Aluminum vs Iron compression on pump gas

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Mad Dart said:
Fishy,

I bought some parts a while ago, the 1.6 Roller Rockers, JOMAR GIRDLES studs etc, and decided to use them on this build. Plus I wanted a CLOSED combustion chamber and attempt a tight quench and run higher compression and bigger camshaft on PUMP fuel if it is possible. I understand that there will be more stress and hopefully the use of BEE-HIVE valve springs will help with this issue.

I really got caught up on the EQ heads and how much flow was available for an Iron Head without the CRACKING issue compared to stock casting Iron Heads.

I hope this explains.
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I gotcha Mad Dart. Same reasoning I used. I'm in the same boat doing a stroker (on hold due to medical bills eating up the engine funds) and I bought a set of the Hughes Iron Rams/EQ heads. After I got them and found out the extra's I needed to make them work I wished I had gone with Eddy's so I wouldn't have had to buy girdles and tall valve covers. Plus the weight savings of aluminum would have been nice.

I have looked all over for a set of tall valve covers but haven't had much luck finding them for the magnum heads. What did you buy?
 
Fishy,

I bought the Hughes Covers, I tried to find out who made them and find them less expensive but these are still a good price at $245.00 Mancini has a set but they are over $400.00 if I am not mistaken. Also Don at 4seconds flat has some that look pretty sweet also but more expensive.

Sorry to hear about the medical bills...........I can totally relate to that for sure!!!!!

http://www.hughesengines.com/Index/...dmUgQ292ZXJzICYgQWNjZXNzb3JpZXM=&partid=25078
 
Fishy,

I also had them put the breathers on. I did not cut in a pvc breather because I used a breather on each cover. I am using the breather as the oil filler also.

They are the Blacked out Aluminum Morosso breathers.
 
Mad Dart said:
I want to learn something, when you say smaller chambers, good quench means less total timing.......does this equate to less power?? I would like to know......

Thanks.
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Mad, when you build with quench in mind, and set it properly, the motion of the piston forces the mixture towards the spark plug as the piston reaches top dead center. That both keeps the mixture the best it can be (so the fuel doesnt seperate out causing detonation prone spots) and also gets it in a smaller volume. That way when it fires, less ignition lead is needed to have the highest pressure on the piston around 17° After TDC on the power stroke.
Think of timing a black powder explosion to go off just as someone's foot is on it. If you have the powder spread out flat on the ground, you light the edge and it burns accross it fairly slowly with a "whoosh" sound to it. If you have a firecracker where it's all in a small spot and held there, it fires very quickly with a loud "pop". Same thing with the air/fuel mix and the ignition timing. If it has to burn over a dome, or accross a large open chamber, there is more chance of wet fuel burning irregularly causing detonation, than is the air and fuel stay well mixed and the area is less than 1/2 the open chamber's volume.
 
Good analogy moper. KB uses this one: "Imagine lighting a soup can of gas on fire, now imagine lighting that same can and hitting it with a baseball bat".
 
Mad Dart said:
Fishy,

I bought the Hughes Covers, I tried to find out who made them and find them less expensive but these are still a good price at $245.00 Mancini has a set but they are over $400.00 if I am not mistaken. Also Don at 4seconds flat has some that look pretty sweet also but more expensive.

Sorry to hear about the medical bills...........I can totally relate to that for sure!!!!!

http://www.hughesengines.com/Index/...dmUgQ292ZXJzICYgQWNjZXNzb3JpZXM=&partid=25078
Click to expand...

Thanks Mad Dart. I saw them but didn't think they looked like they'd clear the girdles. I didn't check much into it yet though since I'm out of money. Now I know. Thanks again, T
 
Moper,

Ok I understand now. Thanks for clearing it up. Reminds me of a kid with m80's light one off in the street and it spreads everywhere. Put a trash can on it and boom 40 ft in the air..........haaaaaaaa
 
fishy68 said:
Thanks Mad Dart. I saw them but didn't think they looked like they'd clear the girdles. I didn't check much into it yet though since I'm out of money. Now I know. Thanks again, T
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I also am using Cometic Armid fiber gaskets that are around 3/8ths thick which helps. We will see when it is all mocked up.
 
Mad Dart said:
I also am using Cometic Armid fiber gaskets that are around 3/8ths thick which helps. We will see when it is all mocked up.
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I'm sure that helps. Let me know if it does work if you would please. No big hurry. Just whenever you get around to it.

Thanks, Tracy
 
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