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| Project 3400 Roller Cam Block (Page 34/82) |
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lou_dias
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MAR 27, 06:03 PM
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| quote | Originally posted by Will:
For obvious reasons, taking that out of the context of the original displacement is absurd. Can they continue to make 1.5 HP/cid on a 3900 and make 350 HP? I think it's clear that statement was originally made in reference to the 2.8 and approximately 260-280 crank horsepower. Regardless of how much displacement is under it, any head will have a horsepower limit.
And yes, we have established that your argument for why the heads are not a restriction is faulty. Over and over again. |
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Actually no. The article was written in the late 90's well aware of the 3.4 and mentioning it. There's no point in saying 1.5HP/ci if it was only referring to a 2.8. They were referring to the heads and all the applications of the heads. I believe I linked the article in a prior post.
EDIT: here is is again: http://www.gafiero.org/docs/60V6Pwr.pdf[This message has been edited by lou_dias (edited 03-27-2013).]
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Will
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MAR 27, 07:02 PM
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| quote | Originally posted by lou_dias:
Actually no. The article was written in the late 90's well aware of the 3.4 and mentioning it. There's no point in saying 1.5HP/ci if it was only referring to a 2.8. They were referring to the heads and all the applications of the heads. I believe I linked the article in a prior post.
EDIT: here is is again: http://www.gafiero.org/docs/60V6Pwr.pdf
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That's the Chevy Power book. I read it in its entirety years ago, and skimmed it again just now. The latest year I saw mentioned was 1987.
Here are some handy quotes for reference:
| quote | Originally posted by The Chevy Power Book:
Nevertheless, competition 2.8-liter engines with production cylinder heads are capable of producing over 1.50 horsepower-per-cubic inch with only minor port work.
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Chevrolet Special Products has not evaluated the potential of the aluminum V6/60 head for racing applications and therefore has not developed recommended procedures for modifying this casting. |
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So clearly the author was referring to 2.8 engines.
Also, because the latest year mentioned in the document is 1987, I think it's a safe bet that's the year it was written (in the absence of copyright or other markings within the document itself).
My interpretation is that because the author previously stated, previous to the quoted material, that the production cylinder heads do not have sufficient material for significant enlargement of the ports, that "minor port work" means basically a maximum effort port job on a production casting, as "major port work" simply isn't possible due to the aforementioned lack of material in the port walls.[This message has been edited by Will (edited 03-27-2013).]
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lou_dias
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MAR 28, 06:56 AM
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| quote | Originally posted by Will:
So clearly the author was referring to 2.8 engines.
Also, because the latest year mentioned in the document is 1987, I think it's a safe bet that's the year it was written (in the absence of copyright or other markings within the document itself).
My interpretation is that because the author previously stated, previous to the quoted material, that the production cylinder heads do not have sufficient material for significant enlargement of the ports, that "minor port work" means basically a maximum effort port job on a production casting, as "major port work" simply isn't possible due to the aforementioned lack of material in the port walls.
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Yes, I got confused with the other V6/60 book, regardless, GM went on to make 300HP with a 3.0L...another nail in the "iron heads don't flow" coffin. As for oiling, a dry sump system robs more hp from a motor than a wet one, so I don't want to hear that excuse about those engines using dry sump oiling. Dry sump systems are for extended periods at high rpm. I can tell you my machinist did more than minor work on the heads. They are night and day compared to stock heads. The pictures on page 1 of this thread don't look impressive until you compare them to stock. However you can see how smooth he made the exhaust ports...as well as how large...
Hopefully Richard at Arrat Motorsports is back in the country and can resolve the issue with my caliper and I can get my car back so I can put to rest the issue with a dyno within the next month. The collision center thinks only my body panels moved and not my frame but they won't be sure until the car sits on all 4 wheels again.
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Will
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MAR 28, 07:13 AM
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There is no "iron heads don't flow" coffin. The idea that they do is the zombie.
Properly designed dry sump systems ADD power to an engine by pulling down crankcase pressure, thereby increasing BMEP. This more than compensates for the extra parasitic loss.
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lou_dias
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MAR 28, 03:20 PM
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| quote | Originally posted by Will:
There is no "iron heads don't flow" coffin. The idea that they do is the zombie.
Properly designed dry sump systems ADD power to an engine by pulling down crankcase pressure, thereby increasing BMEP. This more than compensates for the extra parasitic loss.
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Ah, you just gave me a great idea for naming the car...
Since it already has a SLAYER logo painted on the hood, it shall be named after a SLAYER song: Live Undead
A properly designed dry sump system is designed to provide proper oil flow at both sustained high RPM and sustained lateral acceleration. This is where a wet system could cause an engine to fail. You can't tell me that running 3 or more oil pumps vs. 1 will not rob "net" horsepower. There is no doubt it improves longevity but in my case: useless.
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Will
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MAR 28, 10:16 PM
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That's the primary purpose of a dry sump system.
However, if used with front and rear main seals which can seal vacuum into the crank case, the scavenge pumps will depress crankcase internal pressure. This increases the pressure difference across the pistons, increasing BMEP and giving the engine HIGHER output than it had without the dry sump system. Yes, this actually happens. It is observed. It is not theory. If properly sealed, dry sump engines become MORE powerful than their wet-sump counterparts.[This message has been edited by Will (edited 03-28-2013).]
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Blacktree
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MAR 29, 12:31 AM
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Pulling a vacuum in the crankcase, like Will described, is actually a common racer mod. It does in fact provide a power increase, because it creates a greater pressure differential between the topside of the piston and the underside. The power gain from the pressure differential overcomes the parasitic power loss, just like it does in a forced induction system.
In any case, I'd like to see your dyno results.[This message has been edited by Blacktree (edited 03-29-2013).]
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lou_dias
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MAR 29, 07:54 AM
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| quote | Originally posted by Blacktree:
In any case, I'd like to see your dyno results.
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you and me both...I haven't driven the car in 6 months... :/
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Blacktree
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MAR 29, 10:13 AM
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Six months?!?! OUCH 
I have to admit, I have ulterior motives. I'd like to see how much performance can be coaxed out of the iron heads, because my engine will have to use them. Unfortunately, the Falconer intake won't fit the aluminum heads. In a perfect world, I could "3D print" a LIM that would fit the Gen3 heads. But I don't see that happening anytime soon.
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lou_dias
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MAR 29, 10:56 AM
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| quote | Originally posted by Blacktree:
Six months?!?! OUCH
I have to admit, I have ulterior motives. I'd like to see how much performance can be coaxed out of the iron heads, because my engine will have to use them. Unfortunately, the Falconer intake won't fit the aluminum heads. In a perfect world, I could "3D print" a LIM that would fit the Gen3 heads. But I don't see that happening anytime soon. |
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It's been at an acquaintance's collision center for 6 months... I saw it on Tuesday, they have been waiting for info(and parts) from Richard at Arrat Motorsports. The new bearing seems thicker and is causing the caliper to bind the rotor when you bolt the caliper on. New spindle might be the issue... Something's not matched...
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