Need Cam selection help

[Ronn]

Ok, I am familiar with Clifford and the usual stuff but my question is this;

First let me explain my setup;

I have a 250 Block
#D6DE 6015-AB

Head
#D5DE 6090 BA

this is a complete ready to run fresh re-build by a performance shop nearby me. So, pistons and other internal things like that I think I'll leave alone for now anyways 8)

Withat information, besides that the block is a 76 and the head being a 75, can you give me like flow rates, compression, valve sizes, cumbustion chamber cc's etc that would help determine hwhat cam would work best when using a Holley 350 cfm, or 500 cfm. I have the 350 now but am willing to go bigger if the gains are worth it. I need to order a cam for sure, and would like to know as well how much I can plane off the head to make some compression. All help is needed thanks.

BTW...I am going to be using nitrous...after I get this info I can run a program to get the correct pill sizes for a 50 hp gain.

Another BTW; I am building my own custom aluminum carb adapter plane that will allow this head to flow to 1200 cfm. so I need to open up the cam section due to the fact that the valves are smallish, but I'm using an automatic so I can't be using a .600 lift or something wacky big.

I see you have quite the cam selection here and I'm glad to see there are others besides clifford.

 

[Anonymous]

does your transmission have a stall converter?
If you go higher than 230 D cam you need a stall converter I think.
you need th take your gear ratios in your tranny in consideration with your rear end ratio.
Bigger cam means you need lower gearing.

If you put on a carb too big you will flood the engine out at low revs and too small and you willl not be able to rev high.

THis is why I am leaning toward a 4 barrel with secondaries.

I will probably run a Schneder cam 230D that will rev to 5500 rpm but I am running a manual tranny, Np435

I think that an automatic will work great if you gear it right.

NOw I do not know how to build a nitro motor.

 

[Ronn]

Well I have an 85 AOD out of a Mercury Marquis that had a 302, so I hope that the stock 302 convertor will be a higher stall speed that would suit what I'm doing. Anyone know what stall these AOD's had for the 302 in 85?

So what would I need to buy from you guys here to be able to install the cam? Do the cams you sell also have the springs included? Lifters? I need hydro lifters and I need the oil thru's. Cam installation is new to me but I feel I can handle it but need tricks and advice on what to look out for and whether or not the new bearings that are in the block now will need to be removed or can I use them? And do I really need double springs over stock if I'm not going over 4400 rpm? In fact , I don't even like going over 4000 cause the power drops off anyways. I really want to do this right and have it work so all help is needed.

 

[Anonymous]

have you been to ford six parts .com?
they sell cams, heads, headers ,ect

 

[Ronn]

Oh ya, in fact, I was happy to see that FSParts had options! I just need to know if a dual or single pattern is best for what I'm doing with the juice. Basically I need to know a lot :roll: Wish I did'nt have to ask. I have 1 day a week I can sit and do this on the computer so if I had the time to thumb through pages of search results I would

 

[Anonymous]

Have you talked to Xtaxi?

He is very knollegable and I think that he can help.

Is this a drag car?

 

[Mustangaroo]

Ronn,
Don't go with too much cam on a stock short block. If you didn't have the engine Balanced you won't like taking it past 5000 RPM....Many more things go into picking the right cam, Race/Drag/Daily driver? Manuel/Automatic/Rear Gears? Low end torque/Top end HP? What's your goal for the engine build, does this match how you will be driving the car 75% of the time?

 

[Anonymous]

what about with longer rods?

How much does a balance cost?

 

[Ronn]

Daily driver, automatic (85 Aod),want Midrange/high end horse power and have stock rear/gears.

I drive the freeway everyday to work and back so speeds of 75+ are usual.

Do I see a supercharger on that holley carb on an aussie six? How do you make a carb handle the psi?

 

[Anonymous]

I do not know what gears came stock in your car but I think you should run
3.73-4.11 if you have the .67 overdrive which I think you do.
I think you should cam it to max torque at 2000 and max hp at 4500, 260 avertised duturation and 202 at .50 I think. Dual headers and get the right length for your power band, SHort raises your power band and long shortens it

If you want good gas mileage you may want to consider a 4 barrel because you want strong top end but you also want to cruise on the highway at low revs.

gear it low for snappy quick torque and high for smooth cruising.

I think that this is all right but If something is wrong go on and say so.

 

[Ronn]

sounds good

 

[Mustangaroo]

Ronn,
We paid $95.00 extra to balance but if were $200.00 I would do it again, it really makes the engine run smoother at all rpm's. Without balancing the engine will sound like it wants to explode above 5,000 rpm, with balance it just sounds tight!

 

[Mustangaroo]

Just read!

Do I see a supercharger on that holley carb on an aussie six? How do you make a carb handle the psi?

Yes a Paxton Supercharger everyone should have one Or even a Turbo charger would be better for greater HP as the Supercharger uses up about 35 hp. I installed specal Holley float $16.00 and removed the choke and pluged the rod hole for the choke and made sure all gaskets were sealed. That's it it was very easy to seal the carb.