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SB strokers carb?

Posted By: Voluster

SB strokers carb? - 08/23/10 09:22 PM

What does everyone seem to be running for a carb on their SB stroker?


I have a bigs stage 5 750 on there now
I ran the car at the track this weekend and it ran 7.17 at 94 mph in the 1/8 off the trailer. got worse as the day went on track went away and air got worse. lost 2 10ths in just the 60 after the 1st run

When I got back to the pits pulled some plugs these things had no color on them at all. I started jeeting it up throughout the day. I went up 13 jets from where I was at the start of the day and it just started getting some color on the plugs.

Was just trying to get an idea of what everyone else is running for a carb on thier strokers.

Mine is a 416 with eddy heads 600 lift solid cam m1 intake 727 8 inch conveter 3.91s in the 8 3/4 275 drag radial

Thanks
Posted By: MIKES_DUSTER

Re: SB strokers carb? - 08/23/10 09:28 PM

Im NO expert but it could be the air-bleeds. I have the same problem with my 750dp with a pro-form body. My plugs were WHITE and I mean WHITE!!!! Called Jesse at BIGS and he sent me some air-bleeds and it fixed my problem. I had too much air and not enough fuel.

Call Jesse!!!!
Posted By: Voluster

Re: SB strokers carb? - 08/23/10 09:39 PM

I called jesse he said nothing about air bleeds

He thinks I have an intake leak or something
Posted By: MIKES_DUSTER

Re: SB strokers carb? - 08/23/10 09:42 PM

oh..ok....he would know.
Posted By: emarine01

Re: SB strokers carb? - 08/23/10 10:46 PM

On my 414 cid the bigger the carb the faster we went, 1050 works good
Posted By: MIKES_DUSTER

Re: SB strokers carb? - 08/23/10 11:10 PM

I was gonna say at least a 950.
Posted By: MR_P_BODY

Re: SB strokers carb? - 08/23/10 11:34 PM

I run a 1050 dom on my 405ci... I turn it to 8200
Posted By: Crizila

Re: SB strokers carb? - 08/23/10 11:57 PM

I must be undercarbed with my Demon 750 on a 408??
Posted By: dusturbd340W5

Re: SB strokers carb? - 08/24/10 12:09 AM

my 416 takes every bit of my 950 might like more.
Posted By: tubtar

Re: SB strokers carb? - 08/24/10 04:13 AM

13 jets ?
that's not tuning.........that's an overhaul.
If you need to go that many jets in either direction , you have done something horribly wrong with your life.
Did it keep getting quicker with each change ?
I am no Holley guru by any stretch , but I do think a 408 would want more carb and I do think that more than 4 or 5 jets change means your baseline is off by a good bit or you have other issues at work.
I'd be looking for a friend with a bigger carb to try on there first.
But if there is a problem outside the carb like an air leak.......it won't matter what you put on there.
Posted By: StrokerAspen

Re: SB strokers carb? - 08/24/10 04:53 AM

Quote:

On my 414 cid the bigger the carb the faster we went, 1050 works good



Yup! 1050 dom here too! It made more power on the dyno over the 850 and the 950 HP we tried.



Kenny
Posted By: AndyF

Re: SB strokers carb? - 08/24/10 06:22 AM

We run a 650 DP from Bo Laws on this 427 inch stroker. Works great.

You have something really messed up if you had to change jets by 13 sizes. That sounds like you have an intake manifold leak or some other major issue.

Attached picture 6156007-carb.jpg
Posted By: Voluster

Re: SB strokers carb? - 08/24/10 02:00 PM

I'm gonna look into a air leak this weekend.

If it's not a intake leak what else could it be?
besides to small of a carb.


I have ohmed all the wires none of them are over a 100 ohms. I have done a compression check 155 across the board.


My buddy has a 850 demon we are gonna put on it this weekend and see what gives


Thanks
Posted By: MR_P_BODY

Re: SB strokers carb? - 08/24/10 02:05 PM

Quote:

I'm gonna look into a air leak this weekend.

If it's not a intake leak what else could it be?
besides to small of a carb.


I have ohmed all the wires none of them are over a 100 ohms. I have done a compression check 155 across the board.


My buddy has a 850 demon we are gonna put on it this weekend and see what gives


Thanks



Spray your intake and carb base with a carb spray
but make sure its flammable... if its leaking you
will see a rpm increase
Posted By: AndyF

Re: SB strokers carb? - 08/24/10 03:55 PM

A 750 is not too small of a carb for that engine. Lots of race engines make a lot more power with carbs that are even smaller that what you're running. You have some other problem than carb size.
Posted By: mopar dave

Re: SB strokers carb? - 08/24/10 04:06 PM

what fuel line you runnin? you should have -8 line feeding that. you may be starting to run the bowls dry. i had the same problem and found it on the dyno. the other issue is using the correct heat range spark plug. a rc12yc works good in my 408. i was using a 7 ngk and it was way too hot.
Posted By: Voluster

Re: SB strokers carb? - 08/24/10 05:09 PM

I have 10 an from the tank to my aeromotive a2000 fuel pump goes 10 an up to a y that goes to a big port holley reg and 8 an to the carb

I took the 10 an that goes to the y off and let it flow into a fuel jug. I had a gallon and a half in 20 seconds which should be more then enuff fuel

I run a ngk - 7 for the motor I didn't have any -7s left new So I put a - 8 ngk in there
Posted By: mopar dave

Re: SB strokers carb? - 08/24/10 05:25 PM

that sounds like plenty of fuel. whats your compression?
Posted By: Voluster

Re: SB strokers carb? - 08/24/10 05:38 PM

compression should be right around 10 to 1
Posted By: mopar dave

Re: SB strokers carb? - 08/24/10 05:58 PM

i had the same problem as you with my 408 using a 1000hp. no matter how much jet i put in it i would gain less than 1 mph or less and had no color on plugs. took it to the dyno and seen first hand what was going on. the air/fuel reading looked like the spiked lines on a heart scope,not even close to being a smooth line. i had a ngk7 in it and the dyno operator thought it was too hot and even an 8 to be too hot,so he put a champion 12 in it and the air/fuel reading had a nice smooth line. i'd try a colder plug just to see. my compression is 10.5:1.
Posted By: emarine01

Re: SB strokers carb? - 08/24/10 06:28 PM

Just curious how heat range effects A/F ratio, I can see where a hot plug may clean the plug for plug reading but how does it change ratio?
Posted By: ademon

Re: SB strokers carb? - 08/24/10 06:34 PM

whats the hotter plug doing? ignighting the mixture early?
Posted By: cudadoug

Re: SB strokers carb? - 08/24/10 07:32 PM

25 year old 800 Holley here. On a 416, guessed at the jets/squirters/power valve (none in secondary).

10.33/131 at 3100#.

Oh yea, 1/2 aluminum line to a chrome "dual feed" cheese-ball deal...motor looks like it MIGHT run in the 11's...

Attached File
6156670-Kens_416.bmp  (55 downloads)
Posted By: mopar dave

Re: SB strokers carb? - 08/24/10 08:24 PM

i believe its igniting too early with too hot a plug. you want your air/fuel to have a nice smooth line on the graff. i gained 5hp with the proper plug. i would'nt have believed it if i had'nt seen it with my own eyes. air/fuel looks alittle leaner with hot plug on my graff. i don't have time right now, but i'll post some pics tomorrow if ya want?
Posted By: Thread Ender1

Re: SB strokers carb? - 08/25/10 01:43 AM

Quote:

25 year old 800 Holley here. On a 416, guessed at the jets/squirters/power valve (none in secondary).

10.33/131 at 3100#.

Oh yea, 1/2 aluminum line to a chrome "dual feed" cheese-ball deal...motor looks like it MIGHT run in the 11's...

Lets see the rest of the car and we will let you know.
Posted By: cudadoug

Re: SB strokers carb? - 08/25/10 05:08 AM

It's not much to look at. It's an old leaf spring car built in the mid 80's and kinda/sorta updated over the years. Still has leafs and it's a stock body except the glass hood/deck/bumpers. We think it's a GREAT 60' car...it looks best 60' away!

Don't mean to highjack...back to carb topic!

Attached picture 6157640-in_the_water.jpg
Posted By: fishy340

Re: SB strokers carb? - 08/25/10 03:54 PM

i'f u wanna buy 1 carb that will get you through most any combo..950hp..i have a 900$ 750hp that was awesome on my 416 barton motor,but couldnt even keep up w my 439sdss motor,,950 would work on both
Posted By: ademon

Re: SB strokers carb? - 08/25/10 05:18 PM

I do remember an article on Jake King saying if the S&M hemi was a bit rich in jetting he would just use a hotter plug than rejet.
Posted By: ScottSmith_Harms

Re: SB strokers carb? - 08/25/10 11:13 PM

My friend has a 422 inch stroker with ported/iron W2 heads, TTI 17/8 headers, roller cam which is streetable but rowdy.

We dynoed it with a 750 Holley, A stock 800 cfm Thermoquad, and a brand new OTB Holley 950. The 950 made the most power by 20 HP over the others, 525HP/510TQ.
Posted By: Stroker Scamp

Re: SB strokers carb? - 08/26/10 05:08 AM

ive got a holley 950HP no pvs fwiw

Attached picture 6159437-eng3.jpg
Posted By: MR_P_BODY

Re: SB strokers carb? - 08/26/10 01:50 PM

I have gone quicker and faster with every carb increase...
I started with a 750 on a smaller engine then stepped
up to a 396ci... I started with a 750 on that one then
went to a 850, 950 and finally a 1050 dom... if I had
a 1150 I would try that also..... BUT I launch off a
trans brake and that makes some difference... I dont
need the real fast low end response (mines pretty darn
good) but the smaller carbs will be a little faster
on the low end response
Posted By: Voluster

Re: SB strokers carb? - 08/29/10 02:04 AM

no Vacuum leak found on my car today

we hit all around the carb with carb cleaner and all the intake ports.

then put a rag over the carb and it stalled out once you put pressure on it

what else do you thing it could be?

besides to small of carb

thanks Phil
Posted By: MR_P_BODY

Re: SB strokers carb? - 08/29/10 02:14 AM

Quote:

no Vacuum leak found on my car today

we hit all around the carb with carb cleaner and all the intake ports.

then put a rag over the carb and it stalled out once you put pressure on it

what else do you thing it could be?

besides to small of carb

thanks Phil



When I'm doing what you did with the rag I do that
with my hands so I have a idea how much air is going
in... if its not blowing smoke out of the pipes(oil)
from under the intake then you might have a internal
air leak in the carb... have you torn it down and
checked the gaskets... it sounds like its lean if
you had to press down on the rag... borrow a carb
and try another one... any size that fits...JMO
Posted By: Voluster

Re: SB strokers carb? - 08/29/10 02:30 AM

No oil in the chambers at all all the plugs come out dry. it's not smoking at all.

I have a 850 demon I'm gonna try off a buddies motor
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