Supercharging ?
 

Blocks are Dart Big m 9.8 height decks 509's
Brodix heads, carrillo rods, carrillo crank, Hyd roller cam, sng 1050 carb N/A making 635HP @ 6000 RPM's. These motors only have 10 hrs on them.

9.3:1 compression
4.50 bore
4.00 stroke
6.135 rod length

Question is.
1. Can I slap a BDS 871 on top like it is and go or will I need to change pistons and cam.
2. What Hp will I get with 871's and 509 ci.

What type of fuel did you want to run?



Darrell.

To run 93 octane, you would need to reduce your comp ratio. I would think you should be able to make 750-800hp easily with the right combo.

So basically cam and pistons change to run on 93 oct Thanks guys

You can bolt them on they way you have them all ready, you just won't be able to utelize them as much as you could

If you are good at tuning, you could run 2-4 lbs non intercooled oe 4-6 lbs with an intercooler. Of course if you want to lower the compression to 8.2 or so, you could run 5-7 lbs non intercooled, 8-10lbs intercooled and another 100 hp over the high compression set up.

I spoke with diamond pistons and the said I could go with what I have or they could releive my pistons a little. Debating on going ahead and boring my darts to 4.6 to 532's

I thought you sold those engines??

I traded them then the guy backed out of the trade a couple days ago. So I got them back. I would like a 10.2 dart set-up but these 9.8's is what I have to work with now.

Why not use a carburated Whipple if you want to stay carb. They love some compression and 9.3 is not out of the ordinary. I have done them up to 10.2:1 and 9.5-10:1 is not uncommon.
I did a set about 1 1/2 years ago. They were a pair of my 750 NA's. They are 598, 10:1 with a 1050 dom. We just removed the intake and bolted on the Whipple and went to the dyno. They made 942 hp and 1070 ft lbs at 5.5 psi on 93 octane and 1020 hp and 1190 ft lbs at 8 psi on 100 octane

That is amazing for 93 octane. Do you think that is really long term safe? That has the gears grinding in my head. :crazy: What size Whipples are those?

They have just about 100 hours and going strong. They are owned by Thunderusone on the board.

They are 3.3L Whipples. Actually, the power was down a little over what I expected. However, the torque was up, which is good for the heavy boat they are in. I think the carb. is just a little to small, accounting for the increased torque and lower power.
We really spent the time to tune them to a tee. They drive and run as good or better than any efi engine. It actually surprised me how good they drive and idle.
Eddie

Eddie, do you have any used 3.3's?

I'm running a 3.3 whipple with 9.5 comp 565 inch engine and I usually run 91 octane. my boost is fairly low , 4.5 to 5 lbs , but it runs strong !

No I don't. I don't know anyone that wants to sell them once they get it.:drink:

I'm running 516ci 9:1 with a TBS 10.71 made 760 on 91 octane.

If it aint blowen it just sucks !!! :ernaehrung004:

YEP:party-smiley-004:

I figured you would get a grin out of that.

No doubt huh?

However, I do know where to get some new ones.:drink: It just so happens that I have them on sale this week.

my 598 NA made 760hp at 5950 on precision's dyno. boat runs pretty good, 112 on gps speedo, but takes forever to get there.

with a CR of 10:1, i plan to use a thick cometic gasket, about 0.100", to get the CR to 9.

with the new whipple 4.5L, should make around 1050 with 7-8psi.

i am using the holley HP EFI and will creep up on the timing and AFR.

The important part of being successful with what eddie young mentions above is setting the quench tight. .037-.040 is a good place to be to prevent detonation. Putting on a .100 th head gasket is exactly the wrong direction to head with what you want to do.

Bad idea with the headgasket imo. Ideally blown you wanna be somewhere in the .040-.060 quench area. A little less is ok, but .100 or more, I wouldnt do it.

Just a bit of trivia on the quench deal. I'm rebuilding a couple of Merc 1075's. I was a bit surprised to find they run the pistons .060 down in the hole with .060 head gaskets, so a total of .120. Goes against everything I've believed for over 50 years.

Interesting. Wonder why? I'm sure there must be a reason for it

Hi David, I'm glad to hear the self tuning Holley HP made so much more power and speed then the MEFI system did out west.. (Shameless plug) :thankyouthankyou:

On a boosted application the squish height is not as critical as an NA deal and can be dangerous if too tight. There are also a lot of variables; it's not as simple as one size fits all. However, the preferred method is to run the piston deeper in the hole. Once you get up in the .100" sizes on the cometics they have a tendency to squirm around on the inner layers and can cause sealing issues between cylinders after lots of heat cycles and extreme pressure. SCE makes a nice copper gasket with a built in fire ring that doesn't require O-ringing the block. I'm trying some but don't have any run data yet. I think for what you're trying to accomplish performance wise I'd run a .060 or .080 Fel Pro MLS and start at about 5lbs boost. I think you'll be pleasantly surprised at how much acceleration you pick up.

I have always been told by numerous engine builders just the opposite....that it is more critical on a SC engine than an NA engine. I've always shot for the .050-.060 area, so I don't have any first hand knowledge of how it would act if the quench were any larger. I've always heard that it would be a detonation monster once it got over about .075, assuming it was an already aggressive piece. Not arguing, just trying to get to the bottom of it.

How aggressive of a build have you done with a larger quench (over .075)?
Eddie

I'm very curious to see what comes of this. I always thought 80's emissions motors knocked and pinged easily cuz the quench always sucked on the low compression emissions motors. Always seemed like a few miles and a little carbon build up and all you could hear was rattle!

It really depends on the application. On 2000+hp stuff I'll run .150 in the hole with a .060 gasket. On stuff where you're gonna run meth injection a little extra will help too. AFR of the intake charge, chamber efficiency, piston design, rod material, pin thickness, target rpm, piston to wall clearance, fuel quality, etc. all effect optimal squish. When the engine is not in boost is the only time detonation may become an issue but can be eliminated through proper tuning.

if you run a hemispherical head the rules change again, but most here run BBC so "status quo"

can you please tell more info on this 2000+hp engine with the piston .150 in the hole and a .060 thick head gasget,things like what fuel was used and compression ratio,also what head was used,i know you think i am a joke,but i assure you,i am for real.im not being a smart azz,i am just curious.

Its important in SC apps for cooling the top of the piston (quench) is what I have always understood so I run them close. This is the first I ever heard it could actually be a bad thing with SC. Why might that be? Presuming of course all other design parameters (ie CR) are correct.

+1 usually looking for just a hair under .040 in the quench for optimum combustion, if you dont squeeze it it wont burn right!!! just ask your wife!! lmao!

are we talking BBC or Hemi here hax??? .150 down the hole on a BBC?? plus .060 head gasket? educate me please? cause I've obviously been doing it all wrong for the last 30+ years...

I think the squish/quench debate is worthy of it's own thread as it is a lot more complicated then a general rule of thumb number that floats around the internet. I will start one later this afternoon when I get time. There is always compromises in engine design/building and there are situations where a tight squish is beneficial and others where it will destroy your engine. In an N/A engine a tight squish clearance is for turbulence, not cooling. Look at a modern true dished BBC blower piston, there is virtually no squish/quench pad. Look at the chamber modifications done to a fast burn type SBC chamber that runs high boost. Anyway, I think it's a very interesting topic and I like to hear what works and what doesn't for others as well. Low boost vs high boost vs N/A, cylinder head temp, octane, intercooler efficiency - It's all a factor.

agreed... many variables, and yes quench main function is to create the environment (set up for combustion) aka turbulence...
looking forward to the new thread Hax... I may be old school, but if it ain't broke... don't fix it!! lol

BBC. A little 450" Hemi on alchohol makes 3500+ hp in the 50-60psi range. It's very common to see them at -.250" in the hole.

At a certain level, piston design and sealing becomes a major factor. To run your tight quench of just under .040, at lets say a conservative 1600hp, how far are you sticking the piston out of the bore, and if you're zero decked what head gasket is sealing all that pressure? How do you keep the piston from smashing into the head at 7000+ rpm? None of this pertains to what Dave B is doing by the way but I think this could be an interesting thread. I gotta get some work done though! :lolhit:

Buddy I ran and built the engines for my Alcohol funny car for many years, and on alcohol in a hemi as in Veney or Brad head 525 CID... the lowest compression ratio we ever ran was about 11.5:1 and trust me, that piston was nowhere near 1/4" down the pipe!!!
even when we jumped up to top fuel and ran "NITRO" we never ran a piston that far down the hole and that was @ 6:1 compression... so???? educate me please as I am not sure where your information is coming from... whose head?
what cc chamber? bore size? stroke? I'm dumbfounded by your comments and I'm looking for clarity :lolhit:

+1

I stayed with the 509 CID
Took Eddie's advise with the 3.3 Carbed Whipples.
New cams and blower pistons
Chrome valve covers
Stellings headers

Hoping to get 3000HP each with those chromed valve covers :)