Need Cam Advice
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
You will need a thrust plate and I think shorter pushrods, the roller lifter stick up further than the flat ones. Make sure it is compatiable with the stock distributor gear, and that it has a fuel pump lobe, unless you don't have a mechanical fuel pump.
Scott
Thread Starter
Instructor
Joined: Jun 2010
Posts: 120
Likes: 1
From: CT
Roller??
Aftre a bit if research, it seems to me that Retro Roller CAMs are so cost prohibitive that I may go for a Hydraulic Flat Tappet.
This one seems like a smart move.
http://www.lunatipower.com/Product.aspx?id=2325&gid=297
Looks like a good upgrade from stock L-82 but still boasts some performance as low as 1800. already have the dual plane and headers,so it may add up nicely.
Most of my geearhead buddies swear by Lunati and thier engineering.
oward
This one seems like a smart move.
http://www.lunatipower.com/Product.aspx?id=2325&gid=297
Looks like a good upgrade from stock L-82 but still boasts some performance as low as 1800. already have the dual plane and headers,so it may add up nicely.
Most of my geearhead buddies swear by Lunati and thier engineering.
oward
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Aftre a bit if research, it seems to me that Retro Roller CAMs are so cost prohibitive that I may go for a Hydraulic Flat Tappet.
This one seems like a smart move.
http://www.lunatipower.com/Product.aspx?id=2325&gid=297
Looks like a good upgrade from stock L-82 but still boasts some performance as low as 1800. already have the dual plane and headers,so it may add up nicely.
Most of my geearhead buddies swear by Lunati and thier engineering.
oward
This one seems like a smart move.
http://www.lunatipower.com/Product.aspx?id=2325&gid=297
Looks like a good upgrade from stock L-82 but still boasts some performance as low as 1800. already have the dual plane and headers,so it may add up nicely.
Most of my geearhead buddies swear by Lunati and thier engineering.
oward
Yeah.......they are quite a bit of money, especially considering that you can get a cam and lifters for less than a C-note. Read up on breaking in a new cam, the latest issue of Car Craft had a good article on breaking in flat tappet cams. It's real easy to smoke a new cam if you don't break it in right. That is one of the advantages of rollers, no break in required.
Scott
Scott
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
stock L82 flattops have -3.4cc trough. Most flattops are about -5cc.
allowing for piston chamfer & the area just above top ring .... and with a typical 0.040" gasket & 64cc chambers, I think it'll be real close to 9.9:1.
allowing for piston chamfer & the area just above top ring .... and with a typical 0.040" gasket & 64cc chambers, I think it'll be real close to 9.9:1.
Burning Brakes
Joined: Feb 2011
Posts: 849
Likes: 0
From: Woodland California
I'm doing a 1975 right now or re-redoing one.
I put on ZZ4 heads and a Lunati Voodoo cam and everything was very good.
I found out that they have taken out a lot of the zink and phosphorous
from our motor oil which is bad news for flat tappet so I added a set of roller tipped rocker arms and +.100 push rods to take some pressure off the cam and straighten up everything.
Long story short, I bent a push rod. I'll do a compression test in a little while to confirm the bent valve theroy.
I found out the ZZ4 motor uses a .510 thick head gasket, I did not.
With the stock rocker and P-rods I put about 500 miles on the motor.
With new setup I got about 5 in town miles. When I started on the freeway is when "It" happened.
Here is the cam I used:
http://www.lunatipower.com/Product.aspx?id=1983&gid=287
Here is a nice thread I found last night:
http://www.ls1tech.com/forums/small-...l98-heads.html
This should give you a little to think about.
Last thing; the ZZ4 heads are suppose to be good to 378 hp.
Small enough for a medium modded engine to be drivable but big enough to have some fun with.
Good luck
Ralph
I put on ZZ4 heads and a Lunati Voodoo cam and everything was very good.
I found out that they have taken out a lot of the zink and phosphorous
from our motor oil which is bad news for flat tappet so I added a set of roller tipped rocker arms and +.100 push rods to take some pressure off the cam and straighten up everything.
Long story short, I bent a push rod. I'll do a compression test in a little while to confirm the bent valve theroy.
I found out the ZZ4 motor uses a .510 thick head gasket, I did not.
With the stock rocker and P-rods I put about 500 miles on the motor.
With new setup I got about 5 in town miles. When I started on the freeway is when "It" happened.
Here is the cam I used:
http://www.lunatipower.com/Product.aspx?id=1983&gid=287
Here is a nice thread I found last night:
http://www.ls1tech.com/forums/small-...l98-heads.html
This should give you a little to think about.
Last thing; the ZZ4 heads are suppose to be good to 378 hp.
Small enough for a medium modded engine to be drivable but big enough to have some fun with.
Good luck
Ralph
Thread Starter
Instructor
Joined: Jun 2010
Posts: 120
Likes: 1
From: CT
Heads for Lunati CAM
Well,
To catch up a bit on the thread......The CR for 64cc heads will in fact be closer to around 10:1. I had used an errant figure for stroke. There are a lot of calculators out there and while they will all be relatively close, they do demonstrate some variation even with the same data.
I called Lunati today and asked about appropriate Cylinder Head specs to match up with the:
Voodoo Hyd Cam Kit - Chevrolet Small Block 268/276
•Advertised Duration (Int/Exh): 268/276
•Duration @ .050 (Int/Exh): 227/233
•Gross Valve Lift (Int/Exh): .489/.504
•LSA/ICL: 110/106
•Valve Lash (Int/Exh): Hyd/Hyd
•RPM Range: 1800-6200
The Tech Center Folks stated that with the typical 2.02 Intake Valve, 1.6 Exhaust and 64cc Chamber (CR around 10:1) found on most Aluminum Heads, Intake Runners of about 185cc should be good with Exhaust Runners of around 62-65cc. Sounded pretty typical and amounted to good news for me. Although they stated that you would need 700CFMs for a carb they did state that 600 would be adequate but may leave some HP on the table at 5-6K.
Howard
To catch up a bit on the thread......The CR for 64cc heads will in fact be closer to around 10:1. I had used an errant figure for stroke. There are a lot of calculators out there and while they will all be relatively close, they do demonstrate some variation even with the same data.
I called Lunati today and asked about appropriate Cylinder Head specs to match up with the:
Voodoo Hyd Cam Kit - Chevrolet Small Block 268/276
•Advertised Duration (Int/Exh): 268/276
•Duration @ .050 (Int/Exh): 227/233
•Gross Valve Lift (Int/Exh): .489/.504
•LSA/ICL: 110/106
•Valve Lash (Int/Exh): Hyd/Hyd
•RPM Range: 1800-6200
The Tech Center Folks stated that with the typical 2.02 Intake Valve, 1.6 Exhaust and 64cc Chamber (CR around 10:1) found on most Aluminum Heads, Intake Runners of about 185cc should be good with Exhaust Runners of around 62-65cc. Sounded pretty typical and amounted to good news for me. Although they stated that you would need 700CFMs for a carb they did state that 600 would be adequate but may leave some HP on the table at 5-6K.
Howard
Last edited by hadams; Jun 24, 2011 at 04:48 PM.
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Thread Starter
Instructor
Joined: Jun 2010
Posts: 120
Likes: 1
From: CT
OIL and Break in???
Oh.....About the oil. Absolutely correct!!!!! Must use oil with Zinc and Phosphorus with Flat Tappet CAMS!!!!! I use Mobile 1 15W-50. Specs Below:
Phosphorus 1200 PPM
Zinc 1300 PPM
Boosted, higher viscosity, fully
synthetic formula designed for
performance vehicles.
HT/HS applications.
Racing and Flat tappet
applications. SM
and..... I know there is great importance to the break in procedure, especially after you really study the flat tappet contact geometry and lifter motion but Iv'e always questioned this. Back in the 70s, I don't think they executed any break in with GM Flat Tappet Engines from the factory. They just assembled em and put them on the lot.
Phosphorus 1200 PPM
Zinc 1300 PPM
Boosted, higher viscosity, fully
synthetic formula designed for
performance vehicles.
HT/HS applications.
Racing and Flat tappet
applications. SM
and..... I know there is great importance to the break in procedure, especially after you really study the flat tappet contact geometry and lifter motion but Iv'e always questioned this. Back in the 70s, I don't think they executed any break in with GM Flat Tappet Engines from the factory. They just assembled em and put them on the lot.
Last edited by hadams; Jun 23, 2011 at 05:17 PM.