Edelbrock Heads, I did not know

Well, it seems we continue to learn as we roll along (expensive learning) seems the Edelbrock Performer RPM heads we have require 2 completely different spring set up's whether your running a flat tappet or a roller cam...............well we acquired the car with the heads with a flat tappet cam, now we changed to a roller block as most of you know, during this transition I was on the phone with Edelbrock verifying things such as making sure the heads were good for the .544 lift, I was assured they were good to .575 so all's well, never once was anything said about changing anything going to a roller.

Well I have been in a few conversations with Woody at Forstrokers as we lay out what this thing is going to be and he mention's we need to get the heads into the 21st century......what? huh? those heads are sold today just as what we have...he goes on to say that the valvetrain was what they were using 20 years ago and then get's over my head but I believed what he said anyway.......so I am just doing some reading on how to improve those heads with port/polish, springs, pressure, etc. and thats when I run across the info regarding different valvetrain for roller vs flat tappet....so in case anyone was not aware of this here you are....however I'm probably the only one who didn't know so I ask Woody (Jim) if I should just get new heads all together based on the engine that is being built (big surprise coming) and are those heads going to provide what we need, I was assured when they were done they would be more than adequate...so thought I might should toss this out for anyone having a chance to pick up a pair of these heads, make sure what cam type they were originally set up for.

 

Has to do with spring pressures, and the aggressive ramp profiles that rollers use

 

yeah I understand that somewhat, I'm just perplexed that Edelbrock never mentioned it when I specifically told them what we were changing to...oh well may have just slipped their mind.....it did run fine like it was..now how long it would have lasted is another story

 

my thinking is...you gave them a number off the heads and they went with that.

 

while its not popularly talked about, its a very good idea to use a valve sprig kit recommended for the cam being used in any motor build. also the spring installed heights need to be checked and confirmed to have the proper pressures.

 

I agree and understand....NOW, however I told Edelbrock exactely what cam was going in it, we talked about the fellow I bought it from and how a lifter and cam lobe wiped out, probably from inadequate/improper break in procedure, now in his defense he may not have put 2 and 2 together and realized exactely what was taking place, he just assured me that those heads were good to .575 lift but if I was going over that it required different springs, seems like .700 was the max for those heads........well there is no need to worry this round because I'm going with what Woody says and we are going to redo the springs but also port/polish the heads and the intake, I was told to expect 35-50 h.p. just from opening and smoothing the air flow through the heads and intake WOW, that seems like alot just from port/polish already being aluminum aftermarket heads but I guess everything has room for improvement. Here is a quote direct from Woody in regard to Edelbrock heads; "David, max valve lift is not the concern, Edelbrock packages their heads with the cheapest springs money can buy, this is to try and stay competitive with Trick Flow and AFR. I could design a cam with only .500 lift and garauntee your current springs would never be able to control your valvetrain, because they don't have very much spring rate coupled with heavy stainless steel valves, heavy springs and heavy steel retainers. The cam lobe and how aggressive the lobe opens and closes the valves is whats important, not the springs max lift capacity!" Well now ain't that some poo, why spec a cam and claim it's good for so and so amount of lift when it apparently all they mean is thats how much lift before coil bind..........don't mention your car won't run worth shit because your valves will be floating around most of the time because the cheap ass Chinese springs can't take it.......I sure am glad I'm dealing with Fordstrokers!

 

Not to sound negative but you need to hire a good mechanic that has experience with this stuff or your going to keep spending lots of money and be very unhappy. Maybe just have the guy at Fordstrokes assemble it for ya.

 

Have you considered using different heads other than the Edelbrock? I know I love the way the Trick Flows perform and you are using newer technology by getting away from an inline valve head. As a side note to this even Trick Flow and AFR heads need upgrades to the valves and springs to be at optimum for your engine specs. There is no such thing as an out of box head to be the best for all motors

 

Please elaborate, what is it that gives you that impression, I'm interested and not offended or mad, I really want to know your thoughts as to how you came to that conculsion

 

Yes, I mentioned that to Woody and he said no reason, after the work that will be done on these heads considering maybe $600-$700 and we have a pair of heads that are way out there in performance, also we can't use twisted wedge (I'll tell after motor is done why not, but I don't want to give up the surprise)

 

Edelbrock uses the same springs on their RPM heads regardless of whether you're using a flat tappet or roller cam. Their intention was that you buy either one of their flat tappet cams or one of their roller cams which have very lazy ramps and don't need a lot of spring. That said, I'm running the RPM heads with the original springs and a Comp XE roller cam. When I bought the cam (used) I checked what springs Comp recommended. Turns out the Edelbrock springs measured slightly higher on the seat and over the nose than what the Comp springs were rated. Of course this particular cam runs out of breath at about 5800 rpm so the springs don't need to maintain control at a high rpm.

EDIT: And my valves don't float, the springs and retainers used by Edelbrock (at least on my heads) are Manley. I know from posts that Woody makes that he doesn't care much for Edelbrock heads. They are a middle-of-the-road offering, a step below the AFRs, Trick Flows, etc., but they're nice castings with helicoils and have potential when properly massaged.

 

I'm confused why it has heads that list for use with flat tappet and hydraulic roller and then one that say flat tappet, however things are changing as I write this.....our motor is going solid roller, it was recommended

http://www.edelbrock.com/automotive/mc/cylinder-heads/ford/performer-rpm-sb.shtml

 

and the heli coils already installed are nice

 

Hmmm, back when I bought my RPMs (60259's), about 8 years ago, they didn't come with different springs. They put the same springs on all RPMs.

 

why put up with the hassle of adjusting solid lifters?

"We put both charts next to each other and as you can tell, up to 5000 RPM the engines are pretty much even, which was not a surprise. What we didn’t expect to see was the peak horsepower on both camshafts to come in at the same RPM. The total difference in horsepower between the solid roller and hydraulic roller setup is just slightly over 8 horsepower. In fact, both cams actually made about the same ft-lbs of torque at the same RPM.

So what does it all mean? It means you no longer have to make a choice between solid and hydraulic roller lifter camshaft setups. The differences in power are actually negligible, coming down to the single digits in a serious street application."

http://www.stangtv.com/tech-stories/engine/dyno-shootout-solid-roller-vs-hydraulic-roller/