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Discussion Starter #1 (Edited)
I have decided to go with the new Dart SHP aluminum heads 200cc intake 64cc combustion chamber on my 355sbc. I just am not sure about all of the info such as my compresion ratio, quench, type of head gaskets and thickness...the list goes on. After running this static compression calculator:
http://kb-silvolite.com/calc.php?action=comp
I come up with a 10.306 static comp ratio using these specs:

Cylinder Head Volume 64cc
Piston Head Volume(Flat top w/4 valve Reliefs don't know brand so I though this was a safe number) 6cc
Gasket Thickness .018
Gasket Bore 4.166
Cylinder Bore Dyiameter 4.030
Deck Clearance .020
Stroke 3.48


I checked the piston to deck height only using a straight edge and feeler gauges and came up with .018. Trying to keep the quench at .040 I figuerd I would use a .020 gasket? I have read that a thin gasket is not good to use when replacing iron heads with aluminum heads because they may be more prone to leaks if the deck is not perfect. This engine has only been run for about 1000 miles so should I be ok with that thin of a gasket? What type of gasket is the best and seals the best also? I also read that with aluminum heads you can get away with a higher compression ratio and depending on what cam you have you can run a higher compression ratio because it bleeds some compression off? My paper work says my cam specs are .501/.512 lift, 224/230 duration @ 50, 111 lobe center. My concern is that I only have 91 octane avalable to me in CA. So with my set up and all of the info I gave would I be safe running only 91 octane?
 

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I have decided to go with the new Dart SHP aluminum heads 200cc intake 64cc combustion chamber on my 355sbc. I just am not sure about all of the info such as my compresion ratio, quench, type of head gaskets and thickness...the list goes on. After running this static compression calculator:
http://kb-silvolite.com/calc.php?action=comp
I come up with a 10.306 static comp ratio using these specs:

Cylinder Head Volume 64cc
Piston Head Volume(Flat top w/4 valve Reliefs don't know brand so I though this was a safe number) 6cc
Gasket Thickness .018
Gasket Bore 4.166
Cylinder Bore Dyiameter 4.030
Deck Clearance .020
Stroke 3.48


I checked the piston to deck height only using a straight edge and feeler gauges and came up with .018. Trying to keep the quench at .040 I figuerd I would use a .020 gasket? I have read that a thin gasket is not good to use when replacing iron heads with aluminum heads because they may be more prone to leaks if the deck is not perfect. This engine has only been run for about 1000 miles so should I be ok with that thin of a gasket? What type of gasket is the best and seals the best also? I also read that with aluminum heads you can get away with a higher compression ratio and depending on what cam you have you can run a higher compression ratio because it bleeds some compression off? My paper work says my cam specs are .501/.512 lift, 224/230 duration @ 50, 111 lobe center. My concern is that I only have 91 octane avalable to me in CA. So with my set up and all of the info I gave would I be safe running only 91 octane?
I don't think thats a gasket recomended by Dart, On a performance build it best to square the decks and I have always zero decked and with the Dart and AFR heads I do use the recomended head gaskets, One other reason for the 1003 is this http://www.chevyhiperformance.com/techarticles/90678_small_block_400_cooling_tricks/index.html If the block was not squared and decked it not a good idea to put a new head on those decks

Thats a really big head for your cubic inch and not much lift for a good flowing head like that, The 180 runner I would think would be a better choice.

Properly tuned engine your set up is fine for 91 octane a cam with that much lobe sep will decrease dynmaic compression which will help you.
 

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Discussion Starter #3
I don't think thats a gasket recomended by Dart, On a performance build it best to square the decks and I have always zero decked and with the Dart and AFR heads I do use the recomended head gaskets, One other reason for the 1003 is this http://www.chevyhiperformance.com/techarticles/90678_small_block_400_cooling_tricks/index.html If the block was not squared and decked it not a good idea to put a new head on those decks
Not sure what you mean, I have not choosen a gasket yet so which are you saying is not recommended by Dart? The engine was decked to true it up only. I have only put about 1000 miles on the car before switching to the aluminum heads. If I want to keep the quench close to the .040 could you recommend a few good gasket that are around .020 and will work with aluminum heads? I do not know anything about head gaskets so any help is appreciated.

Thats a really big head for your cubic inch and not much lift for a good flowing head like that, The 180 runner I would think would be a better choice.
Yes, I know the head is a more a little more then I need with my current cam, but I want to leave myself some room to go to a larger cam in the future.
 

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Not sure what you mean, I have not choosen a gasket yet so which are you saying is not recommended by Dart? The engine was decked to true it up only. I have only put about 1000 miles on the car before switching to the aluminum heads. If I want to keep the quench close to the .040 could you recommend a few good gasket that are around .020 and will work with aluminum heads? I do not know anything about head gaskets so any help is appreciated.



Yes, I know the head is a more a little more then I need with my current cam, but I want to leave myself some room to go to a larger cam in the future.
There should have been gasket recomendations in the box or you might want to check with Dart.

Also its a good idea to CC the chambers to see exacltly what you have.
 

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Bryanw80,

You might want to check out the Victor-Reinz 5746 head gasket. It has a compressed thickness of .026, which would help with your quench. It's high performance gasket made for iron or aluminum heads and rated to 12.5:1 compression. I've been using that gasket and have had no problems. Also, I've read that this is the same as the GMPP 10105117, but I haven't confirmed it myself.

Regarding the 200cc heads, I would concur with CNC BLOCKS. I think you would be happier with the 180cc heads, even if you go to a larger cam in the future. The 180's will give you more low-end and mid-range torque (which equals better street manners) and will still have plenty of flow at the top end. I have 195cc heads on my 355 (specs similar to yours) and I wish I had gone with Dart or AFR 180's.

Just my opinion.
 

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I have decided to go with the new Dart SHP aluminum heads 200cc intake 64cc combustion chamber on my 355sbc. My paper work says my cam specs are .501/.512 lift, 224/230 duration @ 50, 111 lobe center. My concern is that I only have 91 octane avalable to me in CA. So with my set up and all of the info I gave would I be safe running only 91 octane?
Check your Dynamic compression ratio for a good indicator of how close you will be to the PING. What is your total duration on that cam? Jack
 

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Discussion Starter #7
Funny that you would mention that, that is the head gasket that I ordered and hoping it works good.Did you put the head gasket on dry? I could not find much info on that head gasket but it does seem to fit my needs. I did finally settle on the Dart SHP 180cc with 64cc chambers so I hoe that they work well also.


Bryanw80,

You might want to check out the Victor-Reinz 5746 head gasket. It has a compressed thickness of .026, which would help with your quench. It's high performance gasket made for iron or aluminum heads and rated to 12.5:1 compression. I've been using that gasket and have had no problems. Also, I've read that this is the same as the GMPP 10105117, but I haven't confirmed it myself.

Regarding the 200cc heads, I would concur with CNC BLOCKS. I think you would be happier with the 180cc heads, even if you go to a larger cam in the future. The 180's will give you more low-end and mid-range torque (which equals better street manners) and will still have plenty of flow at the top end. I have 195cc heads on my 355 (specs similar to yours) and I wish I had gone with Dart or AFR 180's.

Just my opinion.
 

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Discussion Starter #8 (Edited)
Compression calculated out to about 10.3-1 so I hope to be ok with 91 octane and the aluminum heads. Now that I am looking over the paper work that came with the engine the only specs it says for the cam is"Custom Ground .501/.512, Lift 224/230 Duration, 111 Lobe Center". It does not say if the duration is @ 50 or not so I do not know if that it the advertised or @ 50 duration? Any opinions on what it could be? If that was theadvertised duration would that be a pretty mild cam?


Check your Dynamic compression ratio for a good indicator of how close you will be to the PING. What is your total duration on that cam? Jack
 

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Compression calculated out to about 10.3-1 so I hope to be ok with 91 octane and the aluminum heads. Now that I am looking over the paper work that came with the engine the only specs it says for the cam is"Custom Ground .501/.512, Lift 224/230 Duration, 111 Lobe Center". It does not say if the duration is @ 50 or not so I do not know if that it the advertised or @ 50 duration? Any opinions on what it could be? If that was theadvertised duration would that be a pretty mild cam?
It is the duration @ .050. You really should find out what your cam Specs are to have peace of mind relating to the PING factor. With a 111 LSA you should be fine but you never know...Jack
 

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Discussion Starter #10
The engine did not come with any other info on the cam so I have no way off finding out.


It is the duration @ .050. You really should find out what your cam Specs are to have peace of mind relating to the PING factor. With a 111 LSA you should be fine but you never know...Jack
 

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Funny that you would mention that, that is the head gasket that I ordered and hoping it works good.Did you put the head gasket on dry? I could not find much info on that head gasket but it does seem to fit my needs. I did finally settle on the Dart SHP 180cc with 64cc chambers so I hoe that they work well also.
Bryan,

I sprayed copper coat on both sides of the gasket. I've got a feeling that you're going to be very pleasantly surprised by how well those heads will work with your set up, especially after you get it all dialed in.

Gerry
 

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Discussion Starter #12
You think the copper coat is necessary? Can you get that at the local parts store? Also which side of the gasket is the block side and which is the head side, its not labeled? The part numbers are on the side that is face up in the package so i would assume that is the head side?


Bryan,

I sprayed copper coat on both sides of the gasket. I've got a feeling that you're going to be very pleasantly surprised by how well those heads will work with your set up, especially after you get it all dialed in.

Gerry
 
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