hyd roller cam

[feadam]

have a question maybe someone here can answer. Have a motor I am going to build for my new cobra. 482 stroker that I have all parts for, bbm block, bbm heads, two four intake. Bought a hyd roller cam that is big I think 600 lift could be wrong on that, but I do remember its a very large cam. Had heads put together with springs and vales but now am thinking of going to a smaller cam. the cam was going to put the engine in the 550 hp range. I am thinking I am going to want around 450 with good street manners. Can I use the same springs and any recommendations on a hyd roller cam. P.S. Can't get to cam its in storage in colorado I'm in Italy for another year and a half other wise I would give exact specs. 

[blykins]

Without knowing the durations, it would be hard to make a comment on if it's too big.  FWIW, in my 482's that I build for Cobras, I'm usually around the 242-248 @ .050" mark for the intake side and 248-254 @ .050" for the exhaust side.  Lift will generally be around the .570-.610 mark, LSA's can be anywhere depending on if the guys has power brakes, wants a radical idle, etc. 

You should be ok on the valve springs.  I'm not a fan of a huge coil bind clearance, but in most cases it will work ok, especially on a lower rpm engine.  Your open spring pressure will be lower as well.  Again, hard to comment on that exactly without knowing what the spring pressures are. 

With 482 inches and most hydraulic rollers, even 500-550 hp will be streetable.  If you don't want to use the last 100 hp, that's what they make gas pedals for.    My experience with Cobras and customers has shown that most guys get really used to their cars and want more power down the road.

[FE Jonny]

.600 is not really big even for a small block. For a big block usually everything starts around .590 for something mild, I would double check your cam specs.

[feadam]

It's a crane cam and I think the specs for duration sound close to 250, again cam is in colorado I'm in Italy. If I went with lower duration and lift and springs are good to use what lift and duration will get me to 450 HP with a hyd roller

[blykins]

You could put a tow truck cam in there and make 450 hp....not joking.

Did a BBM headed 482 a little while back, hydraulic roller at 224/230 @ .050", .580" lift and made well over 500.

Trust me, a 482 inch motor with duration in the 240's will still make 525-550 hp and will be very streetable.  I wouldn't hamstring myself in trying to cut the motor down to 450 hp.  It will roll down the road without fuss, have plenty of torque, and if you don't want to feel 525 hp, put a block under the gas pedal.....or put a 390 in it. 

[TJ]

First time posting so bear with me on posting correctly.  I've learned a lot from this forum and never thought I had much to contribute but since Brent built that 482 BBM combo for me I thought I could comment on its "street ability".  I put it in my F250 and it moves my 5 ton fifth wheel around the barn yard (in the grass) without touching the gas...at all.  It only needs some throttle on a hill.  Now, my truck's 1st and reverse gear ratio is 6.67 and the rear is 4.10 which helps, but the factory spec pickup minded 390 that I used to have could not move that much weight without some throttle.  So I'm guessing it will move your cobra around while idling with no problem.  As for controlling the gas pedal, this 482 will accelerate my truck faster than my comfort level.  I hit 90mph at a quarter mile and never passed 4500 rpm.  I'm guessing this 482 combo can help your cobra get out of its own way too    Idling, cruising, and towing it's an all around pleasure.

[feadam]

TJ
What rpm does it idle at and does it jump around at idle or just rumble. I am really more concerned with drivability at lower rpm's. My last cobra had 55000 miles on it when I sold it so I drive them a lot and would like ok to good drivability in trafic and on street. Adam

[blykins]

I rarely see people drive their Cobras that much....kudos to you....

I think something in the low 240's duration would be apropo and still give you the street manners you want. 

The camshaft that I put in TJ's 482 was meant for towing....and doesn't really sound or act the part for a Cobra.

[TJ]

Adam,
  To answer your question about jumping at idle, it's actually pretty smooth..no bumping or chugging.  I have it idling at 900 which is faster than the factory spec'd FE for this truck (600 rpm).  This engine is kind of weak at 600 and I like a little more oil movement anyway.  When backing the camper I let the clutch all the way out and take my foot off of it without giving it throttle because the idle rpm barely changes.  This engine moves the load real smooth like a tractor.   I only used the camper example to illustrate this engines strength at idle.  BTW, I would not idle through town with that much weight.  I like to keep it at 2000ish to splash oil and move water.  Hope this helps answer your question about idle with 482cubes that makes over 500hp.
   As example on the far end of the torque range is my wife's 1st generation Duramax.  It's a monster from idle up to 3000 rpms but falls on it's face at 3100.  The torque curve from GM shows that and you feel it in the truck...guessing you don't want that in a cobra. 

[feadam]

I guess I'm kinda looking for something that idles pretty smooth but pulls even and smooth to about 5500 rpm. I know in a 2400 lb car that won't take much torque. Had a mustang gt conv. in early 2000s and loved the way it just pulled smooth from almost idle until 5000 rpm. The last cobra I had would jump and spit, but once you got above 2500 rpm it felt like someone had just ignited a rocket behind you. Trying to avoid that instant almost like turbo feel. 

[Falcon67]

.600 is not really big even for a small block. For a big block usually everything starts around .590 for something mild, I would double check your cam specs.

This.  The cam in the Mustang 351C is a .598/.611 item.  Springs are 140 seat, 400 open - actually Crane solid lifter springs with a bit less installed height to push the pressure up a bit.  With 100+ more CID, a ".600" lift cam is probably not very "big", especially if the LSA is 110 or 112.  I'm like Brent, I'd think a 240+ intake duration with that much displacement isn't going to be anywhere near radical.  The last solid lifter cam I ran in a 351C was 238/248.  The roller going in the 351 I'm building now is  248/254 .670-ish lift, 108 LSA.  I like big cams and I cannot lie, you other fellas can't deny - etc.

[TJ]

Adam, 
  I think I see what you're getting at.  My engine starts making serious power around 1900 rpm.  I've floored it in 4th gear on some hills a few times at that rpm just to see what it'd do.   By 2500 it feels unstoppable which is where I need it.  I run it at 2500-3000 on the freeway and a camper drags a lot of wind at 65mph.  I normally launch in 2nd gear (3.33 ratio)  at idle when empty and I think it accelerates my 4500 lb truck real nice and evenly from idle up to freeway speed. 
  I think Brent did a good job balancing my wants and needs; he put the power where I use it. 

[feadam]

So visited the states and looked at my cam. It's a crane With 242/248 at .050, .616, .616 lift, 112 LS. Still trying to figure out if I should go a little smaller for drivability or is this cam pretty drivable in a light cobra at 482 cubic inches? 

[blykins]

It will be just fine.