Roller cam questions???

[NoAZ68]

My machinist told me that I should not put a roller cam in when I rebuild my 351w (I MAY stroke it to a 396)(see previous posts). He says money is better spent in heads (I agree), but everyone else seems to think that roller cams are so much better than any hyd. flat tappet. Are there any negatives (besides $$$) to using a roller cam? This is going in a daily driver EB. If going with a roller cam is that much better, does it really make a difference if I use a roller block or not (I know that it would need to be converted) or would any block w/ a conversion work just as well???
ANY help would be truly appreciated, as I would like to get this thing going....

 

[76Broncofromhell]

My dad has a 392 roller in his car and it is as fast as hell. The advantage of a rollercam is you can get big lift without an insanely long duration. So you can make horsepower at high rpm but won't have problems with fouling the plugs at low RPM. They really are quite cool. They really aren't any negatives to rollercams that I can think of. A block conversion isn't too hard. I saw one done (drill two holes in the valley and tap them).

 

[45acp]

go for it. all the reasons above are true. in general, big roller vs. same hydro, the roller will be less "lumpy" and more well behaved at low rpms. an all roller motor technically lasts longer too. only downside is initial cost (its worth it).

 

[Broncobowsher]

Like they are saying.
Just remember that you do need heads that can breath for any cam to work. That matching of parts thing...

 

[NoAZ68]

Thank you for the replies.
1. So, there are no negatives besides cost. I was looking to build as efficient a motor as possible for the old beast, and I believe reducing friction is one of the best ways to do it.
2. So if I am not mistake, a roller cam will give me better low-end torque due to a) reduced friction and b)better lobe profiles that allow the cam to open and close quicker?+

 

[Unregistered]

I love my roller cam. It behaves very nice at idle and down low. You'll be able to run a much more agressive cam ( if you want) and still be very streetable. Mine is 238/248 duration @ .050 and .544/.573 lift and runs great. Retrofitting your block is easy and if you can spare the money go for it!

 

[71sport408]

I allways forget to log in

 

[justinsane]

I've looked into this a bit for my 347 stroker. The only disadvantage is cost. If you're going all out, definately go with the roller cam.

 

[justinsane]

I should have mentioned, from what I have read, the retrofit roller lifters are a little heavier than flat tappets, so your valve springs need to be considered.

I'm about to bite the bullet (and cost) and go with a roller. There's probably cheaper ways to make HP, but if you've covered everything else it sounds like a roller cam is the way to go.

Brian

 

[NoAZ68]

Justinsane,

Did you decide to go with the retro-kit or with the bar link lifters?

I am trying to figure out cost wise if it is cheaper and wiser (although not always so ) to buy a roller block, or just retro-fit an old one...

 

[broncnaz]

I dont think the retro fit is worth the price just did a little looking on the crane site and your machinest was right about the cost ($700+) summit catolog was misleading, I think you will see little improvement with the retro kit especailly with a low rpm engine sure it may run a bit smoother and you've reduced some friction (problably wont add any power at low rpm's) but you can get the same power out of a $150 flat tappet cam I would go with some good aftermarket heads and roller rockers you'll see more power for the buck. But if you can find a running 351 roller engine for cheap that would be the way to go along with aftermarket heads and roller rockers.

 

[justinsane]

Justinsane,

Did you decide to go with the retro-kit or with the bar link lifters?

I am trying to figure out cost wise if it is cheaper and wiser (although not always so ) to buy a roller block, or just retro-fit an old one...

Haven't decided yet for sure. The Crane link bar lifters run about $420 from what I seen. $300+ for the roller cam.

Comp Cams retrofit uses alignment bars with the valley pan spider like the newer stock setups, just requires drilling and tapping two holes in the lifter valley, quite a bit cheaper.

I've contacted C.A.T. and they are supposedly coming out with a link bar setup in January, targeting about $180 a set. Mixing and matching takes some time.

I totally agree with broncnaz and your machinest, the roller is very pricey, I'd spend my money elseware first, but if you want to drag all you can out of it, I still think a roller is the way to go.

You can get HP cheaper, just depends on cash flow and what you want to do. I've looked in to modifying my '03 Mach 1, about $100 per HP to do much.

Just Have FUN!!
Brian

 

[bsaunder]

I think its worth it - I bought my linked lifters a year and a half ago when they were $300, so that helps, but the $420 current price is worth it in my eyes. I also had a custom cam ground for me for $325 to fully match my engine combo, vehicle weight and drivetrain, and driving preferences.

If I had gone with a flat tappet I would have had to make more comprimises on how the engine would perform - as it is my cam is designed to have a slightly lopey idle, smooth out completly by 1200rpm, provide a good low rpm torque curve with the HP starting to hit hard as my torque converter reaches its stall rpm, and then keep a fairly flat torque curve all the way to 6500rpm where both the torque and HP should start to drop off. With a flat tappet cam I could have gotten the same low end grunt, but the curves would have started dropping around 4200rpm, or if I wanted the same top end, I would have given up the low end... Unfortunalty - I can't give you real driving results yet as work has kept me from putting the Bronco back together for over a month now