Carbs VS Injection,advantages vs disadvantages

[atxwrangler]

I'm Running Two 850's On My 871 Blown 466 Ford,7 1/2 To 1 Cr.it's Running 93 Gps @10%under.would There Be An Advantage To Switching To A Bird Catcher Style Injection . Would I Have To Manually Squirt Gas In It Every Time I Start It?would Injection Give Me More Hp Leaving Everything Else The Same?would I Use More Fuel? Thanks In Advance For Your Dilligence!

[Morg]

I recently switched from un-blown carburated gas to un-blown injected alky.
First of all the switch for me was very simple due to having someone who knows injection help me out.
Injectors & the way you tune them are very simple. But everyone does it different & many make it way to complicated.
I switched to Alky for the ease of tuning. Anywhere close & she runs like a rapped ape.
An injector (especially a bird catcher)will be more responsive. with that it will be harder to drive when not wide open. for your deal I would look into a bug catcher or a Hilborn. The bug will work it is just bigger.
The injector will be less fuel efficient. Unless wide open you will be fat, especially at idle. Remember no accel. pumps mean you are idling with enough fuel to take full throttle.
Depending on your plumbing you should only need the bottle after she has sat over night. After mine is fired in the morning I am good all day. This also depends how you shut the motor off. I turn the fuel off then pull the mag a few seconds later. She can sit for hours & then turn the fuel on & hit the starter & she fires.
The Kinsler web site has a huge amount of information. Download & print up there catalogs (there are 2) Huge amount of information in there. They don't just list parts they explain how to set them up.
For a performance application I will not ever run a carburater again. I just love the simplicity & performance of an injector. I am starting to get a handle on injected alky. Injected gas I would not do.
Performance wise I don't know if you will gain going to injection, if you switch to alky you will, but on a blown deal the switch is a bit more complicated especially with a ford.

[Liberator TJ1984]

Marty , get someone let you borrow a set of dominators and try them first if possible and see if it makes a differnce ( everyone told me I was stuipid to swap my 850s for 1050's ...stock bore 454 ...yadda yadda but they made a big noticible difference ...a hat would just allow the blower to breath easier > less intake restriction @ WOT ...big carbs work just as well ), you wanna go faster , pulley up :D
injected gas is a mother to tune from just what i've seen ? and most folks just jump to alky and be done with it , but your compression is low for that change . for a lakeable boat you might be happier with carbs ?
anyway be careful BRO ;)

[atxwrangler]

wow, that is a lot of good info,thanks!i've got a lot of reserch to do over the winter.i use the boat as a lake boat,so i'm not sure if i really need injection,but,it sounds easier to tune,and seems to me like it would be more efficient,atomizing the fuel under a higher pressure.i saw in this months ***boat mag where [page 84] race pumps make a manual fuel pump i can bolt right in place of my clay smith 120.they make a carburated and efi version.

[atxwrangler]

Marty , get someone let you borrow a set of dominators and try them first if possible and see if it makes a differnce ( everyone told me I was stuipid to swap my 850s for 1050's ...stock bore 454 ...yadda yadda but they made a big noticible difference ...a hat would just allow the blower to breath easier > less intake restriction @ WOT ...big carbs work just as well ), you wanna go faster , pulley up :D
injected gas is a mother to tune from just what i've seen ? and most folks just jump to alky and be done with it , but your compression is low for that change . for a lakeable boat you might be happier with carbs ?
anyway be careful BRO ;)
good thinking chris,i have 850's ,so would 1050's make a difference still?that may be the way to go.BTW,I just wanna break that 100 mark,then i'll be done!

[Liberator TJ1984]

I picked up about 300 or so rpm's by going to the dominators but tuning could have been a difference too ? thats why I mentioned trying them first. If your goal is only 100mph you should be able to get that swapping pulleys , maybe at just 1:1 ..I was fixing to swap over to alky but when you start adding a hat and other varibles it just wasn't worth the extra hassles to me anyways.And like I said earlier almost everyone I know that ran blown gas got frustrated trying to tune on it ...and jumped to alky ...everyone at jetfest with a hat was running alky ...Not Gas ;) hint ,hint

[Morg]

wow, that is a lot of good info,thanks!i've got a lot of reserch to do over the winter.i use the boat as a lake boat,so i'm not sure if i really need injection,but,it sounds easier to tune,and seems to me like it would be more efficient,atomizing the fuel under a higher pressure.i saw in this months ***boat mag where [page 84] race pumps make a manual fuel pump i can bolt right in place of my clay smith 120.they make a carburated and efi version.
Sounds like for your deal the dominators may be the way to go.
BTW- If you go mechanical injection you wan't a cam driven fuel pump. The key to the whole system is a fuel curve that first follows the motor rpm. You then tune for the required fuel curve.

[IMPATIENT 1]

good thinking chris,i have 850's ,so would 1050's make a difference still?that may be the way to go.BTW,I just wanna break that 100 mark,then i'll be done!
marty, put some damn 112 in it, feed that biatch 12lbs of boost and go do some work man:devil: your not even working your motor yet and its doin 93, overdrive that's 8-71 15% with some race fuel in it and 105mph is gonna come quik when ya mash down hard;) do all of us admirers of your sweet ass boat a favor and OVERDRIVE THAT CHEYENNE!!!!:D :D :D :D 1 TO 1 RATIO AIN'T ENOUGH! my buddy went from 1 to 1 on his 500+cube bbc tx-20and a new weiand 8-71, ran 93, went to 15-17% over(went from @5-6lbs up to 12lbs) and ran 107;) and he still had more timing he could've fed it!

[atxwrangler]

L.M.F.A.O.,,TOM YOU CRACK ME UP!I prolly just need to put the one to one pulley i bought to good use,i just bought one.:D i'm running av gas now,though i really don't need to.i'll prolly buy a drum of 110 next summer and go for it! :D :D :D

[VDRIVERACING]

You go with the 110 gas, 15% OD, and some dominators, and you're gonna think that motor is on steriods. AND, it will be very driveable at lower speeds.
Mixed reviews on the Race Pump; didn't work at all for me. You have a good fuel pump, just make sure you have massive lines and a unrestrictive in line filter. I run 10 all the way to the regulator, then 6's are good to the carbs. The 10 to the regulator just seems to make it happy.
On dominators it's critical for the butterflies to be perfectly spaced in the bores, and open about 5-8/1000's to idle up and down. have a GAS!

[adjones419]

Here's my personal experience/opinion:
Carburetors are nothing more than a semi-controlled fuel leak! We've been running twin 1050 Dominators with Nitrous forever. I'm finally making the leap to a blown-injected setup over the winter. Littlefield 8-71 high-helix retro blower, Enderle birdcatcher and 110 pump. All of my buddies who are running mechanical fuel injection on alcohol (unblown or blown) say it is the easiest thing you will ever do. Tuning gas is hard.
Driveability, like someone already said, may suffer from an injection setup. A smaller injector hat (bug) or the stack injection may be the way to go. My boat is only used at the drags, so I'm either sitting still or full throttle. Alcohol will be less fuel efficient, as it takes more alcohol to run an injection setup than it does a carburetor(s) on gas.
It all depends on what you want to do, but after switching over to my blown-injected setup, I can tell you one thing...I'm never planning on going back to carburetors again.

[atxwrangler]

thanks for the good,opinions,i need to use it for more of a lake boat,so,i am going to stay carburated for now.i am going to jump from 10% under to 1 to 1 tomorrow. i think that will be enough for me! :D

[revndave]

I ran 1050s on a 12-71 it made about 1000hp(515cu.in)Switched to a Birdcatcher made about 150 hp more.Also it was way more responsive.With the carbs my boat would over charge the pump.With the hat no more over charge.My boat was a 21 TPR set up on gas.The hat also kept the blower nice and cool.
http://www.***boat.com/image_center/data/500/medium/686100_0679.JPG
http://www.***boat.com/image_center/data/500/medium/686100_0855.JPG

[atxwrangler]

I ran 1050s on a 12-71 it made about 1000hp(515cu.in)Switched to a Birdcatcher made about 150 hp more.Also it was way more responsive.With the carbs my boat would over charge the pump.With the hat no more over charge.My boat was a 21 TPR set up on gas.The hat also kept the blower nice and cool.
http://www.***boat.com/image_center/data/500/medium/686100_0679.JPG
http://www.***boat.com/image_center/data/500/medium/686100_0855.JPG
are you running gas or alky?

[WannabeRacing]

In a drive around blower boat on gasoline, I do not think injection is the answer. Like adjones stated, tuning blown gas HARD! It is like trying to give yourself a frontal lobotomy. If you are even going to breathe the words alcohol, then there is absolutely no need for a carb ever again. Injection is the answer. In my opinion, there is really only one reason for a carburetor on this big green globe. And you have found it. A blown gas boat.

[Schiada76]

I'm running a hat on my lake boat and I'm very happy with it. No problem with a touchy throttle and the tune is just a pill change.
Wannabe, Are you saying it's tough to tune gas if you're running on kill or just in general where a tad fat or lean depending on air density and temp is not as critical?

[WannabeRacing]

The harder you step on gas, the thinner the tuning window is. Where alcohol the window stays nice and wide. For general performance and good power is the quest, then gas can work just fine. If the primary goal becomes making big power, just sidestep the gas and move to the cool pool. Seen more parts hurt and more people go broke trying to run blown gas. Also heard a famous top fuel tuner state something like; "I can tune a top fuel motor all day long, but blown gas? What do you think I am? A genius?!"

[HONDOG]

You can take this for what it's worth. I would not recommend running a hat on blown gas if you are thinking of ever running pump gas. I was convinced this would be a cool package but after my second meltdown in 2 years I am going to alcohol. Don't get me wrong, it can be done but if you try to push it at all you [B]must check the air and adjust the pill before each pass. Kind of a pain in the ass on the lake. There are way too many variables that can spell disaster if you are not right on top of them.
Just the opinion of one dum country boy.
Bob

[Schiada76]

In other words keep it fat.:D

[WannabeRacing]

In other words keep it fat.:D
NO! That is the gas dilemma. Fat kills stuff just like lean. Fat with the clear stuff is cool if you are really stepping on it. Fat with gas when stepping on it can be every bit as harmful as lean. Those dad gummed skinny windows.
If you are going to really step on it, go clear. If you are just beating it at the lake, gas is fine.

[Schiada76]

How skinny a window?
What would be your benchmark for a lake tune?
Not fat enough to wash the cylinders and what read on the plugs?
I watch my egt's and check plugs once a trip or every couple of days but I'm not pushing it hard.
11#s = or- on the boost gauge, intercooled and AV gas, 500"BBC

[revndave]

are you running gas or alky?
I ran it on gas.Easy to tune.

[adjones419]

I totally agree with Wannabe on what he has said. If you're going to use it as a lake boat where you'll be cruising and running for longer distances, stay with the carburetors and gas. If you ever switch over to an injector hat and want to make serious power, go with alcohol.

[adjones419]

I ran it on gas.Easy to tune.
You're kidding, right? Blown and injected on gas?? Easy to tune?? I only know of one 8 second guy doing it, and I think it took him quite a while to get the tune-up mastered.

[revndave]

You're kidding, right? Blown and injected on gas?? Easy to tune?? I only know of one 8 second guy doing it, and I think it took him quite a while to get the tune-up mastered.
I tuned it on a dyno.I would run same tune up till about August.Then lean it out 5.My next family boat will have a hat on it.

[Unchained]

It's not that gas is so hard to tune or that the tuning window is narrower than alky. It's a matter of having a system that is capable of making small and precise A/F ratio tuning adjustments and at different points across the rpm ranges. MFI is just not capable of it.

[Schiada76]

I tuned it on a dyno.I would run same tune up till about August.Then lean it out 5.My next family boat will have a hat on it.
Shouldn't you fatten it for cooler denser air?
UC are we just talking about max power on a perfect tune or basic lake boat tune which is probably not precise with carbs or MFI in most cases?
I like the throttle response, sound and yes, the look of the hat. I'm not racing and I'm not trying for that max performance dialed in perfect tune.
What are the other downsides of MFI?

[revndave]

In July thru mid Sept. its hotter.

[River Rat 005]

Would injection on gas with a n/a engine be as hard to tune as the blown engine? I've been told to go injected but I never thought the fuel made a difference.

[Schiada76]

Would injection on gas with a n/a engine be as hard to tune as the blown engine? I've been told to go injected but I never thought the fuel made a difference.
Nope, it's easy.
The tune window being discussed is a tune for a max power racing application where altitude, temp, air density, fuel specific gravity etc. all come into play.

[Letscrashyours]

Look you already have everything you need except a pulley. At 10% under and 7.5 cr you arent even working that motor yet. Put some boost in it and some good fuel not av gas. Av gas will work but you know exactly what your getting with 110. Which is critical when you start to push the envelope. Remember drive ratios dont mean crap go by boost pressure. There are to many variables such as chamber volume, valve size, cam, blower efficiency,and so on to base a tune up on drive ratio would be silly. Shoot for about 12 to 15 psi if your head gaskets will take it. You have alot of potential left in your current setup I would utilize that before spending a bunch of money and learning to tune something new. You should more than acomplish your goal and still have a very lake friendly boat.

[atxwrangler]

Look you already have everything you need except a pulley. At 10% under and 7.5 cr you arent even working that motor yet. Put some boost in it and some good fuel not av gas. Av gas will work but you know exactly what your getting with 110. Which is critical when you start to push the envelope. Remember drive ratios dont mean crap go by boost pressure. There are to many variables such as chamber volume, valve size, cam, blower efficiency,and so on to base a tune up on drive ratio would be silly. Shoot for about 12 to 15 psi if your head gaskets will take it. You have alot of potential left in your current setup I would utilize that before spending a bunch of money and learning to tune something new. You should more than acomplish your goal and still have a very lake friendly boat.
thanx,next trip to the lake,i'm gonna go 1 to 1 and see what kind of boost that makes.i'm gonna leave the carbs on for now!thanx for your post!

[VDRIVERACING]

Look you already have everything you need except a pulley. At 10% under and 7.5 cr you arent even working that motor yet. Put some boost in it and some good fuel not av gas. Av gas will work but you know exactly what your getting with 110. Which is critical when you start to push the envelope. Remember drive ratios dont mean crap go by boost pressure. There are to many variables such as chamber volume, valve size, cam, blower efficiency,and so on to base a tune up on drive ratio would be silly. Shoot for about 12 to 15 psi if your head gaskets will take it. You have alot of potential left in your current setup I would utilize that before spending a bunch of money and learning to tune something new. You should more than acomplish your goal and still have a very lake friendly boat.
15PSI is really pushing it on gas. A race setup that's watched closely, OK, but this guy has a lake boat. 5-7 lbs is a "safe" range.