hey Guys.. I was reading a post on another forum trying to figure out my backfiring out the carb problem and I ran across this:
What you do when you put a hydraulic cam in a 914 is use something that
>was *NEVER* engineered by the factory to do this job. And further, I can
>just about certify that it was *NOT* engineered by anyone in the aftermarket.
>They just said, roughly, "oh cool -- we can take this part from here, and
>this part from there, and hey, it's a 914 hydraulic cam kit!"
>
>So how do you make sure that the followers track the cam? Well, you design
>them so that they just do. *OR* you put in *BIG* springs to make damn sure
>that they do (which may wear the bottom surfaces off the followers or just
>eat the surface of the lobes, which ever is softer). How do you keep the
>lifters from either pumping up solid, or going soft (depending on the
>design flaw you wish to exploit here)?? Well, if this is engineered for the
>application, you know what sort of specific heat you have to face, the
>oil recommended, the filtration used, etc and you cope with it. *OR*
>you have a part that is for a different application and can't as a result
>say for sure that won't happen.
I think I may have an idea!
The previous owner had the valves set REALLY loose for a hydro cam. the engine ran great (overheated like a bastard, but thats because he didnt put but one piece of tin on it) but it never backfired out the carb. The valves actually were set with LASH! the thing was clackety as hell for a hydro car, but it still never backfired or gave trouble. that is, until i adjusted the valves to where they were supposed to be, 2 turns past first contact, to put the piston inside the lifter at mid-stroke.
This is when the problems started, now the engine will run like it has tight valves. it only just occured to me that that's how it's running! I'm afraid that i might have burned all 8 seats! because the valve springs were for a 1.8L bus (since they are 1.8L bus heads) is it possible that i have shitty weak valve springs? is that what's causing the backfires and all around un-tunability of this?