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Last weekend I picked up a Gen 6 454 and I'm getting it ready to go in my 79. For those that don't know, the Gen 6 BBC is 4 bolt main, 9:1 motor with a factory hydraulic roller cam and 1 piece rear main seal.
Some day, I plan swap over to aluminum heads but for now I'm going to run the stock big oval iron heads ($2K in heads can go other places). I'm running a Holley Sniper Stealth fuel injection system and I managed to dig up an old Holley street dominator single plane intake. I'm installing a T56 manual transmission, however the car was originally an automatic so it should have 3.55 gears. For exhaust, I have Headman 2" LTs and I'm going to run either 2.5" or 3" exhaust out the back.
So with all of that said, I'm looking for a good "performance" cam to install. My gut tells me somewhere in the 235/240 range duration on perhaps a 110 LSA. I'm not chasing dyno numbers, rather I want a strong, broad torque curve that will be fun to drive. Obviously I want a some burble at idle, but not excessive.
Take a look at the Hyd roller that GM uses in the ZZ502, its the same one used in the current 427 also. It is a good all around street cam designed for your compression ratio. Is mild enough to work with what ya got how and for your head upgrade in the future. Intended for use with GM roller blocks.
GM part number 12366543
Save those headers for when your engine needs 'em and pick up a set of cheap 1 3/4" primary long tubes, make more torque and power with higher velocity exhaust scavenging.
Cam selection is heavily dependent on compression ratio. Do some research and figure out how to calculate dynamic compression ratio. With cast iron heads you should shoot for about 8:1, with aluminum heads about 8.5:1. That will tell you if the cam you are looking for is in the ballpark.
Cam selection is heavily dependent on compression ratio. Do some research and figure out how to calculate dynamic compression ratio. With cast iron heads you should shoot for about 8:1, with aluminum heads about 8.5:1. That will tell you if the cam you are looking for is in the ballpark.
On your suggestion, I ran a dynamic compression calculator on a couple of cams. For a 225/231 with 110LSA on my 9:1 static, it gave 7.8:1 dynamic.
I recently watched an older hot rod video where they did a Trick Flow head/cam kit on an older 8:1 static RV 454 and managed to make 566 HP on 87.
On your suggestion, I ran a dynamic compression calculator on a couple of cams. For a 225/231 with 110LSA on my 9:1 static, it gave 7.8:1 dynamic.
I recently watched an older hot rod video where they did a Trick Flow head/cam kit on an older 8:1 static RV 454 and managed to make 566 HP on 87.
If you blend the large oval heads well.....nice valve job and the cam I mentioned, it will make close to 500hp....easy. Going to a smaller cam to boost Dynamic will not yield big benefits as these heads want to flow and they make very good velocity.......not need to worry about signal as you have a Sniper EFI.......
The key is the heads on this......have a pro do them for good low lift flow.
If you blend the large oval heads well.....nice valve job and the cam I mentioned, it will make close to 500hp....easy. Going to a smaller cam to boost Dynamic will not yield big benefits as these heads want to flow and they make very good velocity.......not need to worry about signal as you have a Sniper EFI.......
The key is the heads on this......have a pro do them for good low lift flow.
Jebby
I thought about having a valve job and the ports cleaned, but I'm guessing that would run me near $1000 by the time I'm finished.
I thought about having a valve job and the ports cleaned, but I'm guessing that would run me near $1000 by the time I'm finished.
Do the ports yourself....get a book and some tools....
It is not hard as it is cast iron and the ports are huge....easy to maneuver a carbide tree....Cast Iron is easy to work with and forgivable....
Then take them to valve job.....
All you are doing is smoothing rough edges and sharp transitions....not changing the port shape or making them larger.....
Jebby
Last edited by Jebbysan; Mar 26, 2021 at 03:01 PM.
Do the ports yourself....get a book and some tools....
It is not hard as it is cast iron and the ports are huge....easy to maneuver a carbide tree....Cast Iron is easy to work with and forgivable....
Then take them to valve job.....
All you are doing is smoothing rough edges and sharp transitions....not changing the port shape or making them larger.....
Jebby
I guess I'll give it a shot. Worst case, I have to tell me wife I need aluminum heads cause my cast iron heads get "broken".
Just blend the ridges in the bowl where the machine cut for valves. There are typically ridges in the bowls and almost always in the short turns. Probably wouldn't hurt to just break the sharp edges on that combustion chamber to help keep you out of detonation.
The L29 heads are built for torque and will make best power with less timing than typical heads.
And...that's a steel core cam, you can send it to a regrinder for a bit more duration and lift. Delta Cams in Washington has reground a few for me without issue.
Do the ports yourself....get a book and some tools....
It is not hard as it is cast iron and the ports are huge....easy to maneuver a carbide tree....Cast Iron is easy to work with and forgivable....
Then take them to valve job.....
All you are doing is smoothing rough edges and sharp transitions....not changing the port shape or making them larger.....
Jebby
I used to have a book that was really good. It walked me through my first porting job with excellent results. Unfortunately I lent it to someone and never saw it again. Can't even remember the title and author, but in addition to Jebby's suggestion it showed how to unshroud the valves, back-cut the intakes, and round over the exhaust valves. I followed up with a 3-angle valve job and those heads were great. If anyone recognizes the book from my description, I'd love to get the name so I could buy another copy.
I used to have a book that was really good. It walked me through my first porting job with excellent results. Unfortunately I lent it to someone and never saw it again. Can't even remember the title and author, but in addition to Jebby's suggestion it showed how to unshroud the valves, back-cut the intakes, and round over the exhaust valves. I followed up with a 3-angle valve job and those heads were great. If anyone recognizes the book from my description, I'd love to get the name so I could buy another copy.
I have this somewhere....it was intensive reading when I was 18-19 years old.....
David Vizard wrote “How to rebuild a Small Block Chevy”.....a book I read back to front at the age of ten like ten times....
Jebby
Last edited by Jebbysan; Mar 26, 2021 at 05:59 PM.
I have this somewhere....it was intensive reading when I was 18-19 years old.....
David Vizard wrote “How to rebuild a Small Block Chevy”.....a book I read back to front at the age of ten like ten times....
Jebby
Thanks!
I'll have to dig through my old engine building and hot rod books. I think I have something similar to that, but I haven't seen it in probably 25 years. Worst case I'll pick up a copy.
I have this somewhere....it was intensive reading when I was 18-19 years old.....
David Vizard wrote “How to rebuild a Small Block Chevy”.....a book I read back to front at the age of ten like ten times....
Jebby
It's entirely possible. I have several of Vizard's books in my library but not that one. Thanks.
Cam for 9:1 454
I used to have a book that was really good. It walked me through my first porting job with excellent results. Unfortunately I lent it to someone and never saw it again. Can't even remember the title and author, but in addition to Jebby's suggestion it showed how to unshroud the valves, back-cut the intakes, and round over the exhaust valves. I followed up with a 3-angle valve job and those heads were great. If anyone recognizes the book from my description, I'd love to get the name so I could buy another copy.
