Port nozzle size stagger

Typical BBC with a high helix retro 14 blower , set back 4", what sort of nozzle jet size difference would you expect from front to rear on a cast type production manifold?

 

The idea of a set back blower is to pump the same amount of air into each cyl, Take it from there, or send your fuel system to a flow guys .gerato, randy anderson, spud miller, oddy.

 

fuel system

Send it to Spud Miller www.fuelinjectionenterprises.com this is his slow time and you could get a quick turn around he gives personal service and supports what he sells customer service is the best

 

When I ran my small block car, I had Jeff Fowler flow and set up my fuel system and when I ran the car for the first time all my EGTs were with in 40* of each other. www.fowlerengines.com

 

Why does everyone say "Send it off to so and so"...

How about learning about what the motor wants and doing it yourself. Give a man a fish and feed him for a day. Teach him to fish and you feed him for a lifetime.

Sending your junk off to so and so isn't going to do anything but make you reliant on them. It's a BBC, not an AJ 481x... This shit isn't that damn difficult.

 

Tell that to someone that just blew-up there motor because they taught they knew what they were doing, And yes it is if you don't know, theres plenty of A$$holes out there telling people how to do $hit and all there doing is experimenting on your motor. Say why don't you send him YOUR tuneup, bet you had that just come to you in a dream? people pay big bucks to have there stuff flowed, I don't think they will give up there tuneup for free!!! Like i said on another post, Don't believe nothing of what you hear and half of what you see!

 

...and almost all of what you read on internet message boards.

 

Thanks Gene, but it didn't come in a dream. I bought Bob Szabo's book, which gives all of the formulas needed to figure out an exact tune, based on desired A/F ratio and blower CID.

You just have to be smart enough to sit down and crunch a few simple numbers. Anyone with an 8th grade education or higher should do just fine.

Sure... Here's the tune up.

Blower is set back 1" from stock on a Littlefield Tented Floor manifold. Full length opening, std helix 14-71 SSI B-Rotor. Blower CID was guestimated at 540.

Pump Enderle 1100 @ 17.3 GPM

Hat nozzles
49.5 51.4
50.6 51.5
51.2 51.9
51.3 51.9
54.2 53.6 (back two nozzles are fatter as it's the hottest part of the blower per SSI)

Ports
35.5 45.8
49.3 48.3
41.2 47.1
32.7 43.5

Weather: 74.2F, 29.49, 49%

Blower at 18% OD (26 PSI)
Pump bypass 135
Main jet 80 (because thats the magic jet, har har)
GPM into motor: 10.1
It's lazy as hell at this setup, and the pump pressure isn't high enough.

Blower at 27.5% OD (33 PSI)
Pump Bypass .093
Main jet 105
GPM into motor: 10.9

Be careful, cylinders 2 & 4 are lean... I haven't upped the fuel back in them yet. This was as it was the last time I went racing. I'm going up about 4 nozzle sizes in 2/4 the next time we go racing.

Additionally, the hat nozzles are a bit too big for the blower OD. I'm only seeing about 90 PSI max out of the system pressure. I'd really like to see it between 125-150 PSI.

It also needs a high speed lean out. The EGTs drop in the last 150-200 feet of the track, but since I dont have a flow meter in the logger, I'm not going to risk it. If I had a flow meter, I could see how much extra fuel is going into the motor at the point the EGTs go fat and remove it with a high speed.

Again, I do this for my amusement. Racing is a hobby for me, not a profession.

Gene, you really sound like a grumpy old man. Maybe you could help educate people rather than bitching at them. I'm sure you have a lot to share, if you simply took the time.

 

On my bbc with a retro high helix littlefield set back about the same on a indy intake, I ran nozzles as follows : 1-#76,2-#66, 3-#54, 4-#59, 5-#52, 6-#48, 7-#40, 8-#43 this got my plugs and egt's pretty close. When i put my new PSI on I had to change some more. When I ran a littlefield non-retro high helix my nozzles were as follows from #1 to #8. 59,58,50,50,52,52,43,46. Still run straight #55 nozzles in the hat. Hope this helps, remember, run out to 330ft the first time then to 660ft and then to 1000ft and the full 1/4 reading the plugs after each pass. Look for Mike Canter's excellent post on here on plug reading for blower motors, THANKS MIKE.

 

Our nozzle jet combo

Hi ! It is of course true that you should take care and seek experianced advice, but still if you take babysteps before trying to run a new world record your own skills can take you a long way. We built ourselves a brand new BBC combo last year, and started the dyno testing with 62-60-56-56-52-52-48-48 (#1 to #8 cyl). It is a 397 CID, 4.25 bore, 3.50 stroke, 48 psi boost, kobelco K9 4" setback, 4 # 40 nozzles in the hat and 4 #40 nozzles in the blower. Runs 6.68@210 in legal AA/D. You then need to optimize each cylinder based on plug readings and EGT. Good luck. www.craftsmanverktoy.com

 

Thanks guys for the responses. We try to do as much as possible without relying on everyone else as we tend to get more experience ourselves, & as mentioned we sneek up on things slowly with out trying to break records on the first race. Its a circuit boat so we do more miles in one race than you drag guys do in a couple of meetings. We ran it today with 56 56 52 52 46 46 44 44 from 1-8 on its maiden voyage and #'s 1 & 2 were still lean so changed to 59 & 58. Just seems like a lot of stagger but I suppose you have to give what the engine wants. I like to see & listen to whats out there & take on board what makes sense .Its not rocket science, you just have to take things slow and things will eventually work out. I dont think its as hard as many believe it to be but then again we only have a basic system with ports & a H/S.Was just wondering if its normal to have so much difference in the stagger but looks like it is.

 

"Pump Enderle 1100 @ 17.3 GPM"

WJ how'd you know that w/out getting your pump flowed??
Runnin the #'s and figuring out what you need is fairly simple for the guy that sits down and figures it out. But throwin a pump on and figuring what you need by what the pump "should" flow is really shootin from the hip and gambling in my opinion.
I'd second taking it to Spud Miller. Super nice guy to deal with.

 

I think most of us are going off of the guy's original post which says nothing about ever having the system flowed or ever running this particular setup or even knowing what his pump flowed... Just a thought

 

The pump was sent in to Enderle to be flowed. The nozzles/jets were flowed by a friend.

I never said I was against having 'known' flowed components. I'm against paying a 'tuner' to flow a system for far more than what the labor is worth.

100.00 for a flowed set of 8 nozzles is just silly. 12.50 a nozzle? Give me a break. You can buy unflowed from Enderle for 4.00/each, or flowed for 6.00/each.

Like Mike Canter said, it's just a rough guess as to what the ports are going to be. Nobody has data on every combination of fuel system. Heads, cam, port work, intake, blower set back, injector location, hat nozzle, blower nozzle, port nozzle location and even valve lash. All too many variables to account for to pay someone too much money for guess work.

Mike stated before, .3 GPM per PSI of boost will get you in the fat ballpark. From there it's baby steps in getting the plugs reading the same before you start to lean the total system out and make good power.

Me posting my combination is probably worthless for what this K-Boat racer is doing. But hey, if it sparks an idea for him and his system, thats great.

Eli... Try sticking a screwdriver tip down the end of your pecker. It'll mess with the 'flow', but at least you'll have your desired hard on.

 

Na, When you get old in the hip you get young in the lip.
P/S we got our flowed nozzles from Gerardo @ $6.00 ea. for our K boat. and I told him what i wanted, using spuds calculater.

 

getting ideas from other guys tunes is what you pay for in a bought tune. but its known to work. it keeps the guess work (fun) out of it. they also keep you from making mistakes like runnung to small a pump or in some to big. 17.3gal when the motor works on 10. no you dont want a 110 but to big a pump causes you to run a low pressure system. nice if you really understand it. been there did that. it can be a very expensive hobby when you try change pressure from 90-125psi. total change in nozzles sizes.
its amazing how much Ive learned, compared to when I knew it all.