The Dodge Challenger Message Board

Hi friends.
Today I raced against 1973 Montecarlo with an big engine, is a 509 ci crate merlin 587hp dyno proven by world products. 3500 stall and the same rear end like me.
My engine is on the other topic ( 440 engine in spain)
The first race my carb had any problem when shifted to second gear, is an old 4010 (750cfm)unit borrowed by a friend to try, my original carb is a edelbrock 750.
We tryed again and on the secons race we ran together until 80mph, then Montecarlo won me a few meters.
I have see the pressure light shine one moment when we were racing, but all is new and the oil pump and pick up too.
What could be the reason? A frien tell me that is possible needed to modify the oil pan due the hard acceleration.
Sorry, this time i have no videos.

Thanks. Alfred.

You need as a minimum the stock HP 440/426 oil pan that has baffles in it.

You also need a windage tray (also known as a crank scraper) fitted between the oil pan and block. Also make sure the oil pick-up is within a few mm of the pan bottom.

Oh while you are on fit a 850cfm Demon carb on there and run 7lbs of fuel pressure. I don't want to hear any more stories about you being beaten by 1973 Monte Carlos!

Ok, I will try to get a good oil pan and I will check the oil pick up clearance, anyway I have the windage tray in it now.

I want to fit a new demon carb but I was thinking in a speed demon 750 I read that this carb is good up to 240º @ 0.050. I have 238-246ª @0.050 and I read that mighty demon is good for 240 to 260º.

I calculate the cfm for my engine 446x6300/3456x0.90(v.e)=731 CFM

I'm sure that 750 is good but I don't know if is better speed or mighty demon, what is the better choice?

http://www.hughesengines.com/general/ca ... /index.asp

http://www.hughesengines.com/general/ca ... elines.asp

I don't have "well prepared" but maybe "moderate big block" isn't it? You can check "well prepared" 440 needs 825 CFM but I I think is too large.

On the other hand you say 850, why?

Thanks.

The theory of how big a carb should be is just that - a theory.

In practice drag racers have always found a bigger carb than "ideal" always produces slightly better times on the drag strip.

Most racers use a 750 double pumper Holley on a 340 inch engine for best results. Even though a smaller carb should be ideal in theory.

But that is Holley. The Demon carbs are much better. I don't know if they measure flow the same way or more accurately?

Also one type might be better for road driving and the other for track use?

I would go with the Mighty Demon.

Have a word with a chap called Neil at http://www.usaimports.co.uk/

He can supply you a Demon carb set up exactly for your engine. Tell him I sent you as he knows me well.
Delivery can be a bit slow but see what he says. His prices are not bad either.

I received an email from Neil, but he must to check it with Don. He think that 750 cfm is good for me but he prefers Don's opinion.
Anyway in case of the oil pan, I'm looking for a milodon 7 quarts baffled,
http://store.summitracing.com/default.a ... search.asp

but there are two different pick ups, 3/8 and 1/2 inch. I read that 1/2 inch is for hemis but i'm not sure that it fits in 440.

http://store.summitracing.com/default.a ... =MIL-18335

http://store.summitracing.com/default.a ... =MIL-18325

And on the photo both have diferent body and as I told you different inlet sizes.

Thanks.

The 3/8 pickup is for the 440. But some prefer to use the 1/2 and just retap the thread size out to 1/2 and open up the passage way a bit, it is supposed to give you more oil flow over the 3/8 stock setup.

The theory is that the pump is weaker on the suction side than on the pressure side. So many people (including myself) have had the 440 block modified to take the 1/2-inch pick-up.

Some people say it is not needed at performance levels below 600hp.

plum-crazy wrote:I received an email from Neil, but he must to check it with Don. He think that 750 cfm is good for me but he prefers Don's opinion.

Has he got back to you yet on the carb?

I would have thought the 825 Mighty Demon or possibly even the 850 would have been the best size?

Most guys like bigger than required/ideal carbs for power to cheat the air effect, especially at any "elevation".
Change the way you think for a minute. The piston/engine doesn't "suck" the incoming charge, rather, the piston moving down creates a "low pressure area", and ambient air pressure, (which surrounds us all) rather PUSHS the air through the carb and intake and ports to the hole.
(pressure X area), in this case the butterflies in the larger carb.
Now I'm not suggesting Massive carbs as the be-all end-all, but slightly overcarbed can be a good thing provided you have the convertor, tuning skills etc., for good stociometric mixtures @ velocity.

As for your oil pump pickup, size required is dependant upon engine bearing clearances or "demand"
Think of it as a garden hose, capped at the end with holes drilled in it down it's length. Big holes leak more than small ones and require more delivery where you're putting it in to maintain supply.

If you drill and tap the block for the 1/2 HEMI pickup to increase the delivery on the suction side of the pump, be sure to enlarge to hole all the way up to where it intersects the 90 deg hole from the pump mount face, as it is smaller.
Don't drill it all the way up at 11/16"(good size for drill to use 1/2" N.P.T.), just the first 1" or so for the 1/2" Pipe tap, but the rest of the hole responds well to enlarging to match the intersecting hole from the pump face. If memory serves me, we used to use a 1/2"bit ? Anyway, just match the size to the one on the intersecting pump face hole and "radius/blend the turn where they meet.