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reidp
Platinum Member Joined: December-06-2003 Location: Mooresville, NC Status: Offline Points: 1804 |
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Mark, I plead incompetent, as I know Herbert is just 45 minutes from me over in Lincolnton, NC, but I've never even been there or bought anything. I've heard they're big on Mopar stuff as well which I like, but know nothing about their backwards marine cam availability. But I'll find out before I see you guys in a few weeks. I'm stoked!
Hey, while were talking corrosion, can anyone tell us why raw water cooled marine engines always came from the factory with a 140-143 degree T-stat while fresh water engines used a 160-180 degree? I had no clue but heard from the knowledgable fossils at Holman Moody and it all clicked. For the record and as a clue, they suggested using a higher degree if you always run fresh water only in a RW cooled engine. For those that weren't aware, the "D0OE" heads 79 is using are the good early model factory Ford 351W heads I was referring to several posts back. I'm running the same heads. It's a head that debuted in 1970 (the "D" is for the 70s decade, the second symbol is a zero, for 1970, and the oh and e are typical head casting numbers. They used this casting number/head up thru about 76-77. Again, these heads use the 13/16" spark plugs as opposed to the smaller 5/8". |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
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got me a little confused raw and fresh seem the same to me. Are you talking about a closed cooling system vs a fresh/raw open system? My take would be the thermal sock, like you don't put cold water in a over heated motor, that pop you hear is the block cracking. |
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quinner
Grand Poobah Joined: October-12-2005 Location: Unknown Status: Offline Points: 5828 |
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Not sure if this has any relevance to this discussion but why is the Excalibur fresh water cooling and the ZR6 a closed cooling system? Does it have anything to do with Alum vs Cast?
Reid, I would guess your question has something to do with salt water, perhaps flushing? |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
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reid you added to your posting.
Mine are actually 1969 302 D0OE heads that have been reworked for 1/2" head bolts, 1.94/1.60 valves and the exhaust bowls cleaned up to flow better, machined for screw in studs and have .600" lift springs, scorpion roller rockers and guide plates as well |
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reidp
Platinum Member Joined: December-06-2003 Location: Mooresville, NC Status: Offline Points: 1804 |
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You inland guys............
A fresh water cooled system is the same as a closed cooling system. Raw water cooling is the opposite of both, as it pertains not to the type of water being sucked in, but that it pulls it from the outside. Check this page for some decent Q&A. http://www.perfprotech.com/home/fresh-water-cooling-benefits.htm quinner, I'm not sure about the Excal-ZR6 thing but I'd guess you're right. I bet we find out here very shortly. And the T-stat deal definitely has something to do with salt water. |
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GottaSki
Grand Poobah Joined: April-21-2005 Location: NE CT Status: Offline Points: 3333 |
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I'm not sold on the anodizing as a solution; one scratch and you have all the electrolysis concentrated on one spot, not good. Fresh water ie closed cooling is the solution. Big temp swings are eliminated by the ma$$ of the heat exchanger and coolant, and corrosion is in check by the gylcol and additives.
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21125 |
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The Excalibur has iron block/iron heads, while the ZR6 is iron block/aluminum heads. Not sure if that was your question. |
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quinner
Grand Poobah Joined: October-12-2005 Location: Unknown Status: Offline Points: 5828 |
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Tim,
I thought the ZR6 had Alum heads, my thought was in regards to Alum head on a cast block, PCM uses closed cooling in that situation, is it to eliminate extreme temp varience from Raw water cooling or for some other reason(s)? |
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eric lavine
Grand Poobah Joined: August-13-2006 Location: United States Status: Offline Points: 13413 |
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My take, cast belongs with cast, The only advantage to aluminum heads is wieght, the personia out there is created by the guys that need to sell them, I would take a set of .202 fuelie heads anyday over a set of alum cnc heads, they are raw cast from the factory and if you spend some time opening them up you can achieve the same results.
I just did a all aluminum ls, that thing leaked oil everywhere, I dyed the oil and found 3 leaks.... major ones, back cover,oil pan and intake |
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"the things you own will start to own you"
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21125 |
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Gotcha. I would like to hear from someone at PCM as to why they went with closed cooling on the ZR6. I a$$ume its due solely to the aluminum heads, but Id like to hear their take as to what the the biggest factor was. Corrosion may have been a bigger issue since some people run in salt, but thats just speculation. |
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backfoot100
Platinum Member Joined: January-03-2007 Location: United States Status: Offline Points: 1897 |
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I'm certainly no expert about this stuff, but I have to agree with 79 on this. At least I've heard the same thing about the different metallurgy (sp) attributes of the two different metals causing issues in a raw water cooled environment. Didn't the very first generation Corvette engines in boats cause problems? I think that was in the mid-90's. I keep thinking the LS1 but that could be the second generation Corvette motor in a boat. Anyway, I remember hearing of issues with that first AL head undertaking, but understand that it was fixed in later versions by going with the closed cooling system. In fact, I have a friend who had the Corvette (not the first generation) engine in a Malibu and he said it was a screamer. No issues with it but he only had it for a couple hundred hours before he got a new iron head 383 Hammerhead that he says is better in performance than the Corvette in all attributes and it doesn't need the closed cooling system.
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21125 |
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Youre right- the LT1 was the first generation Corvette motor used in boats. I believe it was a Mastercraft exlusive. It was first used on the 25th Anniversary Prostar 190 in 1993, and then flowed to the rest of their lineup in 1994. I am not sure if the LT1 has aluminum heads, though I have heard that before. It is a RWC motor, though. Its widely considered a great performing, reliable motor in the MC community. Personally, I have 4 friends with early LT1's (1993 25th 190, 1994 190, 1995 190 and 1996 190), and none have had any major problems. |
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Hollywood
Moderator Group Joined: February-04-2004 Location: Twin Lakes, WI Status: Offline Points: 13512 |
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The heads get the coolant before the block in the LT1, atleast in the cars. This may be why there is issues with the temp swings with the Al/Iron engines. Even with the conventional cooling routes, I would stick with Iron heads as well.
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
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closed cooling means higher engine temp, better combustion, better performance and No issues with thermal expansion rates caused by AL on steel.
And the exhaust manifolds are still raw water cooled and not in series with the closed loop cooling system. |
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backfoot100
Platinum Member Joined: January-03-2007 Location: United States Status: Offline Points: 1897 |
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quinner wrote:
Tim, I thought the ZR6 had Alum heads, my thought was in regards to Alum head on a cast block, PCM uses closed cooling in that situation, is it to eliminate extreme temp varience from Raw water cooling or for some other reason(s)? ReidP wrote: Gotcha. I would like to hear from someone at PCM as to why they went with closed cooling on the ZR6. I a$$ume its due solely to the aluminum heads, but Id like to hear their take as to what the the biggest factor was. Corrosion may have been a bigger issue since some people run in salt, but thats just speculation. The Malibu (Mercruiser) offering is the LS1 which is also closed cooling. Someone from either of these manufacturers must have a valid reason and I don't think it's just corrosion. |
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backfoot100
Platinum Member Joined: January-03-2007 Location: United States Status: Offline Points: 1897 |
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Sorry about the previous post, I have to try and figure out how you guys do the cut and paste thing from one post to another and put in a box. That last one didn't work out as good.
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reidp
Platinum Member Joined: December-06-2003 Location: Mooresville, NC Status: Offline Points: 1804 |
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I'm with you backfoot on not being able to cut and paste a quote. Also I don't know how to post a simple link to where you can just click on it. Anyway, here's a good informative thread regarding T-stat degree usage as well as info about FWC and RWC engines and the relationship to varying T-stats and salt water. It sounds a bit like some of our healthy bantering.
See next post by Hollywood (thanks) for the link. |
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Hollywood
Moderator Group Joined: February-04-2004 Location: Twin Lakes, WI Status: Offline Points: 13512 |
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reidp's link
Well I can't show you how to do it, because it'll just make whatever you do a link. Refer to the top thread in General Discussion, Keith tells you how to do this. |
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bkhallpass
Grand Poobah Joined: March-29-2005 Location: United States Status: Offline Points: 4723 |
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To quote a previous post, click the quote icon on the upper right corner of the post you want to quote. You can now remove any text that you don't want to repeat. Do not remove the words in [] at the beginning and at the end of the quoted material.
To set up a hot link to another post, website, etc, Click the 4th icon from the left in the post reply section "Add Hyperlink." An instruction box will appear. Type in what you want the hotlink called, and hit return. Antother box will pop up. Type in or copy and paste the URL of the material you want to link to, and again, hit return. BKH |
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Livin' the Dream
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87BFN owner
Grand Poobah Joined: August-25-2006 Location: Ypsilanti, MI Status: Offline Points: 2194 |
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I am sold on sticking with cast next year.
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jbear
Grand Poobah Joined: January-21-2005 Location: Lake Wales FL. Status: Offline Points: 8193 |
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[QUOTE=bkhallpa$$] To quote a previous post, click the quote icon on the upper right corner of the post you want to quote. You can now remove any text that you don't want to repeat. Do not remove the words in [] at the beginning and at the end of the quoted material.
Test. 'Cause I am always impressed by the cool things you young guys can do on here. john |
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"Loud pipes save lives"
AdamT sez "I'm Canadian and a beaver lover myself"... |
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jbear
Grand Poobah Joined: January-21-2005 Location: Lake Wales FL. Status: Offline Points: 8193 |
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"Loud pipes save lives"
AdamT sez "I'm Canadian and a beaver lover myself"... |
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jbear
Grand Poobah Joined: January-21-2005 Location: Lake Wales FL. Status: Offline Points: 8193 |
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Duh...don't think I did that right.
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"Loud pipes save lives"
AdamT sez "I'm Canadian and a beaver lover myself"... |
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backfoot100
Platinum Member Joined: January-03-2007 Location: United States Status: Offline Points: 1897 |
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BKH and Hollywood, thanks for the posting info. This is awesome! ReidP, thanks for the link to understand FWC and RWC. Makes complete sense now. It makes more sense as to why a AL head engine needs the FWC system to properly function and the different T-stat temps for each type of cooling setup. Now, "Riddle me this Batman....." I was under the impression that a AL head dissipates heat more efficiently than an iron head, causing lower combustion chamber temps which in turn helps to eliminate detonation. This allows you to run somewhat higher CR's than an equivalent iron head engine which in turn improves HP (not to mention the weight savings). If this is true, why doesn't running a cooler T-stat (like 140-143) make an iron head engine more efficient and produce the same results? I know in a car, running a 180 vs. a 195 T-stat can improve performance in some instances. Or is this the old addage that "if some is good, more isn't necessarily better" apply here. |
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jbear
Grand Poobah Joined: January-21-2005 Location: Lake Wales FL. Status: Offline Points: 8193 |
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If at first you don't succeed john |
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"Loud pipes save lives"
AdamT sez "I'm Canadian and a beaver lover myself"... |
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jbear
Grand Poobah Joined: January-21-2005 Location: Lake Wales FL. Status: Offline Points: 8193 |
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"Loud pipes save lives"
AdamT sez "I'm Canadian and a beaver lover myself"... |
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jbear
Grand Poobah Joined: January-21-2005 Location: Lake Wales FL. Status: Offline Points: 8193 |
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Holy Cow! I did it!
Thanks BKH and Hollywood. Man I am a computer guru. john |
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"Loud pipes save lives"
AdamT sez "I'm Canadian and a beaver lover myself"... |
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MaddMarxx
Platinum Member Joined: June-29-2006 Location: United States Status: Offline Points: 1741 |
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We can use my boat as a test, everybody pitch in, and I will buy these heads, install them on my boat, and then I will let you know how they work...ok..ok.. it was worth a try, but I do like these heads!
MY DREAM HEADS |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21125 |
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MM, dream heads? Ive read quite a bit on the Ford truck and Mustang boards, and I dont believe Ive ever heard of these. Price seems very reasonable (almost cheap). Whats the story?
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reidp
Platinum Member Joined: December-06-2003 Location: Mooresville, NC Status: Offline Points: 1804 |
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i's ben oute celerbating jbare's birfday, so if dis dont make cents just jbere with me.
To attempt to answer backfoot, dissipating heat is not necessarily good for making HP. If you have two identical by-design heads, one in alum and one iron, the IRON theoretically makes MORE horsepower because they said it. I found this quote: Aluminum vs. Cast Iron Heads - Many people don't pay attention to the compression ratio when going from cast iron to aluminum heads. Fact is that if everything was equal the cast iron head will make more power than an aluminum head. This is because the cast iron head doesn't absorb heat from the combustion process as fast at the aluminum head. Therefore more heat is available to push the piston down. The way to get back the lost horsepower is to up the compression on the aluminum head. Typically you can run about a half to full point more compression with an aluminum head over the cast iron. I ran a yahoo query "Cast iron or aluminum, which makes more horsepower?" That's where i found the above and lots more interesting stuff. I've always understood that you needed heat to make horsepower, however too much causes detonation. The quote above may not be the best and a bit confusing in terms of the word absorb, so please read more with a query if interested. I don't know if this totally answers backfoot's question about lower T-stat temps. The lower alum head temps help deton but loose HP, so the alum head's lower temp is a short coming vs iron, but is compensated for by higher allowable comp with same gas octane. So you don't want the cooler 140 T-stat temp with iron as you WANT that heat if your octane can stand it. backfoot, we'll solve this and numerous other world issues as we toss back a few while watching MM install jbear's intake. |
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