Newbie Blower Question

I am still fairly new to blowers, I have a Littlefield 14-71 HH, retro on a 541 Rodeck with Big Chiefs; I am running it 43 over and it is making 48-49 pounds of boost. My question is what is the advantage of stepping up to a roots from someone like DMPE or going with a screw blower? If this is a dumb question I am sorry, thanks for the info. CHris

 

You will be able to make the same boost at a lower od and less hp to spin due to the lower od and cooler discharge temps

 

How much power do you need to make? In my past exp a 540 big chief engine with 49 lb of boost should make 2500 + HP and a littlefield 14 doing that is impressive. What RPM are you turning it? and what is your app?

 

I was told buy a fuel team that a 14-71 takes around 500hp to make it do it's thing,,Dave

 

We are running it in a drag boat and could always use a little more HP. We were a little surprised with the Littlefield ourselves. We were still trying to get the prop and gearing figured out, but we were seeing 9,000 RPM's or more.

 

Not knowing what your combo is just going from 10 years of running a big chief combo's even running a new M5 at 40 over we would see just 43lb, but there are so many things that can make an engine make more boost, ( head flow , compression , cam timing ) boost is a restriction. ,,,, usually when we got the most HP our boost was only 41 to 43 LB so I'm wondering if you can make a change that would make more power and you may even see less boost? just my thoughts

 

roots

our 540 big chief made about 42psi@8800 with a modified superman kobelco and 43%OD. I'm guessing it was making 2400hp.
If you need more power than that you might as well get a screw. It's easier on parts.
I'd hate to see what the main caps on that rodeck look like with that kind of steam.

We put a D rotor on our same longblock and it makes WAY more power at 39psi and a really soft tuneup.

 

I would like to step up to a screw blower for this coming season I think. The bottom end as held up really well, granted we are only making a couple of passes and then pulling it all apart to check things out.

THank you for everyones info, I really appreciate it.

 

Will if I sell my 14 to buy a screw will I need a new fuel system most likely? Right now we run a Enderle 990 pump. Thank you.

 

Psi-d

I live about a hour north of you right along I-5. I have a PSI-D that I have ran in TAFC. It is currently at PSI being recerted. I have been seriously considering buying a newer one and would be willing to sell mine. Feel free to give me a call on my cell phone at 253-973-2619. We could talk about it and the fuel system changes that a screw blower might require. Dave Germain

 

DAve I will give you a call. I am the guy that helped get your clutch grinder to you from Texas. Take care.