cam advice

[zyxvutnow]

I'm trying to decide the cam to use in my 289 build. My friend and I are trying to come to an understanding; not sure we're thinking the same. I have a good 67, 289 that's bored .060 over. I'm not stroking it so it will run about 330+ cubes. I'm making it beefy enough to be cobra (ERA is building the 289FIA for me and should be done springtime): SCAT steel crank, keith black hypereutectics, manley rods, mogul rings, etc.

I'm talking to Comp Cams about an extreme energy cam, I want to use the new technology rather than going with the retro-fit cam. I want an idle that doesn't make it hard to tune--I'll be making it a roller rocker cam. The two I've/we've come down to are the XE266HR and the XE274HR. I'd like to push to the larger cam to use the power, but I don't know how to judge discussions about "idle lopeyness". I know the engine could handle an even larger cam like the XE282HR, but it will be primarily a street machine, and I want it to be the most with the best idle. Define "best": I don't want my wife and daughter to be so frustrated by the ride.

Any help or thoughts would be appreciated

Ralph Caraffa
(soon to be the new guy on the block in St. Louis)

[bobcowan]

The 272 is probably your best bet. Plenty of power. But smooth idle and good vacuum signal for the carb. Should be a real nice ride.

Instead of roller rocker, I assume you mean roller lifter?

A retrofit cam will have exactly the same specs and performance. The differance is in the fit, not the operation of the cam.

For lifters, you have two options. You can use link bar hydraulic rollers with a 5.0/5.8 cam. A little expensive, but drop right in with no hassle.

You can also use stock Ford lifters with a retrofit cam. But, you need to drill the holes for the spider, and do a little grinding in the lifter valley so the dog bones sit flat.

The end results is exactly the same. Price is pretty close to the same, too.

[onefastmustang]

I just did the roller cam install on my 69 block. Piece of cake. I didn't have to machine anything and the dog bones were all flat. I must have lucked out. The only real tedious work was the spider bolt holes and getting it all threaded but that only took like 20 minutes from start to finish. I am so glad I did the roller upgrade too. The engine valvetrain is so much quieter, car runs awesome and very responsive.

[vector1]

if you don't like the "lopey" thing you can always turn the idle up.

[Gaz64]

Ralph,

I don't know how you're going to get 330 cubes from a 289 without stroking it.
41 cubes is big rebore.

As for your cam the .006 figures dictate idle quality, .050 figures dictate mid to high rpm, so if you want the best of both worlds pick your cam for idle quality at say 270 degrees and go for the grinder that can offer the fastest ramps to give you the smallest difference between .006 and .050 figures.

My flat tappet has 276 @ .006, has 242 @ .050.

And as other boys have said, if you have choice go for a roller cam.

[RICK LAKE]

zyxvutnow Ralph No to hurt your feelings but a .060" 289 works out to a max 305 without any stroke change. Need some ideas about what you are looking for in HP and Torque? What gear ratio for the rearend? What trans are you looking at and what gearing is in it? What exhaust are you going to run, side pipes through the body or under the car and out before the rear wheels or out the back like a street car? What compression is in the motor?? How much work is being done to the heads?? What size carb and intake system are you thinking about? You will need a retro fit kit if you go with hydro lifters. No problem. The biggest question is what are you going to do with the car???Road race, autocross, dragrace, show and shine, stress control, or second child hood reborn. To get the BEST and have the motor last the longest you need to match parts. If you want a smooth idle and good lowend power for takeoff and cruising, go with a smaller camshaft. Looking for that hear me coming 1 mile away, bigger camshaft. Without knowing the trans and rearend numbers, no body should be guessing, that alot of money and poor drivability on a $50,000.00 dollar car. I will go on and say that bigger is not always better. This car only wieghts 2,300 lbs. You don't need 400 HP to give you a great cruising car. Rick L.

[vector1]

i've read the 289/302 early ford blocks shouldn't be bored over .040, and from my experience that is good advice, i had a 289 in a rr mustang that somebody had bored .060 and first race, last lap the cylinder side wall blew out, made pretty big mess of the engine and attaching parts.

[zyxvutnow]

To All

As I've read before in these forums your insight and thoughtfulness is rich and appreciated. I know I haven't given all the info about the intended build, but you have provided me with more than I need.

many thanks

Ralph Caraffa

[RICK LAKE]

zyxvutnow Ralph that's all??? NO hug, kiss or trip to the movies??? You are a CHEAP DATE!!!! That is the fastest forplay on this forum to date. Rick

[767Jockey]

Ralph,
All those goodies in the bottom end of the motor, and you're using Keith Black hypereutectic pistons? You may want to SERIOUSLY reconsider that, they're just glorified cast pistons. Good quality forged pistons will cost very little more, and with these pistons in there I would think that your cam is the least of your problems. They're just not up to par quality and durability wise with everything else you're putting into this engine, not even close. The rest sounds good, you're choosing top quality stuff except for the pistons.

As Rick said earlier, cam wise bigger is not always better. A roller with it's quicker rams and all can get you more power across the board without some of the downsides that comes with a flat tappet setup. It's not a miracle worker, but it's a help. Most of your more modern highly developed grinds are in roller format. By the way, if you're buying a new crank anyway, which it sounds like along with new rods and new pistons, why not stroke it?

The easiest, cheapest and smoothest way to get more power and torque is a stroker kit. Unlike bigger cams and bigger heads, there is no real downside to live with from stroking an engine until you start to go to extremes with pin placement into the oil rings, piston speed and / or rod angles. This only happens when stroking to the extreme limits. Best of luck, the car sounds really nice, ERA builds a beautiful FIA car.

[Three Peaks]

Rick is right, you need to match the components to have a truly drivable car that will have decent street manners.
Will you carb and intake flow enough for the cam and maintain vaccuum pressure? Will you heads flow enough to get the most out of the cam and intake? Will your exhaust choke off your gains or have you planned the proper exhaust for flow and/or sound?

Just stating the cam won't give us enough information to give meaningful recommendations without the other information.
Personally, I wouldn't use a 289 block bored .060 over. They are tough blocks, but that doesn't leave much sidewall to handle piston stress and heat transfer.
I will respectfully disagree with 767 above- nothing wrong with the KB Hyper pistons for your build. They are much more than just a cast piston and will work fine for your build.

Good luck with your build.

Bob

[bobcowan]

Originally Posted by Three Peaks

I will respectfully disagree with 767 above- nothing wrong with the KB Hyper pistons for your build. They are much more than just a cast piston and will work fine for your build.

Good luck with your build.

Bob

I would agree with that. The Hyper pistons are used in a lot of street applications by some big name builders. I'v used them on a number of builds over the years without any problems. For your build, they will be more than adequate without stretching the bank account.

[767Jockey]

I agree, guys - I don't mean to sound as if they're garbage, they're certainly not. However, my point is with all the goodies being thrown into the bottom end of this engine, the steel crank, the Manley rods, etc.....the KB's just don't fit in with the overall quality theme here. Certainly if you're counting pennies, you can save a very small amount of money with the KB's over a decent set of forged off the shelf pistons. However with the above components, this doesn't seem like a save every penny build, I am sure the sky's not the limit here budget wise, but really, the cost difference between the KB's and a decent off the shelf forged piston is ridiculously small in the big scheme of things. I have personally hand grenaded a set of Hyper pistons in a Chevy some time ago, and it was a build maybe just a touch hotter than this one, not wild by any means. I know in the 351 Cleveland's, the guys over on that forum won't touch the things with a 10 foot pole. It all comes down to the price difference between run of the mill forged (we're not talking custom Diamond pistons here, just standard TRW type forged) and KB hypers being insignificant in the big scheme of the engine build. It's very cheap insurance.

[J Persons]

a .060 over 289 with stock stroke is a 295, if it doesn't hit water first.