If I put in an RV type cam (next size up from stock) to replace the stock cam will the computer (OBD1) have any issues or does it not make a difference?
305 camshafts
- Thread starter justacruzr2
- Start date
- Status
As long as it makes enough vacuum at idle it should be ok. Which 305 are you working on, LG4 or L69?
Good question. Don't know. It's in a 1984 Grand Prix so I guess whatever was the typical 305 they put in them. It's not high performance.
Likely a LG4, the L69 was a Monte Carlo SS engine unless somewhere in it's life a swap was done.
Years back I had used Elgin brand cams and lifters in my 86 El Camino with the computer controlled 305 then again in a 355 that replaced the 305. If I remember correctly the RV cam was in the .387/.410 lift with a 258/269 duration for the 305 then with the 355 I bumped up to a .404/.414 lift 269/271 duration. Both had a decent idle, not a ton of overlap so it worked with the stock LG4 computer chip in the 305, Just changed to a stock L69 (Monte Carlo SS) prom chip with the 355 as recommended to me for a more "aggressive timing curve".
Hope this helps.
Years back I had used Elgin brand cams and lifters in my 86 El Camino with the computer controlled 305 then again in a 355 that replaced the 305. If I remember correctly the RV cam was in the .387/.410 lift with a 258/269 duration for the 305 then with the 355 I bumped up to a .404/.414 lift 269/271 duration. Both had a decent idle, not a ton of overlap so it worked with the stock LG4 computer chip in the 305, Just changed to a stock L69 (Monte Carlo SS) prom chip with the 355 as recommended to me for a more "aggressive timing curve".
Hope this helps.
RV cams like the Isky in the 305 in my van and its counterpart waiting on the bench for my Monte are stock lift, longer duration sticks. The Engle stick that I ran in my Monza was an RV as well and it did really well, given that the Monza had a really small cube motor, 262 V-8 CID.
Typically they work from around 1500 rpm or just off idle to around 5-5500 at the top end. Where you really feel them is around 35-40 mph; they really start to pull about that point and keep pulling until around 65-70 depending on how you are geared. I have to be careful with mine because the metro speed limit, 30 mph, is just about the point where it wants to come to play. Very easy to hit third and watch the speedo needle head for escape velocity.
The other virtue is that you don't have to visit the valve train and do a rocker upgrade. Of course, you can if you want, it is one of those, "While I'm in there" job add-ons, after all, but strictly speaking, unless you are considering some serious low end activity, the stockers ought to tolerate the cam just fine.
All the longer duration means is that the valves open and stay open slightly longer; all the better to allow the pistons to inhale as much air/fuel mixture as possible. The stock mapping on the CCC shouldn't even notice the difference as you are not adjusting the timing, just taking more advantage of it.
They usually go in straight up in terms of advance/retard but I would use a degree wheel with the piston stop if the heads are off or the whistle if they are still installed to check the actual timing and degree of LSA against the card-stated specs. Peace of mind. And use lots of cam install lube that has Zinc or ZDDP in it as an ingredient and add a bottle of Comp Cams or similar oil additive containing Zinc to the pan oil so the cam has it during the initial start up and continues to get it during the break in. Otherwise you could wipe out a lobe or kill a lifter and that would definitely ruin your day. Roller cams aren't so sensitive but a little bit of zinc doesn't hurt them either.
Typically they work from around 1500 rpm or just off idle to around 5-5500 at the top end. Where you really feel them is around 35-40 mph; they really start to pull about that point and keep pulling until around 65-70 depending on how you are geared. I have to be careful with mine because the metro speed limit, 30 mph, is just about the point where it wants to come to play. Very easy to hit third and watch the speedo needle head for escape velocity.
The other virtue is that you don't have to visit the valve train and do a rocker upgrade. Of course, you can if you want, it is one of those, "While I'm in there" job add-ons, after all, but strictly speaking, unless you are considering some serious low end activity, the stockers ought to tolerate the cam just fine.
All the longer duration means is that the valves open and stay open slightly longer; all the better to allow the pistons to inhale as much air/fuel mixture as possible. The stock mapping on the CCC shouldn't even notice the difference as you are not adjusting the timing, just taking more advantage of it.
They usually go in straight up in terms of advance/retard but I would use a degree wheel with the piston stop if the heads are off or the whistle if they are still installed to check the actual timing and degree of LSA against the card-stated specs. Peace of mind. And use lots of cam install lube that has Zinc or ZDDP in it as an ingredient and add a bottle of Comp Cams or similar oil additive containing Zinc to the pan oil so the cam has it during the initial start up and continues to get it during the break in. Otherwise you could wipe out a lobe or kill a lifter and that would definitely ruin your day. Roller cams aren't so sensitive but a little bit of zinc doesn't hurt them either.
Yep...Thanks. I don't want to srew-up driveability, especially cold winter starts, or gas mileage.
- Status
Similar threads
