84firebird

hey all,

I have a Mallory coil that came with my mallory hei distributor, i can't remember the part number but it's not one of their super high dollar ones, only cost about $170 er something like that, but the coil says it's good idle to 5,500 and the other coil i could get was like 4000-10000, (i say 2 because they came with the distributor, and i had 2 options)

since i drive on the street i got the idle to 5,500 one, but i was wondering how they rate that, and if that could be a reason for a loss of power at high rpm

markinkc69z

The higher rpm coils are usually lower resistance so they charge better at high rpm, they may also have fewer windings. The trouble is that this will also cause them to run hotter at lower rpm due to the longer time available between cylinder firings where the coil is sinking current.

The street coil should be more reliable as it will run cooler.

angel71rs

I remember seeing a test in a mag where they dyno'd an HEI with different components installed. High perf modules, stock modules, cheap parts store replacement modules. No difference. Performance coil, stock coils, parts store coils. Again no difference. If memory serves, this was a typical street/strip type 350 that they ran up to ~ 6k. Now if it was a super high compression or nitrous or supercharged application, that might be different.

84firebird

cool, thanks guys, yea I'm a street/strip 350, pulls like a bat out of hell to around 5000 but seems to fall off up higher

so yea I was having issues yet up top, and so i was checking stuff out, i've got the fuel system worked out and it's sucking plenty of gas, the plugs are changed frequently to keep from having them foul out and cause issues, checking the wires... checked fuel pump and pressure... air cleaner...that kinda stuff...

then, saw an old insruction sheet for the coil and wanted to check on that rpm thing, which is a relief that i dont have to worry about it

and now I was just checking up on some other stuff, and I'm screwin with advance curves and limits now, seeing if maybe a spring or weight was jamming up or something, also got a new transmission and a 2800 stall that it loves. So I'm gonna make a few runs and see if it pulls better now. but if you have any ideas or insight i'm open to suggestions.

thanks guys
Josh

angel71rs

What cam/springs? A lot of times weak springs will start to allow valve float > 5k without it being obvious, especially with cams that use aggresive lobes like the Comp Cams Xtreme series.

84firebird

...crap... well, when i first rebuilt the entire motor i got a set of elgin? or something like that springs with a seat pressure of like 105 lbs, which was what was needed for the cam at the time, an old 222*/222* .448"/.448" @.050" cam,

I didnt change the springs when i changed to the current cam, a 230*/230* .480"/.480" Lunati bracket master II (pn 00010), mainly because i only had about 2500 miles on the engine, and even less on the set of heads, however i had a machine shop rebuild em and told him to use the current springs over stock replacements to save a few bucks since they were relatively new, he may or may not have used them, they looked very similar to stock springs and i didnt check them to make sure