Forged pistons, Cam specs, Etc...

[WhitePony]

Hi folks,

I'm putting the specs together for a new six shooter in my wife's 65 vert and am looking for some advice. I'm building around an OZ 250-2V head and plan on using a US 200CI block. In the past I've done alot of engine 'Pop n' Swap', but never any real custom building, so I'm trying to educate myself before I start.

What I'm wanting to build is an engine that will be a good daily driver that runs relitively smooth (wife's car remember), will run on regular unleaded fuel, but at the same time has considerably more punch than the stock six. I've already found a bunch of answers here on the forum, but still have a couple of questions.

First, at what point do I need to consider forged pistons? With a 250-2V head, a reasonably mild cam and not using any boost, will forged pistons give me any better performance than a good set of cast pistons? I want the engine to be strong, I'm just don't know if they would be worth the expense for my application.

Ok, on to cams. I'm a total noob when it comes to cams, as I always just used stock parts in the past. I've found some good info here, but not enough to make a decision. From one of AzCoupe's recent posts, I would gather that I probably want a cam with a 112* lobe center, but am not sure of what duration I'd want. Plus, what the heck is a 'dual pattern' cam? I'm fairly certain that the wife won't want the idle to be too lopey. Last year I put a 550HP 502 in my boat, and she HATES the way it idles now (But doesn't complain about the performence).

I guess the last question is directed to all of you who have swapped over to the 250-2V head. What is the best carb setup that you guys have found? I know that Slade has gone to a 4V, but I'm not sure I'd want to modify the intake on the OZ head because they are so rare now. Should I go with the highest CFM 2V carb I can find to fit or what?

Well, thanks for reading my ramblings.

Kris

 

[addo]

Forgies are overrated in most applications. I'll suggest hypereutectics.

Our own FTF has a lot of passes on a set of hypers, also they are OEM on the Turbo Falcons and handle boost upgrades to that motor ably. You'll get a quieter running engine with longer life by using hypereutectics. Very few people on the Forum have driven an engine to the point of piston failure. Most motors seem to die a slower death...

Besides work that people regularly bang the drum about, torque plate honing is pretty much essential.

Cheers, Adam.

 

[xctasy]

I'm with Adam. ACL prove there reputation every day in drag races and production modified engines all over Australia.

Unlike Australia, though, you Americans live in the home of a areospace inspiried forged piston industry.

If you can get a set of forged Keith Black or TRW or Ross pistons bound for a 4.8 Gen 3 or 305 SBC then you will perhaps get a better deal than importing the Falcon XR6 ACL pistons. I doubt you'll get better reliability, or a lighter piston for the dollars though.

Forged pistons do tend to create more damage than high silicon cast pistons. The fact is that Aussies never go to froged piustons unless they are over the 2.5 hp per cube level. Plenty of stove hot turbo Toranas and RB30E Nissan Skline. Holden Commodores run stock pistons way over that level.

I'll take a leaf form Sam Blumstein at Chevy Offroad and Marine. Cast cranks, cast pistons, unless you are going nitrous. Turbos build boost gradually, and there is less thermal stress in a turbo 200 cube six cylinder with 500 hp at 5000 rpm than there is in a 200 cube engine with 240 hp at 6200 rpm.



Some one said â€￾Never trust a man who doesn't drink“.

Since I don’t drink, go ahead and take the pi$$ outa me!

 

[ruckus68]

Hello White Pony

I am using a 2V head and 500 cfm holley 2bbl, comp cams 260H and Full rollers (Which you don't really need) - it runs pretty well but i am swapping over to 4V intake. I think that the combo above without the full rollers would be fine for your wife. Good power, good drivability and good gas milage. I want more power, good drivability, OK gas milage, and a supercharger

a dual patter grind has different lift and duration for intake and exhaust. talk to azcoupe and he will help you with selection

get a copy of the "ford falcon 6 cyl performance handbook". it's good reading.

adding headers and a good exhaust will help out then you should be very happy with your performance.

is she running a standard or auto

Good luck
John

 

[AzCoupe]

WhitePony,

In order to make a sound recomendation on the parts you need, more information is required. As a daily driver, will it see more city, backroad, or highway use? Is economy a concern, flat out power, or a combination? Automatic or manual tranny (if manual, how many gears)? What is the rearend gear ratio? What is the planned compression ratio? And so on.

I would suggest reading the Falcon Handbook first. As well as surfing the various websites of our members, as there is a wealth of infomation in them. You may also want to read the tech articles on the various cam manufacturer websites, Comp Cams in particular. And read the info in these two links:
http://www.cquesttechnologies.com/fspp/Selectingcam.asp
http://fordsix.com/recommendedmods.htm

Once you do that, you should have enough information to put together a plan for building the motor. Selecting the right cam is probably the most important, and most difficult task, in my oppinon. But you'll get lots of help along the way. If there's something that isn't quite clear and you need a little help, just post the question. Don't worry about asking anything, even if it does seem trivial. We have a lot of great members, who are more than willing to reply. Feel free to e-mail me once you are to the point of selecting a cam, I'll be more than happy to help.

As one of our members (author of the handbook) puts it, "Enjoy the Journey"

 

[WhitePony]

Thanks for the input folks. I have ordered a Falcon Handbook and will be doing some serious studying when it arrives.

Mike, to answer some of your questions, I have a 3.20 axle ratio, and currently have the standard 3 speed manual. As part of the build, I'm going to install a T5, but don't know what set of gears I'll end up with yet. There are so many different models of the T5 that I don't know which way to go with that. I've been told that Windsor-Fox was a good resource for T5 upgrade info and parts, but they are primarily into late model vee eight conversions, so I'm not sure how much help they will be with the six.

I'm not sure what my target compresion ratio will be, but I want to be able to still use regular unleaded. Recomendations for a target CR would be welcome. I guess that I'm looking for a setup that will provide good power over a wide range of driving conditions. The car will never be raced, but I want to build in as much overall performance as possible while still maintaining good drivability.

From the replies, I guess I'll stick with cast pistons. As far as the head is concerned, I'm planning on having it ported and polished, have oversized valves and seats installed, and am seriously considering a roller tipped rocker set. Will the oversized valves have a bearing on my cam selection?

I definately want to go with a dual out header with a port devider and an electronic ignition.

I appreciate the input. I've been a reasonably proficient backyard mechanic for 30 years, but have always done completely stock work. This is my first adventure into custom engine work, and I don't want to mess up by making the wrong initial choices.

 

[MustangSix]

For a daily driver with a T-5 and that rear, I'd recommend you pick a mild cam that produces peak HP at around 4500-4700.

Something with a duration of no more than 212 @ .050 with a lobe separation of between 112 and 114 degrees will give you a decent idle and a nice flat torque curve.

I'd keep the compression down to around 9:1 or a little less if regular fuel is required. A 350 Holley 2V will be adequate.

You'll end up with a 200 that makes 160-165 hp, and about 180 lb ft of torque in a nice usable range.

 

[twentyover]

xtaxi- you made a comment that I find curious

"Forged pistons do tend to create more damage than high silicon cast pistons."

Can you be more specific?

While I agree that it appears a cast piston is appropriate given the information provided, I'm not sure what you are refering to when you speak of damage.

 

[xctasy]

xtaxi- you made a comment that I find curious

"Forged pistons do tend to create more damage than high silicon cast pistons."

Can you be more specific?

While I agree that it appears a cast piston is appropriate given the information provided, I'm not sure what you are refering to when you speak of damage.

Forged pistons definately scuff bores more than cast pisons while cold. Any forged pisaton is therefore a risk if you don't need them for detonation resistance or heavy duty.

Forged pistons commonly create cold morning piston slap, and can result in damage to the cylinder bore. Becasue of the shape of the uniform grain structure of forged pistons, they tend to expand in a quirky manner which requires greater running clearances and different ring clearances. Most people getting forged pistons are using them in high rev racing applications, and they are set up loose for racing.

Because of the advances in forged piston design, there is a massive difference between a forged Chevy LT1 350 piston designed in the 70's, and a 2004 forged Ford GT 5.4 piston. They have trimed them down and machined and treated them so they areas dimensionally stable as common cast pistons are.

My experiece is that a stock block engine which isn't clearanced for forged pistons will certainly suffer bore scuffing and eventual damage to the bore taper and ovalarity if run like this. My mate scrapped his 351C NASCAR block by fitting TRW's into a stock cast clearnace bore.

The best plus is that forged pistons run cooler all the time, up to 100 degrees F less. This allows you to run more advance without detonation. It also makes them harder to get through the emissions tests.