Is converting a 400 SBC to roller cam any different then any other pre-87 SBC? What all is involved and where can I buy the parts/kit or whatever? Approx. how much does it cost to convert (not including camshaft)? Thanks!

 

It is the same as any other SBC. It pre-dates the factory's strange and twisted nightmare of a roller system, so you just use the same stuff that we had all bee using for decades before the factories jumped on the bandwagon and mutilated it.

All you need is a roller cam and lifters (duh), a cam button which is a little thrust bearing thing that goes between the nose of the cam and the timing cover, a good roller timing set (the one that costs about $50 or $60, not the $30 one), and the right length pushrods, which will be around .400" shorter than ones for a flat-tappet setup. The lifters would need to be the kind that is now referred to as "retrofit", which are haeld from spinning by being joined together by a link bar in pairs, one pair per cylinder. If you buy a billet stel cam ($$$$) rather than the typical cast-iron street pieces like most flat tappets also are, you will need a bronze distributor gear.

A roller cam is about $350; lifters close to $300, timing set $60; thrust button $15; pushrods $40 if you can use regular length ones, or $120 if you have to use the "custom" length ones. Roller rockers are a great idea. Since roller cams almost always have more loft than stock-diameter valve springs can handle, machine work on the heads, to enlarge the valve spring pockets, is usually required.

Most recently I had a Comp XR282HR in my 400... it runs OK for what it is.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Ok, I already have a good double roller timing set and roller rockers (crane energizer 1.6). I have std. length edelbrock chromoly pushrods and a cam button. Can those pushrods be made to work? You made it sound like I have a choice between std. length and "custom" .400 under pushrods. So really all I need to buy is "retrofit" roller lifters and a cam and i'm all set?

Right now I have a CompCams XE284 cam (.507/.510 lift) hydralic flat. It isn't incredibly aggressive, but originally the motor was going into a daily driver. Am I correct in thinking that I will be able to get significantly more lift and be more mildly mannered by converting to a roller cam setup? I'm thinking of something like the CC306 cam...I know alot of LT1 guys run it...good choice or can I go a little more aggressive since I have a bigger motor? Any recommendations? This motor isn't going into a daily driver anymore.

The basics of the motor:
404ci
forged pistons and rods
9.8:1 compression
Dart Pro-1 alum. heads (200cc/64cc - 2.02/1.62)

Thanks!

 

The cc306 is more designed for some type of non naturally asperated motor. There are newer designes that maximize intake lift, which is really what a 400 wants.

Most hydrollers i know of are in the 225 to 250 dollar range. Comp will custom grind one for 253. Cam motion is about the most expensive and I think they are about 293.

Federal mogul now has a hydroller that sells for 258 bucks from competition products. The part number is Ht5000. And, most all rollers can be made with a cast iron distributor gear pressed on the back. I got a hydroller made on a solid roller reduced basecircle billet and it has a iron distributor gear.

Because the hydroller lifter is physically taller than a normal lifter, a standard length pushrod will not work. Best thing to do is get a pushrod length checker from comp. They are 20bucks. Make the pushrods the last thing you order. Assemble the motor and use the tool to determine the proper length. Summitt sells TFS pushrods that are available in about 20 different lengths at .050" increments.


[This message has been edited by jcb999 (edited August 03, 2001).]

 

Yeah I'm sorry, (and I apologize too) I fat-fingered the cost of a roller cam, it's $250 not $350, I've bought enough of them to know better!!

The Comp "306" grind is a computer-controlled fuel-injection grind. It's set up for a LTR system. IMHO it would be a waste of perfectly good parts and money to run any kind of LTR system along with the rest of what you've got; you should be using a MiniRam or Accel ProRam, or a carb.

If I were building a motor with those heads and was looking for maximum results for my money, I'd put a RPM manifold and a Holley or Demon 800 or 850 on it. I'd probably use a Comp XR288HR or XR294HR, maybe more if I thought I could get away with it. If I was going to drive it on the street, I would not use those rockers; I would choose the Comp steel ones. Be aware that any of those cams will give you lifts well above .550" with 1.6 rockers, which is a good thing; but you'll have to make sure you use valve springs that can tolerate it. It doesn't hurt to use the next step up in the spring mfr's line from the minimum they recommend, especially with a roller; the lifters are heavier, and the valve has to be accelerated back down faster, both of which require more spring pressure.

However, in answer to your questions, a roller allows forextemely steep ramps. The net result is that the valves stay farther open for longer. So you can get equivalent performance with less duration,because the "area under the curve" of valve motion is so much greater.

Like jcb said, you can't use the same pushrods you'd use for a flat setup because roller lifters are much taller. Most of them are about .400" different, which is kind of huge with pushrods. However, by the time you get through with as many alterations to the valve train as you will end up with - non-stock heads, rockers, the bigger cam, etc. - chances are the cookie-cutter pushrod length won't be optimum. At that point it makes sense to step up to the better pushrods, and pick exactly the right length with an adjustable one. Usually they'll want to be longer than the standard ones, by anywhere from .050" to .150", which would still be .250" to .350" shorter than what you've already got. Comp also sells pushrods in .050" increments.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Why wouldn't you use those rockers, because of strength issues? Honestly, i'm still trying to decide what to do with this motor. Right now, I don't have a vehicle to put it in. My 86 IROC burned well over a year ago...the motor is practically brand new. Originally it had a Performer RPM and a 750 Holley DP and Hooker Supercomps. When I built it originally, I followed a Car Craft buildup which made 450hp/500lbs with the same intake and cam but with Dart Iron Eagle heads. I wish I had known better and converted to roller instead. So I have about $3500 to play with and still need to buy a car and freshen up the engine (gaskets, balancer, waterpump, headers, carb, aircleaner, etc.) and it looks like roller conversion is gonna cost at least another $700-800. When I finally put this engine back in i'm gonna make sure it's right this time.

 

Right... on a race-only motor, the aluminum ones are fine; but on a street motor, the phenomenon of aluminum fatigue, familiar to all aircraft A&P mechanics, becomes an issue. Keep in mind, a NASCAR motor running at 8000 RPM for 4 hours may be hell on rockers, but they only operate about a million times in one race, then go to the trash; on the street, a motor that goes 100,000 miles at 2500 RPM will operate each rocker some 150,000,000 times. Steel will have a much better chance of surviving.

There are different kinds of durability.

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"So many Mustangs, so little time..."
ICON Motorsports