Heads for a zero decked block
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Heads for a zero decked block
What heads would be good to use on a zero decked block for the street. Currently running GM 882 heads with 2.02/1.60 which have been shaved down to about 74cc.
Thanks
Thanks
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
Any small blocks heads will fit. Need more info:
- Useage of car?
- Desired power range?
- Cam?
- Engine size?
Lots of factors in deciding on heads (and cams). Whether the blocked has been decked is not really one of them.
- Useage of car?
- Desired power range?
- Cam?
- Engine size?
Lots of factors in deciding on heads (and cams). Whether the blocked has been decked is not really one of them.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Engine is a 350 bored 0.030, stock rods, with 2 valve relief floating pistons, Comp cams 268H with 1.6 roller tip rockers, stock '81 aluminum intake, stock E4ME carb, Hooker side exhaust / headers with inserts.
Usage is street, no strip, no racing....just street driving.
Power range of cam is 1500 - 5500 RPM
Reason I stated zero decked block was that a 64cc head would be too high a compression ratio for pump gas (91).
Would like to hear suggestions on heads.
Usage is street, no strip, no racing....just street driving.
Power range of cam is 1500 - 5500 RPM
Reason I stated zero decked block was that a 64cc head would be too high a compression ratio for pump gas (91).
Would like to hear suggestions on heads.
Le Mans Master
Joined: Dec 2006
Posts: 5,557
Likes: 9
From: Oquirrh Mountains
St. Jude Donor '09
You want to shoot for around 0.040" quench regardless of cylinder head. Pick a good composition head gasket with this compressed thickness since you're at zero and you'll be fine.
If you're going to use aluminum heads, you can get away with a 64cc chamber to get you into the 10:1 range.
If you're going to use aluminum heads, you can get away with a 64cc chamber to get you into the 10:1 range.
Burning Brakes
Joined: Jul 2009
Posts: 1,132
Likes: 14
From: A town SC
You want to shoot for around 0.040" quench regardless of cylinder head. Pick a good composition head gasket with this compressed thickness since you're at zero and you'll be fine.
If you're going to use aluminum heads, you can get away with a 64cc chamber to get you into the 10:1 range.
If you're going to use aluminum heads, you can get away with a 64cc chamber to get you into the 10:1 range.
Great advice.
Burning Brakes
Joined: May 2008
Posts: 860
Likes: 0
From: Stratford Ontario
Engine is a 350 bored 0.030, stock rods, with 2 valve relief floating pistons, Comp cams 268H with 1.6 roller tip rockers, stock '81 aluminum intake, stock E4ME carb, Hooker side exhaust / headers with inserts.
Usage is street, no strip, no racing....just street driving.
Power range of cam is 1500 - 5500 RPM
Reason I stated zero decked block was that a 64cc head would be too high a compression ratio for pump gas (91).
Would like to hear suggestions on heads.
Usage is street, no strip, no racing....just street driving.
Power range of cam is 1500 - 5500 RPM
Reason I stated zero decked block was that a 64cc head would be too high a compression ratio for pump gas (91).
Would like to hear suggestions on heads.
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Drifting
Joined: Dec 2005
Posts: 1,360
Likes: 3
From: NORTHEAST
I hope between cutting the decks of the block and cutting the heads I hope someone correction cut the intake side of the heads so the intake will fit!!!
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Yes, the intake had to be shaved down a bit to get a good seal against the heads.
I had used the FelPro head gasket as well.
If I went to a 64 cc head, the static CR comes out to 10.5....would that be to much for 91 octane fuel and the hot temps of Tucson, AZ??
I had used the FelPro head gasket as well.
If I went to a 64 cc head, the static CR comes out to 10.5....would that be to much for 91 octane fuel and the hot temps of Tucson, AZ??
Burning Brakes
Joined: May 2008
Posts: 860
Likes: 0
From: Stratford Ontario
Use the thicker felpro gasket a nice cam will help. Can't remember if You have auto but assuming so, the proper torque convertor for Your cam. Then the timing set properly, You may have to keep it back 1 or 2 degrees and it will be fine. If Your really worried You could have the chambers professionally opened slightly to help. DO NOT TRY THIS YOURSELF YOU WILL MESS THE CHAMBERS UP! With the extra heat down there You want to also be carefull of not enough timing advance. Timing too far retarted will create heat. A cam with more overlap will help reduce compression at idle. A high flowing water pump can help, and or electric fan along with motor driven fan. Sorry about length of thread. The combo You are considering will sound awesome.
Le Mans Master
Joined: Apr 2005
Posts: 6,357
Likes: 427
From: Seattle Area WA
You don't give a piston part number so I assumed that your two valve relief piston has -4cc of piston volume. With that assumption and a
.039" head gasket with 64cc heads your compression is 10.5:1 which is pretty high for that cam.
Using the same assumption with a set of 70cc heads like the better Brodix IK-180's gives you 9.8:1 compression. Based on this info I would go with the 70cc heads.
.039" head gasket with 64cc heads your compression is 10.5:1 which is pretty high for that cam.
Using the same assumption with a set of 70cc heads like the better Brodix IK-180's gives you 9.8:1 compression. Based on this info I would go with the 70cc heads.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Pistons are H631CP which somewhere I had at -5cc for the valve reliefs.
I think the 70cc heads are the way to go, along with a new intake.
billa suggested the E Street heads over the Performers; says the chamber has a better swirl design. I know these heads are new from Edelbrock and the flow numbers are about the same as the Performer, not quite as good as the Performer RPM (if the ones on the web site are correct)...but as billa says, flow is not everything.
I just have no information as the the differences in the chamber designs between the three 70cc heads from Edelbrock. Going to take a look at the Brodix 180's...have not done that yet.
Thanks for all the responses.
I think the 70cc heads are the way to go, along with a new intake.
billa suggested the E Street heads over the Performers; says the chamber has a better swirl design. I know these heads are new from Edelbrock and the flow numbers are about the same as the Performer, not quite as good as the Performer RPM (if the ones on the web site are correct)...but as billa says, flow is not everything.
I just have no information as the the differences in the chamber designs between the three 70cc heads from Edelbrock. Going to take a look at the Brodix 180's...have not done that yet.
Thanks for all the responses.