tipsea

my boat came from the factory with a votec 5.7 an 2 bbl carb,with no advancement for timing.I was told the modual has 8 degrees built in.I just refreshed the engine an added a 600cfm on the dual plane intake an it wont run with this distributor setup.How much advancement is to much,,will hei ignition suit an if i have a lean issue at #8 can i go up to say 65 or 66 jets in the mains,it has 63 from the factory.I just re-valved 6 an 8 intake,it only took bout 4 hrs to suck them in with the current set up.

Jay Gadsby

What do you mean it doesnt run? Does it try to start, just wont idle? Is there any obnoxious popping when you are cranking? I did a Vortec head swap onto my 5.7L and my Thunderbolt IV worked just fine. I would post more symptoms and information so people can help out a bit more.

Mr Maine

If you are running thunderbolt ignition then initial timing may call for 8 degrees btdc, module should provide 22 degrees for a total of 30. I assume this is what you have.

I would set advance for total timing of about 32 for a vortec motor, doesn't matter what initial is. On thunderbolt v ignition there is a wire you have to ground to set the timing.

Too much timing on these motors will tulip intake valves. Number 6 and 8 cylinders are the lean cylinders.

What carb? 600 should be close out of the box (edelbrock or holley)

This is a little generic, but you were not specific in your 1st post.

tipsea

ok sorry for not being specific enough.i have a 1999 24ft baha cruiser,it has the vortec 5.7 with 2bbl carb.In 2003 it froze an busted block,so a new short block was installled.I ran the boat another 5 years with no problems,recently we pulled the engine an went thru it,no mods where done for higher performance just back to original specs.I did however go back with a 600cfm holley,which matched up to the dual plane intake once the restrictor plate was removed.Once i started the test an tune soon realized that the distributor would not advance but 8 degrees,called volvo an they said thats all this distributor was meant to do,this is new to me but ok.I have asked around an some say yes i need to go with a new hei single wire to get full advance an some say no that because the boat is always under load that the advancement will tulip the intake at 6/8,,so im at a draw,,,,i know good an well the motor needs advancement but at how much an should i bump up the main jets to go along with the higher timing advancements so not to have these leaning problems.

tipsea

one thing i did fell to mention,,the distributor,,its the small cap with a stand alone coil.The only thing under the roto is the pick up coil an modual.

Mr Maine

So are you saying that the initial timing is 8 degrees before and that as you rev the motor there is no more advance? That is not right.

Small block chevys should run 8-10 degrees initial and 30-34 total in the 3000-3500 range (stock engines)

I think you need to figure out the ignition problems before you worry about the carb. If it is a new marine version holley it should be fine.

tipsea

what im saying is if i set base time at 10 an rev the engine it will only climb to 18,no more,,,im only getting 8 degrees of advancement from the distributor.Yes its a brand new marine holley 600cfm with vac 2nds.Wot on my engine is 4400 rpm

blue thunder

You should set the all in timing at 32-33 and don't worry about initial timing. Make sure you are grounding the jumper wire as mentioned and that you are revving high enough to have all timing in.

dereknkathy

i think it will start hard with 22 or 24 degrees initia.i would check with somebody else who knows thar volvo ignition...maybe google that motor's tune up specs.

tipsea

There is no jumper wire to ground this distributor has a two wire pin connector that plugs into the module one wire pink the other brown ...what I need advice on is what type of hei works best for a stock vortex 5.7 with 600 Holley with throttle range to 4400rpm,,,,because this outlaw junk distributor just will not get the job done