67 Dart 270...Project Old School
As it turns out the 320HP crate 360 Magnum was a bust. My cheap long block idea turned into a future rebuilder project. So, what's next? Throw in the towel? Take up gardening? Naw...I have decided to build a hybrid.
Ok, not that kind of hybrid. I am going to build a Magnum/LA hybrid. The LA 360 that is in the car now runs and based on the whopping 86 MPH trap speed in a 3300 lbs car it churns out a staggering 142 HP at the rear wheels. (Barf)
Let's review what we are starting with. We have a late 70s 360 with a stock cam, M1 dual plane intake, Holley 3310 750 Vac sec, Summit Racing 1 5/8" long tube headers, B&M SFI spec 360 balanced flex plate, Edge Racing 9.5" 3200 stall converter, 3.91 geared 742 case, and a 904 with the DIY shift kit in it.
I have a roller cam ground on an LA blank with 224/230 .050" and .513 lift I/E on 110 LSA from the now defunct Magnum Adventure. This cam is ground for 1.6 rockers. With 1.5 rockers it would yield .480" lift.
I also have a set of "J" heads that were built by Areohead and have 2.02" intakes installed and .500" lift springs. One option would be to use the roller cam with the "J" heads. The cam is not huge by any means, but with the low compression it would most likely be a turd. The 1.5 rocker ratio would make the cam appear slightly smaller and the ramps that much slower.
Another option would be to shelve the roller cam and get a small flat tappet hydrualic cam to go with the "J" heads. The valve events would be better since the cam would be designed for the 1.5 rocker ratio.
The option I have settled on is to build the hybrid. I will acquire some EQ heads and reuse the rocker gear from the defunct Magnum heads. I will get the EQ heads with the LA bolt pattern and maybe some day I will upgrade to the holy grail...the LA version RPM Air Gap!!! I will have to spring for the hydraulic roller lifters from Hughes. They are not cheap, but I won't have to worry about wiping out a flat tappet cam during break in.
Update: Heads and roller lifters are here!
I am in the process of tearing the old heads off and clearing stuff out of the way to get the old cam out.
As it turns out the 320HP crate 360 Magnum was a bust. My cheap long block idea turned into a future rebuilder project. So, what's next? Throw in the towel? Take up gardening? Naw...I have decided to build a hybrid.
Ok, not that kind of hybrid. I am going to build a Magnum/LA hybrid. The LA 360 that is in the car now runs and based on the whopping 86 MPH trap speed in a 3300 lbs car it churns out a staggering 142 HP at the rear wheels. (Barf)
Let's review what we are starting with. We have a late 70s 360 with a stock cam, M1 dual plane intake, Holley 3310 750 Vac sec, Summit Racing 1 5/8" long tube headers, B&M SFI spec 360 balanced flex plate, Edge Racing 9.5" 3200 stall converter, 3.91 geared 742 case, and a 904 with the DIY shift kit in it.
I have a roller cam ground on an LA blank with 224/230 .050" and .513 lift I/E on 110 LSA from the now defunct Magnum Adventure. This cam is ground for 1.6 rockers. With 1.5 rockers it would yield .480" lift.
I also have a set of "J" heads that were built by Areohead and have 2.02" intakes installed and .500" lift springs. One option would be to use the roller cam with the "J" heads. The cam is not huge by any means, but with the low compression it would most likely be a turd. The 1.5 rocker ratio would make the cam appear slightly smaller and the ramps that much slower.
Another option would be to shelve the roller cam and get a small flat tappet hydrualic cam to go with the "J" heads. The valve events would be better since the cam would be designed for the 1.5 rocker ratio.
The option I have settled on is to build the hybrid. I will acquire some EQ heads and reuse the rocker gear from the defunct Magnum heads. I will get the EQ heads with the LA bolt pattern and maybe some day I will upgrade to the holy grail...the LA version RPM Air Gap!!! I will have to spring for the hydraulic roller lifters from Hughes. They are not cheap, but I won't have to worry about wiping out a flat tappet cam during break in.
Update: Heads and roller lifters are here!
I am in the process of tearing the old heads off and clearing stuff out of the way to get the old cam out.