Carb cam/fuel injected cam, and rocker assembly?

[ectonine]

Are the camshafts the same between the carbureted Festivas, and the fuel injected Festivas? Also, can I use the hydraulic rocker assembly from my fuel injected car, and switch it to my carbureted head? I am switching my carbed car over to fuel injection setup via a fuely car picked up. Thanks--Jeremie

[FB71]

cams and rockers are exclusive, meaning, hydraulic rockers with their cam (efi), solid rockers with their cam (carb), roller rockers with their cam (Aspire). Do NOT mix cams and rockers. The lobe profiles are different between the solid and hydraulic, and may cause slight driveability issues, but Aspire rollers MUST be used with an Aspire cam.

[ectonine]

Will the cam, and rockers from my fuel injected car fit into my carbureted cylinder head?

[FestYboy]

^yes

and i havn't had any issues swapping cams and rockers between festies no matter what the combo, (even used aspire roller rockers on a festy cam with VERY good results)

no matter what combo you use, make sure you use stock valve springs!!!

i found (the hard way) that FMS's valve spring upgrade along with a stock or hi-po cam and aspire rockers DON'T mix.

[ectonine]

I just really want to get rid of my noisy mechanical valvetrain. I'm hoping the hydraulic rockers will quiet everything down.

[kzbill]

Is the whole EFI head good enough to be switched for the carbed head? And can it be done without too much trouble?

[FB71]

I don't you can mix cams and rockers with noticable positive immediate results. However, mixing solid cams with hydro rockers can cause minor driveability issues with efi cars. Probably nothing of great significance, but worth noting. As for swapping Aspire roller rockers onto a non-roller cam, we step into a whole different set of issues... First, both mech and hydro cam lobes are not ground flat. They have a slight bulge to them to reduce wear on the rocker's follower pad. Placing a roller against that rounded profile will cause the rocker to side-load. This has no noticible immediate effect, but will wear the sides of the shaft towers much more quickly. Also, the roller cam is made of a differnent material. It's cast steel, and the solid/hydro cams are cast iron. After a period of time, the roller will cut into the lobes of the cast iron cams, which is why the roller cam was cast in steel. Lastly, the cam profiles for each application are significantly different (as FestYboy discovered). Hydro cams have a much more aggressive profile to compensate for the loss of lift common with hydro lash adjusters. Roller followers allow for the lobe profiles to have smaller base circles, and less aggressive profiles, while retaining accurate valve lift. Smaller base circles and less aggressive ramps lower the loads on the valvetrain, decrease wear, and improve fuel efficiencey. If you expect the cam and head to survive anywhere near normal life expectancy (100k miles or more), do yourself a favor and don't mix rockers and cams.

As for the heads, any cam and rocker set will live quite nickly in any head, carbed or efi. The heads, however, are slightly different between carbed and efi, IIRC... I think the difference was at the intake manifold surface. I could be wrong though...

[ectonine]

I know my block, and head are in great condition. Why would I want to change heads?

[FB71]

as far as noise from the valvetrain, my '88 is not much louder than my '90. Are you sure the rockers are properly adjusted?

[jglutz]

Noisey: maybe it's time to have the valves and seats ground.....or the guides are shot (would attribute to burning oil)...or low oil level/pressure.

[FB71]

valve noise isn't generated by valve sealing issues, and rarely by excessive side clearance (worn guides). It's most often due to improper lash adjustment.

[ectonine]

I set the damn things about every other oil change. Do I need to change the cam in order to run the electronic distributor from the fuel injected car?

[FB71]

no, dizzy will swap right in. I had an Aspire on a carbed car (w/ electric fuel pump) w/ no issues.

[25Horseplay]

Is there any performance gains from any of the heads? Is one more desireable than another?

[FB71]

not that I know of....