72 base motor rebuild
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Instructor
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Jackson: What kind of lobe separation will this cam give me. $89 seems like this would be low quality?? I'm thinking 110 degrees as I seem to remember this.
Checked out the speed pro book and it says with a 76 cc heads and
.025 piston to deck will net 9.35:1 Should I try to get 10:1 for the most HP for this "stock casting combo". Should the cam have a small amount of "lope" for the most seat of the pants feel.
Sorry for all the ?'s as it has been 25 years since I have been wrenching on small block chevy's.
Checked out the speed pro book and it says with a 76 cc heads and
.025 piston to deck will net 9.35:1 Should I try to get 10:1 for the most HP for this "stock casting combo". Should the cam have a small amount of "lope" for the most seat of the pants feel.
Sorry for all the ?'s as it has been 25 years since I have been wrenching on small block chevy's.
Le Mans Master
Joined: Apr 2006
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Whats wrong with a flat top piston 64cc 291 head, I can see using a domed
piston if your just stuck with using a 76cc head, if you have a 64 cc head use
it with a flat top piston.
piston if your just stuck with using a 76cc head, if you have a 64 cc head use
it with a flat top piston.
Last edited by Little Mouse; Nov 15, 2007 at 09:37 PM.
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Could use either one except the 291's don't have holes (not that big of a deal) but the 993's keep the numbers matching. If you guys thought the 291's would give me enough of an HP advantage over the number match combo I would consider it!
Le Mans Master
Joined: Sep 2001
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From: Unreconstructed, South Carolina
not together
You have 1105 cam ? Not 1103 ... but you have 1105?
IMHO, 1105 cam is too much for 350" w/ dished pistons & ~76cc chambers.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Jackson: What kind of lobe separation will this cam give me. $89 seems like this would be low quality?? I'm thinking 110 degrees as I seem to remember this.
Checked out the speed pro book and it says with a 76 cc heads and
.025 piston to deck will net 9.35:1 Should I try to get 10:1 for the most HP for this "stock casting combo". Should the cam have a small amount of "lope" for the most seat of the pants feel.
Sorry for all the ?'s as it has been 25 years since I have been wrenching on small block chevy's.
Checked out the speed pro book and it says with a 76 cc heads and
.025 piston to deck will net 9.35:1 Should I try to get 10:1 for the most HP for this "stock casting combo". Should the cam have a small amount of "lope" for the most seat of the pants feel.
Sorry for all the ?'s as it has been 25 years since I have been wrenching on small block chevy's.
Summit's house brand cam&lifters are good quality ... it's what discount marketers call a loss leader ... they gamble you'll add other hi-profit pieces to an initial order item that's a true bargain. Dig deeper; Summit specifies 109 icl & 114 lsa for K1105. BTW ... just a coupla months ago they were $70. About same % increase as today's propane delivery.
Dig deeper into SP catalog too ... it tells you ... catalog's sbc cr quotes are based on stock deck & 0.038" gasket & are accurate for that combo ... my higher scr quote based on thinner gasket w/ improved quench ... my combo's quote is accurate too.
here's FM's (aka SP) own scr caculator:
http://www.21cgt.com/FMWebCatalog/frmConversion4.aspx
flattops/dish & 64cc are fine ... & so are domes & 76cc ... your car/choice.
If I were starting from scratch / money no object / numbers match no object ... I'd prefer flattops/dish & 64cc. My suggestions based on how I interpreted your posts.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
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surface is a little better. but if the 291s don't have the holes in the
end for accesories and numbers matching is good on a 72, anything
that has steel bumbers is worth money. I have been watching the
forum for awhile and quite a few have used the summit cam and lifters
have not seen anyone come on the forum complaining of a falure.
I don't have any books on casting numbers, I did look at the Z/28 site
for casting numbers it showed a 993 casting going up till 1976 for a 350 with a valve size of 172/150, I find it hard to believe chevy used a 1.72
intake valve on a 350 but if thats the case use the 1.94/1.50, 291.
Last edited by Little Mouse; Nov 16, 2007 at 05:16 PM.
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Your right Jackson I am worried about the money police but I don't want to do something dumb so bear with me. I have not bought small block chevy parts in 20 years. The last time I bought parts was from JC Whitney and back in the day the only heads to get some HP were the 461's. I want my cake and I want to eat it to!! (but I know thats no going to happen)
Thanks again for the help.
Thanks again for the help.
Burning Brakes
Joined: Sep 2005
Posts: 832
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From: Sarasota Florida
Do NOT run H618CP (+3.5cc dv) & Vortecs (64cc) together ... too much compression (~11:1 or more) ... also, maybe not sufficient clearance within vortec chamber for dome.
You have 1105 cam ? Not 1103 ... but you have 1105?
IMHO, 1105 cam is too much for 350" w/ dished pistons & ~76cc chambers.
You have 1105 cam ? Not 1103 ... but you have 1105?
IMHO, 1105 cam is too much for 350" w/ dished pistons & ~76cc chambers.
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Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Burning Brakes
Joined: Sep 2005
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From: Sarasota Florida
all i know is that it's a gm crate 350 290hp with 1977 casting heads (l-48). i would suspect it has flap top pistons. never dug that deep into it lol. but the 1005 cam works fine now...i can tell the low end torque could be greater, but i think the vortec heads will help that.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
all i know is that it's a gm crate 350 290hp with 1977 casting heads (l-48). i would suspect it has flap top pistons. never dug that deep into it lol. but the 1005 cam works fine now...i can tell the low end torque could be greater, but i think the vortec heads will help that.
Instructor
Joined: Oct 1999
Posts: 182
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From: SW Oklahoma
funny, I was thinking about base engine 72 today and how it is a dog. It was rebuilt about 10,000 miles ago and it is stock except for the Comp 268H cam. It is not the right cam for this. The car has air and ps pb. I was thinking about adding a set of votec heads and a votec manifold with headers and keeping the cam. I would like more snap-just a good running car with some snap. The way it is now it is just plain doggy.
I had thought about a crate motor--if so any recommendations.
I had thought about a crate motor--if so any recommendations.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
funny, I was thinking about base engine 72 today and how it is a dog. It was rebuilt about 10,000 miles ago and it is stock except for the Comp 268H cam. It is not the right cam for this. The car has air and ps pb. I was thinking about adding a set of votec heads and a votec manifold with headers and keeping the cam. I would like more snap-just a good running car with some snap. The way it is now it is just plain doggy.
I had thought about a crate motor--if so any recommendations.
I had thought about a crate motor--if so any recommendations.
Instructor
Joined: Oct 1999
Posts: 182
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From: SW Oklahoma
It was rebuilt with dish pistons. What would the compression be with the 64cc heads. I was going to order from Chev, but if I can find some used which ones and part number? I wonder if I put the votec heads on it and the votech intake with a 600 demon or holly would it all fit under the stock hood?
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
It was rebuilt with dish pistons. What would the compression be with the 64cc heads. I was going to order from Chev, but if I can find some used which ones and part number? I wonder if I put the votec heads on it and the votech intake with a 600 demon or holly would it all fit under the stock hood?
If you have base 72 you have very low hood ... lowest vortec intake w/ drop base air cleaner assembly should fit ok.
Burning Brakes
Joined: Sep 2005
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From: Sarasota Florida
thanks again!
Race Director
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From: Millington Illinois
St. Jude Donor '08-'09
Instructor
Joined: Oct 1999
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From: SW Oklahoma
Jackson, Thanks for your help. I was looking at the Eldebrock intakes website they spell out that a vortec intake will not fit or clear a corvette hood. I really would like to do this, but do not want to change hoods or have clearance problems. I am ordering a set of heads from chevy on Friday and getting the intake coming as well., but I want to make sure do not run into clearance issues. I am sure someone has a 68-72 vette so equiped.
Also, are these heads the centerbolt? I think chevy makes adapters to run the old style valve covers which I would like to do as I have had these on the car since 1974.
Also, are these heads the centerbolt? I think chevy makes adapters to run the old style valve covers which I would like to do as I have had these on the car since 1974.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Jackson, Thanks for your help. I was looking at the Eldebrock intakes website they spell out that a vortec intake will not fit or clear a corvette hood. I really would like to do this, but do not want to change hoods or have clearance problems. I am ordering a set of heads from chevy on Friday and getting the intake coming as well., but I want to make sure do not run into clearance issues. I am sure someone has a 68-72 vette so equiped.
Also, are these heads the centerbolt? I think chevy makes adapters to run the old style valve covers which I would like to do as I have had these on the car since 1974.
Also, are these heads the centerbolt? I think chevy makes adapters to run the old style valve covers which I would like to do as I have had these on the car since 1974.