Yah gentlemen, this is a small world. I myself am from Chilli, if yah pay much attention you might've seen my 78 F150...orange, with teeth for a grille. BTW I could start a good forum about my Comp Extreme 4x4 cam (270H)! Its going back to Tennessee because after less than a 1000mi I have a flat intake lobe on the number 1 cylinder. All the others are fine, I hope its a defect and not proof of my stupidity. Any suggestions?

 

I have heard a few other people talk about wiping lobes with that particular cam. I don't know what the deal is.

 

Mshane: I have never met Leon, but my father-in-law knows him and has told me that he's a 'heck of a welder" and a "great guy". (However my father-in-law has some dubious personality traits. )


7.5Greb: yeah, I've seen the truck; with a flatbed, right? Haven't seen the grill though. I think you were at Randy Bachman's house once or twice a while back, maybe?

Who knows, about the cam; I'm assuming you followed break-in procedures according to Comp. A couple of things to think over: Metals under high contact pressure, like a cam lobe, are prone to scuffing under break-in. This can be greatly reduced by using an additive with zinc, or a zinc compound in the oil. This is in addition to the moly cam lube applied to the cam itself, which is mostly helpful during the first few seconds of startup.

One excellent source of this is Crane Super Lube, which can be hard to find. Another, which can be found at any (ahem) GM dealer, is EOS, or Engine Oil Supplement. Pour it all over the cam before replacing the manifold; yes, right over the moly paste. After breaking in the cam, change the oil/filter; don't use any more additive (causes deposits with extended use). Most motor oils no longer have much, if any zinc. So, for about the first thousand miles, I like to use Shell Rotella, which is in 15W-40 weight and is actually intended for diesels; it has a lot of zinc & other anti-wear additives. Farm & Fleet has it.

One other possibility, though a slight one, is that you have a lifter bore that is slightly off in the boring angle. That cam has a pretty aggressive ramp, as do most current Comps; it's possible that the bore is just far enough off that it's a problem with that particular cam. No cure other than to switch cams or get the lifter bore trued, assuming you can find a shop around here capable of accurately doing it. I doubt this is the problem, though.

Powergod: I haven't forgotten about ya; I ran some quick sims last night. Sure I can't talk you into a roller?

 

Yeah you would have seen me there, Randy is my brother. I will keep you guys posted on the cam situation, I am really hoping its a defect. I did follow all the break in procedures minus the removal of the inner spring, had no way to take it out. Even at that, I would have expected more to have a problem if the springs were the cause.

 

I may use a roller but not sure. How much of a difference would it make?

 

"I may use a roller but not sure. How much of a difference would it make?"

A lot. Crower has a good street roller that doesn't go crazy on lift. Comp also has a street roller, part # 34-770-9(H), spec card can be found here:
http://www.compcams.com/Technical/Se...umber=34-770-9

Both are in the 230/240 duration range for I/E at 0.050. This should not be too big for your combo. In fact it would probably be just about right with your stall converter and steep gears. Maybe someone can DD those for you.

I'm running the Comp cam you listed at 218/226 with a stock stall and it is plenty low on the RPM range. Your heads, and the rest of your engine combo would appreciate the bigger cam. I know most people actually end up going too big on the cam, but either of these rollers should be just about right. If you decide to stick with the hydraulic cam, look at the Comp cam one notch bigger than the X4262H. I think you would be happier with the X4270H.

 

I will be switching to a 4000 stall

 

4000 stall is pretty high. I'd think your heads might be running out of wind around 5500 unless they are pretty well ported. With a 4000 stall you would be limiting you usefull powerband to about 1500 RPM's. Is this in a mudder race truck???

 

Powergod, here's some cams & dyno figures for you. There are with the specs you listed above; since you don't have specific flow numbers, I listed each cam with stock (as cast) D3VE heads, then with well ported (professionally) D3VEs. Your figures will fall somewhere between the two.

Comp solid 34-343-4, stock D3VE heads

2000 rpm 158hp 415 lb.-ft.
2500 217 455
3000 277 485
3500 347 520
4000 414 544
4500 470 549
5000 501 527
5500 487 465
6000 489 384


Comp solid 34-343-4, ported D3VE heads

2000 rpm 152hp 398 lb.-ft.
2500 209 438
3000 261 457
3500 333 500
4000 415 545
4500 498 581
5000 567 596
5500 604 576
6000 622 544
6500 601 486
7000 574 431


Comp 34-711-9 roller, stock D3VE heads

2000 rpm 184hp 483 lb.-ft.
2500 245 516
3000 314 549
3500 384 576
4000 448 588
4500 495 578
5000 518 545
5500 483 462
6000 413 362


Comp 34-711-9 roller, ported D3VE heads

2000 rpm 178hp 467 lb.-ft.
2500 238 500
3000 301 527
3500 381 572
4000 466 612
4500 550 642
5000 617 648
5500 654 624
6000 662 580
6500 640 517
7000 597 448


As can be seen, the roller is worth a good amount at the rpm levels you want to turn (and allows a higher rpm level). Neither of these cams is really streetable, and you will need a 3500-4000 stall converter; I'd suggest possibly talking to a custom converter builder, depending on the budget. The roller cam will require some quality valvetrain components as well. I suspect you also could gain by using a better carburetor like a Holley 950HP, and a Victor intake, or even a tunnel ram. Again, with that kind of compression, I'm making the assumption that this is for pulling only. If fuel type is not limited, I'd look at possibly raising the compression more & running methanol.

Hope it helps, Mike

 

Yes, this is for pulling only with just the occasional street play. I am going to be getting the converter from a custom builder and I might be getting some heads from another puller that flow close to the same as SCJ heads. Ireally don't want to spend more on intake and carb because they are both very new. So for now I will just build the motor within their limits. I have thought about a roller but it will come down to $$$$. Thanks for the info.

 

Well I guess I will be going with the roller. I will use the above cam and lifters. Are the numbers on the bottom with the ported d3ve heads with stock size valves or no. Also how well were the heads ported that you used, what type of flow numbers. I am just going to get me heads ported a little better. I was just wondering if I should also check on getting bigger valves put in. Is there a cheaper better way? Thanks again

 

Here's the figures I used. These were tested at 28", & I believe with no pipe.

stock D3VE as cast, with 2.08 intake & 1.66 exhaust valves:

.100 lift: 62 cfm I /47cfm E
.200 119/87
.300 189/119
.400 236/125
.500 263/129
.600 270/129 (pretty well done at this point)

heavily ported D3VE with 2.08 intake & 1.66 exhaust valves:

.100 95/60
.200 163/107
.300 223/140
.400 268/168
.500 301/195
.600 325/202
.700 342/202
.800 355/202

2.19 intake valves will likely hurt flow a little at .3 lift & under on the intake on a ported head & be worth up to 15 cfm above that. Bigger exhaust valves of 1.76 will help also, but the limiting factor is still the exhaust port. The general feeling seems to be that bigger valves won't do anything with stock ports. Fitting even larger valves than 2.19 & 1.76 in PORTED OE Ford heads won't help either.

So far as cheaper/better, it depends on your own capabilities. If you do all the port work yourself, it's cheaper. To pay a professional, IMHO, it's probably better to go with aftermarket. Edelbrock "as delivered" (no porting) RPM heads are roughly equal to the D3VE ported intakes, & up to 20-50 cfm better on the exhaust from .300 lift on up. The RPM CJ heads add up to 15 cfm at higher lifts, with the same exhaust as the std. RPM. The TFS streets are slightly below this but have a lot of potential with a little work. Depends on your class rules, too.

 

We have to use cast iron heads. No aluminum allowed. Are there any cast heads that flow very good available? I don't know of any. Once again thanks for the info.

 

Sort of.

Your best option is probably CJ/SCJ heads, the D0OE. A lot of pullers use them. There's a set on eBay right now.

The EX514 from Flow Technologies (pricey) is another option.

Blue Thunder also made a cast iron version of their head; their web site says they no longer produce it due to casting problems. Someone mentioned that there is a set on eBay right now but I haven't checked. They show up occasionally, used.

Other than that, I can't think of any iron heads that will help significantly except the Police Interceptor heads, which aren't that much better, though some. Kind of 1/2 way between the D3 & the D0OE.

 

I've got a set of fully ported SCJ's laying around right now. One head is perfect. The other has a crack in the floor of an exhaust port. It could be fixed. I'd let them go pretty cheap. LMK. Oh, BTW, the guy that I got them from was making around 700 hp with them.