How Strong are LT1 Connecting Rods??
01-14-2005, 06:40 PM
#16
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Re: How Strong are LT1 Connecting Rods??
I believe the stock pistons are hypereutetic(sp?) one step up from cast one step below forged. From my reading bearing are probably more of a concern than those but I would agree they are the weak link among the rotating parts, not weak but weaker than the rods and crank.
01-14-2005, 07:20 PM
#17
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Re: How Strong are LT1 Connecting Rods??
Originally Posted by TCAL95Z
I took apart a 94 LT1 in my engine class and it had GM forged rods in it
01-14-2005, 11:42 PM
#19
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Re: How Strong are LT1 Connecting Rods??
A 94 LT1 in an F-Body would likely have forged rods, as I mentioned in my earlier post. A quote from the frequently linked article on rebuilding the LT1:
RODS
350 - The original LT1 came with regular forged 350 rods, that were shot peened for localized hardness under the head of the bolt and nut. Powdered metal rods were phased in for the Corvette around 1994 and used in all of the LT1 engines by 1995. GM made the change because the powdered metal rods were cheaper to make and were much stronger than the GM high performance "pink" rods. In fact, they are supposed to be good for up to 450 hp. They are machined at the parting line so they can be reconditioned.
350 - The original LT1 came with regular forged 350 rods, that were shot peened for localized hardness under the head of the bolt and nut. Powdered metal rods were phased in for the Corvette around 1994 and used in all of the LT1 engines by 1995. GM made the change because the powdered metal rods were cheaper to make and were much stronger than the GM high performance "pink" rods. In fact, they are supposed to be good for up to 450 hp. They are machined at the parting line so they can be reconditioned.
01-15-2005, 08:56 AM
#20
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Re: How Strong are LT1 Connecting Rods??
So far all the '94 cars I have done (Vettes included) have had PM rods.
Not sure if they are predominant or if it is pure luck, but thought I would pass this on.
Not sure if they are predominant or if it is pure luck, but thought I would pass this on.
01-15-2005, 12:37 PM
#21
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Re: How Strong are LT1 Connecting Rods??
FWIW the rods shown in the LT1/4 rebuild book are not the PM rods although thats what they call em.....
The earlier LT1's had a lightened version of the "pink" rods before they started using the PM rods... if someone can post pics PM me & I will send you pics of both types of rods to host
Once you see the pics it is super easy to tell the difference
The earlier LT1's had a lightened version of the "pink" rods before they started using the PM rods... if someone can post pics PM me & I will send you pics of both types of rods to host
Once you see the pics it is super easy to tell the difference
01-16-2005, 02:00 PM
#22
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Re: How Strong are LT1 Connecting Rods??
I just emailed some pics of forged rods... from a 93 Corvette & a 94 Z28 & some pics of a PM rod taken from a 96 Firebird... hopefully that will be posted soon
01-16-2005, 08:58 PM
#24
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Re: How Strong are LT1 Connecting Rods??
I see the difference, its quite noticeable. So which are stronger and to what point? I guess the parts catalog I found that said "PM rods were used in ALL LT1/LT4" was wrong. I'll have to act smart and point that out to them 
Anyways, so what are the different types good to? Very useful and informative thread/posts.
I think the same parts catalog rated the PM ones to 450HP. But its accuracy is in question.
-Dustin-
Anyways, so what are the different types good to? Very useful and informative thread/posts.I think the same parts catalog rated the PM ones to 450HP. But its accuracy is in question.
-Dustin-
Last edited by Bersaglieri; 01-16-2005 at 09:02 PM.
01-16-2005, 10:09 PM
#25
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Re: How Strong are LT1 Connecting Rods??
Yep, the ones I took out of the 94 engine were the earlier design.
My engine class instructor said they were forged. I also had a engine built by a GM dealer and they thought the earlier rods were stronger ??????
My engine class instructor said they were forged. I also had a engine built by a GM dealer and they thought the earlier rods were stronger ??????
01-17-2005, 09:30 AM
#26
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Re: How Strong are LT1 Connecting Rods??
It appears to have been a running change over the 1994 model year. My 94 is a very late production model (July 94, about 400 cars before the last one made for 94 model year) and had the PM rods.
01-17-2005, 10:32 AM
#27
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Re: How Strong are LT1 Connecting Rods??
Very informative thread, I have an LT4 block w/internals out of a 96 Grand Sport Vette in my garage going in my '95Z. I will post pics of those rods and my stock '95's as well as the main caps etc when I get the motor shoehorned outta the car. Thanks for the info guys! 
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