Thread:

vortec help please

i got a used 5.7 vortec from a 96 tahoe and i got a nice intake from summit and a edelbrock 600cfm carb. iam running the mallory unilite marine dist. anyway i got it started up it run great. but going down the lake it would bog out when i nailed it in the secondaries.so after a couple burn runs up and down the lake adjustment after adjustment still no change.primaries everything fine seconds not so good. do i need a marine or rv cam?
so here is what i have done. changed the carb,checked timing,new plugs, compression test which all cyl's look good,checked dist which is brand new,so iam stumped.so to give you a better insight here is what i've got..

5.7 vortec totally stock bottom end and stock vortec heads.
weiand dual plane intake
edelbrock 600 cfm
mallory marine dist
carter elect. fuel pump
stock roller cam ?????
this motor is in a 88' miller 21' open bow with a omc cobra outdrive.

any help with this would be greatly appreciated

Had same thing happen with a Edelbrock carb. The secondary springs could be too light. causing the secondaries to open faster than the distributor is advancing. Is the carb made for Marine use? Timing set before putting in the water? Plugs right gap and or right heat range? Spacer plate between carb and manifold? Things to consider as well.