Camshaft input from experience.

[jasonconaway]

Looking to get a cam for my 355 that’s waiting in line at the machine shop to be built. Going into a pretty much stock 84 C10. Th350. 3.42 posi rear. The engine will have stock bottom end. Pro-Filer aluminum heads. About 10:1 compression. I have called and spoke with Lunati, Howard’s and Isky reps. These are the cams they recommended. The truck will be a cruiser. A couple times down the track. Of corse I want that mean idle as well as good overall performance. Any input from guys who have run any of these or guys with engine building experience.
Isky: 280 Mega cam 2500-6800rpm 10120703lk

• Mega Racing Cam
• Hyd.
• Valve Lift Int/Ext. 0.485
• Valve Lash Hot Int/Ext. 0.000
• ADV Duration Int/Ext. 280
• 0.050 Duration Int/Ext. 232
• Lobe Center 108
• 
  
  Lunati: 268 Voodoo 10120703lk
• Advertised Duration (Int/Exh): 268/276; Duration @ .050 (Int/Exh): 227/233; Gross Valve Lift (Int/Exh): .489/.504; LSA/ICL: 110/106; Valve Lash (Int/Exh): Hyd/Hyd; RPM Range: 1800-6200;
  
  Howards: CL110951-10
• Hydraulic Flat Tappet
  Basic RPM Range:
   2000 to 6000
  Valve Lift Intake:
   .470
  Valve Lift Exhaust:
   .470
  Duration Intake:
   275
  Duration Exhaust:
   285
  Duration at 050 Intake:
   221
  Duration at 050 Exhaust:
   231
  Lobe Separation:
   110
  Intake Centerline:
   106
  
  Thanks for any input!
  

 

[BillK]

Of course I want that mean idle as well as good overall performance.

What i tell my customers is that those two really do not go together that well If you talked to Eric at Howards I would feel very comfortable listening to what he suggests.

 

[nvrenuf]

You said the "engine will have stock bottom end" but also 10:1 compression? Are you replacing the pistons? If so, what kind?

Not all pistons like high rpm so make sure all of your parts work together.

 

[Ricko1966]

Give up the mean idle!!!

 

[jasonconaway]

You said the "engine will have stock bottom end" but also 10:1 compression? Are you replacing the pistons? If so, what kind?

Not all pistons like high rpm so make sure all of your parts work together.

Will have hypereutectic pistons prob stock rods with ARP rod bolts. Not gonna be turning this engine high.
A local machine shop is doing the build. I’m just picking the camshaft.


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[Ricko1966]

Lopey idle is too much valve overlap. It kills milage,idle and low end torque.

 

[jasonconaway]

Give up the mean idle!!!

I know. This is my first hot rod and I’m 41. I have always wanted a mean sounding idle. It’s tough to let that go. A good lope is fine with me. From the videos I’ve seen with these cams, they all have a decent lope to them.


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[jasonconaway]

Anyone else with an opinion as to which of the 3 camshafts list I should go with?


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[QBuff02]

if those are your 3 choices, out of those 3 i'd go with the Lunati. The 268 grinds are all good no matter the cam company. A Comp Cams XE268 is also pretty comparable to the Lunati 268 grind but comp cams XE grinds generally tend to be on the noisy side of things and the Lunati will generally make a little more power. Any of these cams is going to require a looser torque converter though, and your taller gears will make the bottom end suffer even more. I'd almost consider a cam one size smaller than any listed above, you'd give up a little of the lope (it would still be noticeable at idle) but have better streetability. I have installed two comp cams XE268's in sbc's and had good luck with both and liked their performance, one in an automatic and one in a 4 speed, but both had 4.10 gears. I currently have a Lunati voodoo 268 in my 454 with a 2,400rpm stall and 4.10 gears and it will absolutely boil the tires at any time from a dead stop up to about 25 mph. But, it's also a big block and that's a big difference from a small block. Any cam of 230 degrees @ .050 and below is good for a mix of street and spirited driving, but i'd go a touch smaller if it's going to be mostly street driven. or throw caution to the wind and let it rip. But that's my .02.

 

[jasonconaway]

if those are your 3 choices, out of those 3 i'd go with the Lunati. The 268 grinds are all good no matter the cam company. A Comp Cams XE268 is also pretty comparable to the Lunati 268 grind but comp cams XE grinds generally tend to be on the noisy side of things and the Lunati will generally make a little more power. Any of these cams is going to require a looser torque converter though, and your taller gears will make the bottom end suffer even more. I'd almost consider a cam one size smaller than any listed above, you'd give up a little of the lope (it would still be noticeable at idle) but have better streetability. I have installed two comp cams XE268's in sbc's and had good luck with both and liked their performance, one in an automatic and one in a 4 speed, but both had 4.10 gears. I currently have a Lunati voodoo 268 in my 454 with a 2,400rpm stall and 4.10 gears and it will absolutely boil the tires at any time from a dead stop up to about 25 mph. But, it's also a big block and that's a big difference from a small block. Any cam of 230 degrees @ .050 and below is good for a mix of street and spirited driving, but i'd go a touch smaller if it's going to be mostly street driven. or throw caution to the wind and let it rip. But that's my .02.

Appreciate the advice! My th350 is turning pretty good at highway speeds. Didn’t wanna go with a 3.73 or higher due to this reason.


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[75gmck25]

If you are not willing to go with lower gears, you need a high stall torque converter (and maybe smaller tires?). Those cams need some RPM to get up into the torque curve and you have a heavy vehicle that needs torque to get off the line. It might feel really peppy from a 1st gear rolling start or kickdown and merge onto the highway, but racing it from a standing start will probably not work well.

If it was my truck and I wanted to drag race it every once and a while I think I would want 4.10 posi gears and a high stall converter in the TH350. Its somewhat of a PIA to put up with the higher RPM on the street, but it will really wake up a high duration cam when you have good compression and performance heads.

 

[jasonconaway]

If you are not willing to go with lower gears, you need a high stall torque converter (and maybe smaller tires?). Those cams need some RPM to get up into the torque curve and you have a heavy vehicle that needs torque to get off the line. It might feel really peppy from a 1st gear rolling start or kickdown and merge onto the highway, but racing it from a standing start will probably not work well.

If it was my truck and I wanted to drag race it every once and a while I think I would want 4.10 posi gears and a high stall converter in the TH350. Its somewhat of a PIA to put up with the higher RPM on the street, but it will really wake up a high duration cam when you have good compression and performance heads.

I’m definitely going with a higher stall converter. I just installed the new 3.42 gears with a Yukon limited slip. This truck will be 95% Street. Maybe a test n tune once or twice a year.


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[jasonconaway]

If you are not willing to go with lower gears, you need a high stall torque converter (and maybe smaller tires?). Those cams need some RPM to get up into the torque curve and you have a heavy vehicle that needs torque to get off the line. It might feel really peppy from a 1st gear rolling start or kickdown and merge onto the highway, but racing it from a standing start will probably not work well.

If it was my truck and I wanted to drag race it every once and a while I think I would want 4.10 posi gears and a high stall converter in the TH350. Its somewhat of a PIA to put up with the higher RPM on the street, but it will really wake up a high duration cam when you have good compression and performance heads.

I’m definitely going with a higher stall converter. I just installed the new 3.42 gears with a Yukon limited slip. This truck will be 95% Street. Maybe a test n tune once or twice a year.


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[Midnightmoon]

After the first engine that I built for my former '70 Nova went horribly wrong, my uncle gave me some advice that I have followed ever since. "When it comes to carbs and cams, you can never go wrong going small for a street engine"

 

[82sbshortbed]

if those are your 3 choices, out of those 3 i'd go with the Lunati. The 268 grinds are all good no matter the cam company. A Comp Cams XE268 is also pretty comparable to the Lunati 268 grind but comp cams XE grinds generally tend to be on the noisy side of things and the Lunati will generally make a little more power. Any of these cams is going to require a looser torque converter though, and your taller gears will make the bottom end suffer even more. I'd almost consider a cam one size smaller than any listed above, you'd give up a little of the lope (it would still be noticeable at idle) but have better streetability. I have installed two comp cams XE268's in sbc's and had good luck with both and liked their performance, one in an automatic and one in a 4 speed, but both had 4.10 gears. I currently have a Lunati voodoo 268 in my 454 with a 2,400rpm stall and 4.10 gears and it will absolutely boil the tires at any time from a dead stop up to about 25 mph. But, it's also a big block and that's a big difference from a small block. Any cam of 230 degrees @ .050 and below is good for a mix of street and spirited driving, but i'd go a touch smaller if it's going to be mostly street driven. or throw caution to the wind and let it rip. But that's my .02.

I'm interested in your RPMs at 55 with 4.10 gears. What tires you got? Od transmission?

Reason I ask is I just put 3.73 gears in my truck with th350 and 275/60/15 tires and a 454. 55 mph =2700rpm. It barks the tires when shifting now and burnouts are easily available but, I can't drive it on the highway at 55 for very long. Lol

 

[jasonconaway]

I'm interested in your RPMs at 55 with 4.10 gears. What tires you got? Od transmission?

Reason I ask is I just put 3.73 gears in my truck with th350 and 275/60/15 tires and a 454. 55 mph =2700rpm. It barks the tires when shifting now and burnouts are easily available but, I can't drive it on the highway at 55 for very long. Lol

I have a new tach that I’m hoping to get out in, today or very soon. I have the Th350 as well. I looked at some gear vs rpm charts and calculators. I wanted to stay close to 2500 as possible. I have 3.42 gears. Not 4.10.


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