A Public Thank you to Greg Brown for the GT rods and the help!
03-20-2009, 07:35 PM
#46
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Norbert:
We just need more information. This is not a debate and no one needs to get angry. No one knows all, and we are all trying to learn. If these rods are indeed, Porsche junk, we just need to know. Perhaps you can get some details of what makes them weak and how they failed? That would help us all.
I have nothing technical that proves they are strong...I've never seen or had one fail. I just assumed that if Porsche made them for, and put them in, the higher performance engines, that they would be stronger. If wrong, that's OK...I've been wrong before....and so has Porsche!
See what you can find out and share it with us, please.
Everybody: Let's all be cool and get to the bottom of this...and see what we can learn. No emotion/opinions...let's be technical.
greg brown
We just need more information. This is not a debate and no one needs to get angry. No one knows all, and we are all trying to learn. If these rods are indeed, Porsche junk, we just need to know. Perhaps you can get some details of what makes them weak and how they failed? That would help us all.
I have nothing technical that proves they are strong...I've never seen or had one fail. I just assumed that if Porsche made them for, and put them in, the higher performance engines, that they would be stronger. If wrong, that's OK...I've been wrong before....and so has Porsche!
See what you can find out and share it with us, please.
Everybody: Let's all be cool and get to the bottom of this...and see what we can learn. No emotion/opinions...let's be technical.
greg brown
Greg, have you seen the S4 rods fail?
03-20-2009, 07:58 PM
#47
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Here is what happens when you put GT Rods in a 16V engine (see pics)..
Just kidding, no idea what caused this one, but worst failure of a 16V (only 40K miles) I have seen.
Oh, and yes the light spot in the first pic is daylight coming up thru thru the oil pan. In the last pic you can see the V of the engine is also FUBAR.
Just kidding, no idea what caused this one, but worst failure of a 16V (only 40K miles) I have seen.
Oh, and yes the light spot in the first pic is daylight coming up thru thru the oil pan. In the last pic you can see the V of the engine is also FUBAR.
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03-20-2009, 10:18 PM
#52
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Greg,
Well said.
One more idea to add to help add clarity to this discussion. It is a no-brainer to say there are stronger lighter faster aftermarket rods available, just as with everything. But, I for one would like to hear more about the specific 928 factory rods I thought we are/were discussing.
Well said.
One more idea to add to help add clarity to this discussion. It is a no-brainer to say there are stronger lighter faster aftermarket rods available, just as with everything. But, I for one would like to hear more about the specific 928 factory rods I thought we are/were discussing.
Please enlighten us.
03-20-2009, 10:33 PM
#53
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So we've got three rods that came in the S4/GT?
1) Early S4 w/944 "forged" rod
2) 87.5 and later S4 with sinter forged rod
3) GT forged rod
Anyone have all three that they could put together in one pic?
1) Early S4 w/944 "forged" rod
2) 87.5 and later S4 with sinter forged rod
3) GT forged rod
Anyone have all three that they could put together in one pic?
03-20-2009, 10:34 PM
#54
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Dave:
I'd guess that the engine pictured has a broken rod from when the rod no longer rotated on the crank. Looks like the usual #2/#6 "vent", from here.
Greg:
Yes. Have seen S-4 rods break. Have also seen more than a few of the forged GTS style rods bend and break...in both 928 and 944 applications. One of the local shops was taking these rods out of the 968's and putting in Carrillos. He then was using the 968 rods in 944 Turbo street applications. They bent and broke pretty quickly. Joe Privatelli had a couple badly bent ones in his GTS, when we took his apart. Got another set out of an engine, here, that has some of them bent. I've always considered these rods to be running right at their design limits, stock. I always thought that anyone that is supercharging one of these rods (GTS) is just asking for a disaster. Have never seen a broken "GT" rod....but again...there are not many of them, out there.
Andrew:
Is that buttered popcorn?
I'd guess that the engine pictured has a broken rod from when the rod no longer rotated on the crank. Looks like the usual #2/#6 "vent", from here.
Greg:
Yes. Have seen S-4 rods break. Have also seen more than a few of the forged GTS style rods bend and break...in both 928 and 944 applications. One of the local shops was taking these rods out of the 968's and putting in Carrillos. He then was using the 968 rods in 944 Turbo street applications. They bent and broke pretty quickly. Joe Privatelli had a couple badly bent ones in his GTS, when we took his apart. Got another set out of an engine, here, that has some of them bent. I've always considered these rods to be running right at their design limits, stock. I always thought that anyone that is supercharging one of these rods (GTS) is just asking for a disaster. Have never seen a broken "GT" rod....but again...there are not many of them, out there.
Andrew:
Is that buttered popcorn?
03-20-2009, 10:39 PM
#55
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This is how ugly rumors get started...I have a friend that says....
So, let me understand this line of thought: Porsche, for some reason, creates a custom, weaker rod for their higher rpm/higher output engines....while they still have the stronger rods on the shelf to put in the lower output engines? Does anyone out there think this is totally absurd, besides me? They contract with a company to build a weaker rod because they just want to spend more money, instead of using the stronger rod, they already have on the shelf?
Any rod that quits turning on the crankshaft is going to break...no matter who made it and what material it is made from. If the rod starts to stick and becomes hard to rotate on the crank, it is going to break, as the engine rotates...pretty much pure physics. I'd guess that this is the problem that the 944 guys had...since those engines destroy rod bearings at an incredible rate.
928 rods and 944 rods are dimensionally the same, except the 944 versions are wider on the "big" end.
So, let me understand this line of thought: Porsche, for some reason, creates a custom, weaker rod for their higher rpm/higher output engines....while they still have the stronger rods on the shelf to put in the lower output engines? Does anyone out there think this is totally absurd, besides me? They contract with a company to build a weaker rod because they just want to spend more money, instead of using the stronger rod, they already have on the shelf?
Any rod that quits turning on the crankshaft is going to break...no matter who made it and what material it is made from. If the rod starts to stick and becomes hard to rotate on the crank, it is going to break, as the engine rotates...pretty much pure physics. I'd guess that this is the problem that the 944 guys had...since those engines destroy rod bearings at an incredible rate.
928 rods and 944 rods are dimensionally the same, except the 944 versions are wider on the "big" end.
I also find it hard to believe that Porsche made a weaker rod for a higher output engine on purpose.
03-20-2009, 10:39 PM
#56
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"Stronger lighter faster aftermarket rods" generally means "rods made from Chinese steel". Pretty tough to build a decent rod made from decent material for less than a couple of hundred dollars, these days. High quality rods (Carrillo) are closer to $300.00 each.
Please enlighten us.
Please enlighten us.
My comment was in reference to this earlier statement(see below) in Post #34 replying to your Post #33....
I am with you 100%, I would really like to know more about any evidence of weakness etc, in the 928 rods.
Have a great weekend,
03-20-2009, 10:48 PM
#57
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Here's a comparison of rods we found in an 85, 88 and 90GT. I don't know if the '85's are the same as the "early S4". The rods in the '88 had a 944 part #.
For more pictures, go here:
https://rennlist.com/forums/928-foru...0-gt-rods.html
03-20-2009, 10:56 PM
#58
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It was definitely a hard impact, even the oil pan is bent downward there. You can barely see the curved OP gasket line at the bottom of one of those photos. Will get a better pic tomorrow.
Back to 32V rods.....
03-20-2009, 11:01 PM
#59
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03-20-2009, 11:11 PM
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So you are saying that the 928 had two distinct sets of forged rods?