Small Block & Big Block Chevy Specific - update on my new motor

well i put the new converter in it which is a yank 3,600 and did a baseline dyno and it put down 380rwhp...... its a 388 stroker with dart pro 1s pnp and T350, with 12 bolt..... i know that tranny and rear end setup it gonna eat some extra power but i really thought it would have had over 400rwhp???? i know i know dont worry about the dyno and yes the car runs good but think if i can harness some extra power and put even more down???? plus i could have make that kinda power with a baby cam 350 with vortech heads i would say right?????


also my plugs look very black and had some fuel on them when i pulled them so i dropped the jets down 2 sizes front and back and it seemed to run a little better but is it possible that it messed the plugs up a little and i shoudl put some fresh ones after i get the fuel dialed in better????? also i run dual cutouts on it and they sound so bad i will never uncork them so i plan on removing them but i assume they create heavy turbulance when i run them that could effect power and air flow...... other than that i am happy with the car cause it out ran a 90mph 8th mile car buy 5+ cars before i hit 6,000rpms so i really cant complain but i wonder if i really have my fuel and timing way off???? timing is set at 36-37 degrees, fuel pressure at 7 with no regulator but i can install one if you think it will help,

anyone gonna reply???

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Yes, but I won't be any help on anything with 380 HP.
Good luck, hope you get it dialed in soon.

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Get a wideband. Trying to tune a carb these days by reading plugs is a waste of time as cheap as widebands have become.

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Yes, but I won't be any help on anything with 380 HP.
Good luck, hope you get it dialed in soon.

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so you know the big stuff but dont know about the small stuff??? thought you gotta learn that stuff first!!! :D

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I can't remember last week, how the heck can an old guy like me remember 20 years ago.
I've been BBC's a long long time. At least I was the 1st to reply!!

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hehe just messing with ya man..... im just trying to figure out where the timing needs to be along with the perfect jet size...... i know that can probly not be known unless the car is in front of someone but still thats what i am trying to figure out

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I was just playing also. Honestly, I haven't touched a SBC in a longggggggg time.
I would hate to give bad info. Good luck.

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thats ok man.... i knew the T350 and yank stal would eat a little more power but damn i figured i could atleast hit 400rwhp with a somewhat beefy cam, mech roller, vic jr ported intake, and ported dart heads!!!! i mean even with issues i thought it would make more power than that.... i just need to take it down the track and see what she does and then i will worry about it if it dont run well!!!

Timing and fuel pressure should be close.I run FR5 NGK plugs N/A on the street. Plugs should never be black though...Maybe check the idle for sure...start at 1.5 turns out on the needles? if it's a 750hp Holley carb, it will probably want 72-74 jets and a Powervalve up front and 82-84 in the rear and no powervalve(plugged). Not sure on air bleed sized, sorry!

well i have a basic holley 700cfm double pumper...... i hear that a 750cfm HP version carb would help me out.... also i dont run a fuel pressure regulator at all..... im just hoping that my plugs being so bad looking and having those nasty cutouts restricting my airflow was keeping me from that extra 20rwhp cause as long as i can atleast get 400 to the tires i will be content with me using the parts i used.... cause i didnt pick a sollid roller and have to adjust the rockers from time to time to get the same power i could have gotten had i used a hyro roller.... you feel me????? also i wonder if i was to get 400rwhp the next time i put it on the dyno ater i fix the issues i have what would my motor be pumping out at the flywheel????? seeing im running a T350, 3600 stall and 12 bolt?

another question to guys who know carbs..... before i put it on the dyno it was actually running fine but the plugs looked black so we dropped the jets down 2 sizes front and back and it seemed to run fine but ater i left the dyno on the way home and until now it stumbles down low until the back barrels kick in and then it cleans up and runs right..... it almost seems like its running too rich down low but i dropped 2 sizes???? and if it was too lean it would hick up when i hit the gas right????


also does anyone know what a holley 110 gph is capable of as far as hp rating???? i run a 110 with no regulator with fuel psi around 6.5 and it seems to be fine up top..... and does anyone know a place i can get on that specializes in SBC carb stuff cause this site leans tward LS1 of course..... i feel like if i get around enough sbc carb guys they might have been through some of my issues.... theres a few on here but 90% of LT1 LS1 which i can understand...... i am on LS1tech LOL

380rwhp in your 1st gen will fly....should go mid to low 11's no problem. Non lockup stalled cars throw down shittiy dyno numbers but kick ass were it really matters.....the track!!

yep your right about that...... this thing goes right to the power when i hit the gas.... the thing is my plugs are wet with blackish gas and crud on them so i know it probly has 20rwhp worth of power i dont have due to it being that much out of wack.....

i would deffinately run a regulator.... and then maybe jet it according to Autoroc....

by any chance you got any motor parts hanging around? I always ask

Sometimes the single plane intake have a tendency to have poor fuel distributon at low rpms. So if you are cruising around a bunch...this can happen.

i would deffinately run a regulator.... and then maybe jet it according to Autoroc....

by any chance you got any motor parts hanging around? I always ask


just wondering but why???? my pump a holley 110 puts out the perfect amount of fuel for my setup i would say around 6.5psi..... explain more if you still think a regulator would help me out

and yeah i got some new fuel pressure regulators, a fairly new billet specialties spark plug wire loom kinda thing that looks cool, sbc alternator and water pump that still work great and much life left, possibly a almost new holley 700cfm double pumper, maybe 300 miles on it, if you can weld a set of hedman headers that are coated for sbc camaro chevelle 1 3/4 but i had to dent them due to my steering setup and i cut out the area i had to bedn which was about 5 inches so if you took a pipe and had it fit and welded i will sell them CHEAP since i had to cut them.... they are NEW but installed and ran for about 20 minutes, also for 1998-2002 LS1 k&N filter charger open air filter setup!!!! and last but not least a 4 inch mufflex cat back...... i got some pretty neat things for sell i guess???? jake

ok guys check this shit out...... i mess with the jets around tonight for a lil while and figure out the car was running way lean..... it was making my plugs bad from having the wrong power valve in there but when i used a vaccume pump on paper it was right..... but in reality it was making my plugs look terribal and made me think it was running way to rich so i kept down sizing the jets....

so tonight i said screw it im gonna add like 4 jet sizes to it and see what happens and the car woke up like crazy..... no stumbling or studdering through the medium rpm range just clean crisp running and then whe i hit the gas at anything under 50 mph the car murders the tires until i let out..... i dont know for sure until i get it back on the dyno and im gonna get these cut outs taken off and re weld some pipes in place but i can bet it picked up some serious power tonight..... so tomarrow im gonna put the right power valve in there, put some fresh clean spark plugs in there see if the jets need to be taken down or added one size and take it to the track..... its hard to say but i would bet that the car is well over the 400rwhp mark after giving it the fuel it wanted

what do you guys think about me putting a 1 inch carb spacer in???? im planning on putting some gas on it anyways so i figured get a little bigger and see if it makes it run stronger up top!!!!

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Spacers are a test & see item. It is impossible to guess.
I do always run a small wood spacer on every car to keep heat out of my carbs.
I would say start with a wood spacer & test, if it helps, add more. Good luck.

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my opinion fwiw,
- don't bother with a fuel pressure regulator. it's somewhat of a myth that > 6psi is bad. 4-6psi is simply recommended, you can usually run up to 10psi fuel pressure with zero problems and you'd know at idle if the pressure is too high because it'll push past the needle and flood the bowl and you'll have a shitty idle if it doesn't stall. holleys and most other late model carbs are of good enough quality that you need quite a bit of fuel pressure to overwhelm the float and needle. the good thing with the higher fuel pressure is it'll help refill the bowl and keep the fuel level in the bowl where it should be under high demand like when you stab the throttle and the accelerator pump shoots a large volume, and usually at idle if it isn't a problem it won't be a problem at higher rpm when the fuel is flowing resulting in less pressure in the fuel line. what you want to be careful of is not losing pressure at high load high rpm, you'll want at least 2psi if you're able to measure it otherwise you're fuel pump can't supply the required volume.

- don't do a spacer until you get the car tuned and you're sure it's 100% otherwise the spacer is just another variable. and like was said, spacers may help or they may hurt.

- when plugs are sooty black, called dry fouled, it may be from too rich a mixture but many times it's because of too cold a spark plug. jump up one, or 2, heat ranges. what you can do to pinpoint this, with idle mixture being easy to set, is get the idle mixture on the lean side, put a clean set of plugs in and it can be your current plugs just clean them off and have the correct gap. Idle the engine at 1000-1500 rpm range for a few minutes, then shut it off and check the plugs, if they are sooty again it's most likely because the plug heat range is too cold.

- i think your main issue is all in the carb, holley website under tech i thought had some good articles explaining tuning the power valve, main jets, secondaries, and accelerator pump. there's an order and methodology in which to do it, and everything needs to work together to make power at all rpms. I thought timing was typically 32-34 deg max, if you're up around 37 you might consider backing off to 32, getting the carb tuned and finding max power then when you know the carb is 100% advance timing 1 deg and see if it makes more power, with & and without a carb spacer.
I don't know what model carb you have, but if it has vacuum secondaries then different springs for the vacuum secondary diaphram might be needed to change their opening response. And, step #1 in carb tuning is always check and re-check the fuel level in the bowl. Everything is based off fuel level in the bowl.

Sometimes the single plane intake have a tendency to have poor fuel distributon at low rpms. So if you are cruising around a bunch...this can happen.

my monte carlo that i just bought has that problem

cool guys, thanks!!!!