Running alky, wet sump, and conv head. which combo and why?

what alky system and what head.

quote:

Originally posted by buddy c:
what alky system and what head.

X 2, but conventional wisdom says always to the cubic inches.

carb and rfd 24-b

Like I said. I'm always for more cubic inches if you can get them. Why conventional heads? Have you thought about a Spreadport head and mechanical injection possibly?

yea thought about 12* profilers for a while, just want to stay conv. I already have the heads on my 582.

I would try to match the displacement to the best fit with the head. Since you have been running the 582 w those heads, I would run the 615. If you put too many inches under the head, you will severely lower the RPM where the power occurs.

This is going to come down to fuel delivery. If you are going carb I would make sure you have a carb that is big enough to flow enough fuel at a higher RPM (IE anything over 6700), if you are running injection then no problem. We just bought a Davinci 1250 that flows north of that number for our 634 with 383 HH's. This carb is made for that cubic inch and will flow what it needs. What heads are you running?

thanks for the replies. ive been impressed with the head so far, the rfd 24-b is still a fairly new head to me, best et to date was 4.64 @ 147 with a 1.02 60ft. I believe they will support a 632. Im not against buying a bigger carb for it either, 1250, possibly 1350?

do you think the windage is an issue at all with the 4 3/4 arm?

i would call Davinci or Ken jones on the carb, you should have no issues feeding that head and running with a 632. I went 4.72@145 + with a 582 and bone stock BB3Xtra 380 heads with a 1150 Ken Jones alky carb at 2000lbs.

Care to share the cam specs on the 582 and what compression ratio you are running. also, what weight are you at and what is your convertor stalling.

quote:

Originally posted by gxp7903:
thanks for the replies. ive been impressed with the head so far, the rfd 24-b is still a fairly new head to me, best et to date was 4.64 @ 147 with a 1.02 60ft. I believe they will support a 632. Im not against buying a bigger carb for it either, 1250, possibly 1350?

While a 615/632 will go down the track with these heads, I wouldn't expect impressive ETs based on this info...

quote:

Originally posted by gxp7903:
1880lb dragster. runs 4.70s 582ci.

and the fact that you are running alcohol.

quote:

Im not against buying a bigger carb for it either, 1250, possibly 1350?

You will never flow enough fuel with a single carb unless you run Gas.

Too small of a head for the cubic inches will make a lot more power on gas because you won't have so much runner volume taken up by fuel.

quote:

Originally posted by 1320racer:

quote:

Originally posted by gxp7903:
1880lb dragster. runs 4.70s 582ci.

and the fact that you are running alcohol.

4.70s was with my dart pro 1s... only have about 60 passes on the 24-b head. its gone 1.02 60ft in 3 different states, with 2 different cams. still trying things. thanks tho

I am also curious to hear which bottom end would run better with a somewhat big/good flowing heads such as the RFD-24b or Headhunter and others.. Being that it would be a conventional head, and not able to support as much air as a spread port could, my question would be is would the 615 be a better option, being a shorter crank it can rev quicker and to more rpms vs a 632 with the spread ports being able to crank out the torque, and not rev as fast? Or am I backwards..?

I know that Tracy Dennis aka Sunset Racecraft preferred the 615 over the 632 regardless conventional or spread port heads.

If you are stuck on alky, you should really consider going injection. A lot of people with 615/632s with conventional heads have tried running a single alky carb and are NORMALLY disappointed. Most 615/632 conventional headed motors @ 1900-1950 will run high .50s/low .60s with injection. Yes I will agree that a GOOD gas carb and the right gas will run mid to low .50s at the same weight, they usually only run those numbers in sub 1000 da. The injection might not give you the extra .03 that the gas carb will, but it will not slow down as much in the worst air. My combo is a brodix allum block, raised 55 mm cam, with an 10+ year old BB 4X head that has been ported twice. The converter goes between 6400-6600 through the year and runs 4.60-4.67 at 1925 in a 10 year old 235" car. I know my converter has some et left in it, but I like it being "snug" because I run a class that has a 4.50 low side and I will spray it for 2 seconds or less to hit the number. My suggestion, is IF you never plan to super class race and you will only bracket race, put a terminator on it and don't look back.

Every engine builder has his own view based on how they do heads, what cam profiles they run and what RPM they want to turn their motors too. Just make sure whatever combination you have you understand what RPM you want to spin the motor which will help dictate what heads and what cubic inch motor you want to build. Obviously the weight of the car, suspension type and what size tire will be major contributing factors as well.

quote:

Originally posted by Bob Nichols:
I would try to match the displacement to the best fit with the head. Since you have been running the 582 w those heads, I would run the 615. If you put too many inches under the head, you will severely lower the RPM where the power occurs.

This is a fact.
A 4.500 stroke, 4.560 bore (588) peaked at 6250 with a set of 305 cc heads. Dart t-ram and 2 doms. 901 hp
A 4.625, 4.560 (604) peaked at 7200 with a set of 370 cc heads ported dart t-ram and 2 doms. 1120 hp.
Both gas. Personally I dont think either of your cubic inch combos will work well on alcohol.
Will they work? yes. Just not up to par.

it sounds like most are saying a 615 is to big. so let me ask this- do you guys think there is a conv head good enough that can support a 615+ motor making 1.8 hp per ci or more on a singe alky carb? if so, which head?