2.000" and the small end is the same at .927". The problem is the beam offset for the V8 where the L6 isn't.
Continued ...
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#61573 - 11/16/10 09:01 AM
Re: GM 4 cylinders 151 153 181
[Re: russk]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Beater:
Continued ...
If you look at a V8 rod from the side and draw a line down through the center of the beam, you'll see that one face of the big end is closer to that center line than the other. The face (larger if I recall) that is closer to the center line is the one that faces the other rod in the V8 that shares the same crank throw. The L6 (not having a neighbor) has the same distance to either face from the beam center line.
Continued ...
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#61574 - 11/16/10 09:06 AM
Re: GM 4 cylinders 151 153 181
[Re: russk]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Beater:
Continued ...
I don't have a V8 rod to look at but I'm guessing there is not much of a "bevel" on the big end on the side that faces the neighboring rod and there is more of one on the "outside" to clear the crank throw fillet. The L6 rod has identical bevels on both side since it has to deal with the crank throw fillets on both sides. I suspect a V8 rod used on a L6 crank (even with the right 1.030" width) would bind on the one side and I don't know how the beam offset would affect operations - I'm thinking not good.
Russ
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#61575 - 11/16/10 09:08 AM
Re: GM 4 cylinders 151 153 181
[Re: russk]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Beater:
PS: Sorry for doing this in 3 parts. Have a strange problem with my email support that limits the size of the text I can send in any one message. Can't get a straight answer as to why from any of the tech support people involved.
Russ
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#61576 - 11/16/10 09:12 AM
Re: GM 4 cylinders 151 153 181
[Re: russk]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Beater:
I know the "pin eye" is evenly balanced on the L6 rod. I'm not sure if it's offset (the same way the big end is) on the V8 rod or not. If I had to guess, I'd say it probably is.
Russ
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#61583 - 11/16/10 02:31 PM
Re: GM 4 cylinders 151 153 181
[Re: jalopy45 #4899]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Jalopy45:
The stock V8 rods I have seen were slightly different and I think the Lunati rods in my son's 406ci Chevy were also slightly offset. I've also read about that somewhere and I'll see if I can dig out the article. As far as aluminum (race) rods are concerned, I'm sure you're right. Maybe the offset isn't a big issue in a race engine but perhaps has an impact if you're trying to get 100K+ miles from a daily driver? Let me see what I can dig up but the offset issue was one that was raised by the folks at K1-Technologies regarding the useability of SBC rods in the 250ci six.
Regards,
Russ
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#61584 - 11/16/10 03:26 PM
Re: GM 4 cylinders 151 153 181
[Re: russk]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Jalopy45, Beater, and others:
I'm beginning to worry that maybe I completely misunderstood what I was told about rod "offset". If I'm not properly informed on this subject I will be back on this thread to apologize for passing on mis-information - that's certainly not my intent. Of course I can't find the article I remember reading that was in one of my vintage Hotrod "Engines" books - ain't that always the way? Let me check with the K1 folks again and I'll pass on what they tell me. But on the issue of the big end width being wider on the L6 (and so the L4?) than the V8, that alone makes the V8 rod an unusable alternative?
Russ
Edited by russk (11/16/10 03:29 PM)
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#61613 - 11/18/10 03:04 PM
Re: GM 4 cylinders 151 153 181
[Re: jalopy45 #4899]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Beater:
You're right about sending "short and sweet" emails. But the problem I'm having is a pain at times. Now there's no (practical) limit to the size of messages I can receive ... go figure.
Russ
Edited by russk (11/18/10 03:14 PM)
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#61614 - 11/18/10 03:12 PM
Re: GM 4 cylinders 151 153 181
[Re: russk]
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russk
Active BB Member
Registered: 03/20/06
Posts: 75
Loc: Southern Oregon
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Jalopy45:
I wish I could say my "heads up" on the V8 vs. L6 rod was due to years of hands on experience and sage wisdom. Sadly, it's far from it. My "insight" was due to the fact that just a few weeks ago I was wandering down the same garden path, thinking I might use "small journal" V8 rods in my 250 project. I wrote K1 asking if they would sell six of them and they replied with an explaination as to why that was NOT a good solution (big end width, beam offset, and such). I ended up sending them an OEM 250 rod so they could take all the critical measurements (except for the 6.200 c/c length I requested) to ensure the finished billet H-beam rods I ordered would be correct. So, more of case of dumb luck on my part.
Russ
Edited by russk (11/18/10 03:19 PM)
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#62085 - 12/11/10 05:20 PM
Re: GM 4 cylinders 151 153 181
[Re: Beater of the Pack]
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tlowe #1716
12 PORT ADVERTISER
Active BB Member
Registered: 04/01/04
Posts: 2333
Loc: Dysart, Iowa
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Beater,
Might be able to help you with a rod, soon. We can PM about that.
Got my cam from them. Solid lifter 220 dur @ .050 , .510 lift after the lash. It should run real good in the farm buggy. The boy and I tore down the shortblock and took it in to get machining going.
What did Steve say about the different lobes? I ran into problems wanting a different lift. Tom
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#62275 - 12/22/10 07:47 PM
Re: GM 4 cylinders 151 153 181
[Re: Beater of the Pack]
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tlowe #1716
12 PORT ADVERTISER
Active BB Member
Registered: 04/01/04
Posts: 2333
Loc: Dysart, Iowa
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Bet they will be sticking out of the hole, just barely. Just file them, better yet use a sawzall! Goodluck, keep us posted.
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#63048 - 01/30/11 06:08 PM
Re: GM 4 cylinders 151 153 181
[Re: jalopy45 #4899]
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jumpinjan
Active BB Member
Registered: 05/30/08
Posts: 10
Loc: Ohio
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Here's a couple of shots from my phone on an altered V8 HEI to use on a 4
I don't understand. Do you use the 8 cyl cap for the 4?
Jan
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#63579 - 03/04/11 06:36 PM
Re: GM 4 cylinders 151 153 181
[Re: jalopy45 #4899]
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Shiny
Bulletin Board Only Member
Registered: 02/02/04
Posts: 3
Loc: victoria bc
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I got a pretty hot lil 181 out of a 1950 Willys that I found for a buddy. He didnt want the 4 banger and offered it to me. I have wanted one forever for a lil T modified project that I have been collecting parts for. Anyways mine came with an Erson cam but its done, few lobes are toast. So Beater what were Ersons prices like? I am thinking of cam #2, what lifters are you running?
My mill came with a Clifford 4 barrel intake meant to go on a 153 head, but someone built an adapter to mate them up?? It came with a header too, and a Mallory dual point dizzy too. The Clifford intake has way smaller ports then the 181 head, making it restrictive for sure. I am going to sell the Clifford intake to a 153 owner to pay for the Erson cam and lifters.
-Shiny
_________________________
paint is for houses,not hot rods
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Never too old to learn.
I got a full set with pistons on eBay for $75. I'm not sure they are the ones for the 2 piece seal crank buy if not I'll stroke the 151 with a new style 181 crank. They are plentiful. 
, 
,
An added bonus is that will make a really flat surface. 
